Neurology Volume 72(4) January 27, 2009

This week in Neurology® Highlights of the January 27 issue

Idiopathic intracranial hypertension in men

Treatment of CNS sarcoidosis with infliximab and mycophenolate mofetil

Idiopathic intracranial hypertension most commonly occurs in young, obese women. The authors found, however, that 10% of cases occur in men, and men have worse visual outcomes. This paper draws attention to the diagnosis of idiopathic intracranial hypertension in men, highlights the differences of the presentation in men, and explores the possibility that more aggressive interventions may be needed.

Sarcoidosis of the CNS is notoriously difficult to treat and tends to relapse during corticosteroid taper. This study reports on the successful treatment of a series of patients with neurosarcoidosis that was refractory to conventional immunosuppressant agents, with a combination of infliximab and mycophenolate mofetil.

See p. 304; Editorial, p. 300

Mutations in GBA are associated with familial Parkinson disease susceptibility and age at onset The authors performed a comprehensive study of all glucocerebrosidase (GBA) exons in one patient with Parkinson disease from each of 96 families. These findings suggest that GBA is a susceptibility gene for familial Parkinson disease and patients with GBA variants have an earlier age at onset than Parkinson disease patients without GBA variants. See p. 310

TP53 codon 72 polymorphism is associated with age at onset of glioblastoma The authors used blood samples from 254 patients with glioblastoma and 238 healthy controls. They found that pro variant on TP53 codon 72 is associated with early-onset glioblastoma and a higher rate of somatic TP53 mutation.

See p. 337

Treatment of intractable chronic cluster headache by occipital nerve stimulation in 14 patients The article suggests that some patients with otherwise unmanageable chronic cluster headache may now have a relatively noninvasive treatment option. These data provide medium-term follow-up in patients with medically intractable chronic cluster headache who have responded to occipital nerve stimulation. See p. 341

Factors associated with resistance to dementia despite high Alzheimer disease pathology

See p. 332

Biochemical indicators of vitamin B12 and folate insufficiency and cognitive decline

Understanding the factors that lead to greater reserve brain capacity may ultimately lead to prevention strategies. This paper supports the observation that various factors mediate whether individuals with Alzheimer disease pathology develop symptoms. See p. 354

This study shows a faster rate of cognitive decline in patients with high concentrations of methylmalonic acid over a 6-year interval. However, high serum concentrations of vitamin B12 were associated with a slower than expected rate of cognitive decline. See p. 361

Podcasts can be accessed at www.neurology.org

Copyright © 2009 by AAN Enterprises, Inc.

299

EDITORIAL

Idiopathic intracranial hypertension in men and the relationship to sleep apnea

Michael Wall, MD Valerie Purvin, MD

Address correspondence and reprint requests to Dr. Michael Wall, University of Iowa Hospitals and Clinics, Department of Neurology, 200 Hawkins Dr., Iowa City, IA 52242 [email protected]

Neurology® 2009;72:300–301

In this issue of Neurology®, Bruce et al.1 use a retrospective chart review to study men who meet the modified Dandy criteria for idiopathic intracranial hypertension (IIH). This is the largest study to date of IIH in men and confirms the earlier suggestion that men with IIH are at greater risk for severe visual outcome than women.2 The study, however, raises as many questions as it answers. By design, retrospective studies tend to underestimate symptoms, signs, and disease associations, even in the best of hands. Bruce et al. report that 24% (16) of the men had sleep studies that met criteria for obstructive sleep apnea (OSA), but we do not know how many of the remaining 76% had negative polysomnography. Thus, the actual incidence of sleep apnea was likely underestimated. This is important because of the complex relationship between OSA and IIH. A previous study3 reported four men with OSA and papilledema. Nocturnal monitoring, performed in one patient, showed repeated episodes of marked intracranial pressure elevation associated with apnea and arterial oxygen desaturation. The authors concluded that intracranial hypertension with sleep apnea was due to episodic nocturnal hypoxemia and hypercarbia resulting in increased intracranial pressure (ICP) secondary to cerebral vasodilation and was sufficient to cause persistent disc edema even in the absence of elevated daytime intracranial pressure. Similar findings,4,5 combined with the report of Bruce et al., suggest the rate of OSA in retrospective series of men with IIH is in the range of 24 –37%. Since there are no published prospective investigations of IIH patients regarding the rate of sleep apnea in men, the true rate remains unknown. To put the rates found by Bruce et al.1 and others in perspective, one needs to know the rate in the population at large. In a random sample of 602 peo-

ple between ages 30 and 60 years, the prevalence of sleep disordered breathing in the general population ranged from 4% to 9% for women and 9% to 24% for men, using a cutoff of an apnea-hypopnea score of 5 or greater. When daytime hypersomnolence was added, 4% of men and 2% of women met OSA syndrome criteria.6 In addition, 30% of adults with a body mass index (BMI) of ⬎30 kg/m2 and 50% of those with a BMI ⬎40 kg/m2 have been reported to have OSA. While these figures suggest the association of sleep apnea and IIH could be related to chance alone, the lack of sleep studies in up to three quarters of men in this series argues against this. Questions regarding the relationship between OSA and IIH remain. Is OSA a comorbidity with obesity or is it a cause of intracranial hypertension that persists through the day? If a cause, should we still consider patients with increased ICP and OSA to have IIH or should these patients be excluded? Recall that the modified Dandy criteria require that no other cause of intracranial pressure be present. If we assume that OSA is a cause of IIH, rather than a comorbidity, is there a plausible mechanism? Demonstrated collapse of the transverse sinus with intracranial hypertension provides us with such a mechanism.7 Patients with OSA could well have enough intracranial hypertension while asleep to collapse the transverse sinuses, obstruct venous outflow, and have continued elevated pressure during the day. Regardless of a possible causal relationship between sleep apnea and increased ICP, does the presence of sleep apnea perhaps affect the visual outcome? Considering that the mechanism for permanent visual loss in patients with papilledema is related to intraneuronal ischemia at the optic disc, the nocturnal oxygen desaturation, vasospasm, and other circulatory changes associated with sleep apnea could further compromise optic disc perfusion.

See page 304 e-Pub ahead of print on October 15, 2008, at www.neurology.org. From the Departments of Neurology and Ophthalmology (M.W.), University of Iowa, College of Medicine, Iowa City; the Iowa City Veterans Affairs Medical Center (M.W.); and Midwest Eye Institute and the Departments of Ophthalmology and Neurology (V.P.), Indiana University Medical Center, Indianapolis. Supported in part by an unrestricted grant from Research to Prevent Blindness, Inc., New York, NY, and grants from the Veterans Administration Merit Review (M.W.). Disclosure: The authors report no disclosures. 300

Copyright © 2009 by AAN Enterprises, Inc.

Might OSA and not male gender thus account for the main finding in this study? The authors conclude that male gender remains an independent risk factor for severe visual loss in at least one eye when adjusted for age, diagnosis of OSA, and headache as first sign of IIH. While their conclusions are clearly supported statistically, OSA was likely underdiagnosed. With prospective data collection, we might find that the reason for the poor visual outcome is OSA rather than being male. The take-home message is that men who meet the Dandy criteria should be extensively evaluated for causes of intracranial hypertension, including obstructive sleep apnea. In spite of these questions, the importance of the article by Bruce et al. is that it establishes that men who the meet the Dandy criteria for IIH have worse visual outcomes than women with this diagnosis. It is prudent to follow visual function in these patients more closely and be more aggressive in treatment, including identification and vigorous treatment of OSA when present. Regardless

of the mechanism, better visual outcomes should be observed in men with intracranial hypertension. REFERENCES 1. Bruce BB, Kedar S, Van Stavern GP, et al. Idiopathic intracranial hypertension in men. Neurology 2009;72:304– 309. 2. Digre KB, Corbett JJ. Pseudotumor cerebri in men. Arch Neurol 1988;45:866–872. 3. Purvin VA, Kawasaki A, Yee RD. Papilledema and OSA syndrome. Arch Ophthalmol 2000;118:1626–1630. 4. Marcus DM, Lynn J, Miller JJ, Chaudhary O, Thomas D, Chaudhary B. Sleep disorders: a risk factor for pseudotumor cerebri? J Neuro-Ophthalmol 2001;21:121–123. 5. Lee AG, Golnik K, Kardon R, Wall M, Eggenberger E, Yedavally S. Sleep apnea and intracranial hypertension in men. Ophthalmology 2002;109:482–485. 6. Young T, Palta M, Dempsey J, Skatrud J, Weber S, Badr S. The occurrence of sleep-disordered breathing among middle-aged adults. N Engl J Med 1993;328:1230–1235. 7. Farb RI, Vanek I, Scott JN, et al. Idiopathic intracranial hypertension: the prevalence and morphology of sinovenous stenosis. Neurology 2003;60:1418–1424.

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301

EDITORIAL

ACGME, test thyself!

Steven Feske, MD

Address correspondence and reprint requests to Dr. Steven Feske, Department of Neurology, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA 02115 [email protected]

Neurology® 2009;72:302–303

Everything is number. —Pythagoras of Samos

In 1998, the Accreditation Council for Graduate Medical Education (ACGME) began an initiative to improve resident education to suit our current complex healthcare system. To this end, they defined six competence domains around which to focus educational assessment: 1) patient care, 2) medical knowledge, 3) practice-based learning and improvement, 4) interpersonal and communication skills, 5) professionalism, and 6) systems-based practice. The ACGME launched the Outcome Project in 2001. The stated goal of this project is to develop and implement a core competencies-based curriculum for medical education and to provide outcomes performance data to drive evaluation and improvement of medical education.1 These performance data will play an increasing role as criteria for accreditation. The plan is for accreditation to move away from the evaluation of the potential to educate—that is, the structure and process components of education— and toward the evaluation of actual educational accomplishments—that is, outcomes.2 The successful achievement of these goals should provide us with the information and organizational structure to improve the quality of graduate medical education. However, success will depend on flexible selfcriticism within the ACGME, prompting it to adjust the design of the project. In this issue of Neurology®, Schuh et al.3 report the results of a survey of neurology residency program directors asked to comment on the current state of affairs. The findings are limited by the survey method, which lacks external confirmation, and by the scope of the questions, which did not seek judgments by the program directors on the effect of the project on education and patient care. However, the responses lead to some interesting conclusions. The demands on program directors have grown in recent years in large part as a result of the ambitious ACGME project, and it comes as no surprise that program directors report that they dedicate more to

this work than their departments compensate in time, personnel support, and money. Based largely on differences of size and types of supporting facilities, programs have varying resources to provide explicit, curriculum-driven education in highly specialized areas of neurology and in nontraditional areas, such as medical ethics and practice management. Program directors welcome efforts by national organizations, such as the American Academy of Neurology, to fill such gaps with topic-focused curricula that can be adapted to use within their programs. The survey asks mainly descriptive questions and avoids judgments about the value of the ACGME mandates. The one exception produces an interestingly negative response. Like their surgical colleagues, program directors do not feel that duty hour requirements have enhanced either patient care or resident education.4,5 It is perhaps here, on the effects on patient care and education, that we should focus our attention. The ACGME is moving into a new phase (Phase 3) of the Outcome Project during which it will expect programs to collect data on outcomes to show that the core competencies are being taught and learned and, one would hope, that they enhance education and patient care. Hearing the rumblings at the Consortium of Neurology Program Directors meetings loud and clear, I am afraid that the ACGME is getting ahead of itself. Phase 2 of the Outcome Project states the following as its goal: “Sharpening the focus and definition of the competencies and assessment tools.”2 This defining step of the project has not been a success. Although it has generated much anxiety among program directors, the ACGME has thus far failed to focus and define the core competencies and their assessment in a way that points to clear and practical actions for program directors. The six competencies are too diffuse and overlapping to be clearly isolated in a way that allows for meaningful measurement. This does not mean that they are not valuable. It simply acknowledges that they represent

See page e15 From the Department of Neurology, Brigham and Women’s Hospital, Boston, MA. Disclosure: The author reports no disclosures. 302

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desirable components of the medical culture that span all practice, and in their complexity they remain hard to reduce to a simple score or number on a Likert scale, a number that is in fact deceptively full of biases and difficult to interpret.6 There is an irony of self-reference here. Those holding the programs accountable are not holding themselves equally accountable. The debate between the ACGME and program directors has never been fully engaged, largely because the accrediting function of the ACGME places program directors in a weak position to oppose the ACGME. There is also little prospect of help from institutional GMEs that are intent on compliance, not dissent. It is time for the ACGME to step back from the approach of mandating the fulfillment of vague directives. It should clarify its mission to determine what parameters are meaningfully measurable and which among these they wish to measure. These should then be made as explicit as possible along with recommended means of measurement and evaluation. The ACGME further needs to recognize

which aspects of medical education, desirable though they may be, are best left in the category of medical culture, to be encouraged but not measured with unproven methods. Perhaps Pythagoras should reconsider: not quite everything is number. REFERENCES 1. Swing S. The ACGME outcome project: retrospective and prospective. Med Teach 2007;29:648–654. 2. Outcome Project: enhancing residency education through outcomes assessment. Available at: www.acgme.org/ outcome. Accessed December 14, 2008. 3. Schuh LA, Adair JC, Drogan O, Kissela BM, Morgenlander JC, Corboy JR. Neurology residency training in the new millennium. Neurology 2009;72:e15–e20. 4. Cohen-Gadol AA, Piepgras DG, Krishnamurthy S, Fessler RD. Resident duty hours reform: results of a national survey of the program directors and residents in neurosurgery training programs. Neurosurgery 2005;56:398–403. 5. Irani J, Mello MM, Ashley SW, et al. Surgical residents’ perception of the effects of the ACGME duty hour requirements: 1 year after implementation. Surgery 2005; 138:246–253. 6. Dawis R. Scale construction. J Couns Psychol 1987;34: 481–489.

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303

ARTICLES

Idiopathic intracranial hypertension in men

B.B. Bruce, MD S. Kedar, MD G.P. Van Stavern, MD D. Monaghan, BS M.D. Acierno, MD R.A. Braswell, MD P. Preechawat, MD J.J. Corbett, MD N.J. Newman, MD V. Biousse, MD

Address correspondence and reprints to Dr. Vale´rie Biousse, Neuro-ophthalmology Unit, Emory Eye Center, 1365-B Clifton Rd., NE, Atlanta, GA 30322 [email protected]

ABSTRACT

Objective: To compare the characteristics of idiopathic intracranial hypertension (IIH) in men vs women in a multicenter study.

Methods: Medical records of all consecutive patients with definite IIH seen at three university hospitals were reviewed. Demographics, associated factors, and visual function at presentation and follow-up were collected. Patients were divided into two groups based on sex for statistical comparisons.

Results: We included 721 consecutive patients, including 66 men (9%) and 655 women (91%). Men were more likely to have sleep apnea (24% vs 4%, p ⬍ 0.001) and were older (37 vs 28 years, p ⫽ 0.02). As their first symptom of IIH, men were less likely to report headache (55% vs 75%, p ⬍ 0.001) but more likely to report visual disturbances (35% vs 20%, p ⫽ 0.005). Men continued to have less headache (79% vs 89%, p ⫽ 0.01) at initial neuro-ophthalmologic assessment. Visual acuity and visual fields at presentation and last follow-up were significantly worse among men. The relative risk of severe visual loss for men compared with women was 2.1 (95% CI 1.4 –3.3, p ⫽ 0.002) for at least one eye and 2.1 (95% CI 1.1–3.7, p ⫽ 0.03) for both eyes. Logistic regression supported sex as an independent risk factor for severe visual loss. Conclusion: Men with idiopathic intracranial hypertension (IIH) are twice as likely as women to develop severe visual loss. Men and women have different symptom profiles, which could represent differences in symptom expression or symptom thresholds between the sexes. Men with IIH likely need to be followed more closely regarding visual function because they may not reliably experience or report other symptoms of increased intracranial pressure. Neurology® 2009;72:304–309 GLOSSARY BMI ⫽ body mass index; HVF MD ⫽ Humphrey visual field mean deviation; IIH ⫽ idiopathic intracranial hypertension; MR ⫽ magnetic resonance; VA ⫽ visual acuity.

Although idiopathic intracranial hypertension (IIH) typically occurs in young, obese women, it does occur in men. Prognosis in IIH is variable, with severe visual loss occurring in up to 10% of patients.1 Although few series have specifically evaluated sex differences in IIH, it has been suggested that men with IIH may have more severe visual outcomes.2,3 The purpose of this study was to compare the characteristics of IIH in men vs women. METHODS The study was approved by each participating university’s institutional review board. All consecutive charts for patients given the diagnosis code of IIH or disk edema seen by the neuro-ophthalmology services at Emory University (1989 –2007), University of Mississippi (1989 –2007), and Wayne State University (2001–2007) were identified and reviewed. Only patients with definite IIH diagnosed according to the modified Dandy criteria were included: 1) signs and symptoms of increased intracranial

Editorial, page 300 e-Pub ahead of print on October 15, 2008, at www.neurology.org. From the Departments of Ophthalmology (B.B.B., N.J.N., V.B.), Neurology (N.J.N., V.B.), and Neurological Surgery (N.J.N.), Emory University, Atlanta, GA; Departments of Neurology (S.K., D.M., J.J.C.) and Ophthalmology (J.J.C.), University of Mississippi, Jackson, MS; Department of Ophthalmology (G.P.V.S.), Wayne State University, Detroit, MI; Department of Ophthalmology (M.D.A.), Louisiana State University, New Orleans, LA; Department of Ophthalmology (R.A.B.), University of Alabama, Birmingham, AL; and Department of Ophthalmology (P.P.), Ramathibodi Hospital, Mahidol University, Thailand. This study was supported in part by a departmental grant (Department of Ophthalmology) from Research to Prevent Blindness, Inc., New York, NY, and by core grants P30-EY06360 (Department of Ophthalmology) from the National Institutes of Health, Bethesda, MD. N.J.N. is a recipient of a Research to Prevent Blindness Lew R. Wasserman Merit Award. Disclosure: The authors report no disclosures. 304

Copyright © 2009 by AAN Enterprises, Inc.

pressure, 2) no localizing signs except abducens nerve palsy, 3) CSF opening pressure ⱖ 25 cm with normal CSF composition, and 4) normal neuroimaging (ruling out venous sinus thrombosis).4 Although the study was a retrospective chart review, all patients had been evaluated in a standardized fashion by experienced neuro-ophthalmologists, including documentation of body habitus, blood pressure, and complete neuro-ophthalmic examination with formal visual fields, fundus photography, review of neuroimaging tests, and recording of factors associated with IIH. Demographic information regarding age, sex, and race were collected. Race was assessed by the judgment of the examiner based on patient appearance. Medication use (current and recent), the presence or absence of several associated factors (recent weight gain, known sleep apnea, anemia [hemoglobin ⬍12 g/dL], systemic hypertension, endocrine disorders, and pregnancy), symptoms (headache, tinnitus, diplopia, and transient visual obscuration), Snellen visual acuity, formal visual fields (static perimetry using a Humphrey automated perimeter and kinetic perimetry using a Goldmann perimeter), and dilated ophthalmoscopic appearance were recorded. Medications considered possibly contributing included vitamin A preparations, minocycline, cyclosporine, doxycycline, tetracycline, and recent discontinuation of steroids. The contributing medications were grouped by their presence or absence in each patient for analysis. Although not all patients had a formal assessment of their weight and height, for those who did, body mass index was calculated for use in statistical analyses according to the World Health Organization body mass index (BMI) guidelines.5 Prediagnosis duration of symptoms, CSF opening pressure, height, weight, medical treatments, surgical treatments, follow-up duration, and visual outcome were also recorded. Snellen visual acuity was converted to logMAR visual acuity for analysis. Formal visual fields were systematically reviewed for all patients. All visual field defects, whether obtained with static or kinetic perimetry, were graded on a 1 to 4 scale as 1) normal, 2) enlargement of the blind spot, 3) nasal or temporal defect, or 4) diffusely constricted. In addition, mean deviations were recorded for those patients who underwent static automated perimetry. Papilledema was graded with the Frise´n staging scheme6 by systematic review of fundus photography: stage 0 defines a normal optic nerve head, and stage 5 defines severe papilledema. Severe visual loss in an eye was defined by the US criteria for legal blindness (best corrected visual acuity less than or equal to 20/200 or total central visual field less than 20 degrees) and assessed at the last available visit. Patients were divided into two groups based on sex for statistical comparisons. All patients had definite IIH by the modified Dandy criteria, but two aspects of our population merit further mention. First, although all patients underwent a lumbar puncture that documented elevation of CSF opening pressure, the specific value was sometimes unavailable. Second, clinically appropriate neuroimaging was performed on all patients to rule out cerebral venous thrombosis. However, because the patient population is representative of an actual clinical practice, there were occasionally practical limitations to obtaining ideal imaging studies, such as body habitus preventing entry into imaging gantries and changes in the clinical usage of MRI and magnetic resonance (MR) venography over the study period.7 MRIs were all reviewed at the time of diagnosis, and MR venography or CT venography was obtained when there was a question regarding possible cerebral venous thrombosis. Those patients who could not have MRI had head CT with contrast, often accompanied by CT venography. Statistical analysis was performed with R: a language and environment for statistical computing (R Foundation for Statis-

tical Computing, http://www.R-project.org). Continuous and ordinal variables were compared between groups using the Mann–Whitney U test. The Pearson ␹2 test with the Yates continuity correction or the Fisher exact test, as appropriate, was used to compare the frequency distribution of categorical variables between groups. These tests were two tailed, and significance was set at 5%. Univariate analyses for sex vs other factors were undertaken on the entire population and on patients older than 12 years of age at diagnosis. A multivariate logistic regression analysis was performed with the outcome of severe visual loss in at least one eye with sex, age, diagnosis of sleep apnea, and headache as first sign of IIH included as predictors.

We included 721 patients in the study. Emory University contributed 486 patients (67%), University of Mississippi contributed 193 (27%), and Wayne State University contributed 42 (6%). There were 66 (9%) men and 655 (91%) women. The table details the differences between men and women with IIH. Men were more likely than women to have a diagnosis of sleep apnea (24% vs 4%, p ⬍ 0.001). Men reported less headache than women as the initial symptom of IIH (55% vs 75%, p ⬍ 0.001) and at the first neuro-ophthalmology evaluation (79% vs 89%, p ⫽ 0.01). Men were more likely than women to report visual changes as their first symptom of IIH (35% vs 20%, p ⫽ 0.004). Tinnitus was less frequently reported by men at first neuroophthalmology evaluation (26% vs 38%, p ⫽ 0.05). MRI was obtained in 92% of all included patients. Those who were unable to undergo MRI had a head CT with contrast, often with CT venography. MR venography or CT venography was obtained in 34% of women and 26% of men (p ⫽ 0.17). Men had significantly worse visual acuities and visual fields than women, at both initial and final evaluations (table). The relative risk of severe visual loss for men vs women was 2.1 (95% CI 1.4 –3.3, p ⫽ 0.002) for one eye and 2.1 (95% CI 1.1–3.7, p ⫽ 0.03) for both eyes. Subset analyses were performed on all patients older than 12 years of age at diagnosis, consisting of 53 men (8%) and 616 women (92%). All differences reported above remained significant within this subset, but men were additionally found to be older than women at diagnosis (37 vs 28 years, p ⫽ 0.02). Male sex remained an independent risk factor for severe visual loss in at least one eye when adjusted for age, diagnosis of sleep apnea, and headache as first sign of IIH (adjusted odds ratio 2.5, p ⫽ 0.004 vs unadjusted odds ratio 2.6, p ⫽ 0.001). RESULTS

We present the largest series of IIH patients reported in the literature. Our study found a 9% prevalence of IIH in men, thereby confirming that IIH in men is rare. The prevalence of IIH in men has been estimated to be between 6% and 50%

DISCUSSION

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305

Table

Demographics, risk factors, CSF opening pressure, treatment, symptoms, and examination of men and women with idiopathic intracranial hypertension Women, n ⴝ 655

Men, n ⴝ 66

n or median

n or median

% or range

% or range

p Value

Demographics/risk factors Age, y (n ⴝ 719) Black

28

(2–67)

28

(2–65)

0.93

311

(48%)

28

(42%)

0.41

Contributing medications

59

(9%)

2

Sleep apnea

25

(4%)

16

Anemia

56

(9%)

3

Endocrine disorder Hypertension Prediagnosis duration of symptoms, wk (n ⴝ 635)

(3%) (24%) (5%)

0.11 ⬍0.001 0.35

83

(13%)

9

(14%)

0.82

140

(21%)

16

(24%)

0.59

6

(0–500)

4

(0–100)

0.10

Follow-up duration, wk (n ⴝ 678)

16

(0–592)

12.5

(0–168)

0.21

CSF opening pressure, cm CSF (n ⴝ 580)

37

(25–75)

37

(25–60)

0.67

(12.4–83.6)

33.2

(17–73.1)

0.32

(14%)

0.07

Weight BMI, kg/m2 (n ⴝ 487) Recent weight gain Amount of recent weight gain, kg (n ⴝ 136)

37.4 153 30

(23%)

9

(5–150)

30

(10–100)

0.63

Treatment Medication

605

(92%)

59

(89%)

0.39

Diet modification

350

(53%)

30

(46%)

0.22

1

(1–30)

1

(1–7)

0.69

104

(16%)

10

(15%)

0.88

No. of lumbar punctures (n ⴝ 717) CSF shunting Repeat CSF shunting

45

(7%)

Optic nerve sheath fenestration

97

(15%)

4 14

(6%)

1.00

(21%)

0.17

Symptoms Initial symptom of IIH Headache

494

(75%)

36

(55%)

⬍0.001

Vision changes

130

(20%)

23

(35%)

0.004

Transient visual obscurations

72

(11%)

7

(11%)

0.92

Diplopia

32

(5%)

5

(8%)

0.37

Tinnitus

40

(6%)

2

(3%)

0.42

None

42

(6%)

8

(12%)

0.08

At first neuro-ophthalmology visit Headache

583

(89%)

52

(79%)

0.01

Transient visual obscurations

251

(38%)

18

(27%)

0.08

Diplopia

145

(22%)

16

(24%)

0.7

Tinnitus

250

(38%)

17

(26%)

0.05

(0–5)

0.93

Examination Papilledema, first visit (n ⴝ 618)

3

(0–5)

3

Papilledema, last visit (n ⴝ 658)

0

(0–5)

0

(0–3)

0.49

Visual field grade, first visit (n ⴝ 599)

2

(1–4)

2.8

(1–4)

0.006

Visual field grade, last visit (n ⴝ 631)

2

(1–4)

2

(1–4)

0.06

HVF MD, first visit (n ⴝ 422)

5

(0–33.5)

7.7

(1.1–33.5)

0.008

HVF MD, last visit (n ⴝ 490)

3.7

(0–33.1)

4.7

(1.1–31.2)

VA logMAR, first visit (n ⴝ 678)

0

(⫺0.3 to 6.9)

0.2

(⫺0.3 to 6.9)

⬍0.001

VA logMAR, last visit (n ⴝ 662)

0

(⫺0.3 to 6.9)

0.2

(⫺0.3 to 4.6)

0.002

0.02

BMI ⫽ body mass index; IIH ⫽ idiopathic intracranial hypertension; HVF MD ⫽ Humphrey visual field mean deviation; VA ⫽ visual acuity. 306

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by prior studies,2 but when one considers only studies applying modern neuroimaging to more than 50 IIH patients,3,8-13 the prevalence range is 8% to 19%. This suggests that older studies may have included men with mimickers of IIH that are more difficult to diagnose without advanced neuroimaging (e.g., venous sinus thrombosis, dural arteriovenous malformations). Our study of IIH in men has the highest rate of MRI reported in the literature (⬎90%), making it less likely that we included patients with these conditions. The most important finding of our study is that men were two times more likely than women to have severe visual loss in one or both eyes. Although sex has been previously suspected to be an important risk factor for visual loss in IIH, only two studies have specifically compared men vs women with IIH.2,3 Although no significant association between male sex and visual loss in IIH has been demonstrated previously,2,3,10,12,13 these studies were likely underpowered to find such an association, even if one was present. Because visual loss in IIH is typically slow and insidious, the worse visual prognosis for men could be because men experience fewer nonvisual symptoms to bring them to medical attention early in the course of their disease. Indeed, men were found to report significantly less headache as both a first sign of IIH and at the initial neuro-ophthalmology visit. Instead, men were more likely to report that subjective visual changes were the heralding symptom of their illness. Men also reported less pulsatile tinnitus at initial neuro-ophthalmology evaluation, but this difference barely met our significance level and should be interpreted with caution. Further caution is warranted because higher symptom rates have been found in prospective studies and may suggest limitations in our retrospective data collection.13,14 However, because our male and female patients were collected in a similar fashion and compared internally, there is no reason to specifically suspect bias to be the cause of the differences found. These symptom differences could suggest that IIH represents a different clinical entity in men and women. However, we believe it more likely represents a difference in headache thresholds for men and women. This is supported by several observations. First, migraine and tension-type headache are reported much more frequently by women than by men.15,16 Second, women seem to have greater temporal summation of noxious mechanical stimuli than men do.17 One could hypothesize from this observation that different responses to a constantly applied stimulus, such as chronically elevated intracranial pressure, may partially account for the sex headache differences in IIH.

Finally, men are less likely than nonpregnant women to have post– dural puncture headaches.18 This is particularly interesting because low-CSF-pressure and high-CSF-pressure headaches likely share a common mechanism, i.e., mechanical deformation of the meninges. It is also possible that there were sex differences in other factors that have been previously associated with visual loss in IIH, such as degree of obesity, hypertension, recent weight gain, anemia, race, CSF opening pressure, sleep apnea, and older age.2,8,13,19-24 Regarding obesity, one case– control study comparing 29 men with IIH to both women with IIH and normal men2 found no differences between the men and women with IIH, but men with IIH were more obese than the age-matched control men. In another study comparing the characteristics of 18 men with IIH to 116 women with IIH,3 men were less likely to be “significantly overweight” compared to women with IIH, but BMI was not used in the analyses. Among our 487 patients (67%) for whom BMI was available, no difference was found between the BMI of men and women with IIH. It is likely that studies that have suggested that obesity does not play a major role in the development of IIH in men were confounded by two problems: 1) inclusion of men with a different disease because of lack of adequate neuroimaging, and 2) the lack of precise anthropometric data (e.g., BMI), instead relying on weight only or the examiner’s assessment of weight status. Although some previous studies have suggested that systemic hypertension may be a poor prognostic indicator,2,13 it was not found to be a significant factor in our study with regard to blindness. Because many of the patients in our study were treated hypertensives, this relationship may have been masked. In addition, we considered hypertension only by its presence or absence and not by a numerical value such as mean arterial pressure. This also reduces the power of finding a potentially significant relationship in this study. We did find that men with IIH had a higher rate of diagnosed sleep apnea than women did. Epidemiologic studies have found a male-to-female ratio of sleep apnea of 5 to 8:1 in sleep clinics, whereas population-based studies have found a lower ratio of 2 to 3:1.25 These observations suggest that although sleep apnea is likely more common in men in general, it may be underdiagnosed in women. The relationship between sleep apnea and IIH remains unclear. It is established that sleep apnea can cause nocturnal elevations in intracranial pressure that can lead to the development of papilledema.26,27 However, there is debate about whether sleep apnea is causal or merely a comorbidity among patients whose Neurology 72

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daytime intracranial pressure remains elevated.28-31 Because of the retrospective nature of this study, we do not know which patients underwent sleep studies but did not have sleep apnea, and thus we are unable to further address this interesting mechanistic question. Regardless, because of the possible association of sleep apnea with worse visual outcome in IIH,19 this relationship merits further study. Excluding our younger, prepubertal patients, we also found that men were significantly older than women with IIH by nearly a decade. This has been observed in other studies of IIH in men but did not reach significance.2,3 The fact that there is no clear sex predilection for IIH among younger children has been observed previously.32,33 Together, these findings suggest that IIH has a bimodal distribution in male patients, with peaks during school age and middle age. This predilection of IIH for women in their childbearing years supports a potential role of hormonal influences in the development of this disorder. However, if hormonal influences were directly responsible for the disorder, we would expect a correlation between development and severity of disease. Instead, IIH follows a paradoxical pattern similar to that of autoimmune disease, where women are affected disproportionately but men are affected more severely.34 Because of the retrospective nature of this study, we do not have data on several potentially pertinent aspects of our male patients (e.g., history of autoimmune disease, use of anabolic steroids, history of sterility or impotence, central vs peripheral obesity), but we believe that these factors merit further study and may lend insight into the development and course of IIH and other similar disorders. There were no differences between our men and women with IIH with regard to recent weight gain, anemia, race, or CSF opening pressure. After accounting for the differences in sleep apnea, headache, and age discussed above, sex remained an independent risk factor for poor visual outcome in IIH, increasing the odds of severe visual loss twofold. Finally, we considered the possibility that the worse visual outcomes among men in our study could have been related to delayed diagnosis. However, median time from first symptom onset to diagnosis of IIH was 2 weeks shorter for men compared with women. Another study of IIH in men3 also found that men were diagnosed earlier after first symptoms than women were (14 vs 28 weeks). However, because men were more likely to have visual complaints as their first symptoms and more likely to have significant visual loss at presentation compared with women, men may have been first examined by eye care professionals more frequently. This would 308

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likely lead to the discovery of disk edema and the correct diagnosis, but after chronic papilledema had already led to visual loss. Conversely, the longer time to diagnosis for women suggests that they were treated for primary headache disorders before their disease was recognized, which emphasizes the importance of examining the ocular fundi of all patients with headache. The main limitation of our study is its retrospective nature, which requires a prudent interpretation of our findings, especially with regard to symptoms. However, all of our patients were systematically evaluated by experienced neuro-ophthalmologists, and we have no reason to believe that our evaluations of men and women differed in such a way to introduce bias. Another limitation of the study was the treatment of visual field data using only a four-point scale. While this was able to show that visual fields were worse among men than women, it does not provide the opportunity for a more refined interpretation of the nature of these visual field differences. Although one should remain mindful of these limitations, our findings that men with IIH frequently have substantial visual impairment at presentation and may report nonvisual symptoms less often than women do suggest that men with IIH likely require more frequent monitoring and more aggressive treatment. AUTHOR CONTRIBUTIONS Statistical analysis was performed by B.B.B.

Received May 13, 2008. Accepted in final form July 18, 2008.

REFERENCES 1. Ball AK, Clarke CE. Idiopathic intracranial hypertension. Lancet Neurol 2006;5:433–442. 2. Digre KB, Corbett JJ. Pseudotumor cerebri in men. Arch Neurol 1988;45:866–872. 3. Kesler A, Goldhammer Y, Gadoth N. Do men with pseudomotor cerebri share the same characteristics as women? A retrospective review of 141 cases. J Neuroophthalmol 2001;21:15–17. 4. Friedman DI, Jacobson DM. Diagnostic criteria for idiopathic intracranial hypertension. Neurology 2002;59:1492– 1495. 5. Physical status: the use and interpretation of anthropometry: report of a WHO expert committee. WHO Tech Rep Ser 1995;854:1–452. 6. Frise´n L. Swelling of the optic nerve head: a staging scheme. J Neurol Neurosurg Psychiatry 1982;45:13–18. 7. Biousse V, Ameri A, Bousser MG. Isolated intracranial hypertension as the only sign of cerebral venous thrombosis. Neurology 1999;53:1537–1542. 8. Corbett JJ, Savino PJ, Thompson HS, et al. Visual loss in pseudotumor cerebri: follow-up of 57 patients from five to 41 years and a profile of 14 patients with permanent severe visual loss. Arch Neurol 1982;39:461–474.

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Durcan FJ, Corbett JJ, Wall M. The incidence of pseudotumor cerebri: population studies in Iowa and Louisiana. Arch Neurol 1988;45:875–877. Galvin JA, Van Stavern GP. Clinical characterization of idiopathic intracranial hypertension at the Detroit Medical Center. J Neurol Sci 2004;223:157–160. Kesler A, Gadoth N. Epidemiology of idiopathic intracranial hypertension in Israel. J Neuroophthalmol 2001;21: 12–14. Mezaal M, Saadah M. Idiopathic intracranial hypertension in Dubai: nature and prognosis. Acta Neurol Scand 2005; 112:298–302. Wall M, George D. Idiopathic intracranial hypertension: a prospective study of 50 patients. Brain 1991;114:155– 180. Giuseffi V, Wall M, Siegel PZ, Rojas PB. Symptoms and disease associations in idiopathic intracranial hypertension (pseudotumor cerebri): a case-control study. Neurology 1991;41:239–244. Schwartz BS, Stewart WF, Simon D, Lipton RB. Epidemiology of tension-type headache. JAMA 1998;279:381– 383. Silberstein SD. Headache and female hormones: what you need to know. Curr Opin Neurol 2001;14:323–333. Sarlani E, Greenspan JD. Gender differences in temporal summation of mechanically evoked pain. Pain 2002;97: 163–169. Wu CL, Rowlingson AJ, Cohen SR, et al. Gender and post– dural puncture headache. Anesthesiology 2006;105: 613–618. Bruce BB, Preechawat P, Newman NJ, Lynn MJ, Biousse V. Racial differences in idiopathic intracranial hypertension. Neurology 2008;70:861–867. Biousse V, Rucker JC, Vignal C, Crassard I, Katz BJ, Newman NJ. Anemia and papilledema. Am J Ophthalmol 2003;135:437–446. Lee AG, Golnik K, Kardon R, Wall M, Eggenberger E, Yedavally S. Sleep apnea and intracranial hypertension in men. Ophthalmology 2002;109:482–485.

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Orcutt JC, Page NG, Sanders MD. Factors affecting visual loss in benign intracranial hypertension. Ophthalmology 1984;91:1303–1312. Radhakrishnan K, Thacker AK, Bohlaga NH, Maloo JC, Gerryo SE. Epidemiology of idiopathic intracranial hypertension: a prospective and case-control study. J Neurol Sci 1993;116:18–28. Thambisetty M, Lavin PJ, Newman NJ, Biousse V. Fulminant idiopathic intracranial hypertension. Neurology 2007;68:229–232. Punjabi NM. The epidemiology of adult obstructive sleep apnea. Proc Am Thorac Soc 2008;5:136–143. Purvin VA, Kawasaki A, Yee RD. Papilledema and obstructive sleep apnea syndrome. Arch Ophthalmol 2000; 118:1626–1630. Sugita Y, Iijima S, Teshima Y, et al. Marked episodic elevation of cerebrospinal fluid pressure during nocturnal sleep in patients with sleep apnea hypersomnia syndrome. Electroencephalogr Clin Neurophysiol 1985;60: 214–219. Corbett JJ. “Pseudotumor cerebri” by any other name. Arch Ophthalmol 2000;118:1685. Marcus DM, Lynn J, Miller JJ, Chaudhary O, Thomas D, Chaudhary B. Sleep disorders: a risk factor for pseudotumor cerebri? J Neuroophthalmol 2001;21:121–123. Kirkpatrick PJ, Meyer T, Sarkies N, Pickard JD, Whitehouse H, Smielewski P. Papilloedema and visual failure in a patient with nocturnal hypoventilation. J Neurol Neurosurg Psychiatry 1994;57:1546–1547. Wolin MJ, Brannon WL. Disk edema in an overweight woman. Surv Ophthalmol 1995;39:307–314. Balcer LJ, Liu GT, Forman S, et al. Idiopathic intracranial hypertension: relation of age and obesity in children. Neurology 1999;52:870–872. Lessell S. Pediatric pseudotumor cerebri (idiopathic intracranial hypertension). Surv Ophthalmol 1992;37:155– 166. Gleicher N, Barad DH. Gender as risk factor for autoimmune diseases. J Autoimmun 2007;28:1–6.

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Mutations in GBA are associated with familial Parkinson disease susceptibility and age at onset W.C. Nichols, PhD N. Pankratz, PhD D.K. Marek, BS M.W. Pauciulo, MBA V.E. Elsaesser, BS C.A. Halter, MS A. Rudolph, PhD J. Wojcieszek, MD R.F. Pfeiffer, MD T. Foroud, PhD For the Parkinson Study Group–PROGENI Investigators*

Address correspondence and reprint requests to Dr. William C. Nichols, Associate Professor of Pediatrics, Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229 [email protected]

ABSTRACT

Objective: To characterize sequence variation within the glucocerebrosidase (GBA) gene in a select subset of our sample of patients with familial Parkinson disease (PD) and then to test in our full sample whether these sequence variants increased the risk for PD and were associated with an earlier onset of disease.

Methods: We performed a comprehensive study of all GBA exons in one patient with PD from each of 96 PD families, selected based on the family-specific lod scores at the GBA locus. Identified GBA variants were subsequently screened in all 1325 PD cases from 566 multiplex PD families and in 359 controls.

Results: Nine different GBA variants, five previously reported, were identified in 21 of the 96 PD cases sequenced. Screening for these variants in the full sample identified 161 variant carriers (12.2%) in 99 different PD families. An unbiased estimate of the frequency of the five previously reported GBA variants in the familial PD sample was 12.6% and in the control sample was 5.3% (odds ratio 2.6; 95% confidence interval 1.5– 4.4). Presence of a GBA variant was associated with an earlier age at onset (p ⫽ 0.0001). On average, those patients carrying a GBA variant had onset with PD 6.04 years earlier than those without a GBA variant.

Conclusions: This study suggests that GBA is a susceptibility gene for familial Parkinson disease (PD) and patients with GBA variants have an earlier age at onset than patients with PD without GBA variants. Neurology® 2009;72:310–316 GLOSSARY CI ⫽ confidence interval; GD ⫽ Gaucher disease; GDS ⫽ Geriatric Depression Scale; MMSE ⫽ Mini-Mental State Examination; NCRAD ⫽ National Cell Repository for Alzheimer’s Disease; NPL ⫽ nonparametric lod; OR ⫽ odds ratio; PD ⫽ Parkinson disease; UPDRS ⫽ Unified Parkinson’s Disease Rating Scale.

Parkinson disease (PD) is the second most common neurodegenerative disease after Alzheimer disease. Mutations in SNCA, PRKN, DJ1, and PINK1 typically result in early onset PD1,2 while mutations in LRRK2 result in idiopathic PD with more typical, later onset.3,4 These mutations result in disease in fewer than 5% of patients with PD. Gaucher disease (GD) is an inherited deficiency of lysosomal glucocerebrosidase arising from mutations in the gene encoding glucosidase beta acid (GBA), more commonly known as glucocerebrosidase.5-7 Over 200 different mutations have been identified. GD is most common in the Ashkenazi Jewish population. While patients with GD presenting with parkinsonian symptoms were reported as early as 1939, only recently has it been hypothesized that a deficiency of glucocerebrosidase might contribute to an increased susceptibility to parkinsonism.8,9 In a recent study, GBA variants were found in 21% of subjects with PD, a much higher Supplemental data at www.neurology.org e-Pub ahead of print on November 5, 2008, at www.neurology.org. *The Parkinson Study Group–PROGENI Investigators are listed in the appendix. From Cincinnati Children’s Hospital Medical Center (W.C.N., D.K.M., M.W.P., V.E.E.), OH; University of Cincinnati School of Medicine (W.C.N.), OH; Indiana University Medical Center (N.P., C.A.H., J.W., T.F.), Indianapolis; University of Rochester (A.R.), NY; and University of Tennessee Health Science Center (R.F.P.), Memphis. Supported by R01 NS37167, MO1 RR-00750, and the National Cell Repository for Alzheimer’s Disease (U24 AG021886). This study used samples and clinical data from the National Institute of Neurological Disorders and Stroke Human Genetics Resource Center DNA and Cell Line Repository (http://ccr.coriell.org/ninds). Disclosure: The authors report no disclosures. 310

Copyright © 2009 by AAN Enterprises, Inc.

Table 1

Patients with Parkinson disease (PD) and control sample demographics

Source

Type

No.

Mean age at onset/ examination, y (range)

% Male

PROGENI (samples reported to have PD)

Cases

1,325

60.9 (15–89)

58.0

PROGENI (Caucasian non-Hispanic with verified PD)

Cases

737

61.9 (15–84)

59.8

PROGENI-CARES

Controls

46

68.4 (55–82)

19.6

National Cell Repository for Alzheimer’s Disease

Controls

44

76.9 (58–92)

43.2

NINDS Human Genetics Resource Center (Coriell)

Controls

269

69.5 (55–88)

48.0

NINDS ⫽ National Institute of Neurological Disorders and Stroke.

estimate than would be expected based on the carrier frequency of GD in the general population.10 In addition, GBA variants were more frequent among younger patients. Subsequent screenings of patients with PD has yielded contradictory results regarding the association of GBA in PD.10-23 In one study of Ashkenazi Jewish patients with PD, GBA variants were more frequently found in patients as compared with controls.11 A large study of both Jewish and non-Jewish samples found an association between GBA mutations and PD in the Jewish group only.15 Chinese patients with PD from Singapore demonstrated a significant association with GBA,21 whereas a similar study of Chinese patients from Taiwan did not.20 A survey of Italian patients with PD for the N370S and L444P mutations found a significant association of these variants with PD,22 while a Norwegian sample showed comparable frequencies of these two mutations in patients with PD and controls.17 Most recently, a study of Portuguese patients with PD detected a significant increase in GBA variants in patients as compared to controls.23 In some studies, patients with PD harboring GBA variants had earlier age at disease onset.12,15,19,21 Whether the discrepant results regarding the association of GBA with disease and age at onset result from true ethnic differences in GBA variant frequencies or from differences in the scope of the studies (i.e., only screening for certain variants as opposed to sequencing the entire coding region) remains to be determined. Of the studies previously reported, none has examined the relationship of GBA to PD sus-

ceptibility in a largely familial cohort.10-23 The goals of this study were to characterize sequence variation within GBA in a select subset of our large sample of patients with familial PD and then to test in the entire sample whether these sequence variants increased the risk for PD or were associated with an earlier onset of disease. METHODS Subjects. A total of 1,325 individuals with PD from 566 multiplex families were ascertained through a pair of siblings, both of whom were reported to have PD (PROGENI study). At the time of these analyses, 1325 individuals with PD from 566 multiplex PD families had been recruited. All available affected individuals were seen by a movement disorder specialist at one of 59 Parkinson Study Group sites located throughout North America (table 1). Each participant completed a uniform clinical assessment that included the Unified Parkinson’s Disease Rating Scale (UPDRS) Parts II (Activities of Daily Living) and III (Motor Exam),24,25 Schwab & England score,26 Hoehn & Yahr stage,27 the Mini-Mental State Examination (MMSE),28 the Geriatric Depression Scale (GDS),29 and the Blessed Functional Activity Scale (Blessed).30 In addition, a diagnostic checklist was used to classify individuals as having either verified PD (65%) or nonverified PD (35%).31 Peripheral blood was obtained after completion of appropriate written informed consent approved by each individual institution’s institutional review board. Microsatellite markers closest to the GBA locus (D1S252, D1S498, D1S484, D1S2878) genotyped as part of a previous 10 cM genome screen31-33 were used to calculate a family-specific nonparametric lod (NPL) score and rank families based on their evidence of linkage to the GBA region. One affected individual from each of the 96 families with the highest NPL scores was selected for GBA sequencing. The control sample consisted of 359 neurologically normal non-Hispanic Caucasians who provided appropriate written informed consent (see table 1). The control samples were obtained from three different sources: the National Cell Repository for Alzheimer’s Disease (NCRAD), the National Institute of Neurological Disorders and Stroke Human Genetics Resource Center at the Coriell Cell Repositories (Camden, NJ; DNA panels NDPT002, NDPT006, NDPT009) and controls recruited as part of an ongoing PD study at Indiana University (PROGENI-CARES).34

Molecular genetic analysis. PCR and sequencing primers were designed using the chromosome 1 genomic contig sequence NT_029419 enabling PCR/sequencing of all 11 coding exons and corresponding intron/exon boundaries of GBA (table e-1 on the Neurology® Web site at www.neurology.org). Primers were designed enabling preferential amplification of GBA over the GBA pseudogene also on chromosome 1. PCR products were purified and sequenced as previously described.34 TaqMan allelic-discrimination assays (Applied Biosystems, Foster City, CA) were developed to screen all 1,325 PD cases and 359 controls for the variants identified in the 96 sequenced samples (except L444P, A456P, V460V) as previously described.34,35 To screen for the L444P variant, exon 11 amplification products were digested to completion with HpaII (New England Biolabs, Beverly, MA) to assay for the L444P variant (gain of HpaII site). Digestion products were electrophoresed through 4% Metaphor Agarose (Cambrex, Rockland, ME). To screen for the RecNciI recombinant allele carrying variants Neurology 72

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311

Table 2

Exon

GBA variants identified by sequencing in 96 familial patients with Parkinson disease (PD) and number of families identified to carry each by screening the full sample

Nucleotide change

Amino acid change

References

No. of families with variant*

7

IVS6 589-2A⬎G

This report

1

8

c. 902 G⬎A

R262H

This report

1

9

c.1026 A⬎G

K303K

This report

9

c.1093 G⬎A

E326K

10, 15

44

9

c.1223 C⬎T

T369M

12, 15

19

10

c. 1226 A⬎G

N370S

8, 10–15, 17, 19

19

11

c.1448 T⬎C

L444P

8, 10–15, 17, 19–21

9

11

IVS10 1389-3C⬎G

This report

1

11

c. 1448 T⬎C

12, 13, 15, 21

4

RecNciI (L444P⫹A456P⫹V60V)

1

c. 1483 G⬎C c. 1497 G⬎C

*Screened in the full sample of 1,325 PD cases from 566 multiplex PD families.

A456P and V460V, PCR primers were synthesized as described previously.13 The gene-specific forward primer (5=ggaaccatgattccctatcttc-3=) and the GBA pseudogene-specific reverse primer (5=-gtttaggacgaccacaacagg-3=) were used in a multiplex PCR reaction with an invariant primer set. The PCR products were electrophoresed through 2% agarose (Invitrogen, Carlsbad, CA) for detection of the RecNciI recombinant allele PCR fragment. Presence of the RecNciI recombinant allele was confirmed using long range PCR and sequencing of the entire GBA gene. Briefly, 200 ng of genomic DNA was amplified using the Invitrogen Elongase Enzyme Mix (Invitrogen, Carlsbad, CA) and primers 5=-cccattctccatgcaaatctgtgt-3= (forward) and 5=ccggaaccagatcctatctgtgc-3= (reverse). Long range PCR products were purified and sequenced as above.

Statistical analysis. Statistical analyses were limited to the subset of the PD sample that met the strictest diagnostic criteria of verified PD.31 This analytic sample consisted of 737 nonHispanic, Caucasian individuals from 450 families (see table 1) and excluded those patients known to harbor a causative PD mutation (a single LRRK2 mutation or 2 PRKN mutations). Two hypotheses were tested. The first was that presence of a GBA variant increased the risk of PD. A logistic model was employed with affection status as the dependent variable and presence or absence of a GBA variant as the independent variable (0 or 1). Age at examination and gender were included as covariates in the initial model; however, neither affected the magnitude or significance of the odds ratios (ORs) and were dropped from the final model. The second hypothesis was that those inheriting a GBA variant have earlier age at PD onset. A linear regression model was fitted with age at onset as the dependent variable and the presence or absence of a GBA variant as the independent variable. Education, gender, and smoking were considered as possible covariates; however, all were found to be nonsignificant and were dropped from the final model. Linear and logistic regression models were also used to test whether other measures relevant to PD (i.e., UPDRS subscores, MMSE, GDS, Hoehn & Yahr stage) differed based on the presence or absence of a GBA variant. All analyses were carried out using SAS software (release 9.13; SAS Institute, Cary, NC). Our analytic sample consisted of 312

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families with multiple patients with PD. To ensure an unbiased analysis of the study hypotheses when using a sample of related individuals, we employed resampling techniques. Specifically, a single individual was sampled at random from each of the families. This was repeated 50,000 times, and common resampling techniques (bootstrapping) were employed to obtain a representative value. The median bootstrapped statistic was determined and the corresponding p values are reported for the tests of the two hypotheses. RESULTS Nine variants were identified by sequencing the entire coding region of GBA in 96 patients with PD (table 2). Four of the detected sequence variants were novel while the remaining five had been previously identified in patients with PD. The four novel variants were each found in additional affected family members of the PD subject in whom the variant was initially found. However, screening of all available PD cases did not identify the four novel variants in any additional families. Three of the variants (IVS6 589-2A⬎G, R262H, IVS10 13893C⬎G) were not identified in any of the control samples, making the estimated frequency of each ⬍0.002 in the neurologically normal population. The frequency of the remaining novel variant, K303K, was not evaluated in the control samples as the designed TaqMan allelic discrimination assay failed. The remaining five variants had been previously reported in patients with PD and GD, as well as controls.8,10-15,17,19-21 An unbiased estimate (using resampling techniques as described in Methods) of the frequency of the five previously reported GBA variants in the subset of the familial PD sample that met our strictest diagnostic criteria of verified PD was 12.6% and in the control sample was 5.3% (table 3). The mean age at onset of the patients with PD harboring a GBA variant was 56.8 years (median: 58, range: 30 –79). The presence of a previously described GBA variant significantly increased the risk for PD; 12.6% of verified PD cases carried a GBA mutation (permuted one per family as described in Methods), as compared with 5.3% of controls (OR 2.6, 95% confidence interval [CI] 1.5– 4.4) (table 3). The analysis of individual variants showed nonsignificant ORs ranging from 1.7 (95% C.I. 0.4 – 6.8) for the N370S variant to 2.8 (95% C.I. 0.3–25.8) for the RecNciI recombinant allele variant. Presence of a GBA variant was also associated with an earlier age at onset (p ⫽ 0.0001) (table 4). PD cases carrying a GBA variant were more likely to have onset ⱕ50 years as compared to those without a GBA variant (p ⫽ 0.0004). Among those with early onset disease, there was no difference in age at onset between the GBA variant carriers and the noncarriers; however, among those with onset ⬎50 years, those

Table 3

Odds ratios and proportions of cases and controls with a previously identified GBA variant permuted one per family Cases (n ⴝ 450), % carriers

Controls (n ⴝ 359), % carriers

OR (95% CI)

All GBA variants

12.6

5.3

2.6 (1.5–4.4)

E326K variants

6.2

3.1

2.1 (1.0–4.3)

T369M variants

2.3

1.1

2.1 (0.7–6.8)

N370S variants

1.4

0.8

1.7 (0.4–6.8)

L444P variants

1.9

0.0

Ø

A456P/V460V/L444P variants

0.8

0.3

2.8 (0.3–25.8)

Figure

Cumulative incidence rates of Parkinson disease among carriers and noncarriers of GBA variants

Ø ⫽ OR cannot be calculated as all carriers were cases (divide by zero); Fisher exact test yields a p value of 0.01. OR ⫽ odds ratio; CI ⫽ confidence interval.

with a GBA variant had earlier age at onset (61.59 years) as compared to late-onset cases without a GBA variant (65.37 years) (p ⫽ 0.001). When a linear regression model was fitted to predict age at onset, presence of a GBA variant was associated with an earlier age at onset (p ⫽ 0.0001). On average, our model suggests that those patients carrying a GBA variant had onset with PD 6.04 years earlier than those without a GBA variant. The cumulative incidence of PD was higher in patients with GBA variants compared with noncarriers over nearly the entire age distribution (figure). We also compared the clinical characteristics of the PD cases that carried a GBA variant with the PD cases that did not carry a GBA variant. There were no significant differences between GBA variant carriers Table 4

Comparison of clinical features of GBA variant carriers and noncarriers with a diagnosis of verified Parkinson disease Carriers

Noncarriers

No.

56.8*

393.2

Male, %

58.9

59.2

0.56

Age at onset, y

56.8

62.8

0.0001

Early onset (<50 y), %

63.3

37.8

0.0004

Duration of disease, y

p Value

9.6

8.3

0.15

Affected parent, %

35.3

28.3

0.25

Education, y

13.7

13.6

0.55

9.9

9.0

0.25

MMSE

26.2

26.7

0.34

UPDRS Part II (motor)

28.6

27.7

0.49

UPDRS Part III (ADL)

14.4

13.6

0.36

4.7

3.9

0.10

74.9

77.9

0.22

2.5

2.5

0.53

Depression (GDS)

Blessed Functionality Schwab Examiner Hoehn & Yahr stage

*To produce unbiased results, all values and statistics are permuted one per family, which leads to counts containing fractions.

and noncarriers for any of the clinical characteristics examined, including MMSE, UPDRS Parts II and III, Blessed, and Hoehn & Yahr (table 3). The goals of this study were to characterize sequence variation within GBA in a select subset of our larger sample of familial patients with PD and to test in the larger sample whether these sequence variants increased the risk for PD and were associated with an earlier onset of disease. We identified four novel variants and five previously reported variants. In our sample, a subject was 2.6 times more likely to develop PD if they carried one of the five previously identified GBA variants (table 3). Furthermore, presence of a GBA variant was associated with an earlier onset of disease. Our results replicate the association of GBA with PD reported in other studies10-23; however, we extend the association to include later onset patients with PD as well as familial disease. Our screening for these nine variants in 1,325 affected individuals from 566 families represents the largest study to date of GBA variants in patients with PD and PD families. In total, GBA variants were detected in 161 patients (12.2%) from 99 different PD families (17.5%). The frequency observed in our sample is intermediate with that in a recent study that reported 16.9% of Jewish PD cases carried a GBA variant, while only 8% of non-Jewish PD cases carried a variant.15 While the exact percentage of our sample which is of Jewish ancestry is not known, it is likely less than 10%. As we did not sequence any of our control samples, our statistical analyses included only the five previously published GBA variants to avoid any ascertainment bias. While the analysis for these five variants combined yielded an OR of 2.6 (95% CI 1.5– 4.4), individual ORs for each of the variants were not significant (table 3). For the N370S variant in our patients, the OR of 1.7 (95% CI 0.4 – 6.8) was

DISCUSSION

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313

less than the 5.6 (95% CI 1.3–24.3) in a recent report15; however, the CIs do overlap. This difference is likely due to the large number of Jewish PD cases (179/278) included in their study and the high frequency of the N370S variant in that population, in general. No other study has reported ORs for individual GBA variants as we have in this study. Since the variant observed most often in our verified patients with PD, E326K (table 3), has been described as a “mild” mutation or modifier allele,34,35 the analyses were also performed without those patients carrying this variant. Even when those patients are removed, the frequency of GBA variants in the cases remains greater than in the controls (p ⫽ 0.002) suggesting that the GBA effect is not solely due to E326K. In our study, a single patient not meeting our strictest diagnostic criteria of verified PD was shown to be homozygous for the E326K variant. We have also demonstrated that those patients with PD carrying a GBA variant had onset with PD 6 years earlier than patients without a GBA variant. Among the patients with later onset disease (after age 50), those with a GBA variant had a significantly earlier age at onset (61.6 years) as compared to those without a GBA variant (65.4 years). However, the earlier age at onset in GBA variant carriers was not observed when limiting the analysis to those patients having earlier onset (ⱕ age 50). These results differ from those of a recent study that reported the presence of a GBA variant decreased age at onset by nearly 2 years among patients with early onset PD.15 Analysis of the later onset PD cases in this same study did not detect a significantly earlier age at onset in carriers of a GBA variant. It is unclear whether this results from a difference in the ethnicity of two sample populations studied or any bias in collection of the samples. When those with the E326K variant are removed from the analyses, patients with PD with a GBA variant continue to have earlier age at onset compared to those without a variant (p ⫽ 0.008). Four novel variants were each identified in a single family. None of these variants have been reported in either patients with PD or GD, and none was identified in 359 normal control subjects. Two of the novel variants were intronic (IVS6 589-2A⬎G and IVS10 1389-3C⬎G), and their close proximity to the 3= end of the intron (either ⫺2 or ⫺3 position) suggests that either could alter the splice donor site resulting in altered splicing of the GBA mRNA. One synonymous (K303K) and one nonsynonymous (R262H) variant were each identified in a single family. As the synonymous variant does not alter the amino acid sequence of glucocerebrosidase, it is not predicted to be pathogenic for either PD or GD. However, the possibility that the nucleotide substitu314

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tion results in creation of either a cryptic splice donor or acceptor site cannot be ruled out. Any disease susceptibility attributable to the R262H variant could not be determined in this study. Thus, while none of these four GBA variants have been previously identified, each either alters or could potentially alter the glucocerebrosidase sequence and may contribute to disease pathogenesis. In all, GBA variants were identified in 99 of 566 (17.5%) families. Discordance for GBA variant carrier status among affected individuals (both verified and nonverified PD) within the 99 families was common. Of the 99 GBA variant-carrying families, 63 demonstrated discordance for inheritance of the GBA variant among affected individuals. Among the discordant families, we compared age at onset between those PD cases who carried a GBA variant and those cases who did not. Those with a pathogenic variant (N370S, L444P, RecNciI) had a earlier age at onset (p ⫽ 0.01) than those without a variant (56.4 years vs 66.5 years). Interestingly, among the discordant families, carriers of a polymorphic variant (either E326K or T369M) also had lower age at onset than those without a variant (57.1 years vs 61.4 years; p ⫽ 0.03). Our study is unique in that 96 unrelated familial patients with PD were selected for sequencing of the glucocerebrosidase gene based on their lod score in the GBA chromosomal region that exceeded 0.60. Previous reports focused primarily on sporadic or idiopathic PD except for that of Sato et al., for which 51% of patients with PD reported a positive family history.13 Nine GBA variants were identified in 21 of the 96 patients, making the yield for this lod score strategy 21.9%. The nine GBA variants were only identified in 16.5% of the remaining 470 families. Thus, while linkage methods have very limited specificity for identifying causative mutations when a majority of the families in a study contain only a single affected sibling pair, the apparent increase in sensitivity illustrates that this is a helpful strategy for prioritizing which individuals to sequence in the evaluation of potential PD susceptibility genes. ACKNOWLEDGMENT The authors thank the subjects for their participation in this research study.

APPENDIX The following are members of the PROGENI Steering Committee: University of Tennessee Health Science Center: R.F. Pfeiffer; University of Rochester: F. Marshall, D. Oakes, A. Rudolph, A. Shinaman; Columbia University Medical Center: K. Marder; Indiana University School of Medicine: P.M. Conneally, T. Foroud, C. Halter; University of Kansas Medical Center: K. Lyons; Eli Lilly & Company: E. Siemers; Medical College of Ohio: L. Elmers; University of California, Irvine: N. Hermanowicz. The following are Parkinson Study Group Investigators and Coordinators: Albany Medical College: S. Factor, D. Higgins, S. Evans; Barrow Neurological Institute: H. Shill, M. Stacy, J. Danielson, L. Marlor, K.

Williamson; Baylor College of Medicine: J. Jankovic, C. Hunter; Beth Israel Deaconess Medical Center: D. Simon, P. Ryan, L. Scollins; Beth Israel Medical Center: R. Saunders-Pullman, K. Boyar, C. Costan-Toth, E. Ohmann; Brigham & Women’s Hospital: L. Sudarsky, C. Joubert; Brown University (Memorial Hospital of RI): J. Friedman, K. Chou, H. Fernandez, M. Lannon; Cleveland Clinic Florida-Weston: N. Galvez-Jimenez, A. Podichetty; Clinical Neuroscience Center: P. Lewitt, M. DeAngelis; Colorado Neurological Institute: C. O’Brien, L. Seeberger, C. Dingmann, D. Judd; Columbia University Medical Center: K. Marder, J. Fraser, J. Harris; Creighton University: J. Bertoni, C. Peterson; Evanston Northwestern Healthcare: M. Rezak, G. Medalle; Hotel-Dieu Hospital-Chum: S. Chouinard, M. Panisset, J. Hall, H. Poiffaut; Hunter Homes Mcguire Veterans Medical Center: V. Calabrese, P. Roberge; Indiana University School of Medicine: J. Wojcieszek, J. Belden, C. Halter; Institute for Neurodegenerative Disorders: D. Jennings, K. Marek, S. Mendick; Johns Hopkins University: S. Reich, B. Dunlop; London Health Sciences Centre: M. Jog, C. Horn; LSU Medical Center: J. Rao, M. Cook; Mayo Clinic Jacksonville: R. Uitti, M. Turk; Mcfarland Neurosciences: T. Ajax, J. Mannetter; McGill Centre for Studies in Aging: M. Panisset, J. Hall; Medical College of Georgia: K. Sethi, J. Carpenter, B. Dill, K. Ligon, S. Narayan, L. Woodward; Medical College of Wisconsin: K. Blindauer, K. Abou-Samra, J. Petit; Medical University of Ohio: L. Elmer, E. Aiken, K. Davis, C. Schell, S. Wilson; Mount Sinai School of Medicine New York: M. Velickovic, W. Koller (deceased), S. Phipps; North Shore-Long Island Jewish Health System: A. Feigin, M. Gordon, J. Hamann, E. Licari, M. Marotta-Kollarus, B. Shannon, R. Winnick; Northwestern University: T. Simuni, A. Kaczmarek, K. Williams, M. Wolff; Ochsner Clinic Foundation: J. Rao, M. Cook; Ohio State University: M. Fernandez, J. Hubble, S. Kostyk, A. Campbell, C. Reider, A. Seward; Oregon Health & Science University: J. Nutt, R. Camicioli, J. Carter, P. Andrews, S. Morehouse, C. Stone; Ottawa Hospital Civic Site: T. Mendis, C. Alcorn-Costa, D. Grimes, P. Gray, K. Haas, J. Vendette; Pacific Neuroscience Medical Group: J. Sutton, B. Hutchinson, J. Young; Saskatoon Dist Health Board Royal University Hospital: A. Rajput, A. Rajput, L. Klassen, T. Shirley; Scott & White Hospital/Texas A&M University: B. Manyam, P. Simpson, J. Whetteckey, B. Wulbrecht; The Parkinson’s & Movement Disorder Institute: D. Truong, M. Pathak, N. Luong, T. Tra, A. Tran, J. Vo; Toronto Western Hospital, University Health: A. Lang, L. Johnston, G. Kleiner-Fisman, A. Nieves, J. So; UMDNJ-School of Osteopathic Medicine: G. Podskalny, L. Giffin; University of Alabama at Birmingham: P. Atchison, C. Allen; University of Alberta: W. Martin, M. Wieler; University of Calgary: O. Suchowersky, M. Klimek; University of California Irvine: N. Hermanowicz, S. Niswonger; University of California San Diego: C. Shults (deceased), D. Fontaine; University of California San Francisco: M. Aminoff, C. Christine, M. Diminno, J. Hevezi; University of Chicago: A. Dalvi, U. Kang, J. Richman, S. Uy, J. Young; University of Cincinnati: A. Dalvi, M. Gartner, A. Sahay, D. Schwieterman, B. Wolthoff; University of Colorado Health Sciences Center: D. Hall, M. Leehey, S. Culver, T. Derian; University of Connecticut: T. Demarcaida, S. Belber; University of Iowa: R. Rodnitzky, J. Dobson; University of Kansas Medical Center: R. Pahwa, K. Lyons, T. Gales, S. Thomas; University of Maryland School of Medicine: L. Shulman, S. Reich, W. Weiner, K. Dustin; University of Miami: C. Singer, W. Koller, K. Lyons, W. Weiner, L. Zelaya; University of Minnesota: P. Tuite, V. Hagen, J. Kosowicz, S. Rolandelli, R. Schacherer; University of New Mexico: P. Gordon, J. Werner; University of Puerto Rico School of Medicine: C. Serrano, S. Roque; University of Rochester: R. Kurlan, D. Berry, I. Gardiner; University of South Florida: R. Hauser, J. Sanchez-Ramos, T. Zesiewicz, H. Delgado, K. Price, P. Rodriguez, S. Wolfrath; University of Tennessee Health Science Center: L. Davis, B. Pfeiffer; University of Texas Southwestern Medical Center: R. Dewey, B. Estes, B. Hayward, A. Johnson, M. Meacham; Wake Forest University School of Medicine: F. Walker, V. Hunt, C. O’neill; Washington University: B. Racette, L. Good, M. Rundle. Biostatistics and Clinical Trials Coordination Centers Staff included A. Watts, A. Wang, T. Ross, S. Bennett, D. Kamp, E. Julian-Baros, S. Daigneault, and R. Doolan.

2. 3.

4.

5. 6. 7. 8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

Received February 26, 2008. Accepted in final form July 2, 2008. REFERENCES 1. Farrer MJ. Genetics of Parkinson disease: paradigm shifts and future prospects. Nat Rev Genet 2006;7:306–318.

22.

Gasser T. Genetics of Parkinson’s disease. Curr Opin Neurol 2005;18:363–369. Zimprich A, Biskup S, Leitner P, et al. Mutations in LRRK2 cause autosomal-dominant parkinsonism with pleomorphic pathology. Neuron 2004;44:601–607. Paisan-Ruiz C, Jain S, Evans EW, et al. Cloning of the gene containing mutations that cause PARK8-linked Parkinson’s disease. Neuron 2004;44:595–600. Sidransky E. Gaucher disease: complexity in a “simple” disorder. Mol Genet Metab 2004;83:6–15. Butters TD. Gaucher disease. Curr Opin Chem Biol 2007; 11:412–418. Germain DP. Gaucher’s disease: a paradigm for interventional genetics. Clin Genet 2004;65:77–86. Tayebi N, Walker J, Stubblefield B, et al. Gaucher disease with parkinsonian manifestations: does glucocerebrosidase deficiency contribute to a vulnerability to parkinsonism? Mol Genet Metab 2003;79:104–109. Tayebi N, Callahan M, Madike V, et al. Gaucher disease and parkinsonism: a phenotypic and genotypic characterization. Mol Genet Metab 2001;73:313–321. Lwin A, Orvisky E, Goker-Alpan O, LaMarca ME, Sidransky E. Glucocerebrosidase mutations in subjects with parkinsonism. Mol Genet Metab 2004;81:70–73. Aharon-Peretz J, Rosenbaum H, Gershoni-Baruch R. Mutations in the glucocerebrosidase gene and Parkinson’s disease in Ashkenazi Jews. N Engl J Med 2004; 351:1972–1977. Eblan MJ, Nguyen J, Ziegler SG, et al. Glucocerebrosidase mutations are also found in subjects with early-onset parkinsonism from Venezuela. Mov Disord 2006;21:282– 283. Sato C, Morgan A, Lang AE, et al. Analysis of the glucocerebrosidase gene in Parkinson’s disease. Mov Disord 2005; 20:367–370. Clark LN, Nicolai A, Afridi S, et al. Pilot association study of the beta-glucocerebrosidase N370S allele and Parkinson’s disease in subjects of Jewish ethnicity. Mov Disord 2005;20:100–103. Clark LN, Ross BM, Wang Y, et al. Mutations in the glucocerebrosidase gene are associated with early-onset Parkinson disease. Neurology 2007;69:1270–1277. Goker-Alpan O, Giasson BI, Eblan MJ, et al. Glucocerebrosidase mutations are an important risk factor for Lewy body disorders. Neurology 2006;67:908–910. Toft M, Pielsticker L, Ross OA, Aasly JO, Farrer MJ. Glucocerebrosidase gene mutations and Parkinson disease in the Norwegian population. Neurology 2006;66:415–417. Eblan MJ, Walker JM, Sidransky E. The glucocerebrosidase gene and Parkinson’s disease in Ashkenazi Jews. N Engl J Med 2005;352:728–731. Tan EK, Tong J, Fook-Chong S, et al. Glucocerebrosidase mutations and risk of Parkinson disease in Chinese patients. Arch Neurol 2007;64:1056–1058. Ziegler SG, Eblan MJ, Gutti U, et al. Glucocerebrosidase mutations in Chinese subjects from Taiwan with sporadic Parkinson disease. Mol Genet Metab 2007;91:195–200. Wu YR, Chen CM, Chao CY, et al. Glucocerebrosidase gene mutation is a risk factor for early onset of Parkinson disease among Taiwanese. J Neurol Neurosurg Psychiatry 2007;78:977–979. De Marco EV, Annesi G, Tarantino P, et al. Glucocerebrosidase gene mutations are associated with Parkinson’s disease in southern Italy. Mov Disord 2008;23:460–463.

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Bras J, Paisan-Ruiz C, Guerreiro R, et al. Complete screening for glucocerebrosidase mutations in Parkinson disease patients from Portugal. Neurobiol Aging EPub 2007 Dec 19. 24. Fahn S, Elton R, Committee UD. Unified Parkinson’s Disease Rating Scale. In: Fahn S, Marsden C, Goldstein M, eds. Recent Developments in Parkinson’s Disease. Florham Park, NY: Macmillan Healthcare Information, 1987:153–163. 25. Lang AE, Fahn S. Assessment of Parkinson’s disease. In: Munsat T, ed. Quantification of Neurologic Deficit. Boston: Butterworth, 1989:285–309. 26. Schwab R, England A. Projection technique for evaluating surgery in Parkinson’s disease. In: Gillingham F, Donaldson I, eds. Third Symposium on Parkinson’s Disease. Edinburgh: E&S Livingstone, 1969:152–157. 27. Hoehn MM, Yahr MD. Parkinsonism: onset, progression and mortality. Neurology 1967;17:427–442. 28. Folstein MF, Folstein SE, McHugh PR. “Mini-mental state.” A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975;12:189–198. 29. Yesavage JA, Brink TL, Rose TL, et al. Development and validation of a geriatric depression screening scale: a preliminary report. J Psychiatr Res 1982;17:37–49.

30.

Blessed G, Tomlinson BE, Roth M. The association between quantitative measures of dementia and of senile change in the cerebral grey matter of elderly subjects. Br J Psychiatry 1968;114:797–811. 31. Pankratz N, Nichols WC, Uniacke SK, et al. Genome screen to identify susceptibility genes for Parkinson disease in a sample without parkin mutations. Am J Hum Genet 2002;71:124–135. 32. Pankratz N, Nichols WC, Uniacke SK, et al. Genomewide linkage analysis and evidence of gene-by-gene interactions in a sample of 362 multiplex Parkinson disease families. Hum Mol Genet 2003;12:2599–2608. 33. Pankratz N, Uniacke SK, Halter CA, et al. Genes influencing Parkinson disease onset: replication of PARK3 and identification of novel loci. Neurology 2004;62:1616– 1618. 34. Nichols WC, Elsaesser VE, Pankratz N, et al. LRRK2 mutation analysis in Parkinson disease families with evidence of linkage to PARK8. Neurology 2007;69:1737–1744. 35. Nichols WC, Pankratz N, Hernandez D, et al. Genetic screening for a single common LRRK2 mutation in familial Parkinson’s disease. Lancet 2005;365:410–412.

Calling All New and International Members! Don’t miss these FREE AAN Annual Meeting events designed just for you: • New Member Information Session Sunday, April 26 / 5:00 p.m. to 6:00 p.m. Learn about the AAN, its resources and benefits, and network with Academy leaders. • International Attendee Summit Monday, April 27 / 7:00 a.m. to 9:00 a.m. Meet Academy leaders and make your voice heard on matters most important to you. Learn more at www.aan.com/specialevents.

Learn. Earn. Network. 2009 AAN Annual Meeting: An Excellent Value • Learn about the latest scientific advances in neurology • Earn valuable CME credit and fulfill Maintenance of Certification requirements • Network with your peers at exciting social events all week long • Enjoy the convenience and value of all this and more—in just one meeting Early registration and hotel deadline is March 20, 2009. Register today at www.am.com/AM2009.

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Effect of aerobic training in patients with spinal and bulbar muscular atrophy (Kennedy disease) N. Preisler, MD G. Andersen, BSc F. Thøgersen, BSc C. Crone, MD, PhD T.D. Jeppesen, MD F. Wibrand, PhD J. Vissing, MD, PhD

Address correspondence and reprint requests to Dr. Nicolai Preisler, Neuromuscular Research Unit 3342, University of Copenhagen, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark [email protected]

ABSTRACT

Objective: We examined the effect of aerobic exercise in patients with spinal and bulbar muscular atrophy (SBMA). SBMA is caused by a defect androgen receptor. This defect causes motor neuron death, but considering the important function of androgens in muscle, it is possible that muscle damage in SBMA also occurs independently of motor neuron damage.

Methods: Eight patients with SBMA engaged in regular cycling exercise for 12 weeks. Maximum oxygen uptake (VO2max), maximal work capacity (Wmax), muscle morphology, citrate synthase (CS) activity, body composition, EMG, static strength measurements, lung function, plasma proteins, and hormones were evaluated before and after training. Evaluation of improvements in activities of daily living (ADL) was conducted after training.

Results: Wmax increased by 18%, and CS activity increased by 35%. There was no significant change in VO2max or any of the other variables examined before and after training, and the patients with SBMA did not feel improvements in ADL.

Conclusions: Frequent, moderate-intensity aerobic conditioning is of little beneficial effect in patients with spinal and bulbar muscular atrophy (SBMA). High levels of plasma creatine kinase and muscle regeneration indicate a primary myopathic affection, which, in parallel with the motor neuron deficiency, may attenuate the response to exercise training in patients with SBMA. Neurology® 2009;72:317–323 GLOSSARY ADL ⫽ activities of daily living; AR ⫽ androgen receptor; ASI ⫽ androgen sensitivity index; BMI ⫽ body mass index; CK ⫽ creatine kinase; CS ⫽ citrate synthase; FSH ⫽ follicle-stimulating hormone; LH ⫽ luteinizing hormone; MU ⫽ motor unit; SBMA ⫽ spinal and bulbar muscular atrophy; VO2max ⫽ maximum oxygen uptake; Wmax ⫽ maximal work capacity.

Spinal and bulbar muscular atrophy (SBMA), also know as Kennedy disease,1 is caused by a CAG-repeat expansion (range 38 – 62 repeats) in the gene on the X chromosome, encoding the androgen receptor (AR).2-4 The AR is believed to influence the expression of a large variety of genes by acting as a transcription factor. When testosterone or dihydrotestosterone binds to the AR, the AR–ligand complex binds to the target gene and regulates its expression.5 SBMA is primarily believed to be a neuronopathy, caused by a toxic gain of function of the AR when associated with testosterone.5 This is supported by the fact that only men express this characteristic phenotype, although heterozygous and homozygous females may have some symptoms.6,7 SBMA is a slowly progressive disease, with age at onset of muscle weakness in the third to sixth decade of life. Clinically, the patients experience weakness, atrophy, and fasciculations in the muscles of the extremities and of the bulbar and facial muscles. The dysfunctional AR renders patients partially androgen insensitive, with an increased androgen sensitivity index (ASI) and gynecomasty.8 A potential primary effect of dysfunctional AR on muscle itself has been Supplemental data at www.neurology.org From the Neuromuscular Research Unit, Department of Neurology and Copenhagen Muscle Research Center (N.P., G.A., F.T., T.D.J., J.V.), Department of Clinical Neurophysiology (C.C.), and Department of Clinical Genetics (F.W.), University of Copenhagen, Rigshospitalet, Denmark. Supported by grants from the Sara and Ludvig Elsass Foundation, The Danish Medical Research Council, the NOVO Nordic Foundation, and the Copenhagen Hospital Community Foundation. Disclosure: The authors report no disclosures. Copyright © 2009 by AAN Enterprises, Inc.

317

Table

Demographic data on eight patients with spinal and bulbar muscular atrophy

Patient no.

Age, y

BMI, kg/m2

No. of CAG repeats

Gynecomastia

1

63

21

45

No

None

2

56

25

46

Yes

Sildenafil 25 mg/wk ⫹ calcium tablet 1/d

Medication

3

53

23

52

Yes

Fluoxetine 20 mg/d ⫹ pantoprazole 20 mg 1–2/mo

4

49

22

44

No

None

5

59

27

42

No

Calcium tablet 1/d

6

58

18

45

Yes

Testosterone undecanoate 40 mg/d

7

61

26

45

Yes

Bendroflumethiazide/KCl 1/d ⫹ atenolol 25 mg/d ⫹ carbimazole 5 mg/d ⫹ zolpidem 5 mg/d

8

51

27

42

Yes

None

Mean ⴞ SD

56 ⫾ 5

24 ⫾ 3

45 ⫾ 3

—

—

Patient 6 continued treatment with testosterone after a clinical trial of testosterone, where he felt better while taking the drug. BMI ⫽ body mass index.

given little attention in SBMA, although it is well established that androgens have an important anabolic function in skeletal muscle.9 There is no specific treatment for SBMA. We have successfully implemented cycle exercise programs to treat patients with muscular dystrophies and metabolic myopathies. All of these patients improved their maximum oxygen uptake (VO2max) and maximal work capacity (Wmax) with training and subjectively felt improvement in activities of daily living (ADL), and the training was well tolerated and never induced muscle damage.10-14 Most of these patients share clinical characteristics of patients with SBMA, such as muscle weakness and wasting and sedentary lifestyles. We studied the effect of aerobic training for 3 months in eight patients with SBMA. METHODS Subjects. Inclusion criteria for participation in this study were 1) confirmed diagnosis of SBMA by DNA analysis, 2) age between 18 and 65 years, 3) capability of uninterrupted cycling for at least 20 minutes, and 4) completion of 70% of the planned exercise sessions. Exclusion criteria were 1) other serious medical conditions, 2) regular exercise training of more than 1 hour per week, and 3) inability to cooperate mentally. Based on the predicted treatment response and variability in training effects, it was calculated that a minimum of seven patients was needed to provide enough power to the study (appendix e-1 on the Neurology® Web site at www.neurology.org). Eleven patients were originally selected for the study. One patient (age 63 years, body mass index [BMI] 33 kg/m2, 46 CAG repeats) was wheelchair bound and could only walk a few meters with assistance. He could only cycle for 3 minutes at a resistance of 20 watts, the lowest possible resistance on the cycleergometer, and was therefore excluded. Two other patients were excluded because they completed less than 70% of the planned exercise sessions. One of these patients (age 59 years, BMI 30 318

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kg/m2, 42 CAG repeats) never started the exercise protocol, because of illness in his close family. The other patient (age 49 years, BMI 20 kg/m2, 47 CAG repeats) had completed just 16 of 42 sessions after 3 months. The low compliance was due to lack of motivation. Data in this study are shown for the remaining eight patients with SBMA, all of whom completed the study. DNA analyses confirmed the diagnosis in each patient (see the table for demographic data). The study was approved by The Committee on Biomedical Research Ethics of the Capital Region of Denmark (project ID: H-KF-01 297836 KF). All the participants received written and oral information about the experiment and potential risks and gave informed consent to participate.

Experimental protocol. Pre-experimental evaluations. The patients were instructed to work for 12 weeks on a stationary cycleergometer at home. They were equipped with a Polar pulse watch and transmitter. Before training was started, an incremental exercise test was conducted to assess the maximal oxidative capacity of the patients. The patients were tested in the postabsorptive state on a cycle-ergometer (T6, Tunturi, Finland). Pulmonary gas exchanges were evaluated with a gas analyzer/flowmeter (Quark b2, Cosmed, Italy). Heart rate was monitored continuously with pulse watches and a three-lead electrocardiogram. After the max test, the pulse interval corresponding to 65% to 70% of VO2max was identified during cycling at constant workload. Patients were instructed to train at home at this heart rate, and heart rate limits were stored on the pulse watch, thus providing patients auditory feedback if limits were violated during training. Patients trained 30 minutes per session and were instructed to adjust workload according to the target heart rate. Each training session at home was recorded on the pulse watch. These data were downloaded on a computer and analyzed with Polar ProTrainer 5 software (version 5.20.132), enabling us to view precise recordings of heart rate and of time and duration of training for each training session. Data from each patient were analyzed to validate frequency and compliance to training. The subjects were instructed to gradually increase the training frequency from two training sessions in weeks 1 and 2, to three sessions in weeks 3 and 4, and then to five sessions per week in the remaining eight weeks. Endpoints, efficacy, and safety evaluations. Changes in VO2max, Wmax, and ADL with training were defined as primary

Figure 1

Activities of daily living

Self-reported training-induced changes in physical fatigue, daily physical activities, endurance, leg muscle strength, and walking distance in eight patients with spinal and bulbar muscular atrophy. Changes were rated as worse (black bar), no change (gray bar), or improvement (white bar). The number in the bars refers to number of patients.

endpoints. Secondary endpoints were changes in muscle morphology, citrate synthase (CS) activity, body composition, EMG, static strength measurements, and lung function. All these variables were assessed before and at the end of training, with the exception of the questionnaire for ADL, which was given only at the end of training. Safety endpoints were plasma creatine kinase (CK), androgen hormone levels, and reports of adverse effects of training. Assessment of maximal work capacity. An incremental exercise test was performed before and at the end of the 12 weeks of training, as described under pre-experimental evaluation. Venous blood samples were obtained from a forearm vein for lactate analyses to validate the level of physical exertion. Questionnaire and interview. After 12 weeks of training, the patients completed a questionnaire to assess training-induced changes in the ADL items shown in figure 1. The principal investigator was in contact with the subjects every week, and the patients were interviewed about any adverse effects of training. Muscle morphology, CS activity, body composition, and EMG. Muscle biopsy was obtained from the left vastus lateralis muscle and evaluated for CS activity15 and morphologic items shown in table e-1. A whole-body dual energy x-ray absorptiometry scan was performed to evaluate whole-body and leg changes in lean tissue and fat mass.16 Needle EMG in the right brachial biceps and right medial vastus muscle was performed in all patients.17 Detailed descriptions of methods used are described in appendix e-1. Static strength measurements and lung function. Static strength was measured in the muscles primarily involved in cycling.18 Lung function was also measured. For details on methods, see appendix e-1. Plasma proteins and hormones. As an index of muscle injury, plasma CK was measured periodically as shown in figure 2. Concomitantly with CK measurements and at the same time of the day, blood was drawn for measurement of plasma testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, and albumin levels. For details on methods, see appendix e-1. ASI is a product of total testosterone and LH and was used as an indicator of androgen insensitivity.19,20

Statistical analysis. Values are expressed as mean ⫾ SD unless otherwise stated. P ⬍ 0.05 (two-tailed testing) was consid-

Figure 2

Plasma creatine kinase

Plasma creatine kinase levels in eight patients with spinal and bulbar muscular atrophy, measured before training; in weeks 2, 4, and 8; and after training. None of the patients had normal plasma creatine kinase levels at any time.

ered significant. Within-group changes with training were assessed by a paired Student t test. RESULTS Safety endpoints. Adverse effects of training.

On entering the fifth week of training, three patients reported difficulties in completing 30 minutes of training because of fatigue and lack of recovery between sessions. Plasma CK levels were unchanged. At the end of the fifth week, subject 2 reported worsening in all ADL variables, and the CK had increased to 4,043 U/L from 1,659 U/L, measured 5 days after his last training session. For safety reasons, the number of training sessions per week was consequently reduced to four. Thus, patients with SBMA had to complete a total of 42 sessions during the 3 months of training. Plasma CK and hormone levels. There were no training-induced increases in plasma CK levels (figure 2) besides the single aforementioned case. There were no significant changes in ASI, plasma testosterone, LH, FSH, prolactin, or albumin concentrations with training (table e-2). Increased ASI (above 88 U/L ⫻ nmol/L2) was found in four patients before training and in six after training. Two patients with normal ASI had gynecomasty. Primary endpoints. Compliance. The final evaluations were conducted after 95 ⫾ 11 days of training (range 83–114 days). Based on pulse watch data, patients completed 42 ⫾ 7 sessions (range 35–56) in this period. They all kept their pulse within the preset pulse intervals during sessions. The overall compliance to the training was 89% (range 71%–126%). The relative exertion during max tests before and after training was similar, as indicated by similar peak heart rates and plasma lactate levels. Resting heart rate did not change after training. VO2max, Wmax, and ADL. There was no significant increase in VO2max after training (figure 3), but Wmax Neurology 72

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Figure 3

Maximal oxygen uptake

Maximal oxygen uptake (VO2max), before and after 12 weeks of training, shown individually for eight patients (1– 8) with spinal and bulbar muscular atrophy. Patient number in this figure corresponds with patient number in the table.

increased by 18% (p ⬍ 0.014), from 84 ⫾ 24 to 99 ⫾ 20 watts. Changes in VO2max and Wmax were unrelated to the degree of compliance. ADL functions in the questionnaire did not change with training (figure 1). Secondary endpoints. Muscle morphology and CS activity.

Because of severe muscle wasting of the quadriceps muscle, biopsies could not be obtained in subjects 2 and 8. The number of split fibers doubled with training (p ⬍ 0.04; table e-1), but no other morphologic variable changed. The number of central nuclei was as high as that seen in classic myopathic conditions Figure 4

(table e-1). Necrotic fibers where found in four patients, and there was a general spherical appearance of most fibers. Fat infiltration was seen in five subjects, and fibrosis was seen in all subjects. Morphologic findings are shown in figure 4. CS activity increased 35% with training (140 ⫾ 22 mU per milligram protein before training and 188 ⫾ 33 mU per milligram protein after training; p ⬍0.005). EMG. In all patients, EMG of the brachial biceps and medial vastus muscles showed signs of severe chronic partial denervation with considerable reinnervation by demonstrating severely prolonged/increased mean duration and amplitude of motor units (MUs) and a discrete recruitment pattern with very high amplitudes at maximal effort. However, no significant change in mean duration of the MUs or recruitment pattern was seen between the two tests in each patient (table e-3). Spontaneous activity was present in three patients and absent in the rest, but the spontaneous activity in the medial vastus muscle was unchanged in two patients and decreased in one after exercise. Complex repetitive discharges were seen in the brachial biceps and medial vastus muscles in one patient, and this activity increased somewhat after exercise in the arm but not in the leg. Body composition, static strength, and lung function

There were no training-induced changes in whole-body or leg lean tissue and fat mass (table e-4). Likewise, training caused no change in muscle strength (table e-5) or lung function (table e-6).

measurements.

Skeletal muscle morphology

Skeletal muscle morphology in spinal and bulbar muscular atrophy patients 1 (A) and 5 (B). The sections were stained with hematoxylin and eosin (white bars ⫽ 100 ␮m). Neurogenic findings were present in all biopsies, as evidenced by type grouping (not visible in this stain); angulated fibers; and, as seen in picture A, groups of pyknotic nuclei and clusters of small atrophied fibers (black arrow) among hypertrophied fibers. Pronounced myopathic findings were also found in all biopsies, as indicated by a high percentage of central nuclei, split fibers (white arrows, A and B), and myofibrillar disorganization (stars, A and B) in all patients. 320

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DISCUSSION The results of this study show that patients with SBMA do not improve their VO2max or ADL functions with 12 weeks of moderate-intensity aerobic training. Furthermore, the training was not well tolerated and had to be decreased in frequency. These findings are surprising, because a number of other neuromuscular conditions have been trained with this protocol with great improvements in objective and subjective measures.10-14 The results indicate that, unlike numerous other neuromuscular conditions, frequent, moderate-intensity aerobic training in patients with SBMA is ineffective and may potentially cause muscle damage. It could be argued that the poor response to training in patients with SBMA was caused by the reduction in training frequency. However, it is well known that VO2max can be improved in men training at the same duration, frequency, and intensity as those used in the revised protocol.21-23 Thus, even the revised protocol should have been expected to yield a positive training effect. Although the patients with SBMA did not improve their VO2max with training, they significantly improved their Wmax. Patients with neuromuscular conditions generally have a low work efficiency compared with healthy subjects. The discrepancy in VO2max and Wmax training responses could relate to a training-induced improvement in work efficiency. In line with this, patients struggled less with their upper body during cycling after 12 weeks of training. This means that an improvement in VO2max may have been overlooked in patients with SBMA, but still, the magnitude of improvements with training in SBMA is far from that seen in other neuromuscular conditions.10-14 The increase in CS activity was also lower than we previously have observed and supports that patients with SBMA have an attenuated response to exercise.13 Our results suggest that the limiting factor for training effects in SBMA is not only due to a central fatigue mechanism, involving limited number of motor neurons, but probably also involves primary myogenic factors. Considering that the AR has significant functions in muscle as well as in motor neurons, a degree of primary myopathic contribution to the pathogenesis of SBMA is likely. In support of this, the pronounced myopathic pathology in the muscle biopsies and high CK levels of our patients point to a high level of primary muscle involvement in SBMA, which is otherwise primarily considered a neurogenic disorder. The mixed findings on biopsies have recently been described by others.24 With exception of the number of split fibers, muscle pathology did not change with training, but these results should be interpreted with caution because of the relatively small sample size and the high baseline

pathology. However, the unchanged EMG findings support these findings. In agreement with a direct myogenic pathogenesis in SBMA, two recent studies indicate that the AR can cause a toxic effect directly on skeletal muscle. In a mouse model of SBMA, signs of muscle disease preceded motor neuron pathology.25 In another mouse model, expressing excessive amounts of wildtype AR exclusively in skeletal muscle, a phenotype resembling SBMA developed after testosterone exposure.26 If this disease mechanism also applies in humans, a primary myopathic contribution might be working in parallel with motor neuron damage to restrain the exercise capacity of patients with SBMA. In accord with a myogenic contribution to the disease process in SBMA, it seems that patients who are exclusively affected in the motor neurons of the spinal cord can benefit well from aerobic training. This evidence is provided by experiments in an SMA II mouse model, in which training had a beneficial effect on strength and survival,27 and from a single SMA III patient, who we trained with a similar protocol as used in the present study. The SMA III patient improved her VO2max by 48% and Wmax by 30%, after just 2½ months of training. Unlike SBMA, the pathogenic mechanism underlying the disease in SMA III affects a protein (the survival motor neuron protein 1), which has no known function outside motor neurons.28,29 Larger studies of training effects in SMA III patients are warranted to confirm the apparent beneficial effect of training in SMA III, suggested by this single case observation. Endurance trained athletes tend to have a low resting level of circulating androgens, but acute bouts of exercise give rise to an increase in testosterone levels.30 This increase is normalized within hours after cessation of exercise.31,32 Given a toxic gain of function of activated AR, any increase in testosterone levels might potentially be deleterious for patients with SBMA. Whether patients with SBMA have the same androgen response to exercise as healthy subjects remains to be investigated. Another possible mechanism that could explain the poor training response in patients with SBMA is the loss of AR function. This loss has been attributed to a reduced trans-activation, a reduction of AR messenger RNA, and a reduced binding affinity of the AR.33-36 In skeletal muscle, the AR is expressed in satellite cells and in 50% of the myonuclei. Fibroblasts, vascular endothelial cells, smooth muscle, and mast cells in skeletal muscle also express the AR.37 Satellite cells are crucial for regeneration of skeletal muscle,38 and androgens are believed to be important for satellite cell function.39 Thus, dysfunctional AR could affect the regenerative capacity in skeletal musNeurology 72

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cle of patients with SBMA. In accord with dysfunctional AR, signs of androgen insensitivity were evident in our patient group, as indicated by increased ASI and gynecomasty in five of eight patients. Similar findings of androgen insensitivity have been demonstrated previously.8 After a long string of highly beneficial results from training various groups of neuromuscular diseases, this study emphasizes the importance of accessing treatment effects in individual neuromuscular disorders and further studying the effect of different exercise protocols on fitness and muscle strength in this patient group.

13.

14.

15.

16. 17.

18. AUTHOR CONTRIBUTIONS Statistical analysis was conducted by N.P.

19.

Received June 16, 2008. Accepted in final form October 15, 2008. 20. REFERENCES 1. Kennedy WR, Alter M, Sung JH. Progressive proximal spinal and bulbar muscular atrophy of late onset: a sexlinked recessive trait. Neurology 1968;18:671–680. 2. La Spada AR, Wilson EM, Lubahn DB, Harding AE, Fischbeck KH. Androgen receptor gene mutations in X-linked spinal and bulbar muscular atrophy. Nature 1991;352:77–79. 3. Lund A, Udd B, Juvonen V, et al. Founder effect in spinal and bulbar muscular atrophy (SBMA) in Scandinavia. Eur J Hum Genet 2000;8:631–636. 4. Tanaka F, Doyu M, Ito Y, et al. Founder effect in spinal and bulbar muscular atrophy (SBMA). Hum Mol Genet 1996;5:1253–1257. 5. Adachi H, Waza M, Katsuno M, Tanaka F, Doyu M, Sobue G. Pathogenesis and molecular targeted therapy of spinal and bulbar muscular atrophy. Neuropathol Appl Neurobiol 2007;33:135–151. 6. Schmidt BJ, Greenberg CR, Allingham-Hawkins DJ, Spriggs EL. Expression of X-linked bulbospinal muscular atrophy (Kennedy disease) in two homozygous women. Neurology 2002;59:770–772. 7. Ishihara H, Kanda F, Nishio H, Sumino K, Chihara K. Clinical features and skewed X-chromosome inactivation in female carriers of X-linked recessive spinal and bulbar muscular atrophy. J Neurol 2001;248:856–860. 8. Dejager S, Bry-Gauillard H, Bruckert E, et al. A comprehensive endocrine description of Kennedy’s disease revealing androgen insensitivity linked to CAG repeat length. J Clin Endocrinol Metab 2002;87:3893–3901. 9. Bhasin S, Woodhouse L, Storer TW. Proof of the effect of testosterone on skeletal muscle. J Endocrinol 2001;170:27–38. 10. Orngreen MC, Olsen DB, Vissing J. Aerobic training in patients with myotonic dystrophy type 1. Ann Neurol 2005;57:754–757. 11. Sveen ML, Jeppesen TD, Hauerslev S, Krag TO, Vissing J. Endurance training: an effective and safe treatment for patients with LGMD2I. Neurology 2007;68:59–61. 12. Olsen DB, Orngreen MC, Vissing J. Aerobic training improves exercise performance in facioscapulohumeral muscular dystrophy. Neurology 2005;64:1064–1066. 322

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Jeppesen TD, Schwartz M, Olsen DB, et al. Aerobic training is safe and improves exercise capacity in patients with mitochondrial myopathy. Brain 2006;129:3402–3412. Haller RG, Wyrick P, Taivassalo T, Vissing J. Aerobic conditioning: an effective therapy in McArdle’s disease. Ann Neurol 2006;59:922–928. Wibrand F, Ravn K, Schwartz M, Rosenberg T, Horn N, Vissing J. Multisystem disorder associated with a missense mutation in the mitochondrial cytochrome b gene. Ann Neurol 2001;50:540–543. Mattsson S, Thomas BJ. Development of methods for body composition studies. Phys Med Biol 2006;51:R203–R228. Buchthal F, Pinelli P. Analysis of muscle action potentials as a diagnostic aid in neuro-muscular disorders. Acta Med Scand Suppl 1952;266:315–327. Merlini L, Mazzone ES, Solari A, Morandi L. Reliability of hand-held dynamometry in spinal muscular atrophy. Muscle Nerve 2002;26:64–70. Aiman J, Griffin JE, Gazak JM, Wilson JD, MacDonald PC. Androgen insensitivity as a cause of infertility in otherwise normal men. N Engl J Med 1979;300:223–227. Hiort O, Holterhus PM, Horter T, et al. Significance of mutations in the androgen receptor gene in males with idiopathic infertility. J Clin Endocrinol Metab 2000;85:2810–2815. Badenhop DT, Cleary PA, Schaal SF, Fox EL, Bartels RL. Physiological adjustments to higher- or lower-intensity exercise in elders. Med Sci Sports Exerc 1983;15:496–502. Gass G, Gass E, Wicks J, Browning J, Bennett G, Morris N. Rate and amplitude of adaptation to two intensities of exercise in men aged 65-75 yr. Med Sci Sports Exerc 2004;36:1811–1818. van Aggel-Leijssen DP, Saris WH, Wagenmakers AJ, Senden JM, van Baak MA. Effect of exercise training at different intensities on fat metabolism of obese men. J Appl Physiol 2002;92:1300–1309. Soraru G, D’Ascenzo C, Polo A, et al. Spinal and bulbar muscular atrophy: skeletal muscle pathology in male patients and heterozygous females. J Neurol Sci 2008;264:100–105. Yu Z, Dadgar N, Albertelli M, et al. Androgen-dependent pathology demonstrates myopathic contribution to the Kennedy disease phenotype in a mouse knock-in model. J Clin Invest 2006;116:2663–2672. Monks DA, Johansen JA, Mo K, et al. Overexpression of wild-type androgen receptor in muscle recapitulates polyglutamine disease. Proc Natl Acad Sci USA 2007;104: 18259–18264. Grondard C, Biondi O, Armand AS, et al. Regular exercise prolongs survival in a type 2 spinal muscular atrophy model mouse. J Neurosci 2005;25:7615–7622. Monani UR. Spinal muscular atrophy: a deficiency in a ubiquitous protein; a motor neuron-specific disease. Neuron 2005;48:885–896. Sumner CJ. Molecular mechanisms of spinal muscular atrophy. J Child Neurol 2007;22:979–989. Hackney AC. Endurance exercise training and reproductive endocrine dysfunction in men: alterations in the hypothalamic-pituitary-testicular axis. Curr Pharm Des 2001;7:261–273. Tremblay MS, Copeland JL, Van HW. Effect of training status and exercise mode on endogenous steroid hormones in men. J Appl Physiol 2004;96:531–539. Jensen J, Oftebro H, Breigan B, et al. Comparison of changes in testosterone concentrations after strength and endurance exercise in well trained men. Eur J Appl Physiol Occup Physiol 1991;63:467–471.

33.

Kazemi-Esfarjani P, Trifiro MA, Pinsky L. Evidence for a repressive function of the long polyglutamine tract in the human androgen receptor: possible pathogenetic relevance for the (CAG)n-expanded neuronopathies. Hum Mol Genet 1995;4:523–527. 34. Thomas PS Jr, Fraley GS, Damian V, et al. Loss of endogenous androgen receptor protein accelerates motor neuron degeneration and accentuates androgen insensitivity in a mouse model of X-linked spinal and bulbar muscular atrophy. Hum Mol Genet 2006;15:2225–2238. 35. Choong CS, Kemppainen JA, Zhou ZX, Wilson EM. Reduced androgen receptor gene expression with first exon CAG repeat expansion. Mol Endocrinol 1996;10:1527–1535.

36.

MacLean HE, Choi WT, Rekaris G, Warne GL, Zajac JD. Abnormal androgen receptor binding affinity in subjects with Kennedy’s disease (spinal and bulbar muscular atrophy). J Clin Endocrinol Metab 1995;80:508–516. 37. Sinha-Hikim I, Taylor WE, Gonzalez-Cadavid NF, Zheng W, Bhasin S. Androgen receptor in human skeletal muscle and cultured muscle satellite cells: up-regulation by androgen treatment. J Clin Endocrinol Metab 2004;89: 5245–5255. 38. Morgan JE, Partridge TA. Muscle satellite cells. Int J Biochem Cell Biol 2003;35:1151–1156. 39. Chen Y, Zajac JD, MacLean HE. Androgen regulation of satellite cell function. J Endocrinol 2005;186:21–31.

Editor’s Note to Authors and Readers: Levels of Evidence coming to Neurology® Effective January 15, 2009, authors submitting Articles or Clinical/Scientific Notes to Neurology® that report on clinical therapeutic studies must state the study type, the primary research question(s), and the classification of level of evidence assigned to each question based on the classification scheme requirements shown below (left). While the authors will initially assign a level of evidence, the final level will be adjudicated by an independent team prior to publication. Ultimately, these levels can be translated into classes of recommendations for clinical care, as shown below (right). For more information, please access the articles and the editorial on the use of classification of levels of evidence published in Neurology.1-3 REFERENCES 1. French J, Gronseth G. Lost in a jungle of evidence: we need a compass. Neurology 2008;71:1634 –1638. 2. Gronseth G, French J. Practice parameters and technology assessments: what they are, what they are not, and why you should care. Neurology 2008;71:1639 –1643. 3. Gross RA, Johnston KC. Levels of evidence: taking Neurology® to the next level. Neurology 2008;72:8 –10.

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Comparing explorative saccade and flicker training in hemianopia A randomized controlled study

T. Roth, MSc A.N. Sokolov, PhD A. Messias, MD P. Roth, MD M. Weller, MD S. Trauzettel-Klosinski, MD

Address correspondence and reprint requests to Dr. Susanne Trauzettel-Klosinski, Low Vision Clinic and Research Laboratory, Centre for Ophthalmology, University of Tu¨bingen, Schleichstr. 12-16, D 72076 Tu¨bingen, Germany [email protected]

ABSTRACT

Objective: Patients with homonymous hemianopia are disabled on everyday exploratory activities. We examined whether explorative saccade training (EST), compared with flicker-stimulation training (FT), would selectively improve saccadic behavior on the patients’ blind side and benefit performance on natural exploratory tasks.

Methods: Twenty-eight hemianopic patients were randomly assigned to distinct groups performing for 6 weeks either EST (a digit-search task) or FT (blind-hemifield stimulation by flickering letters). Outcome variables (response times [RTs] during natural search, number of fixations during natural scene exploration, fixation stability, visual fields, and quality-of-life scores) were collected before, directly after, and 6 weeks after training. Results: EST yielded a reduced (post/pre, 47%) digit-search RT for the blind side. Natural search RT decreased (post/pre, 23%) on the blind side but not on the seeing side. After FT, both sides’ RT remained unchanged. Only with EST did the number of fixations during natural scene exploration increase toward the blind and decrease on the seeing side (follow-up/pre difference, 238%). Even with the target located on the seeing side, after EST more fixations occurred toward the blind side. The EST group showed decreased (post/pre, 43%) fixation stability and increased (post/pre, 482%) asymmetry of fixations toward the blind side. Visual field size remained constant after both treatments. EST patients reported improvements in social domain.

Conclusions: Explorative saccade training selectively improves saccadic behavior, natural search, and scene exploration on the blind side. Flicker-stimulation training does not improve saccadic behavior or visual fields. The findings show substantial benefits of compensatory exploration training, including subjective improvements in mastering daily-life activities, in a randomized controlled trial. Neurology® 2009;72:324–331 GLOSSARY ANOVA ⫽ analysis of variance; CI ⫽ confidence interval; EST ⫽ explorative saccade training; FT ⫽ flicker-stimulation training; HH ⫽ homonymous hemianopia; PC ⫽ personal computer; RT ⫽ response time; SLO ⫽ scanning laser ophthalmoscope; TAP ⫽ Tu ¨bingen automated perimetry; WHOQOL ⫽ World Health Organization Quality of Life assessment.

Homonymous hemianopia impacts quality of life, drastically reducing the patient’s spatial orientation, reading ability, and educational and occupational outcome, which represents an important socioeconomic factor. Two distinct rehabilitation approaches have been proposed: 1) compensation with extended saccadic eye-movement exploration toward the blind hemifield to improve the field of gaze and make better use of residual vision, and 2) restitution by stimulating the blind hemifield with the intention to activate potentially unaffected neurons and restore visual function. Despite reports to the contrary,1,2 there is no evidence that restitution intervention enlarges visual fields. Control studies3,4 did not confirm reports of visual-field enlargement after restitution training, such that adult visual-cortex revival by training remains unproven.5 The main problem of restitution-training studies is insufficient fixation control, Supplemental data at www.neurology.org From the Centre for Ophthalmology, Low Vision Clinic and Research Laboratory (T.R., A.N.S., A.M., S.T.-K.), and Department of Neurology (P.R., M.W.), University of Tu¨bingen, Germany; and Department of Neurology (P.R., M.W.), University Hospital Zurich, Switzerland. Supported by the Adolf Messer Foundation. Disclosure: The authors report no disclosures. 324

Copyright © 2009 by AAN Enterprises, Inc.

missing eye movements during conventional perimetry.4-6 In contrast, several studies show substantial visual-search improvements after saccade training.7-11 However, none of these studies used a control patient group and randomized assignment to ensure that potential confounds were evenly distributed. Another general difficulty in training studies is to reliably exclude spontaneous recovery, which can occur during initial months after brain damage,12,13 but rarely after 6 months.14 The present study aimed to apply compensatory explorative saccade training (EST) in a randomized controlled trial with hemianopic patients beyond spontaneous recovery range, using outcome variables that are relevant for everyday life. In the control group, we used flicker-stimulation training (FT), which is unlikely to affect visual-search behavior. Additionally, we wanted to examine visual-field effects, if FT occurred more peripherally in the blind hemifield instead of stimulating the vertical field border.1 The study therefore provided a direct comparison of compensation and potential restitution training. We hypothesized that in contrast to FT, EST would improve saccadic behavior and natural exploratory performance on hemianopic patients’ blind side. METHODS Patients. The study was approved by the University of Tu¨bingen Medical School ethics committee, and informed written consent was obtained from all participants. Thirty patients with postchiasmatic lesions participated, with an equal number of patients assigned randomly to either the EST or the FT group (table). Two FT patients dropped out because of illness and insufficient compliance. Finally, data from 15 EST and 13 FT patients were included. Inclusion criteria were age 18 – 80 years, isolated homonymous hemianopia or quadrant defect (not crossing the vertical line, no other visual field defects) with duration exceeding 6 months, distance to the midline ⱕ5°, and visual acuity ⱖ0.6 (20/33). Exclusion criteria were other diseases of the eye or brain, motor impairments hampering personal computer (PC) use, and other neurologic impairments, particularly epilepsy and hemineglect. Neuropsychological tests were performed to exclude cognitive disorders: dementia (MiniMental State Examination15) and hemineglect (clock-drawing16 and line-bisection17 tests). The groups did not differ regarding age, diagnoses, or duration of disease (table). Twenty-four patients had hemianopia, and 3 of each group had quadrant defects.

Training methods. EST was implemented as an explorative saccadic-search task aimed to improve visual search in the blind hemifield and the use of the total field of gaze. The task was

practiced on a laptop placed 30 cm from patients’ eyes (total visual field 35° ⫻ 47.7°). A custom software program (Borland Delphi 7.0) was used to generate a random array of digits (0 –9; 12-point Arial font) distributed with equal probabilities on the blind and seeing sides. Patients had to find and move the mouse pointer over the predefined digit (digit 4). Upon passing over the digit, the program generated a beep and turned it into a red $ symbol, providing positive feedback and preventing double search for the digit. After finding all digits, the screen automatically cleared, and the patient started the next trial by clicking a button centered on the screen; this ensured the initial central fixation. Position and latency for all digits found were stored in a Paradox database for off-line analysis. FT, potential restitution training, was implemented as a modification of a flickering-letter procedure described recently.18,19 The training was not supposed to foster exploratory eye movements, but rather stimulate the blind hemifield by suprathreshold stimuli with the intention to improve the sensitivity of this hemifield. Borland Delphi 7.0 was used to generate the flicker stimulus (letters A, H, K, or T; 11.68° ⫻ 9.46°, viewed from 30 cm at 21.8° eccentricity; flicker frequency 10 Hz). The eccentric letter presentation reduced the likelihood of eliciting saccades toward the stimulus. As shown previously,4 stimulation along the vertical field border does not enlarge the visual field, but may induce eye movements toward the blind side. The flicker letters occurred one per trial randomly on both sides with a constant proportion (blind:seeing, 3:1) preventing extended periods without seeing a stimulus. During a session, a panel with all four letters (without flicker), arranged vertically, remained centered on the screen. Patients had to fixate the panel and, within 10 seconds, click the mouse on the panel letter matching the flickering letter. On the seeing side, a green symbol appeared with the correct response as positive feedback; a red symbol along with an annoying beep indicated an error. The presented and clicked letters, along with associated response latency, were recorded in a Paradox databank for off-line analysis.

Training procedure. The patients trained at home, using our laboratory’s laptops to ensure standard training conditions (screens, fixed viewing distance, and visual-field area trained), twice for 30 minutes per day, 5 days a week, for 6 weeks. Patients were instructed to avoid head movements during either training. Data were collected three times, before (T1), immediately after (T2), and 6 weeks after training (T3). Log-in file analysis indicated that patients of both groups practiced on average 34 days with 40 blocks per day (no group differences, t test, p ⫽ 0.926). Outcome variables. Digit-search task. The task, identical to EST practiced in one group but administered on a 15-in monitor, provided a more precise response time (RT) assessment than a natural search task described below. It also allowed assessment of EST success as opposed to mere learning effects due to repeated task exposure in both groups. Head stability in this task and during natural scene exploration, fixation task, and perimetry was maintained by a chin rest. Natural search task (table test). RT (seconds per item) was measured using common objects featured in an uneven but fixed fashion on a table (10 in each quadrant). In a session (one per time point), patients had to find, in each hemifield, 20 distinct objects presented in succession by the investigator. Distinct object-category prototypes (e.g., various toy cars) were used to avoid confounds such as semantic influences or agnosia. Natural scene exploration and fixation stability. Eye movements during initial fixation and subsequent free exploraNeurology 72

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Table

Summary data of patients involved in the study

Patient ID

Affected side

HH duration, mo

Age, y

Sex

Diagnosis

101

46

M

Ischemic stroke

L

26

102

63

M

Hemorrhage

R

9

Explorative saccade training group

103

59

M

Ischemic stroke

L

18

104

65

F

Arteriovenous malformation

R

228

105

54

M

Ischemic stroke

L

48

106

67

M

Ischemic stroke

R

6

107

66

M

Ischemic stroke

L

26

108

69

F

Ischemic stroke

L

17

109

65

M

Ischemic stroke

L

48

110

73

M

Ischemic stroke

L

20

111

58

M

Cerebral abscess

R

28

112

67

M

Stroke*

R

54

113

71

M

Ischemic stroke

L

9

114

31

F

Head injury

R

43

115

53

F

Ischemic stroke

R

Mean

60.467

39.200

SD

10.980

54.588

Median

65

26

95% CI

⫾5.556

8

⫾27.625

Flicker-stimulation training group 201

59

M

Ischemic stroke

R

7

202

76

F

Stroke*

R

7

203

65

F

Hemorrhage

L

292

204

63

F

Ischemic stroke

R

50

205

49

M

Stroke*

R

9

206

69

M

Ischemic stroke

L

104

207

68

F

Ischemic stroke

R

35

208

74

M

Stroke*

L

4

209

61

F

Arachnoidal cyst

R

708

210

65

M

Ischemic stroke

L

22

211

71

M

Stroke*

R

7

212

54

M

Hemorrhage

L

16

213

46

F

Ischemic stroke

L

7

214

50

M

Ischemic stroke

L

36

215

34

F

Hemorrhage

R

14

Mean

60.267

87.867

SD

11.671

186.660

Median

63

95% CI

⫾5.906

⫾94.461

0.999

0.589

p Value

16

The groups were compared with two-tailed Mann–Whitney tests; p values are shown in the bottom row. *Not otherwise specified. HH ⫽ homonymous hemianopia; CI ⫽ confidence interval.

326

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tion of natural scenes were recorded by a video eye tracker (EyeLink, SensoMotoric Instruments, Teltow, Germany). During the fixation task, patients had to maintain stable fixation of a cross presented for 20 seconds on a PC monitor (resolution 1,024 ⫻ 768). Their fixation stability was measured and computed as the difference between the 90th and 10th percentiles of the gaze positions’ distribution along the horizontal coordinate.20 The distance between the two yields the fixationstability measure (i.e., the horizontal extent of “eye wandering”); the greater the extent is, the less stable the fixation is. In addition, we assessed the asymmetry of fixational eye movements by computing the difference between the mean and median from the individual distributions of fixations. Although these measures refer to the fixation rather than the exploration task, they could reflect patients’ tendency to look toward their blind side. We showed that hemianopic patients spontaneously develop eye movements toward their blind side.20 During natural scene exploration, the patients scanned novel scenes (landscapes, street scenes) with a salient object (tower, sculpture) located on either the blind or the seeing side. A total of 30 scenes were selected (10 at T1, T2, and T3) and then mirrored such that the scenes with salient objects on the blind and seeing sides were the same. Twenty single scenes per time point, viewed from 30 cm, were presented randomly for 20 seconds each. Patients had to look at the scene without a specific task or thematic focus. Perimetry. Standardized threshold-oriented, slightly supraliminal static grid Tu¨bingen automated perimetry (TAP 2000; Oculus, Wetzlar, Germany) was accomplished in the 30° visual field in both eyes with special regard to the vertical field border and the area trained by FT. Fundus-controlled perimetry was performed with a scanning laser ophthalmoscope (SLO 101; Rodenstock, Munich, Germany) using a special triplet stimulus to determine the vertical field border and the 10° visual field with precise fixation control (spatial resolution 0.5°–1.0°).4,20,21 Reading speed. Reading speed (words per minute) was assessed during reading black print on a paper. We used standardized texts (International Reading Speed Test, IReST22) developed in our collaborative European Union project (www.amd-read.net). Quality of life. Patients completed a custom vision-related questionnaire and the World Health Organization questionnaire on quality of life, WHOQOL-BREF.23

Statistical analysis. Statistical differences were assessed using t tests, provided that according to the Shapiro–Wilks test, normality assumptions were met, or otherwise using the Mann– Whitney test. Data were processed (by A.N.S.) using JMP7.0 (SAS Institute, Cary, NC) in a repeated-measures analysis of variance (ANOVA) with side (blind, seeing) and repetition (T1/pre, T2/post, T3/follow-up) entered as within-subject factors, and group (experimental/EST, control/FT) as a betweensubjects factor.

The means and variability measures are found in table e-1 on the Neurology® Web site at www.neurology.org. RESULTS

Digit-search task. Figure 1 plots average RT in the

task administered to both groups three times, and additionally only in the EST group between T1 and T2 as the training procedure. At T1, longer RT occurred for the blind side, with no group differences

Figure 1

Digit-search response times

Figure 2

Natural search response times

Mean response time (⫾1 SEM) for the digit-search task on the screen in the explorative saccade training (EST) group (squares, solid line) and the flicker-stimulation training (FT) group (circles, dashed line), for the blind (filled symbols) and seeing sides (open symbols) before training, after training, and at 6 months follow-up. EST yields greatly reduced response time (post/pre, 47%) for the blind side compared with FT (18%; analysis of variance, group-by-repetition interaction, p ⬍ 0.015).

Mean response time (⫾1 SEM) for the natural search task (table test) in the explorative saccade training (EST) group (squares, solid line) and the flicker-stimulation training (FT) group (circles, dashed line), for the blind (filled symbols) and seeing sides (open symbols). Response time selectively decreased (post/pre, 23%) on the blind side after EST, and the improvement persisted at follow-up (paired t test; T2/T1, p ⬍ 0.03; T3/T2, p ⫽ 0.691).

for each side [paired t test; blind/seeing, t(26) ⫽ 2.127, p ⬍ 0.04; group differences, lowest p ⫽ 0.508]. After training, the EST group exhibited a substantial uniform RT reduction on both sides, and the improvement persisted until T3. The FT group showed a weaker, uniform RT decrease for both sides [EST: main effects of side, F(1,28) ⫽ 12.989, p ⬍ 0.001, repetition, F(2,28) ⫽ 37.26, p ⬍ 0.0001; FT: main effect of repetition, F(2,26) ⫽ 6.086, p ⬍ 0.01]. Importantly, solely for the blind side, the EST group gained much greater RT reduction after training (47% relative to pretraining throughout) than the FT group. We found main effects of repetition and a striking group-by-repetition interaction for the blind side, but no such interaction for the seeing side. This highlights EST specificity for the improvement of search behavior on the blind side (main effects of repetition, blind: F(1,26) ⫽ 16.451, p ⬍ 0.0004, seeing: F(1,26) ⫽ 24.286, p ⬍ 0.0001; interactions, blind: F(1,26) ⫽ 7.132, p ⬍ 0.015, seeing: F(1,26) ⫽ 1.835, p ⫽ 0.188).

blind side, with no group differences [t test; blind/ seeing, t(26) ⫽ 2.536, p ⬍ 0.02; group differences, lowest p ⫽ 0.497]. In the EST group, fixation behavior diverged over time; fixations increased on the blind and decreased on the seeing side (figure e-1). The difference was most pronounced at T3 (238%), suggesting adoption of the learned search strategy in the EST group after training completion. In contrast, the corresponding curves in the FT group remained parallel [main effects of side, EST: F(1,28) ⫽ 51.143, p ⬍ 0.0001, FT: F(1,26) ⫽ 16.634, p ⬍ 0.0002; side-byrepetition interactions, EST: F(2,28) ⫽ 4.882, p ⬍ 0.01, FT: F ⬍ 1]. The salient object’s location markedly affected saccadic exploration. Figure 3B shows the number of fixations with the object located on the blind side. In the EST group, the divergence between the sides became more pronounced. In the FT group, the curves diverged as well [main effects of side, EST: F(1,28) ⫽ 93.184, p ⬍ 0.0001, FT: F(1,26) ⫽ 43.97, p ⬍ 0.0001; interactions, EST: F(2,28) ⫽ 23.829, p ⬍ 0.0001, FT: F(2,26) ⫽ 7.071, p ⬍ 0.005]. Importantly, with the object location on the seeing side (figure 3C), in both groups at T1, more numerous fixations occurred on the blind side than on the seeing side [paired t test; EST: t(14) ⫽ 2.407, p ⬍0.035; FT: t(10) ⫽ 2.593, p ⬍ 0.03]. However, ANOVA indicated that this prevalence (on average 12%) persisted over time only with EST. In the FT group, neither differences occurred between the sides, nor any changes in this measure [EST: main effect of side, F(1,28) ⫽ 7.46, p ⬍ 0.01, interaction, F(2,28) ⫽ 1.462, p ⫽ 0.243; FT: lowest p ⫽ 0.122].

Natural search task. At T1, RT showed no group dif-

ferences for both sides (figure 2; t test; lowest p ⫽ 0.639). Solely in the EST group, blind-side RT decreased after training at T2 (23%), and the improvement persisted until T3. In contrast, seeing-side RT remained unchanged (paired t test; blind, T2/T1: t(14) ⫽ 2.278, p ⬍ 0.03, T3/T2: t(14) ⫽ 0.406, p ⫽ 0.691; seeing: F ⬍ 1). The FT group showed neither side nor repetition effects. Natural scene exploration. Figure 3A shows the aver-

age number of fixations while scanning natural scenes. At T1, more fixations occurred toward the

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Figure 3

Natural scene exploration: Number of fixations

Mean number of fixations (⫾1 SEM) during natural scene exploration in the explorative saccade training (EST) group (squares, solid line) and the flicker-stimulation training (FT) group (circles, dashed line), on the blind (filled symbols) and seeing sides (open symbols): independent of the location of the salient object (A), and when the object was found on the blind side (B) or on the seeing side (C). Fixations become overall more numerous on the blind side and decrease on the seeing side after EST (follow-up/pre difference, 238%; analysis of variance, side-by-repetition interaction, p ⬍ 0.01). Even with the salient object located on the seeing side, fixations in EST group, unlike in FT group, remain more numerous on the blind side than on the seeing side (post/pre, on average 12%; analysis of variance, main effect of side, p ⬍ 0.01).

Fixation stability. Figure 4A plots fixation stability as-

sessed as the average difference between the 90th and 10th percentiles of the gaze positions’ horizontal coordinate, and figure 4B plots the asymmetry of the distribution as the difference of its mean and median. The groups did not differ on either measure at T1, but after training (T2) only the EST group exhibited both much reduced (43%) fixation stability and increased (482%) asymmetry of fixations toward the blind side. 328

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Figure 4

Fixational eye movements

Fixational eye movements while fixating a cross in the explorative saccade training (EST) group (squares, solid line) and the flicker-stimulation training (FT) group (circles, dashed line). The distribution of the patient’s gaze positions over time is recorded by the eye tracker and represented as an x,y plot. Two spatial locations along the x coordinate are then computed that correspond to the 10th and 90th percentiles of the distribution. The difference between the two (i.e., the horizontal extent of “eye wandering”) yields the fixation-stability measure used; the greater the extent is, the less stable the fixation is. (A) Mean fixation stability (⫾1 SEM), as an averaged difference between the 90th and 10th percentiles of the individual fixation distributions (degrees of visual angle) and (B) asymmetry of fixation distributions toward the blind side, as an averaged difference between the individual means and medians (degrees of visual angle). After EST, fixation stability markedly decreases (post/pre, 43%), and asymmetry of fixations toward the blind side increases (post/pre, 482%). In the FT group, these measures also change, but to a lesser extent. At T3, both groups yield similar fixation stability. This is presumably because by this time, the EST group develops a systematic exploratory strategy, gains a clear distinction between the exploration and the fixation tasks, and better complies with the instruction of stable fixation. In turn, FT may trigger unsystematic eye movements, yielding a gradual decrease in fixation stability.

Visual fields. Neither the EST group nor the FT group showed any differences in their TAP or SLO outcomes, quantified as the total number of stimuli detected in the blind hemifield (lowest p ⫽ 0.204). Quality of life. The EST group reported greater improvements (T2 minus T1 scores) in the WHOQOL social-relationships domain (t test; t(20) ⫽ 2.217, p ⫽ 0.038) and, as a trend, physical-status domain

(p ⫽ 0.084) than the FT group. The vision-related questionnaire outcome suggested that the social domain benefited from the patients’ reported tendency to better visually spot persons (p ⫽ 0.065). The EST group tended to judge better their ability to master daily-life activities (p ⫽ 0.064). Reading speed. Reading speed stayed unaffected by either training. Although the EST and FT groups differed in their reading speeds at T1, this difference remained unchanged [main effect of group, F(1,26) ⫽ 133.074, p ⬍ 0.0001, interaction, F ⬍ 1].

The present study showed a substantial beneficial effect of EST in hemianopic patients. The digit-search task, the training method of the EST group, yielded a markedly improved performance. An FT group enhancement could be explained by mere learning due to the repeated task exposure. The striking superior digit-search performance in the EST group after training, significant only for the blind side, indicates EST specificity for improving the exploratory behavior. After EST, natural search performance (figure 2) selectively improved on the blind side, and the improvement persisted until follow-up. Furthermore, EST induced an increased exploratory eye-movement activity on the blind side during free scanning of natural scenes (figures 3A and e-1). With the salient object’s location on the blind side, both groups showed more numerous fixations on that side (figure 3B). This is especially surprising for the FT group and might be explained by a shift of attention toward the blind side, triggered by negative feedback during training, presumably provoking eye movements toward the object. In contrast, dissociation between the groups occurred with the objects located on the seeing side (figure 3C). Before training, both groups’ fixations were more numerous on the blind side, but only with EST, this prevalence persisted over time. This suggests that EST specifically supports exploratory saccadic activity into the blind hemifield. All three outcome variables from the search and natural exploration tasks show a strong and specific effect of EST compared with FT. The effects are robust and maintained or even enhanced beyond the training period, i.e., EST patients had learned to consistently apply the search strategy to everyday tasks. Thus, this study substantially extends previous evidence for the benefits of saccade training7-10,24,25 by using an alternative treatment in a control group and random patient assignment, as has been required by many authors.26,27 Interestingly, solely with EST did the fixation stability decrease and asymmetry toward the blind side inDISCUSSION

crease, indicating an enhanced “readiness” (lowered threshold) to perform eye movements toward that side. Indirect triggering of eye movements is seen with FT at follow-up, although less pronounced than with EST (figure 4), yielding similar fixation-behavior values in both groups. Presumably, the EST group developed a systematic explorative strategy, clearly distinguished the exploration and fixation tasks, and better complied with the instruction of stable fixation. This account is supported by an increased difference in explorative eye movements between the sides in the EST group at follow-up (figure 3, A and C). In turn, as in previous flicker-training studies,18 FT might trigger unsystematic eye movements, yielding a gradual decrease in fixation stability. The visual fields did not differ over time in either group, either along the field border (SLO) or across the total 30° area (TAP), indicating that neither EST nor FT, as implemented in this study, enlarged the blind field. The result agrees well with previous findings4,28 that visual stimulation along the vertical field border, introduced as visual restitution training,1 does not enlarge visual fields but can trigger eye movements. Recent studies18,19 used a letter flickering at 10° eccentricity, which reduces the risk of eye movements toward the stimulus. Reportedly, two patients normalized their contrast sensitivity in the blind hemifield,18 and one patient19 showed ipsilateral (intact) visual-cortex activation by checkerboard stimulation at 10° to 20°. These results could be explained by indirect triggering of eye movements, as observed in our study with even more peripheral stimuli (21.8°) that did not improve visual fields. Therefore, convincing evidence is still lacking that visual stimulation of the blind hemifield leads to restitution of the occipital cortex in a clinically relevant way.5,6,13,27,29,30 Because in both groups disease duration exceeded 6 months while dissociations in post-training performance occurred in the EST group compared with the FT group, spontaneous recovery is unlikely to account for the present findings. The groups were uniform and did not differ with respect to essential patient characteristics. It is worth noting that even in patients with longstanding hemianopia who might already have acquired some adaptive strategies, EST shows its effectiveness by specifically activating eyemovement exploration toward the blind side. The lack of dropouts in the EST group indicates good acceptance of the training. Importantly, EST translates into subjective improvement for the patient’s functional ability in real-world situations, especially the social domain (likely due to a better person detection) and tendency to better judge physical status, including mastering daily-life activities. Neurology 72

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329

Our study focused on the hemianopic orientation disorder and provides a training method to improve visual search in the midperipheral visual field requiring large saccades. As expected, neither EST nor FT specifically affected reading speed. Rehabilitation of the hemianopic reading disorder requires training with small saccades8,9,17,31 considering the necessary size of perceptual span.32-34 Reading training has to take account of the reading direction, field-defect side, its distance to the visual-field center, and adaptive strategies20,35 such as eccentric fixation36 and predictive saccades.37 The outcome of this randomized controlled study indicates that in patients with hemianopic orientation disorder, compensatory EST selectively improves exploration behavior on the blind side in everyday tasks. FT improves neither exploration nor visual fields. ACKNOWLEDGMENT The authors thank Detlef Axmann, PhD, for statistical advice; Egon Weidle, MD, Petra Biermann, and Sonja Maier for support in patient recruiting and examination; Iris Reckert for providing natural scenes; and William F. Hoyt, MD, Manfred MacKeben, PhD, and Nhung Nguyen, MD, for helpful comments.

12.

13.

14.

15.

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18.

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Received July 9, 2008. Accepted in final form October 15, 2008. 20. REFERENCES 1. Kasten E, Wu¨st S, Behrens-Baumann W, Sabel BA. Computer-based training for the treatment of partial blindness. Nat Med 1998;4:1083–1087. 2. Zihl J, von Cramon D. Restitution of visual function in patients with cerebral blindness. J Neurol Neurosurg Psychiatry 1979;42:312–322. 3. Balliet R, Blood KM, Bach-Y-Rita P. Visual field rehabilitation in the cortically blind? J Neurol Neurosurg Psychiatry 1985;48:1113–1124. 4. Reinhard J, Schreiber A, Schiefer U, et al. Does visual restitution training change absolute homonymous visual field defect? A fundus controlled study. Br J Ophthalmol 2005; 89:30–35. 5. Horton JC. Vision restoration therapy: confounded by eye movements. Br J Ophthalmol 2005;89:792–794. 6. Plant GT. A work out for hemianopia. Br J Ophthalmol 2005;89:2. 7. Kerkhoff G, Mu¨nssinger U, Haaf E, Eberle-Strauss G, Sto¨gerer E. Rehabilitation of homonymous scotomas in patients with postgeniculate damage of the visual system: saccadic compensation training. Restor Neurol Neurosci 1992;4:245–254. 8. Kerkhoff G, Mu¨nssinger U, Meier EK. Neurovisual rehabilitation in cerebral blindness. Arch Neurol 1994;51: 474–481. 9. Zihl J. Visual scanning behavior in patients with homonymous hemianopia. Neuropsychologia 1995;33:287–303. 10. Pambakian AL, Mannan SK, Hodgson TL, Kennard C. Saccadic visual search training: a treatment of patients with homonymous hemianopia. J Neurol Neurosurg Psychiatry 2004;75:1443–1448. 11. Nelles G, Esser J, Eckstein A, Tiede A, Gerhard H, Diener C. Compensatory visual field training for patients with hemianopia after stroke. Neurosci Lett 2001;306:189–192. 330

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Tiel K, Kolmel HW. Patterns of recovery from homonymous hemianopia subsequent to infarction in the distribution of posterior cerebral artery. Neuroophthalmology 1991;11:33–39. Trobe JD, Lorber ML, Schlezinger NS. Isolated homonymous hemianopia: a review of 104 cases. Arch Ophthalmol 1973;89:377–381. Zhang X, Kedar S, Lynn MJ, Newman NJ, Biousse V. Natural history of homonymous hemianopia. Neurology 2006;66:901–905. Folstein MF, Folstein SE, McHugh PR. Mini-Mental State: a practical method for grading the cognitive state of patients for the clinician. J Psychiat Res 1975;12:189–198. (Kessler J, Markowitsch HJ, Denzler P. MMST: Deutschsprachige Fassung. Go¨ttingen: Beltz; 2000.) Shulman KI. Clock-drawing: is it the ideal cognitive screening test? Int J Geriatr Psychiatry 2000;15:548–561. Kerkhoff G. Restorative and compensatory therapy approaches in cerebral blindness: a review. Restor Neurol Neurosci 1999;15:255–271. Henriksson L, Raninen A, Na¨sa¨nen R, Hyva¨rinen L, Vanni S. Training-induced cortical representation of a hemianopic hemifield. J Neurol Neurosurg Psychiatry 2007;78:74–81. Raninen A, Vanni S, Hyva¨rinen L, Na¨sa¨nen R. Temporal sensitivity in a hemianopic visual field can be improved by long-term training using flicker stimulation. J Neurol Neurosurg Psychiatry 2007;78:66–73. Trauzettel-Klosinski S, Reinhard J. The vertical field border in hemianopia and its significance for fixation and reading. Invest Ophthalmol Vis Sci 1998;39:2177–2186. Reinhard J, Trauzettel-Klosinski S. Nasotemporal overlap of retinal ganglion cells in humans: a functional study. Invest Ophthalmol Vis Sci 2003;44:1568–1572. Hahn GA, Penka D, Gehrlich C, et al. New standardised texts for assessing reading performance in four European languages. Br J Ophthalmol 2006;90:480–484. The WHOQOL Group. Development of the World Health Organization WHOQOL-BREF quality of life assessment. Psychol Med 1998;28:551–559. (Angermeyer MC, Kilian R, Matschinger H. WHOQOL und WHOQOL-BREF. Handbuch fu¨r die deutschsprachigen Versionen der WHO-Instrumente zur internationalen Erfassung von Lebensqualita¨t. Go¨ttingen: Hogrefe; 2000.) Kerkhoff G. Neurovisual rehabilitation: recent developments and future directions. J Neurol Neurosurg Psychiatry 2000;68:691–706. Bolognini N, Rasi F, Coccia M, La`davas E. Visual search improvement in hemianopic patients after audio-visual stimulation. Brain 2005;128:2830–2842. Sahraie A. Induced visual sensitivity changes in chronic hemianopia. Curr Opin Neurol 2007;20:661–666. Pelak VS, Dubin M, Whitney E. Homonymous hemianopia: a critical analysis of optical devices, compensatory training, and NovaVision. Curr Treat Options Neurol 2007;9:41–47. Schreiber A, Vonthein R, Reinhard J, Trauzettel-Klosinski S, Connert C, Schiefer U. Effect of visual restitution training on absolute homonymous scotomas. Neurology 2006; 67:143–145. Glisson CC, Galetta SL. Visual rehabilitation: now you see it; now you don’t. Neurology 2007;68:1881–1882. McFadzean RM. NovaVision: vision restoration therapy. Curr Opin Ophthalmol 2006;17:498–503.

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Spitzyna GA, Wise RJ, McDonald SA, et al. Optokinetic therapy improves text reading in patients with hemianopic alexia: a controlled trial. Neurology 2007;68:1922–1930. Legge GE, Ahn SJ, Klitz TS, Luebker A. Psychophysics of reading, XVI: the visual span in normal and low vision. Vis Res 1997;37:1999–2010. McConkie GW, Rayner K. The span of the effective stimulus during a fixation in reading. Percept Psychophys 1975;17:578–586. O’Regan K. Saccade size control in reading: evidence for the linguistic control hypothesis. Percept Psychophys 1979;25:501–509.

35. Trauzettel-Klosinski S, Brendler K. Eye movements in reading with hemianopic field defects: the significance of clinical parameters. Graefes Arch Clin Exp Ophthalmol 1998;236:91–102. 36. Trauzettel-Klosinski S. Eccentric fixation with hemianopic field defects: a valuable strategy to improve reading ability and an indication of cortical plasticity. Neuroophthalmology 1997;18:117–131. 37. Meienberg O, Zangemeister WH, Rosenberg M, Hoyt WF, Stark L. Saccadic eye movement strategies in patients with homonymous hemianopia. Ann Neurol 1981;9:537– 544.

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TP53 codon 72 polymorphism is associated with age at onset of glioblastoma

S. El Hallani, MD F. Ducray, MD A. Idbaih, MD, PhD Y. Marie, MSc B. Boisselier, MSc C. Colin, PhD F. Laigle-Donadey, MD M. Rode´ro, MSc O. Chinot, MD J. Thillet, PhD K. Hoang-Xuan, MD, PhD J.-Y. Delattre, MD M. Sanson, MD, PhD

ABSTRACT

Background: Functional single nucleotide polymorphisms (SNP) in codon 72 of TP53 have been shown to be a risk factor, a prognostic marker, and related factor to age at onset in various cancers.

Methods: We investigated blood samples from 254 patients with glioblastoma and 238 healthy controls.

Results: TP53 codon 72 status was not correlated with prognosis and did not differ between glioblastoma and control populations. However, the Pro/Pro genotype was overrepresented in patients ⬍45 years (20.6% vs 6.4% in patients with glioblastoma ⬎45 years, p ⫽ 0.002, vs 5.9% in control group, p ⫽ 0.001). We then confirmed this result on an independent series of young patients with glioblastoma. Finally, the analysis of tumor DNA found the Pro allele associated with occurrence of TP53 somatic mutation.

Conclusion: Our data suggest that TP53 functional variation is particularly critical for oncogenesis of glioblastoma in young patients. Neurology® 2009;72:332–336 GLOSSARY

Address correspondence and reprint requests to Dr. Marc Sanson, Service de Neurologie Mazarin, Hoˆpital de la Salpeˆtrie`re, 47, Bd de l’Hoˆpital, 75013 Paris, France [email protected]

CI ⫽ confidence interval; GBM ⫽ glioblastoma multiforme; SNP ⫽ single nucleotide polymorphisms.

With a median survival of 12–15 months, glioblastoma multiforme (GBM) is the most frequent and the most malignant subtype of glioma.1 The majority of glioblastomas are sporadic, and little is known about the environmental and genetic risk factors in this context. One of the critical molecular steps of gliomagenesis involves the p53 pathway, which plays a central role in oncogenesis.2 A functional single nucleotide polymorphism at codon 72 of TP53 gene results in the presence of either proline (Pro) or arginine (Arg) in the amino acid sequence of TP53. This change involves DNA-binding motifs of p53. The pro72 variant results in stronger transcriptional activation but weaker induction of apoptosis than the arg72 variant.3-5 Then this polymorphism has been associated with susceptibility to various cancers,6-10 poor prognosis,11-13 and early age at onset.14 Among the few studies devoted to glial tumors germline variants of the TP53,15-18 only one suggested a possible association of TP53 codon 72 polymorphism with susceptibility to adult and pediatric high-grade astrocytomas.17 However, its impact on age at onset and prognosis is still unknown. Based on a large GBM case-control analysis, we investigated the potential role of the TP53 codon 72 polymorphism as risk factor or marker for prognosis, as well as its relation to age at onset. METHODS Patient and control selection. Patients were selected according to following criteria: histologic diagnostic of primary glioblastoma without previous history of glial tumor, age ⱖ18 years, clinical data and follow-up available on the neurooncology database, and available blood DNA. Written informed consent was obtained from all participants and the study was

From INSERM, U711 (S.E.H., F.D., A.I., Y.M., B.B., C.C., J.T., K.H.-X., J.-Y.D., M.S.), Biologie des Interactions Neurones & Glie, Paris; AP-HP (F.D., A.I., F.L.-D.), Groupe Hospitalier Pitie´-Salpeˆtrie`re, Service de Neurologie Mazarin, Paris; Service de Neurologie B (F.D.), Hoˆpital Neurologique, Lyon; INSERM, U543 (M.R.), Laboratoire d’Immunologie Cellulaire, Paris; 5. Service de Neurochirurgie (O.C.), Hoˆpital de la Timone, Marseille; and Universite´ Pierre et Marie Curie (K.H.-X., J.-Y.D., M.S.), Faculte´ de Me´decine, Paris, France. Supported by the De´le´gation a` la Recherche Clinique (AP-HP; grant no. MUL 03012). Disclosure: The authors report no disclosures. 332

Copyright © 2009 by AAN Enterprises, Inc.

Table

Comparison of genotype and allele frequencies in patients and controls, and correlation with TP53 mutation No. per genotype (%)

No. per allele (%)

Population

No. of individuals

Arg/Arg*

Arg/Pro*

Pro/Pro*

Healthy controls

238

142 (59.6)

82 (34.5)

156

95 (61.4)

52 (32.9)

Male Female GBM Male Female GBM p53 mutation Normal

Pearson ␹² p value

Arg*

Pro*

14 (5.9)

366 (76.9)

110 (23.1)

9 (5.7)

242 (77.8)

70 (22.2)

82

47 (57.3)

30 (36.6)

5 (6.1)

254

140 (55.1)

92 (36.2)

22 (8.7)

168

89 (52.9)

67 (39.9)

12 (7.2)

0.35

245 (72.9)

91 (27.1)

0.17

86

51 (59.3)

25 (29.1)

10 (11.6)

0.33

127 (73.8)

45 (26.2)

0.70

28 (68.3)

11 (26.8)

2 (4.9)

67 (81.7)

15 (18.3)

0.39

124 (75.6)

40 (24.4)

372 (72.6)

136 (27.4)

0.18

73 41

<45 y

13

9 (69.2)

2 (15.4)

2 (15.4)

20 (76.9)

6 (23.1)

>45 y

28

19 (67.8)

9 (32.2)

0 (0.0)

47 (83.9)

9 (16.1)

Mutant

Pearson ␹² p value

32

13 (40.6)

15 (46.9)

4 (12.5)

0.05

41 (64.1)

23 (35.9)

0.01

<45 y

13

4 (30.8)

6 (46.1)

3 (23.1)

0.12

14 (53.8)

12 (46.2)

0.08

>45 y

19

9 (47.4)

9 (47.4)

1 (5.2)

0.22

27 (71.1)

11 (28.9)

0.13

*TP53 codon 72. GBM ⫽ glioblastoma multiforme.

approved by the local ethics board. Controls DNA were obtained from unrelated cancer-free and healthy Caucasian volunteers (volunteer blood donors and laboratory staff).

Tp53 codon 72 genotyping. Blood DNA was extracted according to standard procedures. TP53 codon 72 was characterized using C_2403545_10 TaqMan SNP genotyping assay (Applied Biosystems, Foster City, CA) containing the probe for G allele (Arg), 5= labeled with VIC (CTGCTCCCC G CGTGGCCC ), the probe for “C” allele (Pro), 5= labeled with FAM (CTGCTCCCC C CGTGGCCC), the forward primer (5=ATGAAGCTCCCAGAATGC-3=), and the reverse primer (5=GCCGGTGTAGGAGCT-3=). DNA was mixed to a reaction containing the forward and reverse primers and allele-specific probes labeled with the fluorescent dye FAM for Pro or VIC for Arg at the 5=. The PCR reaction, performed in 15 ␮L with 20 ng genomic DNA, 1x TaqMan universal PCR master mix, forward and reverse primers (450 nmol/L each), 200 nmol/L VIC-labeled probe, 200 nmol/L FAM-labeled probe, was performed as follows: 95°C for 15 minutes, 50 cycles of 92°C for 30 seconds, 60°C for 1 minute. Completed PCR plates were read on an Mx3000P sequence detector and analyzed using the Mx Pro Q-PCR Software (Stratagene).

Screening for TP53 gene mutations. Tumor DNA was extracted from frozen tumors using the QIAmp DNA minikit, as described by the manufacturer (Qiagen, Venlo, LN). TP53 gene mutations were screened for exons 5– 8 by using previously reported primers and method.4 Statistical analysis. The independence of alleles (HardyWeinberg equilibrium) was ensured using the ␹2 test at one degree of freedom for each polymorphism. ␹2 Test (or Fisher exact test when one subgroup was ⬍5) was used to compare the genotype distribution. Overall survival was defined as the time between the diagnosis and death or last follow-up. The survival curves were obtained by Kaplan-Meier methods and compared by log-rank test. Multivariable analysis was performed using a

Cox proportional-hazard regression model. The t-test was used to compare the mean age at onset. RESULTS We analyzed DNA from 254 selected patients (168 M/86 F ⫽ 1.95) and 238 healthy controls (156 M/82 F ⫽ 1.9), aged 16 to 75 years. Patients’ median age at diagnosis was 56.5 years (range: 19.2– 83.6) and median survival was 13.5 months (range: 0.13–191.8). Treatment consisted of surgery (72 biopsies, 64 partial and 112 complete removals), followed by radiotherapy (43), radio ⫹ chemotherapy (149), chemotherapy alone (32), or supportive care (30). The frequencies of the TP53 codon 72 variants for both the control and GBM population are reported in the table. Both populations met the HardyWeinberg equilibrium (p ⫽ 0.64 for control and p ⫽ 0.22 for GBM). There was no difference between the two populations for both genotype and allele frequencies. The same result was obtained when considering separately female and male populations. We investigated then a possible correlation between TP53 variants and the occurrence of TP53 somatic mutation in 73 frozen tumor samples available for analysis: 32 mutations were found (13/26 ⬍45 years vs 19/47 ⬎45 years); the Pro allele was associated with a higher rate of TP53 somatic mutations (p ⫽ 0.01; table). Median survival for the whole population of GBM was 13.5 months. Overall survival did not differ between the TP53 codon 72 variants (figure 1). In multivariate analysis, surgery (hazard ratio ⫽ Neurology 72

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Figure 1

Survival curves according to genotype

Figure 2

Pro/Pro frequency according to the age at diagnosis

(A) The cumulative incidence of glioblastoma multiforme (GBM) for each codon 72 variant is plotted as a function of age. (B) The relative ratios of (Arg/Arg ⫹ Arg/Pro) group and Pro/Pro group for the healthy controls, GBM patients diagnosed at ⬎45 years of age, GBM patients diagnosed ⬍45 years of age, and the independent series of GBM patients diagnosed at ⬍45 years of age.

Survival curves did not show any correlation between survival and genotype (A) in the whole population (p ⫽ 0.83), (B) in the male population (p ⫽ 0.86), and (C) in the female population (p ⫽ 0.41).

0.48; 95% confidence interval [CI] 0.29 – 0.79; p ⫽ 0.004) and radiotherapy (HR ⫽ 0.59; 95% CI 0.35– 0.97; p ⫽ 0.04) but not chemotherapy (HR ⫽ 0.71: 95% CI 0.43–1.19; p ⫽ 0.19) were found to be independent factors of outcome. Again, when these data were entered into multivariate analysis, codon 72 TP53 was not related to survival (HR ⫽ 1.13; 95% CI 0.81–1.59; p ⫽ 0.47). Finally, we compared the age at onset for each TP53 codon 72 variant and found that the Pro/Pro polymorphism was associated with earlier onset in GBM population (49.1 ⫾ 16.5) compared to Arg/ Arg (56.6 years ⫾ 10.9; p ⫽ 0.006) and Arg/Pro (55.9 years ⫾ 11.3; p ⫽ 0.02). 334

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The cumulative incidences of each TP53 codon 72 variant were plotted as a function of onset age, and are shown in figure 2A. A difference in the agedependent incidence of the Pro/Pro genotype was noticed in GBM population ⬍45 years of onset age. As shown in figure 2B, the overall frequency of Pro/ Pro genotype was statistically higher in young patients (⬍45 years) (20.6% in 37 cases) compared to older patients (⬎45 years) (6.4% in 217 cases; p ⫽ 0.002) and healthy controls (5.9% in 238 cases; p ⫽ 0.001). To confirm this correlation, we gathered an independent series by collecting 29 other samples from Caucasian GBM patients ⬍45 years (blood DNA bank, the ANOCEF network). Again, the Pro/Pro genotype frequency was higher in GBM ⬍45 years (17.2%) of the independent series compared to GBM ⬎45 years (p ⫽ 0.04) and healthy controls (p ⫽ 0.02) of our series. DISCUSSION The two polymorphic variants of TP53 are functionally distinct and may influence cancer risk or response to treatment: the Arg72 variant induces apoptosis markedly better than does the

Pro72 variant, in part because of its greater ability to translocate to the mitochondria and to release cytochrome C into the cytosol.4 A former study suggested a possible association between TP53 codon 72 polymorphism and susceptibility to high grade astrocytoma in adult and child,17 but the small size of this study based on tumoral DNA and the multiethnic composition of the population made this result controversial. Indeed, we did not find any association between TP53 codon 72 variant and risk of adult GBM, in accordance with two other studies of gliomas with varied histology.15,16,18,19 The TP53 codon 72 polymorphism might alter the sensitivity of the tumors to irradiation and chemotherapy. Indeed, the Pro/Pro genotype appears to be an independent prognostic marker in breast cancer patients.20-22 However, our results suggest that the TP53 codon 72 does not have any prognostic impact on the survival of patients with GBM, neither on less aggressive histologic subgroups of glial tumors.18 We found that the Pro/Pro genotype was significantly overrepresented in young patients with GBM, and confirmed this data on an independent series. The accelerating effect of functional p53 insufficiency on tumorigenesis was previously demonstrated. In a model of mice lacking the xeroderma pigmentosum group A gene (XPA ⫺/⫺ mice) and highly predisposed to tongue tumors when exposed to 4-nitroquinoline 1-oxide (4NQO), the p53 haploinsufficiency (TP53⫺/⫹) and complete inactivation (TP53⫺/⫺) did not increase the incidence of cancer but accelerated dramatically tumor development.23 In patients with Lynch syndrome, the Proline 72 variant of TP53 accelerates the age at colorectal cancer onset.14,24 Pro/Pro genotype has also been associated with an earlier age at onset in pharynx,25 larynx,25,26 and oral cancer,25 and in pulmonary cancer in African Americans27 and Japanese patients.28 Genomic alterations and molecular pathways involved in GBM differ between young and older patients. Indeed, TP53 inactivation is a prominent mechanism in the GBM of child and young adult compared to the GBM of older patient.29-32 As a consequence, young patients might be more sensitive to the functional variation of the TP53 codon 72, explaining that Pro/Pro genotype constitutes a risk factor of GBM in this population. According to this hypothesis we can expect a higher rate of somatic TP53 mutation in the tumor of Pro/Pro patients: this has been confirmed for a subset of patients whose frozen tumor was available. Because genetic susceptibility is more identifiable in young individuals, this finding encourages further investigation. Combining knowledge of an individual’s TP53 genotypes with information on the known

DNA repair genes polymorphisms and environmental risk factors may improve risk estimates and help to identify individuals who are genetically susceptible to develop glioblastoma, and at an earlier age. ACKNOWLEDGMENT The authors thank the ANOCEF network and Pr. Jerome Honnorat and Dr. Franc¸ois Caire for providing blood samples.

Received July 17, 2008. Accepted in final form October 15, 2008.

REFERENCES 1. Behin A, Hoang-Xuan K, Carpentier AF, et al. Primary brain tumours in adults. Lancet 2003;361:323–331. 2. Sanson M, Thillet J, Hoang-Xuan K. Molecular changes in gliomas. Curr Opin Oncol 2004;16:607–613. 3. Thomas M, Kalita A, Labrecque S, et al. Two polymorphic variants of wild-type p53 differ biochemically and biologically. Mol Cell Biol 1999;19:1092–1100. 4. Idbaih A, Boisselier B, Sanson M, et al. Tumor genomic profiling and TP53 germline mutation analysis of firstdegree relative familial gliomas. Cancer Genet Cytogenet 2007;176:121–126. 5. Pim D, Banks L. p53 Polymorphic variants at codon 72 exert different effects on cell cycle progression. Int J Cancer 2004;108:196–199. 6. Damin AP, Frazzon AP, Damin DC, et al. Evidence for an association of TP53 codon 72 polymorphism with breast cancer risk. Cancer Detect Prev 2006;30:523–529. 7. Hu Y, McDermott MP, Ahrendt SA. The p53 codon 72 proline allele is associated with p53 gene mutations in nonsmall cell lung cancer. Clin Cancer Res 2005;11:2502– 2509. 8. Matakidou A, Eisen T, Houlston RS. TP53 polymorphisms and lung cancer risk: a systematic review and metaanalysis. Mutagenesis 2003;18:377–385. 9. Storey A, Thomas M, Kalita A, et al. Role of a p53 polymorphism in the development of human papillomavirusassociated cancer. Nature 1998;393:229–234. 10. Koushik A, Platt RW, Franco EL. p53 codon 72 polymorphism and cervical neoplasia: a meta-analysis review. Cancer Epidemiol Biomarkers Prev 2004;13:11–22. 11. Wegman P, Stal O, Askmalm MS, et al. p53 polymorphic variants at codon 72 and the outcome of therapy in randomized breast cancer patients. Pharmacogenet Genomics 2006;16:347–351. 12. Sousa H, Santos AM, Catarino R, et al. Linkage of TP53 codon 72 pro/pro genotype as predictive factor for nasopharyngeal carcinoma development. Eur J Cancer Prev 2006;15:362–366. 13. Gadducci A, Di Cristofano C, Zavaglia M, et al. P53 gene status in patients with advanced serous epithelial ovarian cancer in relation to response to paclitaxel- plus platinumbased chemotherapy and long-term clinical outcome. Anticancer Res 2006;26:687–693. 14. Jones JS, Chi X, Gu X, et al. p53 polymorphism and age of onset of hereditary nonpolyposis colorectal cancer in a Caucasian population. Clin Cancer Res 2004;10:5845– 5849. 15. Wang LE, Bondy ML, Shen H, et al. Polymorphisms of DNA repair genes and risk of glioma. Cancer Res 2004;64: 5560–5563. Neurology 72

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16.

17.

18.

19.

20.

21.

22.

23.

24.

Malmer B, Feychting M, Lonn S, et al. p53 Genotypes and risk of glioma and meningioma. Cancer Epidemiol Biomarkers Prev 2005;14:2220–2223. Parhar P, Ezer R, Shao Y, et al. Possible association of p53 codon 72 polymorphism with susceptibility to adult and pediatric high-grade astrocytomas. Brain Res Mol Brain Res 2005;137:98–103. Idbaih A, Boisselier B, Marie Y, et al. TP53 codon 72 polymorphism, p53 expression, and 1p/19q status in oligodendroglial tumors. Cancer Genet Cytogenet 2007;177: 103–107. Lima-Ramos V, Pacheco-Figueiredo L, Costa S, et al. TP53 codon 72 polymorphism in susceptibility, overall survival, and adjuvant therapy response of gliomas. Cancer Genet Cytogenet 2008;180:14–19. Toyama T, Zhang Z, Nishio M, et al. Association of TP53 codon 72 polymorphism and the outcome of adjuvant therapy in breast cancer patients. Breast Cancer Res 2007; 9:R34. Tommiska J, Eerola H, Heinonen M, et al. Breast cancer patients with p53 Pro72 homozygous genotype have a poorer survival. Clin Cancer Res 2005;11:5098–5103. Damin AP, Frazzon AP, Damin DC, et al. Evidence for an association of TP53 codon 72 polymorphism with breast cancer risk. Cancer Detect Prev 2006;30:523–529. Ide F, Kitada M, Sakashita H, et al. p53 haploinsufficiency profoundly accelerates the onset of tongue tumors in mice lacking the xeroderma pigmentosum group A gene. Am J Pathol 2003;163:1729–1733. Kruger S, Bier A, Engel C, et al. The p53 codon 72 variation is associated with the age of onset of hereditary non-

25.

26.

27.

28.

29.

30.

31.

32.

polyposis colorectal cancer (HNPCC). J Med Genet 2005; 42:769–773. Shen H, Zheng Y, Sturgis EM, et al. P53 codon 72 polymorphism and risk of squamous cell carcinoma of the head and neck: a case-control study. Cancer Lett 2002;183: 123–130. Gottschlich S, Maune S, Preugschat J, et al. p53 analysis of laryngeal cancer in exon 4 to 9. Anticancer Res 2000;20: 2613–2616. Jin X, Wu X, Roth JA, et al. Higher lung cancer risk for younger African-Americans with the Pro/Pro p53 genotype. Carcinogenesis 1995;16:2205–2208. Murata M, Tagawa M, Kimura H, et al. Correlation of the mutation of p53 gene and the polymorphism at codon 72 in smoking-related non-small cell lung cancer patients. Int J Oncol 1998;12:577–581. Sung T, Miller DC, Hayes RL, et al. Preferential inactivation of the p53 tumor suppressor pathway and lack of EGFR amplification distinguish de novo high grade pediatric astrocytomas from de novo adult astrocytomas. Brain Pathol 2000;10:249–259. Von Deimling A, Von Ammon K, Schoenfeld D, et al. Subsets of glioblastoma multiforme defined by molecular genetic analysis. Brain Pathol 1993;3:19–26. Ganigi PM, Santosh V, Anandh B, et al. Expression of p53, EGFR, pRb and bcl-2 proteins in pediatric glioblastoma multiforme: a study of 54 patients Pediatr Neurosurg 2005;41:292–299. Nakamura M, Shimada K, Ishida E, et al. Molecular pathogenesis of pediatric astrocytic tumors. Neuro Oncol 2007;9:113–123.

New Categories of Resident & Fellow Section Clinical Reasoning: Case presentations to aid in developing clinical reasoning skills. Right Brain: Neurology and the medical humanities — history, literature, and arts. Child Neurology: Patient case with detailed discussion about topic of focus. Pearls and Oy-sters: Clinical insights (pearls) and advice for avoiding mistakes (oysters). International: Educational exchanges, experiences in low and middle income countries. Emerging Subspecialities: History of fields such as Pain Medicine and Headache. Continue to submit articles about education research and educational topics, training videos, and teaching NeuroImages!

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Treatment of CNS sarcoidosis with infliximab and mycophenolate mofetil

Michael Moravan, BS Benjamin M. Segal, MD

ABSTRACT

Objective: To describe the effects of the anti–tumor necrosis factor neutralizing antibody, infliximab, and the antiproliferative immunosuppressant, mycophenolate mofetil, in refractory neurosarcoidosis.

Address correspondence and reprint requests to Dr. Benjamin M. Segal, Dept. of Neurology, Holtom-Garrett Program in Neuroimmunology, University of Michigan, 4009 BSRB, 109 Zina Pitcher Place, SPC 2200, Ann Arbor, MI 48109-2200 [email protected]

Methods: We treated patients with biopsy-proven sarcoidosis and CNS involvement, who had failed treatment with steroids, with infliximab (5 mg/kg on weeks 0, 2, and 6, and then every 6 – 8 weeks thereafter). Six out of seven patients were co-treated with mycophenolate mofetil (1,000 mg PO BID). Patients underwent a review of symptoms and complete neurologic examination every 3 months and MRI scanning before and after 3– 4 infusions of infliximab. Results: All patients reported significant symptomatic improvement by the fourth infusion of infliximab, including relief of headache and neuropathic pain, reversal of motor, sensory, or coordination deficits, and control of seizure activity. Furthermore, infliximab therapy was universally associated with a decrease in lesion size or suppression of gadolinium enhancement as documented by MRI. A positive treatment response was attained irrespective of location or distribution of CNS involvement by sarcoidosis (dural/leptomeningeal based vs intraparenchymal; cord vs brain; single lesion vs multifocal). There were no serious adverse effects in a follow-up period spanning 6 –18 months.

Conclusions: Combination treatment with mycophenolate mofetil and infliximab is a promising therapeutic approach for neurosarcoidosis. Neurology® 2009;72:337–340 GLOSSARY A ⫽ azathioprine; AA ⫽ African American; Cy ⫽ cyclophosphamide; E ⫽ etanercept; EDSS ⫽ Expanded Disability Status Scale; MMF ⫽ mycophenolate mofetil; MMSE ⫽ Mini-Mental State Examination; N ⫽ neurologic; O ⫽ ophthalmologic; P ⫽ pulmonary; Pq ⫽ Plaquenil; R ⫽ rheumatologic; Si ⫽ sinuses; S ⫽ steroids; TNF ⫽ tumor necrosis factor; VPS ⫽ ventriculoperitoneal shunt; W ⫽ white.

CNS infiltration occurs in approximately 5% of patients with sarcoidosis; it is associated with a less favorable course and accounts for a disproportionate amount of disability.1 Neurosarcoidosis is often difficult to manage. In one of the larger clinical series, over 70% of patients relapsed or progressed despite treatment with corticosteroids and oral immunosuppressant agents.2 Since neurosarcoidosis tends to flare in the midst of prednisone tapers, those afflicted are often subject to the complications of chronic corticosteroid usage. Hence, there is a clear need for novel therapeutic strategies in this disorder. It has been speculated that tumor necrosis factor (TNF)␣ neutralizing agents might be effective in sarcoidosis based on animal studies demonstrating a critical role of TNF␣ in granulomatous inflammation and an association between TNF␣ expression in alveolar macrophages and active pulmonary sarcoidosis.3,4 Infliximab is a chimeric monoclonal humanmurine IgG antibody directed against TNF␣ approved for the treatment of rheumatoid Supplemental data at www.neurology.org From the Department of Neurobiology and Anatomy (M.M.) and the Departments of Neurology, Microbiology, and Immunology and the Cancer Center (B.M.S.), University of Rochester School of Medicine and Dentistry, NY. B.M.S. is supported by grants from NINDS (NS047687-01) and NIAID (U19 AI056390; Project 2) of the National Institutes of Health, and the National Multiple Sclerosis Society. Disclosure: Dr. Segal has received honoraria and grant support from Centocor for lectures, consultation, and research activities unrelated to the subject of this manuscript. He has also served as a consultant for Biogen, Serono, and TEVA. Copyright © 2009 by AAN Enterprises, Inc.

337

Table 1

Patient characteristics

Patient no./sex/age, y/race

Neuroanatomic localization

Extra-CNS involvement

Initial symptoms*/ duration, mo

1/F/53/AA

Extradural

Trigeminal neuralgia; facial numbness (V1-2)

O, Si, P, R

P/33

2/F/42/AA

Meningeal

Headache; complex partial seizures

R, Si

R/180

3/F/40/W

Intracerebral

Bifrontal headache

P

N/12

4/F/52/W

Meningeal

Global headache; facial diplegia

P, O

N/24

5/M/35/W

Intramedullary spinal cord

Lhermitte; numbness and paresthesias in hands/feet; urinary urgency

P

N/8

6/F/54/W

Intramedullary spinal cord

Spastic paraparesis; fatigue

P

N/72

7/F/52/W

Meningeal/intramedullary spinal cord

Ataxia; memory loss; urinary urgency

—

N/23

Neurologic symptoms

*Organ targeted during the presenting episode of sarcoidosis/length of time between clinical presentation of sarcoidosis and treatment with infliximab. AA ⫽ African American; O ⫽ ophthalmologic; Si ⫽ sinuses; P ⫽ pulmonary; R ⫽ rheumatologic; W ⫽ white; N ⫽ neurologic.

arthritis, ankylosing spondylitis, psoriasis, and inflammatory bowel disease. In standard practice infliximab is administered in combination with oral immunosuppressant agents in order to prevent the development of human antichimeric antibodies (that can be associated with infusion reactions acutely and diminution of therapeutic efficacy chronically) as well as to capitalize on the synergistic effects of multimodal therapy.5 Mycophenolate mofetil (MMF), an antiproliferative drug, is increasingly used to treat immune-mediated disorders. Here we report the successful treatment of refractory neurosarcoidosis with infliximab and MMF. METHODS Subjects. Patients were referred to the neurology outpatient clinic at Strong Memorial Hospital, Rochester, NY. Each patient had neurologic disease in the context of biopsy-proven sarcoidosis characterized by the presence of noncaseating granulomas in hilar or mediastinal lymph nodes (patients 2, 4, 5, 6), nasal mucosa (2), leptomeninges (7), an extradural mass (1), intramedullary lesions (6), or an intracerebral lesion (3). Cultures and stains of biopsied tissue were negative for mycobacterial or fungal infection. Six of seven patients had pulmonary or hilar abnormalities demonstrated by CT scanning. None of the subjects had a concurrent inflammatory condition that might confound the diagnosis or a history or signs suggestive of lymphoproliferative disease or infections. Patients were screened for latent tuberculosis infection by purified protein derivative skin testing prior to institution of corticosteroids. All patients also had a chest X-ray shortly before starting infliximab.

Treatment. For primary therapy, patients were given corticosteroids in the form of IV methylprednisolone (1 g daily ⫻ 3 days) followed by a gradual prednisone taper (starting at 80 mg/ 338

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day with 10-mg decrements every 2 weeks). All of the patients flared during the midst of the taper, warranting additional measures. Six of seven patients were started on MMF (500 mg twice daily) in combination with corticosteroids. The dose was increased to 1,000 mg BID over the next 4 weeks. Patients were given a 3-month trial of MMF or longer prior to initiation of infliximab, since the benefit of MMF therapy is usually evident in 2–3 months. Cell count, electrolytes, and liver function tests were monitored on a monthly basis during therapy. Infliximab was administrated by IV infusion at 5 mg/kg on weeks 0, 2, and 6 and then at 6- to 8-week intervals thereafter. Infusions were given over 2 hours at an outpatient center.

Monitoring and evaluation. Patients underwent a complete history and neurologic and physical examination at the time of diagnosis. Neurologic examinations and interval histories were obtained at 2- to 3-month intervals thereafter by the same examiner (B.M.S.). MRI scans with gadolinium enhancement were performed using a 1.5 T magnet immediately before the first infusion of infliximab and following the third or fourth infusion. RESULTS Study population. Patient characteristics are shown in table 1. The neurologic symptoms that brought patients 3, 4, 5, and 7 to our clinic were their presenting symptoms of sarcoidosis. Patients 3, 4, and 5 had asymptomatic pulmonary involvement detected by thoracic CT scanning; patient 7 had no evidence of organ involvement outside of the CNS. Surprisingly, none of the subjects had an elevated serum angiotensin converting enzyme level at the time of evaluation. Patients were considered eligible for aggressive treatment due to the failure of conventional therapy to alleviate severe, debilitating headaches/neuralgia associated with a biopsy-proven granulomatous mass lesion (1, 3) or persistent meningeal enhancement

Figure

MRI scans performed prior to institution of infliximab therapy (Pre-Tx) and after the third or fourth infusion (Post-Tx)

Response to corticosteroids and MMF. Each patient

experienced a recrudescence of symptoms during the course of a prednisone taper, precluding a reduction in the dose below 50 –20 mg daily. Six out of seven patients were started on MMF after 4 –10 months of corticosteroid treatment failed to yield persistent remission. (Patient 5 elected not to go on oral immunosuppressant agents.) Although MMF resulted in symptomatic and radiologic stabilization, often at a reduced dose of prednisone, none of the patients could be completely weaned off corticosteroids after starting the immunosuppressant. The mean duration of MMF treatment prior to the introduction of infliximab was 8.5 months (with a range of 3–14 months). Response to infliximab. Seven out of seven patients

reported a dramatic improvement in symptomatology after 1–3 infusions of infliximab that was corroborated by MRI findings in every case (figure, table 2, table e-1 on the Neurology® Web site at www. neurology.org). Attempts to wean patient 1 after 31 months and patient 3 after 20 months of infliximab therapy resulted in recurrence of symptoms and MRI abnormalities. Both patients were restarted on infliximab with a positive response and remain on that treatment to the present time. The other five patients have consistently been treated with infliximab and MMF until the present (mean duration 31 months; range 24 –39 months). MMF and infliximab combination therapy was generally well tolerated with no incidents of leukopenia, liver dysfunction, or injection reactions. Patient 1 experienced transient fatigue immediately following the third infusion that did not recur thereafter. Patient 7 developed shingles after the second infusion, warranting a temporary discontinuation of infliximab/MMF for 2 months until the outbreak resolved. Otherwise there were no infections or other complications. The current study contributes to a growing body of literature that supports the use of infliximab in the treatment of sarcoidosis.6-9 We found that combination therapy with infliximab and MMF ameliorated CNS complications of sarcoidosis that had previously flared during a corticosteroid taper, irrespective of the site (cerebral hemispheres vs spinal cord; leptomeningeal vs extradural vs parenchymal) or distribution (solitary vs multifocal) of lesions. Patients universally experienced symptomatic improvement by the fourth infusion of infliximab that was sustained throughout a 24- to 39-month follow-up period. Although randomized studies will need to be conducted to assess the efficacy as well as the safety profile of our therapeutic regimen more

DISCUSSION

Postgadolinium T1-weighted images are shown. (A) Patient 3. An enhancing lesion in the occipital horn of the left lateral ventricle was reduced following infliximab infusions. (B) Patient 1. Axial (upper panels) and coronal (lower panels) views of an enhancing lesion in the left trigeminal cistern that extended through the foramen ovale and into the infratemporal fossa. The mass shrunk significantly by the fourth infusion. (C) Patient 2. Leptomeningeal/ dural thickening and enhancement were reduced after treatment. (D) Patient 5. An enhancing intramedullary lesion receded after treatment.

and cranial neuropathies (4); refractory seizures or dementia and ataxia associated with meningeal enhancement and hydrocephalus (3, 7); and myelopathy associated with enhancing lesions in the spinal cord (5–7).

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339

Table 2

Clinical response to infliximab

Patient no.

Previous treatment/ concurrent treatment

Duration of treatment with steroids/MMF*/ infliximab (mo)

1

S, A/MMF

5/10/39

Response to infliximab Alleviation of neuralgia (from 10/10 to 2/10 in intensity†); partial recovery of facial sensation

2

S/MMF

5/14/36

Resolution of headaches (from 5/10 to 0/10†); control of seizures

3

S/MMF

9/3/33

Alleviation of headaches (from 7/10 to 2 /10 in intensity†; from daily to rare in frequency)

4

S, A/MMF

8/13/35

Resolution of headaches (from 8/10 to 0/10 in intensity†); partial recovery of facial movement and eye closure on left

5

S

5/–/26

Recovery of sensation; normalization of bladder and erectile function

6

S, Cy, E, Pq/MMF

10/7/24

Improvement in EDSS from 6.5 to 5; increase in energy level

7

S, VPS/MMF

4/4/28

Improvement in EDSS from 7 to 5.5; improvement in MMSE from 22 to 28

*Duration of treatment with MMF before addition of infliximab. †Assessed using the visual analog scale. MMF ⫽ mycophenolate mofetil; S ⫽ steroids; A ⫽ azathioprine; Cy ⫽ cyclophosphamide; E ⫽ etanercept; Pq ⫽ Plaquenil; EDSS ⫽ Expanded Disability Status Scale; VPS ⫽ ventriculoperitoneal shunt; MMSE ⫽ Mini-Mental State Examination.

rigorously, our patients experienced relatively few side effects and no serious adverse events. None experienced infusion reactions or showed signs of resistance to infliximab therapy over time, perhaps due to suppression of human antichimeric antibodies by MMF. Of interest, one of our patients (6) did not respond to etanercept, but did respond to infliximab. Future studies are required to determine when and how to wean patients off infliximab and MMF once a satisfactory therapeutic response has been achieved. The suggestion that TNF inhibitors may be therapeutic in neurosarcoidosis should not be extrapolated

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to all neuroinflammatory disorders. Indeed, TNF neutralizing agents have been found to exacerbate multiple sclerosis.10 Therefore, we recommend that this treatment regimen be restricted to patients with biopsy-proven sarcoidosis. Received December 23, 2006. Accepted in final form October 15, 2008. REFERENCES 1. Ferriby D, de Seze J, Stojkovic T, et al. Long-term follow-up of neurosarcoidosis. Neurology 2001;57:927– 929. 2. Zajicek JP, Scolding NJ, Foster O, et al. Central nervous system sarcoidosis: diagnosis and management. QJM 1999;92:103–117. 3. Baughman RP, Strohofer SA, Buchsbaum J, Lower EE. Release of tumor necrosis factor by alveolar macrophages of patients with sarcoidosis. J Lab Clin Med 1990;115:36–42. 4. Kindler V, Sappino AP, Grau GE, Piguet PF, Vassalli P. The inducing role of tumor necrosis factor in the development of bactericidal granulomas during BCG infection. Cell 1989;56:731–740. 5. Han PD, Cohen RD. Managing immunogenic responses to infliximab: treatment implications for patients with Crohn’s disease. Drugs 2004;64:1767–1777. 6. Pritchard C, Nadarajah K. Tumour necrosis factor alpha inhibitor treatment for sarcoidosis refractory to conventional treatments: a report of five patients. Ann Rheum Dis 2004;63:318–320. 7. Carter JD, Valeriano J, Vasey FB, Bognar B. Refractory neurosarcoidosis: a dramatic response to infliximab. Am J Med 2004;117:277–279. 8. Pettersen JA, Zochodne DW, Bell RB, Martin L, Hill MD. Refractory neurosarcoidosis responding to infliximab. Neurology 2002;59:1660–1661. 9. Sollberger M, Fluri F, Baumann T, et al. Successful treatment of steroid-refractory neurosarcoidosis with infliximab. J Neurol 2004;251:760–761. 10. Sicotte NL, Voskuhl RR. Onset of multiple sclerosis associated with anti-TNF therapy. Neurology 2001;57:1885– 1888.

Treatment of intractable chronic cluster headache by occipital nerve stimulation in 14 patients Brian Burns, MRCP Laurence Watkins, PhD Peter J. Goadsby, MD, PhD

ABSTRACT

Background: Cluster headache is a primary headache involving repeated attacks of excruciatingly severe headache usually occurring several times a day. Most patients with chronic cluster headache (CCH) have an unremitting illness requiring daily preventive therapy for years.

Objective: To describe the clinical outcome of occipital nerve stimulation (ONS) for 14 patients Address correspondence and reprint requests to Professor P.J. Goadsby, Headache Group, Department of Neurology, University of California, San Francisco, 505 Parnassus Ave, San Francisco, CA 19143-0114 [email protected]

with intractable CCH.

Methods: Fourteen patients with medically intractable CCH were implanted with bilateral electrodes in the suboccipital region for ONS and a retrospective assessment of their clinical outcome obtained. Results: At a median follow-up of 17.5 months (range 4 –35 months), 10 of 14 patients reported improvement and 9 of these recommend ONS. Three patients noticed a marked improvement of 90% or better (90%, 90%, and 95%), 3 a moderate improvement of 40% or better (40%, 50%, and 60%), and 4 a mild improvement of 20 –30% (20%, 20%, 25%, and 30%). Improvement occurred within days to weeks for those who responded most and patients consistently reported their attacks returned within hours to days when the device was off. One patient found that ONS helped abort acute attacks. Adverse events of concern were lead migrations and battery depletion.

Conclusion: Intractable chronic cluster headache (CCH) is a devastating, disabling condition that has traditionally been treated with cranially invasive or neurally destructive procedures. ONS offers a safe, effective option for some patients with CCH. More work is required to evaluate and understand this novel therapy. Neurology® 2009;72:341–345 GLOSSARY CCH ⫽ chronic cluster headache; DBS ⫽ deep brain stimulation; DHE ⫽ dihydroergotamine; ONS ⫽ occipital nerve stimulation.

Cluster headache is a form of primary headache characterized by bouts during which patients experience many attacks of very severe headache. Chronic cluster headache (CCH) is defined as having a break of no more than a month in every 12 months, unless there is some form of treatment.1 A proportion of patients with CCH are refractory to medical management, although it is unclear how large this problem is since guidelines have only recently defined such patients.2 Destructive surgery for CCH, such as trigeminal nerve root section, has been reported to be useful after long-term follow-up despite serious side effects, including death, corneal anesthesia, anesthesia dolorosa, and jaw deviation.3 Although this surgery is performed for those with strictly unilateral attacks, there is a risk of attacks swapping sides or persisting on the same side despite trigeminal nerve root section.3 Neurostimulation involves central or peripheral nervous system targets. Central neurostimulation has been used for medically intractable cluster headache and utilizes deep brain stimulation (DBS) of the posterior hypothalamus but carries a small risk of fatal hemorrhage.4 Peripheral stimulation of the occipital nerve has been used in a number of open label trials and Supplemental data at www.neurology.org From the Headache Group (B.B., P.J.G.) and Division of Neurosurgery (L.W.), Institute of Neurology, The National Hospital for Neurology and Neurosurgery, Queen Square London, UK; and Department of Neurology (P.J.G.), University of California, San Francisco. Disclosure: The study had no external support from conception through data collection, analysis, and manuscript preparation. B.B., L.W., and P.J.G. receive financial support for other unrelated studies of neurostimulation therapy in headache from Medtronic and Advanced Bionics. Copyright © 2009 by AAN Enterprises, Inc.

341

Table 1

Patients’ estimates of cluster frequency, severity, and duration of attacks before and after use of stimulator Duration, min Frequency

Severity (peak/average)*

Before

After

Before

After

Before

After

Without abortive

After using SSC 6 mg

Without abortive

After using SSC 6 mg

1

2/d

2–3/d

10/No data

10/8

240

No data

240

No data

2

10–20/d

Same

10/9

10/8

120

15

60–70

Same

3

1–6/d

Same

10/No data

10/No data

120

10

120

10

4

8–12/d

1–4/mo

10/8

10/10

15–90

N/A

15–90

N/A

5

3/d

Same

10/8

10/8

15–30

⬍30

⬍30

No data

Patient no.

6

2–3/d

4–5/wk

8/6–7

7–8/6–7

120

20

N/A

8–15

7

1–2/d

0–1/d

10/10

10/9

60–600

60–120

180

60

8

2–12/d

0–8

10/5

10/5

30–90

5–20

30–60

Same

9

4–5/d

2–3/d

10/9

5–10/7–8

180–240

20

N/A

20

10

3–4/d

1–6/wk

10/6–10

10/6–10

30–180

⬍30

N/A

⬍15

11

6–8/d

Same

10/9

10/8

60–180

90*

N/A

60*

12

0–2/d

1/wk–2/d

10/8

10/7

180–240

30

Same

Same

13

2–8/d

3–5/d

10/8

5/5

40–120

10

15–30

10

14

0–4/d

Same

10/9

10/9

180–240

Inconsistent

Same

Using DHE

No. 11: Triptan changed from rizatriptan wafer to SSC after implant. No. 14: Does not use abortive as on IM DHE. No. 13: Values for bilateral electrodes only. *Values based on verbal rating scale out of 10. SSC ⫽ subcutaneous sumatriptan; N/A ⫽ not applicable, always uses abortive; DHE ⫽ dihydroergotamine.

series for several primary headaches5 but more information on the long-term outcome for medically intractable CCH is required. This report of occipital nerve stimulation (ONS) for CCH follows our initial report for eight patients6 with extended follow-up and a further six patients. METHODS Patient selection. Patients with medically refractory CCH from outpatients at the National Hospital, Queen Square, London, UK, were offered ONS. Patients were offered the choice of a destructive trigeminal nerve procedure or DBS as alternatives and the first 14 such patients all opted for ONS and were implanted over a 40-month period from 2003 to 2006. Patients fulfilled the standard criteria for CCH,1 with the exceptions of one who had long attacks (case 1) and two who had a high frequency of attacks (cases 2 and 4) whose lack of an indomethacin response ruled out chronic paroxysmal hemicrania.1 Occipital nerve block using lidocaine and corticosteroid and a trial of ONS did not form part of the selection criteria. Patients were implanted on compassionate grounds and the study was an audit of outcome and, as such under UK guidelines, does not require ethics committee approval.

Surgical technique. Bilateral ONS electrodes, leads, and battery were implanted after informed consent was obtained (L.W.). In brief, a single stage procedure with two parts was used to allow an intraoperative trial of stimulation. The first part was performed under local anesthetic and gentle sedation, with care taken to avoid anesthetizing the occipital nerves. The patient was placed in the lateral position and a sterile field was established. A 342

Neurology 72

January 27, 2009

midline posterior cervical incision was made and bilateral cylindrical style, quad electrodes (Medtronic, Inc., Minneapolis, MN) were introduced with curved Tuohy needles using an image intensifier to aid position. A dual program pulse generator (Medtronic Synergy from Medtronic, Inc.) was then used to test stimulation and confirm paresthesia was felt bilaterally. The second part of the insertion was performed under a general anesthetic. The electrodes were looped and anchored to the cervical fascia then tunneled to a lateral cervical or subclavicular skin crease intermediate incision. A left/right subclavicular or abdominal incision was made (according to patient preference) to form a pocket to implant the pulse generator. Electrodes were tunneled to the intermediate incision and a pair of extensions lead (Medtronic, Inc.) attached. Silicone sheaths were used to protect the lead connections. Topical antibiotic cover with gentamicin was introduced around the pocket. The incisions were closed. Patients were provided with and instructed how to use remote controls to communicate with the implanted pulse generators. It was possible for patients to adjust their stimulator settings if they chose to by using the remote control although the pulse generators were programmed to provide continuous stimulation. Patients could turn the stimulator on/off or vary the pulse width, frequency, or amplitude, although most patients tended only to vary the amplitude. The polarity of the electrodes was adjusted during follow-up visits to achieve comfortable bilateral paresthesia in the occipital region. Patients remained in hospital for several days after implantation.

Follow-up and data collection. Data were collected from patient records, outpatient visits, and mail and telephone by one investigator (B.B.). Patients retrospectively compared their attacks before and after the procedure; patient diaries were not

Table 2

Follow-up for main outcomes

Patient no.

Months since implantation at follow-up

Patients’ overall view of outcome since implantation

31

Same

1

Triptan use before vs after implantation

Would patient recommend use of stimulator?

0

Same

No

20

Same

Yes

0

Same

Yes

2

6

3

35

Same

4

10

Improved

90

Not using

Yes

5

19

Improved

95

Less

Yes

6

25

Improved

60

Less

Yes

7

14

Improved

50

Less

Yes

8

9

Improved

25

Same

Not sure

9

35

Improved

20

Same

Yes

10

16

Improved

90

11

19

Same

12

11

Improved

13*

32 (23)

Improved

14 Summary

4 17.5 (4–35)

Improved

Patients’ estimate of % change in cluster headache since implantation

Less

Yes

Same

Yes

30

Less

Yes

40

Less

Yes

0

Same

Not using†

Not sure

10 Improved

3 at ⱖ90%

0

6 Less

11 Yes

4 The same

3 at 40–60%

6 Same

1 No

4 at 20–30%

2 Not using

2 Not sure

4 at 0%

*Value for left electrode (bilateral electrodes). Median (ranges for bilateral electrodes). †Using IM dihydroergotamine. No. 2: Improvement mainly due to reduction in background pain. No. 8: Improvement could be accounted for by patient using intermittent steroids. No. 11: Not achieving consistent stimulation for 7– 8 months and feels he is no better than before implant although previously reported 25% improvement. No. 12: Improvement in both background headache and frequency of attacks. No. 13: Patient did not have stimulator on since 23 months after bilateral electrodes (40% improvement occurred in first 12 months).

used. Triptan use was similarly assessed and the following question was asked: Would you recommend the procedure to a fellow cluster headache sufferer? Additionally, patients’ opinion as to how long it took before minimal and maximal improvement and if deteriorated occurred when their device was switched off, together with the time taken for this and recovery.

Ten men and four women with a median age of 44 years (range 31–58 years) were implanted. Median duration of CCH at the time of operation was 6 years (range 2–17). Seven had secondary CCH, the chronic form evolved from an episodic form, and seven had primary CCH, i.e., chronic since the beginning.

RESULTS Patient demographics.

Previous therapies. All patients were intractable ac-

cording to a recent definition,2 having tried and failed or being unable to tolerate at least four of the most commonly used preventive medications. Baseline headache pattern. Table 1 provides the cluster headache frequency, duration, and severities prior to ONS. Follow-up and overall outcome. Median follow-up for

bilateral electrodes was 17.5 months (range 4 –35; table 2). Ten of 14 (71%) patients improved. Eleven

patients recommended ONS to others. No patient became pain free. Improvement occurred in frequency, severity, or duration but a reduction in frequency was most apparent. Change in attacks. Of the 10 patients who improved, 3 improved by 90% or better, 3 by 40% or better, and 4 by 20 –30% (table 2). Some patients noticed a reduction in background pain (see notes for table 2). Patients who improved did so without the addition of new therapy, other than patient 8, who occasionally used intermittent dexamethasone. Triptan use. With regards to triptans, one patient

stopped use, five reduced use, six did not alter use, and two were not using triptans for other reasons (table 2). Time to effect and time to reappearance. Five patients (cases 4, 5, 6, 7, 10) who benefited by 50% or more improved within weeks (table 3). Slower improvement occurred for those with less benefit (cases 2, 8, 12, and 13), with the exception of case 9, who improved quickly. When a technical fault developed, patients reported an immediate (hours or days) worsening of their headache in five cases (cases 2, 4, 6, 7, Neurology 72

January 27, 2009

343

Table 3

Patient no.

Patient estimates of time taken to improve and response to stopping and restarting occipital nerve stimulation

Time to improvement?

Cluster response to stopping occipital nerve stimulation?

Cluster response to restarting occipital nerve stimulation?

Minimal

Maximal

Worse

Time taken

Improved

Don’t know

Yes

Few hours

Waiting battery

Yes

3d

Time taken

1

N/A

2

6 mo

3

N/A

4

48 h (50%)

4 wk (60–70%), 6 mo (90%)

Yes

1h

5

Immediate

Immediate

No

N/A

6

3–7 d

3–7 d

Yes

Immediate

Yes

2d

7

Immediate

5 mo

Yes

Few hours

Yes

Few hours

8

4 mo

6 mo

Not been off

N/A

9

Next day

2 wk

Yes

3 wk

Yes

Next day

10

2–3 wk

3–4 wk

Yes

Immediate

Yes

Immediate

11

N/A

12

6 mo

Improving

Not been off

N/A

13

3 mo

18 mo

Not been off

N/A

14

N/A

N/A ⫽ not applicable.

10), but over 3 weeks for a sixth (case 9). After fixing faults, all patients rapidly improved within 3 days (see table 3). Technical issues. Twelve patients used continuous,

two used intermittent stimulation. A wide range of stimulator settings were used (table e-1 on the Neurology® Web site at www.neurology.org). As a group, the range for amplitude was 0 –10.5 volts, pulse width 60 – 450 ␮sec, and frequency 3–130 Hz. Complications. Complications are listed in table e-2.

Occipital paresthesia was considered a reassuring marker of activity, although one patient (case 5) found this unpleasant and only used stimulation intermittently. The mean battery life was 15.1 months and as a result, the most common “complication” was battery depletion requiring replacement for 6 of the 14 patients (43%). Four patients required new electrodes/leads (29%). Muscle recruitment, neck stiffness, skin discomfort, superficial infections, and painful overstimulation were also seen. ONS for CCH was initially abstracted for two cases and was safe and effective.7 Larger series have followed6,8 and the general outcome seems to be positive for a significant proportion of otherwise highly disabled patients. Although response rates are better for DBS, with over two-thirds of patients reported as completely pain free in the largest study to date,9 one might conclude that ONS should be tried first, since its side DISCUSSION

344

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January 27, 2009

effect profile is modest. Interestingly, it has been reported in abstract that five of six patients with drugresistant CCH who failed to respond to ONS had a 60% or better response to hypothalamic DBS. In our initial description,6 the time to improvement was months, in keeping with other data.8 Retrospective exploration of this issue (table 3) appears to show two groups, the first being patients with quick improvement within weeks going on to report most benefit (cases 4, 5, 6, 7, 10) and the second being those gradually improving over months reporting less substantial benefit (cases 2, 8, 12, and 13). The exception is case 9. A limitation of this study is the absence of a control group. This is of particular concern as there is little doubt placebo effects are seen in cluster headache and the natural history of cluster headache is to fluctuate. Blinding with ONS is a particular challenge since it seems paraesthesia is a requirement for the clinical effect. Two main observations in this report suggest more than natural history or a placebo effect: the preceding duration of chronicity for this patient group was a median of 6 years (range 2–17 years) and the rapid deterioration and recovery after technical failures, which appears a consistent finding in other similar series.8 Randomized controlled trials are now ongoing in migraine (PRISM NCT00286078 and ONSTIM), with provisional results for ONSTIM suggesting effectiveness over sham stimulation.10 Taken together, our data and current studies suggest at least an

open mind and more careful prospective work is required. Neither we nor others11 have so far been able to identify a favorable set of stimulator settings or paresthesia to predict or improve efficacy. For the future, electrode migration needs to be minimized and although battery depletion is not strictly a complication it did require further surgery. However, with the recent availability of rechargeable batteries this issue will probably become a historic one. The outcome of this study provides hope for patients whose lives have been devastated and an opportunity to understand the biology of primary headache syndromes. Received July 30, 2008. Accepted in final form October 21, 2008. REFERENCES 1. Headache Classification Committee of The International Headache Society. The International Classification of Headache Disorders (second edition). Cephalalgia 2004; 24:1–160. 2. Goadsby PJ, Schoenen J, Ferrari MD, Silberstein SD, Dodick D. Towards a definition of intractable headache for use in clinical practice and trials. Cephalalgia 2006;26: 1168–1170.

3.

4.

5. 6.

7.

8.

9.

10.

11.

Jarrar RG, Black DF, Dodick DW, Davis DH. Outcome of trigeminal nerve section in the treatment of chronic cluster headache. Neurology 2003;60:1360–1362. Schoenen J, Di Clemente L, Vandenheede M, et al. Hypothalamic stimulation in chronic cluster headache: a pilot study of efficacy and mode of action. Brain 2005;128: 940–947. Goadsby PJ. Neurostimulation in primary headache syndromes. Exp Rev Neurotherapeutics 2007;7:1785–1789. Burns B, Watkins L, Goadsby PJ. Successful treatment of medically intractable cluster headache using occipital nerve stimulation (ONS). Lancet 2007;369:1099–1106. Dodick DW, Trentman T, Zimmerman R, Eross EJ. Occipital nerve stimulation for intractable chronic primary headache disorders. Cephalalgia 2003;23:701. Magis D, Allena M, Bolla M, et al. Occipital nerve stimulation for drug-resistant chronic cluster headache: a prospective pilot study. Lancet Neurol 2007;6:314–321. Leone M, Franzini A, Broggi G, Bussone G. Hypothalamic stimulation for intractable cluster headache: longterm experience. Neurology 2006;67:150–152. Saper J, Goadsby PJ, Silberstein S, Dodick DW. ONSTIM Investigators. Occipital nerve stimulation (ONS) for treatment of intractable migraine headache: 3-month results from the ONSTIM Feasibility Study. Headache 2008;48 (in press). Trentman TL, Zimmerman RS, Seth N, Hentz JG, Dodick DW. Stimulation ranges, usage ranges, and paresthesia mapping during occipital nerve stimulation. Neuromodulation 2008;11:56–61.

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Neurology 72

January 27, 2009

345

Epidemiology of ischemic stroke from atrial fibrillation in Dijon, France, from 1985 to 2006 Y. Be´jot, MD D. Ben Salem, MD G.V. Osseby, MD G. Couvreur, MD J. Durier, PhD C. Marie, PhD Y. Cottin, MD T. Moreau, MD M. Giroud, MD

Address correspondence and reprint requests to Dr. Yannick Bejot, Dijon Stroke Registry–Department of Neurology, University Hospital, 3 Rue du Faubourg Raines, 21000 Dijon, France [email protected]

ABSTRACT

Background: Atrial fibrillation (AF) is strongly associated with age, and epidemiologic studies are needed to evaluate the impact of both aging of the population and the use of anticoagulant therapy in patients with AF on the incidence of cardioembolic stroke with AF (CE/AF stroke).

Methods: We evaluated trends in incidence rates, risk factors, prestroke therapy, and survival in CE/AF stroke from a prospective population-based registry, from 1985 to 2006.

Results: A total of 3,064 ischemic strokes, including 572 (18.7%) CE/AF strokes, were recorded. Over the 22 years, a decrease in the incidence of overall CE/AF stroke was noted (incidence rate ratio 0.9858, 95% confidence interval [CI] 0.9731– 0.9986; p ⫽ 0.03). We observed a higher prevalence of previous AF, previous myocardial infarction, and patients aged ⬎70 years in CE/AF stroke (p ⬍ 0.0001) whereas hypercholesterolemia was more prevalent in other ischemic strokes (p ⫽ 0.003). A significant increase in the use of anticoagulants and antiplatelet agents was noted, and was particularly pronounced for CE/AF stroke with previous AF. For CE/AF stroke, survival rates were 72% at 1 month (95% CI 0.68 – 0.76), 52% at 1 year (95% CI 0.48 – 0.56), and 43% at 2 years (95% CI 0.39 – 0.48), and remained lower than those of other ischemic stroke.

Conclusions: The decrease in the incidence of cardioembolic/atrial fibrillation stroke in our study was probably due to a slight increase in the utilization of antithrombotic therapy in patients with atrial fibrillation, but the use of such therapies will have to increase further because of the expected aging of the population in coming years. Neurology® 2009;72:346–353 GLOSSARY AF ⫽ atrial fibrillation; CE ⫽ cardioembolic; CI ⫽ confidence interval; IRR ⫽ incidence rate ratios.

Cardioembolic (CE) stroke accounts for 25 to 30% of ischemic strokes among white populations.1-6 This ischemic stroke subtype is usually regarded as severe because of the poor prognosis, characterized by both high case-fatality rates and a high risk of stroke recurrence.1,7,8 In addition, atrial fibrillation (AF) accounts for more than half of CE strokes. AF affects approximately 1% of adults,9 and its prevalence is strongly associated with age, since it has been evaluated at 6% in people older than 65 years of age, increasing to 9% at the age of 80 to 89 years.9-11 As a result, the risk of stroke attributed to AF increases with age, from 1.5% for people aged between 50 and 59 years to 23.5% for those between 80 and 89 years,12 and with the dramatic ageing of the population, the absolute number of strokes due to AF is expected to increase. However, clinical trials conducted in the early 1990s clearly demonstrated that the use of adjusted-dose warfarin is effective in primary prevention in patients with AF, and can reduce the risk of stroke by almost 60%.13 Consequently, this therapeutic strategy may counterbalance the effect of age on the incidence of CE stroke. Supplemental data at www.neurology.org From Stroke Registry of Dijon (Inserm et Institut de Veille Sanitaire) (Y.B., G.V.O., G.C., J.D., T.M., M.G.), EA4184, University Hospital and Faculty of Medicine and Department of Neurology; Department of Neuroimaging (D.B.S.), University Hospital, Dijon; Laboratory of Pharmacodynamics (C.M.), Inserm U887, University of Burgundy, Dijon; and Department of Cardiology and Observatoire des Infarctus de Coˆted’Or (RICO) (Y.C.), LPPCE, IFR Sante´-STIC, University of Burgundy, University Hospital and Faculty of Medicine of Dijon, France. Disclosure: The authors report no disclosures. 346

Copyright © 2009 by AAN Enterprises, Inc.

Table 1

Number of CE/AF ascertained, stratified by sex and by age, according to the study period Men

Period/age, y

Women

No.

At risk

Rate

(95% CI)

No.

At risk

Rate

(95% CI)

1985–1988 <40

0

43,208

0.0

(0–1.7)

1

45,378

0.6

(0–3.1)

40–50

0

8,464

0.0

(0–8.8)

0

8,530

0.0

(0–8.8)

50–60

0

5,913

0.0

60–70

5

5,658

22.1

70–80

18

3,131

143.7

(85.2–227.2)

16

4,763

84.0

>80

21

1,891

277.6

(171.9–424.4)

48

4,346

276.1

Total

44

68,265

16.1

(12–21.2)

69

77,131

22.4

(0–12.7)

1

6,210

4.0

(0.1–22.4)

(7.2–51.6)

3

7,905

9.5

(2–27.7) (48–136.4) (203.6–366.1) (17.7–27.9)

1989–1992 <40

0

42,850

0.0

(0–1.7)

0

45,426

0.0

(0–1.6)

40–50

0

8,615

0.0

(0–8.7)

0

8,986

0.0

(0–8.3)

50–60

1

6,369

3.9

(0.1–21.9)

0

6,729

0.0

60–70

5

5,393

23.2

(7.5–54.1)

6

7,345

20.4

(7.5–44.5)

70–80

21

3,449

152.2

(94.2–232.7)

16

5,429

73.7

(42.1–119.6)

>80

12

1,928

155.6

(80.4–271.9)

45

4,396

255.9

Total

39

68,602

14.2

(10.4–19)

67

78,310

21.4

(0–11.1)

(186.7–342.5) (16.9–26.8)

1993–1996 <40

0

42,491

0.0

(0–1.8)

1

45,475

0.5

(0–3.1)

40–50

1

8,766

2.9

(0.1–15.9)

1

9,442

2.6

(0.1–14.8)

50–60

1

6,826

3.7

60–70

7

5,128

34.1

70–80

16

3,767

106.2

(60.7–172.5)

26

6,096

106.6

(69.7–156.2)

>80

17

1,964

216.4

(126.1–346.5)

37

4,445

208.1

(146.5–286.9)

Total

42

68,941

15.2

(11.3–20.2)

65

79,490

20.4

(0.1–20.4)

0

7,248

0.0

(0–10.3)

(13.7–70.3)

0

6,786

0.0

(0–11)

(16.1–25.7)

1997–1999 <40

0

42,178

0.0

(0–2.4)

0

45,518

0.0

(0–2.2)

40–50

0

8,898

0.0

(0–11.2)

0

9,841

0.0

(0–10.1)

50–60

2

7,226

9.2

(1.1–33.3)

0

7,702

0.0

60–70

4

4,896

27.2

(7.4–69.7)

4

6,296

21.2

(5.8–54.2) (34.5–111)

70–80

7

4,044

57.7

>80

13

1,995

217.2

Total

26

69,237

12.5

(23.2–118.9)

13

6,679

64.9

(115.6–371.4)

25

4,486

185.7

(8.6–17.8)

42

80,522

17.4

(0–13)

(120.2–274.2) (12.9–23)

2000–2003 <40

0

41,863

0.0

(0–1.8)

0

45,560

0.0

(0–1.6)

40–50

0

9,029

0.0

(0.8 .3)

0

10,240

0.0

(0–7.3)

50–60

2

7,624

6.6

(0.8–23.7)

2

8,155

6.1

(0.7–22.1)

60–70

6

4,665

32.2

(11.8–70)

2

5,807

8.6

(1–31.1)

70–80

11

4,323

63.6

(31.8–113.8)

15

7,261

51.6

>80

13

2,028

160.3

(85.3–274)

34

4,531

187.6

Total

32

69,531

11.5

(8.2–15.8)

53

81,553

16.2

(28.9–85.2) (129.9–262.1) (12.4–20.9)

2004–2006 <40

0

41,551

0.0

(0–2.4)

0

45,605

0.0

(0–2.2)

40–50

0

9,161

0.0

(0–10.9)

1

10,639

3.1

(0.1–17.5)

50–60

0

8,024

0.0

(0–12.4)

0

8,609

0.0

(0–11.6) —Continued

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347

Table 1

Continued Men

Period/age, y

No.

Women At risk

Rate

(95% CI)

No.

(8.2–77)

3

At risk 5,317

Rate 18.8

(95% CI)

60 –70

4

4,433

30.1

(3.9–55)

70–80

18

4,601

130.4

(77.3–206.1)

15

7,845

63.7

>80

18

2,060

291.3

(172.6–460.3)

34

4,574

247.8

Total

40

69,830

19.1

(14–25.4)

53

82,588

21.4

<40

0

42,402

0.0

(0–0.3)

2

45,487

0.2

(0–0.7)

40–50

1

8,803

0.5

(0–2.9)

2

9,556

1.0

(0.1–3.4)

(1.4–8.6)

(0.4–5.4)

(35.7–105.1) (171.6–346.2) (16.4–27.5)

1985–2006

50–60

6

6,940

3.9

60–70

31

5,062

27.8

70–80

91

3,846

107.6

>80

94

1,973

216.5

223

69,025

14.7

Total

3

7,377

1.8

18

6,646

12.3

(86.6–132.1)

101

6,262

73.3

(175–265)

223

4,457

227.4

(12.9–16.7)

349

79,785

19.9

(18.9–39.5)

(7.3–19.5) (59.7–89.1) (198.6–259.3) (11.1–22)

Rate: n/100,000/year. CE ⫽ cardioembolic; AF ⫽ atrial fibrillation; CI ⫽ confidence interval.

Therefore, we aimed to evaluate trends in the incidence of CE stroke secondary to AF, as well as the associated mortality and risk factors, in a prospective population-based study conducted from 1985 to 2006, in order to determine the impact of the large-scale application of anticoagulant therapy in patients with AF. METHODS The incidence of CE stroke with AF (CE/AF stroke) and its prognosis were studied in patients included from January 1, 1985, to December 31, 2006, in the prospective population-based stroke registry of Dijon, which complies with epidemiologic criteria for stroke incidence studies.14,15

Study area and population. The study population comprised all residents of the city of Dijon, a town located in eastern France. According to the national census, the population of Dijon was 146,723 in 1990, and 150,138 in 1999. The proportion of individuals aged 65 years and above increased from 14.3% in 1985 to 15.8% in 2006, whereas that of individuals aged 75 years or more rose from 7.0% to 8.5%. Case ascertainment. Only residents of the city of Dijon with a first-ever stroke were included in the study. To ensure the completeness of case ascertainment, information was provided by six sources16: 1) from the emergency rooms, and all of the clinical and radiologic departments of Dijon University Hospital, with diagnosis of stroke made by one of the neurologists of the Department of Neurology; 2) from the emergency rooms and all of the clinical departments of the three private hospitals of the city and its suburbs, with diagnosis made by private neurologists working in these establishments; 3) from the patient’s home or from the nursing homes of the city, with diagnosis assessed by the 250 general practitioners with the help of an outpatient clinic with either a public or private neurologist who notified and registered the case; 4) from the three private radiologic centers, where the medical records were reviewed to identify missed cases that had not been transferred to the Registry by the general practitioners; 5) from the ultrasound Doppler centers 348

Neurology 72

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of the University Hospital and private centers, where medical records were reviewed; and 6) from the death certificates obtained from the local Social Security Bureau that is responsible for registering all deaths in the community in order to identify fatal strokes occurring in nonhospitalized patients.

Ischemic stroke definition and classification. Stroke was defined according to World Health Organization recommendations.17 The clinical diagnoses were always validated on the basis of either CT or MRI. Only first-ever ischemic stroke was considered. The diagnosis of stroke subtypes was always performed on clinical, cerebral imaging, and complementary investigations including two-dimensional echocardiography (transthoracic or trans-esophageal cardiography), carotid and vertebral ultrasonography, and standard blood and urine tests.15 Diagnosis of AF was defined by a 12-lead electrocardiogram or Holter recordings showing replacement of consistent P waves by rapid oscillations of fibrillatory waves that varied in size, shape, and timing, associated with an irregular ventricular response. Cardioembolic ischemic stroke was determined from focal neurologic symptoms and signs with brain evidence of infarction and a definite cardiac source of embolism without evidence of large-artery disease by noninvasive vascular testing. For this study, we considered AF as the source of cardiac embolism to define CE/AF stroke. Hence, stroke occurring in patients with a history of AF and compatible clinical and neuroimaging was considered CE/AF stroke. Stroke occurring in patients with newly diagnosed AF and compatible clinical and neuroimaging was also considered CE/AF stroke if the diagnosis of AF was confirmed in subsequent 12-lead electrocardiogram or Holter recordings. When it was difficult to differentiate between CE/AF and ischemic stroke from other origins, medical staff meetings were held to determine the cause. Vascular risk factors and prestroke antithrombotic therapy. Vascular risk factors were collected with the methodology previously described.15 Briefly, hypertension was defined by a history of known hypertension with a systolic blood pressure ⱖ160 mm Hg or diastolic blood pressure ⱖ95 mm Hg or antihypertensive treatment. Diabetes mellitus was recorded if a glucose level of ⱖ7.8 mmol/L had been reported in the medical

0.797

20.9

464.2

Age <70 y

Age >70 y

CE ⫽ cardioembolic; AF ⫽ atrial fibrillation; CI ⫽ confidence interval; IRR ⫽ incidence rate ratios.

0.001 (1.0141–1.0368)

(0.9935–1.0086) 1.0010

1.0253 (25.8–36.3)

(358.9–461.4) 410.1

31.0 (23.9–32.5)

(333.6–421.5) 377.5

28.2 (18.5–27.4)

(424.9–544.8) 484.9

23.0 (18.7–26.3)

(388.9–489.6) 439.2

22.5 (15.4–22.2)

(339.8–440.2)

18.8

390.0

38.6 Overall

(17.2–24.6)

25.5 Women

(404.6–523.8)

0.002

0.006 (1.0025–1.0150)

(1.0048–1.0226) 1.0136

1.0087

(31.2–44.7)

(40.8–51.6)

37.9

46.2

(28.2–38.8)

(37.7–46.7) 42.2

33.5 (24.6–35.3)

(36.6–46.3)

(25.0–34.5)

(35.0–43.3)

29.7

39.2 (34.3–42.9)

(21.3–30) 25.6

33.6

(21–30.1)

(29.8–37.5)

29.9

1.0036 (48.6–66.5) 57.5 (46.1–61.4) 53.8 (48–65.6) 56.8 (45.1–59.8) 52.4 (37.9–51.6) 44.7 (48.1–63.8) 56.0 Men

Other ischemic stroke

41.4

(0.9948–1.0126)

0.425

0.009

0.358 (0.9795–1.0592)

(0.9684–0.9954) 0.9818

1.0185 (0.6.3.3)

(102.9–160.4) 131.6

2.0 (0.9–3.1)

(66.2–107.5) 86.9

2.0 (0.8–3.5)

(69.8–121.2) 95.5

2.2 (0.7–2.8)

(104.6–160.5)

1.8

132.5

(0.8–2.7)

(105.4–163.6) 134.5

1.8 (0.5–2.4) 1.5

149.9

Age <70 y

Age >70 y

(118.2–181.6)

0.033

0.030 (0.9731–0.9986)

(0.9659–0.9985) 0.9820

0.9858

(4–8.2)

(5.4–8.9)

6.1

7.1

(3.1–6.1)

(4–6.7) 5.4

4.6 (3.3–7.2)

(4.2–7.5) 5.9

5.3 (4.3–7.7)

(5.5–8.5)

6.0

7.0

(4.5–7.9)

(5.6–8.6)

6.2

7.1

(4.7–8.6)

(5.9–9)

6.7

7.4

(3.8–9.4) 6.6 (5.7–11.1) 8.4 (5.4–10.8) 8.1 (5.9–11.3) 8.6 Men

CE/AF stroke

Women

0.9917 (5.9–12) 8.9 (3.9–8.8) 6.4

Rate (95 % CI) Rate (95 % CI) Rate (95 % CI) Rate (95 % CI) Rate

Overall

0.430 (0.9713–1.0125)

p (95% CI) IRR Rate (95 % CI)

(95% CI)

Trends 2004 –2006 2000 –2003 1997–1999 1993–1996 1989 –1992 1985–1988

Standardized overall incidence of CE/AF stroke and other ischemic stroke by study periods from 1985 to 2006 according to world population per 100,000 per year (95% CI) Table 2

record or if the patient was under insulin or oral hypoglycemic agents. Hypercholesterolemia was considered if total cholesterol level ⱖ5.7 mmol/L was reported in the medical history of the patient or was found in the blood sample taken at the time of the stroke, or if patients were treated with lipid-lowering therapy. To ensure the comparability of our results, we kept these cutoff values throughout the study period. We also recorded previous myocardial infarction, peripheral vascular disease, and history of TIA, defined as sudden development of signs and symptoms affecting motor, sensory, sensorial and speech, brainstem, and cerebellum functions lasting less than 24 hours. A history of AF was also listed as vascular risk factor, whatever the stroke mechanism diagnosed. Smoking was not included in the analysis because of missing data ⬎10%. Prestroke antithrombotic therapy was also recorded. We distinguished between anticoagulants (warfarin, acenocoumarol, or fluindione) and antiplatelet agents (aspirin, clopidogrel, ticlopidine, or dipyridamole).

Statistical analysis. The statistical analysis was performed by Je´roˆme Durier, a professional statistician working in the Population Epidemiology Study Center (EA4184, Faculty of Medicine of Dijon), including the Dijon Stroke Registry. To measure the incidence rates, the National Institute of Statistics provided census data for 1982, 1990, and 1999 concerning the population in Dijon in l-year age groups and by sex. The population was estimated from these censuses by linear interpolation from 1985 to 1999, then by extrapolation after 1999. The crude incidence rate per age group and the standardized rate in terms of world populations were calculated for every year and according to sex using the direct method with the SEGI 1996 world population.18 We assumed Poisson distribution for the annual number of events to calculate 95% confidence intervals (CI) for the rates. To evaluate the impact of the time period on stroke incidence, incidence rate ratios (IRR) were calculated using a Poisson regression in which time was considered a continuous variable. The Pearson ␹2 test was used to compare the proportion of cerebrovascular risk factors in CE strokes with AF and other ischemic strokes. Vital status at 2 years was found for 99% of the patients over the study period. Survival rates after stroke were estimated by the Kaplan-Meier method. Comparison between groups was performed by the log-rank test. A Cox regression model, adjusted for age and sex, was used to determine the effect of CE strokes with AF vs other ischemic strokes on death at 2 years. CIs were calculated using the Greenwood method. Statistical analysis was performed with STATA 9.0 software. Ethics. Our registry was approved by the National Ethics Committee (CNIL), and the Ethics Committee of the University Hospital of Dijon, and complies with national rules on the informed consent of patients.

From 1985 to 2006, 3,064 ischemic strokes were recorded (1,449 in men and 1,615 in women). Of these, 572 (18.7%) were classified as CE/AF strokes (223 men and 349 women) and 2,492 (81.3%) were identified as ischemic strokes from other etiology (1,226 men and 1,266 women) (table 1). In the whole study period, 73% of stroke patients were managed at the University Hospital, 16% in one of the private hospitals, and 11% as outpatients. A progressive increase in the crude incidence was observed with each decade of life in both CE/AF and other

RESULTS

Neurology 72

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349

Table 3

ischemic strokes. Mean age at onset was 80.6 years in patients with CE/AF stroke, whereas it was lower in patients with other ischemic stroke (73.6 years).

Prevalence of cerebrovascular risk factors in CE/AF vs other ischemic stroke over the 22-year study period CE/AF stroke, %

Other ischemic stroke, %

p

Trends in incidence rates. From 1985 to 2006, a de-

Hypertension 1985–1991

70.4 (64.0–76.9)

65.9 (62.7–69.1)

1992–1999

67.2 (60.6–73.8)

63.9 (61.1–66.7)

2000–2006

65.7 (58.7–72.8)

64.9 (62.0–67.9)

1985–2006

67.8 (64.0–71.7)

64.8 (63.1–66.5)

1985–1991

8.2 (4.3–12.0)

13.3 (11.0–15.7)

1992–1999

10.6 (6.3–14.9)

18.3 (16.0–20.5)

2000–2006

32.0 (25.1–38.9)

32.7 (29.8–35.6)

1985–2006

16.4 (13.4–19.5)

21.9 (20.4–23.4)

0.166

Hypercholesterolemia

0.003

Distribution of cerebrovascular risk factors and prestroke therapy. Over the whole study period, we ob-

Diabetes 1985–1991

10.2 (5.9–14.4)

11.9 (9.7–14.1)

1992–1999

12.1 (7.5–16.7)

14.5 (12.4–16.6)

2000–2006

18.5 (12.8–24.3)

18.4 (16.0–20.8)

1985–2006

13.5 (10.7–16.3)

15.1 (13.8–16.4)

1985–1991

18.9 (13.3–24.4)

21.1 (18.3–23.9)

1992–1999

11.6 (7.1–16.1)

11.4 (9.5–13.2)

2000–2006

10.1 (5.6–14.6)

1985–2006

13.6 (10.8–16.5)

13.2 (12.0–14.5)

1985–1991

73.0 (66.7–79.2)

13.7 (11.4–16.1)

1992–1999

86.3 (81.5–91.2)

16.9 (14.7–19.1)

2000–2006

78.1 (72.0–84.2)

13.1 (11.1–15.2)

1985–2006

79.2 (75.9–82.5)

14.7 (13.4–16.0)

1985–1991

31.6 (25.1–38.2)

18.7 (16.0–21.4)

1992–1999

26.8 (20.5–33.0)

22.5 (20.0–24.9)

2000–2006

23.0 (16.8–29.3)

14.4 (12.3–16.6)

1985–2006

27.3 (23.6–30.9)

18.6 (17.2–20.0)

1985–1991

11.7 (7.2–16.3)

11.2 (9.0–13.3)

1992–1999

13.1 (8.4–17.9)

11.1 (9.3–12.9)

2000–2006

12.9 (7.9–17.9)

8.1 (6.4–9.8)

1985–2006

12.6 (9.9–15.3)

10.1 (9.0–11.2)

1985–1991

89.3 (84.9–93.7)

64.8 (61.5–68.1)

1992–1999

88.9 (84.4–93.3)

69.8 (67.1–72.5)

2000–2006

88.8 (84.1–93.4)

65.1 (62.2–68.1)

1985–2006

89.0 (86.4–91.6)

66.8 (65.1–68.5)

0.305

TIA

9.0 (7.2–10.7) 0.799

Previous atrial fibrillation

⬍0.001

Myocardial infarction

⬍0.001

0.072

Age >70 y

⬍0.001

Previous AF is related to patients with CE/AF stroke who were known to have a medical history of AF, not patients with AF diagnosed at the moment of the stroke. CE ⫽ cardioembolic; AF ⫽ atrial fibrillation.

Neurology 72

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served a significantly higher prevalence of previous AF, previous myocardial infarction, and patients aged ⬎70 years in CE/AF stroke vs other ischemic stroke (table 3). In contrast, the prevalence of hypercholesterolemia was higher in other ischemic strokes (p ⫽ 0.003). The use of antiplatelet agents and anticoagulants was significantly higher in patients with CE/AF stroke with history of AF (table 4). Over the 22 years, a significant increase in the use of these two treatments was noted, whatever the ischemic stroke subtypes. This calendar effect was particularly pronounced for CE/AF stroke with previous AF. According to the age, some differences in the distribution of prestroke treatments were noted (table e-1). Hence, the proportion of CE/AF stroke patients ⬎70 years old with history of AF and under treatment with anticoagulants was lower than that of patients ⬍70 years old (11.6% vs 35.4%, p ⬍ 0.001). Survival rates. The figure presents Kaplan-Meier esti-

Peripheral vascular disease

350

crease in the incidence of overall CE/AF stroke was noted (IRR 0.9858, 95% CI 0.9731– 0.9986; p ⫽ 0.03), explained by a decrease in the incidence in women (IRR 0.982, 95% CI 0.9659 – 0.9985; p ⫽ 0.033) and in people ⬎70 years (IRR 0.9818, 95% CI 0.9684 – 0.9954; p ⫽ 0.009) (table 2 and figure e-1 on the Neurology® Web site at www.neurology. org). In contrast, an increase in the incidence of other ischemic strokes was observed (IRR 1.0087, 95% CI 1.0025–1.015; p ⫽ 0.006).

mates of survival rates among patients with CE/AF stroke vs other ischemic stroke. Ischemic stroke was a predictor of survival (log-rank p ⬍ 0.001). For CE/AF stroke, survival rates were evaluated at 72% at 1 month (95% CI 0.68 – 0.76), 52% at 1 year (95% CI 0.48 – 0.56), and 43% (95% CI 0.39 – 0.48) after 2 years of follow-up. Concerning other ischemic strokes, these were respectively 88% (95% CI 0.87– 0.89), 76% (95% CI 0.74 – 0.78), and 69% (95% CI 0.67– 0.71). The survival rate following other ischemic stroke was higher than that following CE/AF stroke (HR, 1.87; 95% CI 1.62–2.15, p ⬍ 0.001). A trend toward an improvement in 1-month survival was observed over the study period for CE/AF stroke since it was 74% over the period 1985–1989 vs 84% over the period 2000 –2006 (p ⫽ 0.09). The change was significant for other ischemic strokes (85% vs 95%).

Table 4

Prevalence of prestroke therapies among patients with CE/AF stroke, with or without previous AF, vs other ischemic strokes from 1985 to 2006 CE/AF stroke with previous AF, %

CE/AF stroke without previous AF, %

Other ischemic stroke

p

Anticoagulants 1985–1991

6.3 (2.3–10.3)

1.9 (0–5.7)

3.0 (1.9–4.2)

1992–1999

14.6 (9.3–20.0)

7.4 (0–18.0)

5.5 (4.1–6.8)

2000–2006

21.6 (14.6–28.5)

5.1 (0–12.4)

5.8 (4.4–7.3)

1985–2006

14.1 (10.9–17.3)

4.2 (0.1–7.8)

4.9 (4.1–5.7)

⬍0.001

Antiplatelet agents 1985–1991

6.3 (0.2–10.3)

11.3 (2.5–20.1)

1992–1999

39.2 (31.8–46.6)

22.2 (5.5–39.0)

23.4 (20.9–25.9)

6.2 (4.5–7.8)

2000–2006

35.3 (27.2–43.3)

17.9 (5.3–31.0)

25.6 (22.9–28.3)

1985–2006

27.6 (23.5–31.7)

16.0 (9.3–22.6)

19.4 (18.0–20.8)

⬍0.001

CE ⫽ cardioembolic; AF ⫽ atrial fibrillation.

Our study conducted over 22 years revealed a decrease in the incidence of CE/AF stroke between the end of the 20th century and the beginning of the 21st. This result cannot be explained by a decrease in the prevalence of AF among the studied population since the proportion of people aged 70 years or more in Dijon increased by 35% between 1985 and 2006, and it has been established that the prevalence of AF shows a marked correlation with age,9-11 with a doubling of the likelihood of AF associated with each decade of life.11 The most reliable explanation is rather the changes in clinical practice, particularly improvements in the use of antithrombotic agents that took place in the 1990s, after the demonstration of the efficacy of both adjusted-dose warfarin and antiplatelet agents in reducing the risk of stroke in patients with AF.13,19-22 Nevertheless, the magnitude of the decrease in CE/AF stroke in our study was not as great as expected given the theoretical efficacy of warfarin. To explain this modest result, we can assume that despite an increase in the proportion of people DISCUSSION

Figure

Kaplan-Meier estimation of survival rates in cardioembolic/atrial fibrillation and other ischemic strokes

with AF receiving anticoagulants, the treatment remained underused, although we cannot extrapolate our results to all patients with AF in our community since patients who suffer from stroke represent a failure of preventive therapies. Several studies have previously pointed to the underutilization of anticoagulants in AF, with a proportion of patients on anticoagulation therapy ranging from 30% to 55% despite increased use over the years.19-20,23,24 Predictors of low warfarin use included previous intracranial or gastrointestinal hemorrhage, and age 85 or older.24 However, age difference explains most of the variability observed across different studies, and the decreasing likelihood of receiving anticoagulation therapy with increasing age appears paradoxical considering that the incidence of CE/AF stroke increases with age and anticoagulants are also beneficial in elderly people with AF.25 The increase in the utilization of anticoagulants is probably not the only explanation of the decrease in CE/AF stroke incidence. Better monitoring of the international normalized ratio in AF patients receiving anticoagulants could also explain this reduction, even though it has been suggested that adherence to this protocol is still a challenge.26 In addition, other factors could have been involved, such as the improvement in the management of congestive heart failure, since AF occurs in 10 to 50% of patients with this disorder, with the highest incidence in those with the most severe symptoms.27 It is also likely that better primary prevention of other classic vascular risk factors had an impact. The decrease in the incidence of CE/AF stroke was significant in women but not in men. One hypothetical explanation could be a lower adherence to treatment in men. Another result is the tendency of higher incidence rates of CE/AF stroke in the last study period (2004 –2006) compared with the previous one (2000 –2003) in both men and women. The methodology of case ascertainment did not change over time except for an increase in the use of MRI, but only a small proportion (24%) of patients benefited from it and we only included symptomatic stroke in our study, which reduces diagnosis bias. Hence, this tendency will have to be verified in coming years. Finally, despite a decreasing incidence, CE/AF stroke appears to account for one sixth to one fifth of the total incidence of ischemic stroke, with standardized rates in the whole study period of 21.4/100,000/year according to the French population, 12.7/100,000/year according to the European population, and 6.6/100,000/year according to the world population. Neurology 72

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351

Concerning prognosis, our results were similar to those of previous other studies, which reported lower survival after either CE/AF stroke or more generally cardioembolic stroke, compared with other ischemic strokes.1,7,28-31 In our study, the difference between survival in CE/AF and that in other ischemic stroke was observed in the first 90 days. After this delay, trends in survival rates appeared to be very similar, suggesting that the worse survival in patients with CE/AF stroke was mostly due to high early mortality. This high mortality could be the consequence of the marked risk of early stroke recurrence,1 the large volume of the infarct, existing cardiac disease, most often advanced coronary atherosclerosis, causing the arrhythmia,29 and the age of patients with CE/AF, since they were significantly older than those with other ischemic strokes. The major advantage of our study is the continuous and prospective ascertainment from 1985 to 2006 in a well-defined population. Owing to the overlapping sources of information to identify both hospitalized and nonhospitalized patients, case ascertainment was exhaustive, and the recommendations for the conduct of ideal stroke incidence studies were followed.14 In addition, the population of the city was very stable, with less than 5% of migration, which avoids bias due to changes in ethnic mix, and there was no change in the economic status of local residents. However, our study has several possible limitations. First, our population is predominantly white with a high socioeconomic level, and this prevented us from making comparisons of CE/AF stroke distribution according to ethnic groups. This is important since differences such as higher incidence of cardioembolic stroke among black or Maori populations, for example, have been identified.4-5,32 In addition, we only started using TOAST classification33 in our community-based study in January 2005, so we were not able to classify the non-CE/AF stroke according to this classification. Furthermore, no distinction was made between valvular/nonvalvular AF and in patients with history of AF, we did not distinguish between permanent and intermittent AF. Finally, neither the possible contraindications for antithrombotic drugs in patients with AF who were not under this treatment nor biologic assessment of international normalized ratio in those who were treated were recorded in our registry. This prevented us from understanding the reasons for the underutilization of anticoagulants or from identifying an inappropriate dose. ACKNOWLEDGMENT The authors thank the University Hospital and the Faculty of Medicine of Dijon, the Community Association Grand-Dijon, the General Council of 352

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Coˆte d’Or, the Burgundy Health Agency, Regional Council and University, Inserm, and Institut de Veille Sanitaire. The authors also thank Philip Bastable for reviewing the English.

Received July 15, 2008. Accepted in final form October 15, 2008. REFERENCES 1. Kolominsky-Rabas PL, Weber M, Gefeller O, Neuendorfer B, Heuschmann PU. Epidemiology of ischemic stroke subtypes according to TOAST criteria: incidence, recurrence, and long-term survival in ischemic stroke subtypes: a population-based study. Stroke 2001;32:2735–2740. 2. Petty GW, Brown RD, Jr., Whismant JP, Sicks JD, O’Fallon WM, Wiebers DO. Ischemic stroke subtypes: a population-based study on incidence and risk factors. Stroke 1999;30:2513–2516. 3. Grau AJ, Weimar C, Buggle F, et al. Risk factors, outcome, and treatment in subtypes of ischemic stroke: the German stroke data bank. Stroke 2001;32:2559–2566. 4. Schneider AT, Kissela B, Woo D, et al. Incidence of firstever ischemic stroke subtypes among blacks and whites: a population based study. Stroke 2004;35:1552–1556. 5. White H, Boden-Albala B, Wang C, et al. Ischemic stroke subtype incidence among whites, blacks, and Hispanics: the Northern Manhattan Study. Circulation 2005;111: 1327–1331. 6. Uchino K, Risser JM, Smith MA, Moye´ LA, Morgenstern LB. Ischemic stroke subtypes among Mexican Americans and non-Hispanic whites: the BASIC Project. Neurology 2004;63:574–576. 7. Petty GW, Brown RD Jr, Whisnant JP, Sicks JD, O’Fallon WM, Wiebers DO. Ischemic stroke subtypes: a population-based study of functional outcome, survival, and recurrence. Stroke 2000;31:1062–1068. 8. Bejot Y, Rouaud O, Durier J, et al. Decrease in the stroke case fatality rates in a French population-based twenty-year study: a comparison between men and women. Cerebrovasc Dis 2007;24:439–444. 9. Go AS, Hylek EM, Phillips KA, et al. Prevalence of diagnosed atrial fibrillation in adults: national implications for rhythm management and stroke prevention: the AnTicoagulation and Risk Factors in Atrial Fibrillation (ATRIA) Study. JAMA 2001;285:2370–2375. 10. Kannel WB, Wolf PA, Benjamin EJ, Levy D,. Prevalence, incidence, prognosis, and predisposing conditions for atrial fibrillation: population-based estimates. Am J Cardiol 1998;82:2N–9N. 11. Tsang TS, Petty GW, Barnes ME, et al. The prevalence of atrial fibrillation in incident stroke cases and matched population controls in Rochester, Minnesota: changes over three decades. J Am Coll Cardiol 2003;42:93–100. 12. Wolf PA, Abbott RD, Kannel WB. Atrial fibrillation as an independent risk factor for stroke: the Framingham Study. Stroke 1991;22:983–988. 13. Hart RG, Pearce LA, Aguilar MI. Meta-analysis: antithrombotic therapy to prevent stroke in patients who have nonvalvular atrial fibrillation. Ann Intern Med 2007;146: 857–867. 14. Sudlow CL, Warlow CP. Comparing stroke incidence worldwide: what makes studies comparable? Stroke 1996; 27:550–558. 15. Benatru I, Rouaud O, Durier J, et al. Stable stroke incidence rates but improved case-fatality in Dijon, France, from 1985 to 2004. Stroke 2006;37:1674–1679.

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Giroud M, Lemesle M, Quantin C, et al. A hospital-based and a population-based stroke registry yield different results: the experience in Dijon, France. Neuroepidemiology 1997;16:15–21. WHO.The World Health Report 2000: Health Systems Improving Performance. Geneva: WHO; 2000. Ahmad OB, Roschi-Pinto C, Murray CJL, Lozano R, Inoue M. Age standardization of rates: a new WHO world standard. Available at: http//www.who.int/whosis/discussionpaper/ htm/paper31.htm. Accessed November 31, 2002. Miyasaka Y, Barnes ME, Gersh BJ, et al. Time trends of ischemic stroke incidence and mortality in patients diagnosed with first atrial fibrillation in 1980 to 2000: report of a community-based study. Stroke 2005;36:2362–2366. Smith NL, Psaty BM, Furberg CD, et al. Temporal trends in the use of anticoagulants among older adults with atrial fibrillation. Arch Intern Med 1999;159:1574–1578. Smithard DG, Perez I, Kalra L. Secular trends in the management of hypertension and atrial fibrillation in patients presenting with stroke. QJM 2000;93:41–44. Kalra L, Perez I, Melbourn A. Stroke risk management: changes in mainstream practice. Stroke 1998;29:53–57. Stafford RS, Singer DE. Recent national patterns of warfarin use in atrial fibrillation. Circulation 1998;97:1231–1233. Go AS, Hylek EM, Borowsky LH, Phillips KA, Selby JV, Singer DE. Warfarin use among ambulatory patients with nonvalvular atrial fibrillation: the anticoagulation and risk factors in atrial fibrillation (ATRIA) study. Ann Intern Med 1999;131:927–934. Mant J, Hobbs FD, Fletcher K, et al. BAFTA investigators; Midland Research Practices Network (MidReC). Warfarin versus aspirin for stroke prevention in an elderly community population with atrial fibrillation (the Birmingham Atrial Fibrillation Treatment of the Aged Study, BAFTA): a randomised controlled trial. Lancet 2007;370: 493–503.

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McBride D, Bru¨ggenju¨rgen B, Roll S, Willich SN. Anticoagulation treatment for the reduction of stroke in atrial fibrillation: a cohort study to examine the gap between guidelines and routine medical practice. J Thromb Thrombolysis 2007;24:65–72. Maisel WH, Stevenson LW. Atrial fibrillation in heart failure: epidemiology, pathophysiology, and rationale for therapy. Am J Cardiol 2003;91:2D–8D. Sandercock P, Bamford J, Dennis M, et al. Atrial fibrillation and stroke: prevalence in different types of stroke and influence on early and long term prognosis (Oxfordshire Community Stroke Project). BMJ 1992;305:1460–1465. Kaarisalo MM, Immonen-Ra¨iha¨ P, Marttila RJ, et al. Atrial fibrillation and stroke: mortality and causes of death after the first acute ischemic stroke. Stroke 1997;28:311– 315. Saxena R, Lewis S, Berge E, Sandercock PA, Koudstaal PJ. Risk of early death and recurrent stroke and effect of heparin in 3169 patients with acute ischemic stroke and atrial fibrillation in the International Stroke Trial. Stroke 2001; 32:2333–2337. Lamassa M, Di Carlo A, Pracucci G, et al. Characteristics, outcome, and care of stroke associated with atrial fibrillation in Europe: data from a multicenter multinational hospital-based registry (The European Community Stroke Project). Stroke 2001;32:392–398. Feigin V, Carter K, Hackett M, et al. Auckland Regional Community Stroke Study Group. Ethnic disparities in incidence of stroke subtypes: Auckland Regional Community Stroke Study, 2002–2003. Lancet Neurol 2006;5: 130–139. Adams HP Jr, Bendixen BH, Kappelle LJ, et al. Classification of subtype of acute ischemic stroke. Definitions for use in a multicenter clinical trial: TOAST Trial of Org 10172 in Acute Stroke Treatment. Stroke 1993;24: 35–41.

Resident & Fellow Section: Call for Teaching Videos The Neurology® Resident section is featured online at www.neurology.org. The Editorial Team of this section is seeking teaching videos that will illustrate classic or uncommon findings on movement disorders. Such videos will aid in the recognition of such disorders. Instructions for formatting videos can be found in the Information for Authors at www.neurology.org.

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Factors associated with resistance to dementia despite high Alzheimer disease pathology D. Erten-Lyons, MD R.L. Woltjer, MD H. Dodge, PhD R. Nixon, MD R. Vorobik, BA J.F. Calvert, MD M. Leahy, RN T. Montine, MD J. Kaye, MD

Address correspondence and reprint requests to Dr. Deniz Erten-Lyons, Layton Aging and Alzheimer’s Disease Center, 3181 SW Sam Jackson Park Road CR 131, Portland, OR 97239 [email protected]

ABSTRACT

Background: Autopsy series have shown that some elderly people remain with normal cognitive function during life despite having high burdens of pathologic lesions associated with Alzheimer disease (AD) at death. Understanding why these individuals show no cognitive decline, despite high AD pathologic burdens, may be key to discovery of neuroprotective mechanisms.

Methods: A total of 36 subjects who on autopsy had Braak stage V or VI and moderate or frequent neuritic plaque scores based on Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) standards were included. Twelve had normal cognitive function and 24 a diagnosis of AD before death. Demographic characteristics, clinical and pathologic data, as well as antemortem brain volumes were compared between the groups.

Results: In multiple regression analysis, antemortem hippocampal and total brain volumes were significantly larger in the group with normal cognitive function after adjusting for gender, age at MRI, time from MRI to death, Braak stage, CERAD neuritic plaque score, and overall presence of vascular disease. Conclusion: Larger brain and hippocampal volumes were associated with preserved cognitive function during life despite a high burden of Alzheimer disease (AD) pathologic lesions at death. A better understanding of processes that lead to preservation of brain volume may provide important clues for the discovery of mechanisms that protect the elderly from AD. Neurology® 2009; 72:354–360 GLOSSARY AD ⫽ Alzheimer disease; CDR ⫽ Clinical Dementia Rating Scale; CERAD ⫽ Consortium to Establish a Registry for Alzheimer’s Disease; CIRS ⫽ Cumulative Illness Rating Scale; ICV ⫽ intracranial volume; LB ⫽ Lewy bodies; MMSE ⫽ Mini-Mental State Examination; NCSE ⫽ Neurobehavioral Cognitive Status Examination; NFT ⫽ neurofibrillary tangle; NIA ⫽ National Institute on Aging; NP ⫽ neuritic plaques; OHSU ⫽ Oregon Health & Science University; Ref ⫽ reference; SES ⫽ socioeconomic status; UPDRS ⫽ Unified Parkinson’s Disease Rating Scale.

Autopsy series of elderly subjects with normal cognitive function have consistently found high burdens of pathologic lesions associated with Alzheimer disease (AD).1-5 Some studies refer to this state as preclinical AD, suggesting that this is a precursor to AD.3 While some studies report subtle changes in neuropsychological measures in cognitively intact individuals with high AD pathology burdens compared to those with no or low AD pathology burdens, other studies have not found such changes.1,2,6 It remains unknown why these individuals do not show symptoms of overt dementia despite these pathologic changes. One explanation is that the high burdens of classic AD lesions found in these subjects may be necessary but not sufficient to cause cognitive impairment because of compensatory mechanisms or brain reserve. Most previous studies are descriptive and report pathology results of autopsy series according to premorbid clinical state. In contrast to these studies, we specifically designed our study to Supplemental data at www.neurology.org From the Veterans Affairs Medical Center (D.E.-L., J.K.), Portland; Departments of Neurology (D.E.-L., R.L.W., H.D., R.V., J.K.), Family Medicine (J.F.C.,), and Pathology (R.L.W., R.N.), Oregon Health & Science University, Portland; Oregon State University (H.D.), College of Health and Human Sciences, Corvallis; University of Pittsburgh (H.D.), Graduate School of Public Health, PA; Merle West Center for Medical Research (J.F.C., M.L.), Klamath Falls, OR; and University of Washington (T.M.), Department of Pathology, Seattle. Supported by Merit Review Grant & Research Career Development Award, Office of Research and Development, Department of Veterans Affairs, National Institute on Aging, National Institutes of Health (AG08017, MO1 RR000334). Disclosure: The authors report no disclosures. 354

Copyright © 2009 by AAN Enterprises, Inc.

investigate factors that may protect individuals with high AD pathology from having overt symptoms of dementia and cognitive decline. Using a case control design, subjects who remained with normal cognitive function despite a high burden of AD pathologic lesions were matched to a group of patients with AD with an equivalent burden of lesions. Clinical and pathologic characteristics as well as antemortem brain volumes obtained by MRI scans were compared between the two groups. METHODS The Oregon Health & Science University (OHSU) institutional review board approved this study.

Description of cohorts. Subjects were from the longitudinal cohort studies conducted at the National Institute on Aging (NIA)-OHSU Layton Aging and AD Center. Recruitment, exclusion, and inclusion criteria for these studies and subject evaluations have been described previously.7 Briefly, these longitudinal aging studies ongoing since 1989 recruit cognitively intact elders who are 65 years of age and older from the community, are without conditions that impair cognition, and have no risk factors for vascular disease. Only those with no evidence of cognitive impairment, questionable dementia, or memory problems and no evidence of clinical depression are enrolled. Subjects with AD are recruited from the NIA-Layton Aging and AD Center clinic at OHSU. Subject evaluations. All subjects were evaluated semiannually with standardized clinical examinations. Cognition and functional status were assessed using the Clinical Dementia Rating Scale (CDR),8 Mini-Mental State Examination (MMSE),9 Neurobehavioral Cognitive Status Examination (NCSE),10 and a psychometric test battery that covers key domains.11,12 From this psychometric battery we used the animal fluency test and the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) Word List Memory task since these were available for almost all of the study subjects. The CERAD Word List Memory task has three components12: word list memory (involves learning a list of 10 words over three trials; the maximum score is 30); word list delayed recall (involves recalling the words after a 3–5 minute delay; the maximum score is 10); and word list recognition (involves recognizing the 10 words of the Word List Memory task when presented among 10 distractor words; the maximum score is 20). Raw scores not adjusted for education were used. Clinical assessment data related to general chronic disease burden was assessed with the Cumulative Illness Rating Scale (CIRS).13 Parkinsonism was assessed with a modified Unified Parkinson’s Disease Rating Scale (UPDRS) motor subscale.14 Demographic data included socioeconomic status (SES),15 years of education, and the presence of family history of AD. A subgroup of subjects had annual MRI scans and some subjects donated their brains upon death. All subjects had APOE genotyped. For this study, we used the clinical assessments most proximal to death. Subject selection. From the autopsy case series of 477 subjects at the OHSU NIA-Layton Aging and AD Center, the subjects meeting the following criteria were included in the current study: having a diagnosis of probable or possible AD based on

previously published criteria16 or remaining cognitively intact on last evaluation (cognitively intact was described as having a CDR score ⫽ 0); having a last clinical evaluation within 1 year of death; found on autopsy to have high AD pathology burden (high AD pathology was described for this study as having a Braak stage V or VI and moderate or frequent neuritic plaques [NP] based on CERAD criteria17,18); and having antemortem MRI brain volumes and neuropsychological tests. Following these criteria, 24 AD and 12 cognitively intact subjects met the inclusion criteria.

MRI methods. MRI scans measuring intracranial, total brain, ventricular, and hippocampal volumes were obtained before death. Scan protocols and analysis methods for MRI volumes have been described previously.19 Briefly, MR images were obtained using a 1.5-Tesla magnet. The protocol consisted of continuous-slice, multiecho, multiplanar image acquisition, with 4-mm-thick coronal slices and a 24-cm2 field of view using a 256 ⫻ 256 acquisition matrix with 0.5 excitations. Multiecho coronal sequence with repetition time 3,000 msec, echo time 30 and 80 msec was used to visualize the brain. To orient the coronal plane, T1-weighted sagittal images centered in the midsagittal plane were used. MR images were analyzed using REGION, a semiautomated analysis program developed by our research team.19 Recursive regression was used to discriminate between different tissue types for ventricular and total brain volumes. Hippocampal volumes were manually traced. Interrater reliability for all regions assessed by intraclass correlation coefficient was ⱖ0.9. Time from MRI to death was calculated by subtracting age at MRI from age at death. All brain volumes of interest were divided by intracranial volume to adjust for differences in head size. Neuropathologic methods. Brains were examined for neurofibrillary tangle (NFT) and NP pathology and staged by Braak and Braak and CERAD systems.17,18 Neuropathologic evaluation of subjects has been described previously.20 Briefly, brains were fixed in neutral-buffered formaldehyde solution for at least 2 weeks and examined grossly as well as microscopically. For microscopic evaluation, tissue samples were taken from all cortical lobes bilaterally or unilaterally, frontal lobe white matter, anterior cingulate gyrus, hippocampus, amygdala, bilateral striatum and thalamus, midbrain, pons, medulla, and cerebellum. Sixmicrometer sections were routinely stained with hematoxylineosin, Luxol fast blue, Congo red-gallocyanin, and by the modified Bielschowsky silver impregnation method. Selected sections of hippocampus and neocortical regions were immunostained with antibody to tau (tau2, Sigma, St. Louis, MO). Pathologic diagnoses were established using current consensus criteria.21 Information related to NP and NFT burdens, presence of ischemic, hemorrhagic, or vascular pathology, amyloid angiopathy, large vessel strokes, lacunes, presence of Lewy bodies (LB), hippocampal sclerosis, and degree of arteriosclerosis were summarized using the National Alzheimer’s Coordinating Center Neuropathology Data Form.22 Statistical analysis. Statistical analysis was performed by Dr. Erten-Lyons (from the Portland Veterans Affairs Medical Center and OHSU Neurology Department). The following characteristics were compared univariately between the AD and cognitively intact groups: 1) demographic characteristics: gender, age at last evaluation, age at death and at MRI, time from last evaluation to death, years followed, SES, years of education, presence of family history of AD and the APOE ␧4 allele; 2) clinical characteristics: CIRS, UPDRS, MMSE, CERAD word list task, animal fluency Neurology 72

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355

Table 1

Selected demographic characteristics AD, n ⴝ 24

Cognitively intact, n ⴝ 12

p Value

Age at death, y

88.75 (10.25)

91.27 (3.52)

0.42

Age at last visit, y

88.38 (10.35)

90.83 (3.49)

0.31

Years followed

7.13 (3.38)

4.28 (2.21)

0.01

Time from last visit to death, y

0.37 (0.19)

0.45 (0.19)

0.23

% Women

50

33.33

0.48

% With family history of AD

58.33

25

0.08

Education, y

14.67 (3.51)

13.92 (3.67)

0.56

Socioeconomic status index

48.71 (12.86)

49.25 (9.21)

0.89

% With at least one APOE e4 allele

41.67

16.67

0.26

Time from MRI to death, y

3.63 (2.9)

Age at MRI, y

0.86 (0.52)

85.13 (9.52)

90.42 (3.55)

0.002 0.07

Numbers are mean (standard deviation) or percent. AD ⫽ Alzheimer disease.

scores; 3) neuropathologic characteristics: Braak NFT and CERAD NP scores, presence of ischemic, hemorrhagic, or vascular pathology, large vessel strokes, lacunes, hippocampal sclerosis, LBs, amyloid angiopathy, and degree of arteriosclerosis; 4) morphometric characteristics: brain weight and intracranial volume. Univariate analyses were conducted by using ␹2 or Fisher exact test for categorical variables and t test for continuous variables. Multiple regression models were run for the outcomes hippocampal, total brain, and ventricular volume proportions with a group membership (AD vs cognitively intact) as an independent variable, adjusting for age at MRI, time from MRI to death, gender, Braak NFT and CERAD NP scores, and presence of ischemic, hemorrhagic, or vascular pathology. Multiple regression analysis was also performed for the outcome intracranial volume with a group membership as an independent variable, adjusting for gender. Significance was set at p ⱕ 0.05. Statistical analysis was conducted using JMP 5.0.1a (SAS Institute, Cary, NC). RESULTS Univariate analyses. Demographic and clinical characteristics.

Table 2

Age at last evaluation and death,

Selected clinical characteristics Cognitively intact, n ⴝ 12

p Value

12.29 (7.35)

27.42 (1.56)

⬍0.0001

8.13 (4.95)

17.67 (3.29)

⬍0.001

1 (1.38)

5.92 (2.07)

⬍0.0001

14.04 (3.09)

19.33 (0.65)

⬍0.0001

6.61 (4.24)

14.42 (5.66)

⬍0.0001

21.21 (4.26)

21.64 (1.96)

0.77

6 (4.48)

3.5 (2.27)

0.11

AD, n ⴝ 24 Mini-Mental State Examination Word List Acquisition (20) Word List Delayed Recall (10) (n ⴝ 23 AD and 12 cognitively intact) Word List Recognition (20) Animal Fluency (n ⴝ 23 AD and 12 cognitively intact) Cumulative Illness Rating Scale (n ⴝ 14 AD and 10 cognitively intact) Modified UPDRS (n ⴝ 20 AD and 10 cognitively intact)

Numbers are mean (standard deviation). Some subjects have missing values. N listed if there is a missing value. AD ⫽ Alzheimer disease; UPDRS ⫽ Unified Parkinson’s Disease Rating Scale. 356

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gender distribution, education, SES, time from last evaluation to death, presence of family history of AD, and presence of APOE ␧4 allele were not different between the groups. The AD group was followed longer and time from last MRI to death was longer in this group (table 1). No subjects had PD. UPDRS and CIRS scores were not different between the groups. The cognitively intact group scored higher on all cognitive tests (table 2). Neuropsychological testing most proximal to death was not always at the last clinical evaluation before death. All cognitively intact subjects had neuropsychological tests within 1 year of death. For AD subjects, neuropsychological tests were available at a mean of 1.58 (⫾1.22) years before death (range 0.2– 4.8 years). Neuropathologic and morphometric characteristics. The AD group had more individuals with Braak stage VI NFTs. The presence of frequent NPs, presence of ischemic, hemorrhagic, or vascular pathology, presence of amyloid angiopathy, and degree of arteriosclerosis were not significantly different between the groups. Seven subjects with AD had coexisting LB pathology, and none of the cognitively intact subjects had LBs. Five AD and two cognitively intact subjects had large vessel strokes; six AD and two cognitively intact subjects had lacunar infarcts. One subject with AD had hippocampal sclerosis (table 3). Brain weight and intracranial volume were not different between the groups. Multiple regression analysis. In multiple regression

analyses after adjusting for gender, age at MRI, time from MRI to death, Braak and CERAD scores, presence of ischemic, hemorrhagic, or vascular pathology, hippocampal and total brain volumes were significantly associated with group membership. These remained significant at p ⬍ 0.01 after Bonferroni correction for multiple comparisons. Ventricular volume did not show a significant association with group membership (table 4). Intracranial volume was not associated with group membership after adjusting for gender. We repeated the above analysis by adding presence of lacunar infarcts and LBs as independent variables. Group membership remained significantly associated with total brain and hippocampal volume proportions, while presence of lacunes or LBs were not significantly associated with either of the brain volumes. The results did not change when excluding the subject with AD with hippocampal sclerosis. We repeated the above analysis in a subgroup of subjects with Braak stage V and frequent NPs (11 AD and 5 cognitively intact). Hippocampal volume remained significantly different between the two groups.

Table 3

Selected pathologic characteristics

AD, n ⴝ 24

Cognitively intact, n ⴝ 12 8.33

p Value

Braak VI

45.83

Frequent neuritic plaques

79.17

50

0.13

Ischemic, hemorrhagic, or vascular pathology

79.17

58.33

0.25

Moderate to severe arteriosclerosis

37.5

50

0.49

Large vessel strokes

20.83

16.67

1

Lacunar infarcts

25

16.67

0.69

Hippocampal sclerosis

4.17

Amyloid angiopathy

75

Lewy bodies

29.17

0 66.67 0

0.03

1 0.7 0.07

Numbers are percents. AD ⫽ Alzheimer disease.

Our results suggest that having a larger hippocampal and total brain volume sets cognitively intact individuals with a high burden of AD pathology apart from individuals with overt dementia and a similar amount of AD pathologic changes. This may be interpreted in several ways. First, larger brain volumes may indicate a greater preexisting brain reserve. Second, the cognitively intact group may have other forms of compensation or protection from the pathologic processes that underlie ADrelated changes. Third, the brain volume loss in the AD group is not directly caused by the NFTs and NPs. In this case NFTs and NPs are makers of other pathologic processes that actually lead to brain atrophy in AD. The relationship between preexisting brain reserve and risk of AD has been investigated in several studies. While some studies have shown an association between indirect measures of brain size such as

DISCUSSION

Table 4

head circumference or intracranial volume and risk of AD, others have failed to show such an association.23-27 In our study, there was no difference in intracranial volume between the two groups. If we assume that intracranial volume is a crude measure of maximum brain size attained during life, then this argues that the larger brain volume we observed does not reflect a preexisting reserve. We also did not observe a difference in education or SES between our cases and controls. Both education and SES have been suggested to be an index of cognitive reserve providing protection against dementia.28 The second interpretation of our results is that there are other physiologic or molecular mechanisms providing protection against the pathologic changes associated with AD. An example of such mechanisms that may promote or protect cognitive function are the number of synapses.29 A study investigated the number of synapses in individuals with AD, mild cognitive impairment, and no cognitive impairment.29 The authors reported that synapse loss was higher in the AD group compared to the mild cognitive impairment and cognitively intact groups, and was a structural correlate of cognitive decline. The authors also investigated an association between total Braak scores, NIA Reagan scores, and synapse numbers, and these did not show an association. Lack of such an association further supports the notion that features such as synapse number may contribute to whether cognitive decline proceeds in the presence of AD pathology. Studying protein expression in the brains of cases and controls like ours with equivalent AD pathology may also improve our understanding of other mechanisms playing a role in AD pathophysiology.30

Multiple regression models for brain volume proportions

Group membership (AD) (Ref: cognitively intact) Age at MRI Gender (men) (Ref: women) Time from MRI to death

Outcome: total brain/ICV

Outcome: ventricular/ICV

Outcome: hippocampal/ICV

Coefficient (SD)

Coefficient (SD)

Coefficient (SD)

⫺0.03 (0.009)

p Value 0.001

0.009 (0.005)

p Value 0.08

⫺0.0001 (0.00003)

p Value 0.006

⫺0.002 (0.0009)

0.01

0.0009 (0.0005)

0.08

⫺0.000006 (0.000003)

0.07

⫺0.02 (0.007)

0.01

0.005 (0.004)

0.19

⫺0.00005 (0.00003)

0.05

0.002

0.00002 (0.00001)

0.03

0.008 (0.007)

0.29

⫺0.005 (0.004)

0.25

0.00004 (0.00003)

0.11

Neuritic plaques (frequent) (Ref: moderate)

0.003 (0.008)

0.7

⫺0.003 (0.004)

0.48

0.00006 (0.00003)

0.05

0.53

⫺0.004 (0.005)

0.38

⫺0.0001 (0.00003)

0.62

Ischemic, hemorrhagic, or vascular pathology (not present) (Ref: present)

0.01 (0.003)

⬍0.0001 ⫺0.005 (0.002)

Braak stage (V) (Ref: Braak stage VI)

⫺0.005 (0.008)

ICV ⫽ intracranial volume; AD ⫽ Alzheimer disease; Ref ⫽ reference. Neurology 72

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Apoptotic pathways represent another mechanism that may play a role in resistance to dementia in these individuals. Apoptosis has been suggested to be one of the main causes for the cell loss accompanying neurodegenerative diseases such as AD.31 Brain volume loss in patients with AD may be secondary to activation of apoptotic pathways by the NFT and plaques.32 Thus differences in regulators of apoptosis may lead to resistance to neurodegeneration and associated brain volume loss. For example, the FAS gene, which is a member of the tumor necrosis factor receptor superfamily, plays a role in apoptosis and has been associated with AD.33 It has also been shown to be associated with brain volumes obtained by MRI scans in patients with AD.34 Polymorphisms in genes such as FAS, which play a role in regulation of apoptosis, may mediate the relationship between plaques and tangles and the degree of neurodegeneration, brain volume loss, and presence of symptoms of AD. Another interpretation of our finding is that the plaques and tangles do not directly cause loss of brain volume observed in patients with AD. Other mechanisms that are closely correlated with plaques and tangles may lead to brain volume loss in patients with AD. Several studies have shown a correlation between postmortem brain volumes and postmortem Braak stage, NFT measures, and neuron numbers.35-37 One study found that postmortem neocortical NFT and NP pathology correlated well with last ventricular volume prior to death and rate of ventricular volume increase in patients with AD while in cognitively intact individuals such a correlation did not exist.37 The authors also reported that the last hippocampal volume prior to death correlated well with hippocampal NFT pathology in patients with AD, while in the cognitively intact subjects the hippocampal NFT pathology did not correlate with antemortem hippocampal volume. Lack of an association between brain volumes and pathology in the cognitively intact subjects may mean that NFTs and NPs are markers of another process in AD, but do not lead to brain volume loss in the absence of these other processes related to AD. However, a correlation between brain volume and AD neuropathology in nondemented individuals has been reported in some other studies.35,36 This may be because the nondemented group in these studies may represent a more heterogeneous group with some having preclinical AD or some mild memory problems. Our entry criteria and prospective clinical evaluations enhanced the likelihood that subjects in our study do not fall into the preclinical AD group and did not have subtle memory problems. When we 358

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compared several psychometric tests between the cognitively intact group with high AD pathology and another group of cognitively intact elderly who were found to have low AD neuropathology (Braak stage I or II and no or sparse NPs by CERAD criteria), we did not find significant differences between these two groups (table e-1 on the Neurology® Web site at www.neurology.org). Similarly, a study using Pittsburgh compound to image amyloid deposition reported no significant differences in cognitive performance between cognitively intact elderly with high vs low amyloid binding.38 Another study suggested that the relationship between postmortem brain volumes and cognitive function is more robust than the relationship between neuropathology and cognitive function.39 This further supports the notion that brain volume seems to play a major role whether cognitive decline occurs in the setting of AD neuropathology. This study has several limitations. First, matching subjects with high AD pathologic lesion burden and selecting only those with antemortem MRI scans resulted in a restricted sample size. Nevertheless, we observed a statistically significant difference in the brain volumes between AD and cognitively intact subjects even with our relatively small sample size. Our results need replication in a larger sample. Second, since most patients with AD at the final stages of their disease become housebound, subjects in the AD group had a longer time between their MRI and death. This has an effect of minimizing the magnitude of difference in the brain volumes. Ideally one would prefer to have MRI scans within 1 year of death for both groups and we tried to correct for this confounder statistically. Finally, we matched the subjects based on widely used semiquantitative methods to assess the presence of tangles and plaques. Given the possibility of individual variation within the same Braak or CERAD scores, quantitative pathologic assessment methods may be needed in future studies to be able to match cases and controls more precisely. Our results suggest that individuals with a high burden of AD pathologic lesions do not manifest overt cognitive impairment if they also have larger hippocampal and brain volumes. Identifying the mechanisms whereby larger hippocampal and brain volumes are protective, either by providing more brain reserve or as a result of other processes leading to resistance to neuronal loss traditionally attributed to NFT and NPs, warrants further investigation. ACKNOWLEDGMENT The authors thank Robin Guariglia, the volunteers and staff at the Layton Aging and Alzheimer’s Disease Center, Dr. Robert Edwards, and the

Merle West Center for Medical Research for their contribution to this research.

Received May 30, 2008. Accepted in final form September 29, 2008. REFERENCES 1. Bennett DA, Schneider JA, Arvanitakis Z, et al. Neuropathology of older persons without cognitive impairment from two community-based studies. Neurology 2006;66: 1837–1844. 2. Goldman WP, Price JL, Storandt M, et al. Absence of cognitive impairment or decline in preclinical Alzheimer’s disease. Neurology 2001;56:361–367. 3. Hulette CM, Welsh-Bohmer KA, Murray MG, Saunders AM, Mash DC, McIntyre LM. Neuropathological and neuropsychological changes in “normal” aging: evidence for preclinical Alzheimer disease in cognitively normal individuals. J Neuropathol Exp Neurol 1998;57:1168–1174. 4. Katzman R, Terry R, DeTeresa R, et al. Clinical, pathological, and neurochemical changes in dementia: a subgroup with preserved mental status and numerous neocortical plaques. Ann Neurol 1988;23:138–144. 5. Knopman DS, Parisi JE, Salviati A, et al. Neuropathology of cognitively normal elderly. J Neuropathol Exp Neurol 2003;62:1087–1095. 6. Schmitt FA, Davis DG, Wekstein DR, Smith CD, Ashford JW, Markesbery WR. “Preclinical” AD revisited: neuropathology of cognitively normal older adults. Neurology 2000;55:370–376. 7. Howieson DB, Holm LA, Kaye JA, Oken BS, Howieson J. Neurologic function in the optimally healthy oldest old: neuropsychological evaluation. Neurology 1993;43:1882–1886. 8. Morris JC. Clinical Dementia Rating: a reliable and valid diagnostic and staging measure for dementia of the Alzheimer type. Int Psychogeriatr 1997;9 suppl 1:173–176; discussion 177–178. 9. Folstein MF, Robins LN, Helzer JE. The Mini-Mental State Examination. Arch Gen Psychiatry 1983;40:812. 10. Kiernan RJ, Mueller J, Langston JW, Van Dyke C. The Neurobehavioral Cognitive Status Examination: a brief but quantitative approach to cognitive assessment. Ann Intern Med 1987;107:481–485. 11. Hickman SE, Howieson DB, Dame A, Sexton G, Kaye J. Longitudinal analysis of the effects of the aging process on neuropsychological test performance in the healthy young-old and oldest-old. Dev Neuropsychol 2000;17:323–337. 12. Morris JC, Mohs RC, Rogers H, Fillenbaum G, Heyman A. Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) clinical and neuropsychological assessment of Alzheimer’s disease. Psychopharmacol Bull 1988;24: 641–652. 13. Miller MD, Paradis CF, Houck PR, et al. Rating chronic medical illness burden in geropsychiatric practice and research: application of the Cumulative Illness Rating Scale. Psychiatry Res 1992;41:237–248. 14. Fahn S, Elton R. Unified Parkinson’s Disease Rating Scale. In: Fahn S, Marsden CD, Goldstein M, Calne DB, eds. Recent Developments in Parkinson’s Disease. Florham Park, NJ: MacMillan Healthcare Information; 1987:153–163. 15. Hollingshead A. Two-Factor Index of Social Position. New Haven, CT: A.B. Hollingshead; 1957. 16. McKhann G, Drachman D, Folstein M, Katzman R, Price D, Stadlan EM. Clinical diagnosis of Alzheimer’s disease: report of

the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer’s Disease. Neurology 1984;34:939–944. 17. Braak H, Braak E. Staging of Alzheimer’s disease-related neurofibrillary changes. Neurobiol Aging 1995;16:271– 278; discussion 278–284. 18. Mirra SS, Heyman A, McKeel D et al. The Consortium to Establish a Registry for Alzheimer’s Disease (CERAD), part II: standardization of the neuropathologic assessment of Alzheimer’s disease. Neurology 1991;41:479–486. 19. Mueller EA, Moore MM, Kerr DC, et al. Brain volume preserved in healthy elderly through the eleventh decade. Neurology 1998;51:1555–1562. 20. Green MS, Kaye JA, Ball MJ. The Oregon Brain Aging Study: neuropathology accompanying healthy aging in the oldest old. Neurology 2000;54:105–113. 21. Consensus report of the Working Group on Molecular and Biochemical Markers of Alzheimer’s Disease: The Ronald and Nancy Reagan Research Institute of the Alzheimer’s Association and the National Institute on Aging Working Group. Neurobiol Aging 1998;19:109–116. 22. Beekly DL, Ramos EM, van Belle G, et al. The National Alzheimer’s Coordinating Center (NACC) Database: an Alzheimer disease database. Alzheimer Dis Assoc Disord 2004;18:270–277. 23. Edland SD, Xu Y, Plevak M, et al. Total intracranial volume: normative values and lack of association with Alzheimer’s disease. Neurology 2002;59:272–274. 24. Graves AB, Mortimer JA, Larson EB, Wenzlow A, Bowen JD, McCormick WC. Head circumference as a measure of cognitive reserve. Association with severity of impairment in Alzheimer’s disease. Br J Psychiatry 1996;169:86–92. 25. Jenkins R, Fox NC, Rossor AM, Harvey RJ, Rossor MN. Intracranial volume and Alzheimer disease: evidence against the cerebral reserve hypothesis. Arch Neurol 2000; 57:220–224. 26. MacLullich AM, Ferguson KJ, Deary IJ, Seckl JR, Starr JM, Wardlaw JM. Intracranial capacity and brain volumes are associated with cognition in healthy elderly men. Neurology 2002;59:169–174. 27. Schofield PW, Logroscino G, Andrews HF, Albert S, Stern Y. An association between head circumference and Alzheimer’s disease in a population-based study of aging and dementia. Neurology 1997;49:30–37. 28. Stern Y. What is cognitive reserve? Theory and research application of the reserve concept. J Int Neuropsychol Soc 2002;8:448–460. 29. Scheff SW, Price DA, Schmitt FA, DeKosky ST, Mufson EJ. Synaptic alterations in CA1 in mild Alzheimer disease and mild cognitive impairment. Neurology 2007;68:1501–1508. 30. Montine TJ, Woltjer RL, Pan C, Montine KS, Zhang J. Liquid chromatography with tandem mass spectrometrybased proteomic discovery in aging and Alzheimer’s disease. NeuroRx 2006;3:336–343. 31. Cotman CW, Su JH. Mechanisms of neuronal death in Alzheimer’s disease. Brain Pathol 1996;6:493–506. 32. Cotman CW, Anderson AJ. A potential role for apoptosis in neurodegeneration and Alzheimer’s disease. Mol Neurobiol 1995;10:19–45. 33. Su JH, Anderson AJ, Cribbs DH, et al. Fas and Fas ligand are associated with neuritic degeneration in the AD brain and participate in beta-amyloid-induced neuronal death. Neurobiol Dis 2003;12:182–193. Neurology 72

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Silbert LC, Quinn JF, Moore MM, et al. Changes in premorbid brain volume predict Alzheimer’s disease pathology. Neurology 2003;61:487–492. Jack CR Jr, Lowe, VJ Senjem ML, et al. 11C PiB and structural MRI provide complementary information in imaging of Alzheimer’s disease and amnestic mild cognitive impairment. Brain 2008;131:665–680. Mortimer JA, Gosche KM, Riley KP, Markesbery WR, Snowdon DA. Delayed recall, hippocampal volume and Alzheimer neuropathology: findings from the Nun Study. Neurology 2004;62:428–432.

Activate Your Online Subscription At www.neurology.org, subscribers can now access the full text of the current issue of Neurology® and back issues. Select the “Login instructions” link that is provided on the Help screen. Here you will be guided through a step-by-step activation process. Neurology® online offers: • e-Pub ahead of print • Extensive search capabilities • Complete online Information for Authors • Access to Journal content in both Adobe Acrobat PDF and HTML formats • Links to PubMed • Examinations on designated articles for CME credit • Resident & Fellow section • Patient Page • Access to in-depth supplementary scientific data

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Biochemical indicators of vitamin B12 and folate insufficiency and cognitive decline

Christine C. Tangney, PhD Yuxiao Tang, PhD Denis A. Evans, MD Martha Clare Morris, ScD

ABSTRACT

Background: In some prospective studies, associations of serum vitamin B12 and homocysteine concentrations with cognitive decline have been reported but few have examined the role of methylmalonic acid, a more specific marker of vitamin B12 deficiency than homocysteine.

Objective: The aim of the study was to determine whether serum concentrations of vitamin B12 or selected metabolites are related to cognitive decline. Methods: A total of 516 subjects were selected in a stratified random sampling design from

Address correspondence to Dr. Christine C. Tangney, Department of Clinical Nutrition 425 TOB, 1700 West Van Buren St., Chicago, IL 60612 [email protected]

among Chicago Health and Aging Project participants for clinical evaluation. We used linear mixed models to examine the association of blood markers of vitamin B12 status to change in cognitive scores over 6 years. Cognitive function was assessed every 3 years and measured as the sum of standardized scores on four tests.

Results: Probable vitamin B12 deficiency was observed in 14.2% of the sample. Elevated serum concentrations of homocysteine were present in 19.2% of subjects, and of methylmalonic acid, in 36.4%. Higher serum methylmalonic acid concentrations were predictive of faster rates of cognitive decline (␤ ⫽ ⫺0.00016, SE ⫽ 0.0001, p ⫽ 0.004) and higher serum vitamin B12 concentrations were associated with slower rates of cognitive decline (␤ ⫽ ⫹0.00013, SE ⬍ 0.0001, p ⫽ 0.005) in multivariable adjusted mixed models. Serum concentrations of homocysteine had no relationship to cognitive decline. Conclusions: Serum methylmalonic acid and vitamin B12 concentrations may be the more important risk factors for cognitive decline when compared to serum homocysteine concentrations, particularly in older populations exposed to food fortification and possible supplements containing folic acid. Neurology® 2009;72:361–367 GLOSSARY CHAP ⫽ Chicago Health and Aging Project; CI ⫽ confidence interval; FFQ ⫽ food frequency questionnaire; NHANES ⫽ National Health and Nutrition Examination Survey; OR ⫽ odds ratio.

Since the mandatory folic acid fortification of all grain products in the United States, the number of persons with elevated serum folate concentrations (⬎45.3 nmol/L) increased from approximately 7% prior to fortification to 38% postfortification.1 The significance of elevated folate concentrations is not clearly understood, but concern about adverse effects of high folic acid intake on neurologic function in people with undiagnosed vitamin B12 deficiency has delayed mandatory fortification in the United Kingdom.2 In a sample of older subjects from the 1999 –2002 National Health and Nutrition Examination Survey (NHANES),3 those with low vitamin B12 status and elevated serum folate concentrations (⬎59 nmol/L) were more likely to manifest impaired cognitive performance than those with low vitamin B12 status but normal serum folate concentrations (ⱕ59 nmol/L). Supplemental data at www.neurology.org From the Department of Clinical Nutrition (C.C.T.), Rush Institute for Healthy Aging (Y.T., D.A.E., M.C.M.), Department of Internal Medicine (M.C.M.), Department of Preventive Medicine (D.A.E., M.C.M.), Rush Alzheimer’s Disease Center (D.A.E.), Rush University Medical Center, Chicago, IL. Y.T. is currently affiliated with the Program for Appropriate Technology in Health (PATH), Seattle, WA. Supported by grants (AG11101 and AG13170) from the National Institute on Aging. Disclosure: The authors report no disclosures. Copyright © 2009 by AAN Enterprises, Inc.

361

Previously, in the Chicago Health and Aging Project (CHAP), we reported greater cognitive decline in persons with folate intakes exceeding 400 ␮g per day compared to those with lower intakes.4 Biochemical markers for vitamin status were not measured. While the relationship of elevated homocysteine concentrations on cognitive changes has been examined,5-7 there is limited information on other vitamin markers such as serum methylmalonic acid. Thus, in an effort to further understand the complex relationships between vitamin B12 and folate and age-related cognitive decline, we examined whether biochemical indicators of vitamin B12 (serum vitamin B12, methylmalonic acid, homocysteine) and folate (serum homocysteine) insufficiency were associated with cognitive decline. METHODS Study population. Study subjects were participants in CHAP, an ongoing cohort study of older residents on the south side of Chicago. Exactly 6,158 participated in in-home interviews that included four cognitive tests (79% participation overall; 81% among black subjects, 75% among white subjects). Follow-up interviews including cognitive assessments were conducted in 3-year cycles on all participants (figure). Stratified random samples from the study population were drawn at each

Figure

Timeline and protocol of selected samples from Chicago Health and Aging Project subjects at cycle 2, cycle 3, and cycle 4

cycle for clinical neurologic evaluations during which phlebotomies were performed.8 For the present study, biochemical analyses were performed on nonfasting bloods drawn from clinically evaluated participants at cycle 2 (1996 –1999), and related to cognitive changes from cycle 2 to cycle 4. As shown in the figure, of the 842 participants clinically evaluated at cycle 2, 516 had cognitive assessments at cycle 3 or at cycle 4 or both. Serum vitamin B12 was measured immediately following the participant’s clinical evaluation because this measurement was part of a routine diagnostic panel. All other vitamin B12 metabolites were analyzed from additional aliquots of blood that had been frozen for a period of 7–10 years. By chance, 174 of these were also selected for the cycle 3 clinical evaluation sample. Cycle 3 blood samples were analyzed for vitamin B12 metabolites to examine the change in metabolite concentrations in relation to changes in cognitive function. This study was approved by the Institutional Review Board of Rush University Medical Center; all participants gave written informed consent.

Biochemical analyses. Bloods were drawn into red top Vacutainers, placed on ice, and centrifuged within 2 hours of phlebotomy. Sera was partitioned into aliquots and frozen at ⫺80ºC. Aliquots were sent to the Metabolite Labs at the University of Colorado Health Sciences Center (Denver, CO) for analysis of homocysteine, methylmalonic acid, 2-methylcitric acid, and cystathionine. These metabolites were assayed as described previously by stable-isotope dilution and capillary gas chromatography-mass spectrometry.9-11 Intra-assay and interassay CVs for these metabolites averaged 2% and 5%, respectively (private communication, Dr. Sally Stabler). Serum creatinine measurements were performed by Rush University Medical Laboratories. Because homocysteine and methylmalonic acid are elevated when there is renal failure,9 adjustment for creatinine was included in all models to account for possible confounding. Vitamin B12 determinations were performed by automated competitive displacement immunoassay (Quest Laboratories, Wooddale, IL).

Cognitive function assessment. The population interviews included administration of four cognitive tests during in-home interviews at each cycle. Tests included the East Boston tests of immediate and delayed recall,12 the Mini-Mental State Examination,13 and the Symbol Digit Modalities Test.14 Scores on each were expressed as z-scores and averaged for a global measure of cognitive function that was approximately normally distributed, and reduced the floor and ceiling effects and other measurement errors of the individual tests.

At cycle 2, a random sample is obtained for clinical evaluations at which time bloods were drawn. Of the 666 cycle 2 participants with frozen sera and cognitive assessments, there were 516 subjects at cycle 2 for whom bloods were available as well as additional cognitive testing at cycles 3 or cycle 4 or both cycles. There were also 174 subjects with bloods that were available at both cycle 2 and cycle 3 or 174 pairs. 362

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Other covariates. Gender and race were obtained at the time of the census and verified at the baseline population interview. Race was determined by questions and categories of the 1990 US census. Information on non-dietary variables was collected at participants’ baseline interview. Age was computed from selfreported birth date and date of baseline cognitive assessment. Education was computed from self-reported highest grade or years of formal education. A composite score reflecting the mean frequency of participation in seven cognitive activities was also constructed as described previously.15 Questions on cigarette smoking allowed for the computation of an indicator variable (never, former, or current smoker). Daily consumption of alcohol (grams per day) was based on three questions about usual consumption during the past year of beer, wine, and liquor. Dietary intakes of vitamin B12, folate, and other components were measured by a modified Willett food frequency questionnaire (FFQ).16 All dietary variables were energy-adjusted using the re-

Table 1

Characteristics (unadjusted) of the total sample of Chicago Health and Aging Project subjects, 1997–2000, in contrast to the analyzed sample

Characteristics

Total sample, n ⴝ 842

Analyzed sample, n ⴝ 516

Proportion female

58.0

59.9

80 ⫾ 6 [69, 98]

Age, y* Proportion black

44.5 12.8 ⫾ 3.5

Education (y)†

80 ⫾ 6 [69, 98] 45.3 12.8 ⫾ 3.5

Proportion with education of 12ⴙ y

72.9

72.7

Proportion currently smoking

10.0

10.3

Proportion with elevated serum creatinine concentrations‡

15.0

14.5

Proportion with anemia§

24.1

23.3

Global cognitive score†

0.13 ⫾ 0.64 [0.20]

0.18 ⫾ 0.65 [0.24]

Mini-Mental State Examination score†

26.5 ⫾ 3.6 [27]

26.7 ⫾ 3.7 [28]

3.1 ⫾ 0.6 [3.1]

3.1 ⫾ 0.7 [3.1]

Cognitive Activity Index† Reported supplement user (%) Folate

34.8

33.0

Vitamin B12

36.5

34.7

Multivitamins

37.1

36.3

462.1 ⫾ 177.4 [428.5]

456.0 ⫾ 171.6 [428.5]

Serum measures (mean ⴞ SD) [median]¶ Vitamin B12 (pg/mL)† Homocysteine (␮mol/L)† Methylmalonic acid (nmol/L)†

11.8 ⫾ 4.8 [10.6] 294.5 ⫾ 186.9 [244.5]

11.5 ⫾ 4.8 [10.5] 279.2 ⫾ 173.4 [237.5]

Cystathionine (nmol/L)†

316.2 ⫾ 318.9 [247.0]

299.1 ⫾ 327.8 [240.0]

2-Methylcitric acid (nmol/L)†

220.3 ⫾ 108.9 [199.0]

209.9 ⫾ 92.6 [194.5]

*Values reflect means ⫾ SD (minimum, maximum). †Values reflect means ⫾ SD [medians]. ‡Elevated creatinine concentrations were defined as ⱖ133 ␮mol/L for men and ⱖ115 ␮mol/L for women. § Anemia defined by hemoglobin less than 13 g/dL for men and less than 12 g/dL women. ¶ For incident sample, bloods for 666 subjects were available for analyses out of the 842 possible subjects.

gression residual method.17 FFQs were obtained on all subjects at cycle 2—a median of 7 months before bloods were drawn.

Statistical analyses. Possible sample bias between the incident sample drawn (n ⫽ 842) and the sample with available bloods and repeated cognitive testing over the 6-year period (n ⫽ 516) was examined by comparing characteristics of participants of both samples using ␹2 and Wilcoxon rank sum test as appropriate. Similar difference tests were also conducted between those identified as probably deficient and those adequate with respect to vitamin B12. Pearson correlation tests were used to examine associations between biochemical markers of vitamin B12 status, age, and nutrient intake. Our primary analyses were designed to estimate the effect of biochemical markers for vitamin B12 and folate on withinperson rate of change in cognitive score using mixed-effects models.18 The adjusted model for change included terms for age (years), sex, race, education (years), participation in cognitive activities and serum creatinine concentrations, and the interaction between time and each covariate (basic model). Additional adjustment for dietary and lifestyle factors included energyadjusted intakes of saturated fat, trans unsaturated fat, food vita-

min E, total vitamin C, food niacin and fish intakes, smoking status, and alcohol use (multiple-adjusted model). The selection of dietary covariates is based on previous CHAP studies.19-21 The interaction terms with time represent the effects of the variables on the rate of change in cognitive score. Because a large portion of the sample was not included in the analyses, models were not weighted for the stratified random sampling design. Secondary analyses were performed on 174 sample participants who had biochemical measurements at both cycle 2 and cycle 3. We used a linear regression model in which global cognitive score at cycle 3 was regressed on a dichotomous variable for homocysteine increase, baseline global cognitive scores, and the basic model variables. RESULTS There were no significant differences in demographic, biochemical, and lifestyle characteristics between the full and analyzed samples (table 1). The analyzed sample comprised nearly 60% women, 45% black, with an average age of 80 years. Renal impairment was evident for 14% of incident sample participants as indicated by elevated serum creatinine concentrations. Exactly 19.2% of the analyzed sample had elevated homocysteine values (⬎13.9 ␮mol/L) and 36.4% had elevated methylmalonic acid concentrations (⬎271 nmol/L). Only 1% of participants met the criteria for definite vitamin B12 deficiency (serum vitamin B12 ⬍148 pmol/L, methylmalonic acid concentrations ⬎271 nmol/L, and methylmalonic acid ⬎ 2-methylcitric acid).9-11 Probable vitamin B12 deficiency was observed for 14.2% of the sample (table 2, table e-1 on the Neurology® Web site at www. neurology.org). Those probably deficient were more likely white (p ⫽ 0.002), and consumed lower amounts of total vitamin C, total folate, total vitamin B12 as well as less fish per week. Global cognitive scores did not differ between the groups, but serum concentrations of homocysteine (p ⬍ 0.0001) and methylmalonic acid (p ⬍ 0.0001) were higher among the probably deficient group. Serum vitamin B12 was correlated with serum homocysteine (r ⫽ ⫺0.33, p ⬍ 0.0001) and methylmalonic acid (r ⫽ ⫺0.23, p ⬍ 0.0001), but not with age (r ⫽ 0.001, p ⫽ 0.97). Serum methylmalonic acid and homocysteine concentrations were correlated with age (r ⫽ 0.27, p ⬍ 0.0001, and r ⫽ 0.09, p ⫽ 0.042, respectively). Serum homocysteine concentrations were associated with energy-adjusted intakes of total vitamin B12 (r ⫽ ⫺0.12, p ⬍ 0.01) and of total folate (r ⫽ ⫺0.13, p ⬍ 0.01). Serum vitamin B12 values were correlated with total intakes of vitamin B12 and of folate (both r ⫽ 0.17, p ⬍ 0.0001). In the mixed effects models to examine the associations of each biochemical marker with cognition separately, only serum methylmalonic acid was associated with global cognitive scores cross-sectionally in basic (␤ ⫽ ⫺0.00033, SE ⫽ 0.0002, p ⫽ 0.03) Neurology 72

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Table 2

Characteristics (unadjusted) of the sample of 516 Chicago Health and Aging Project subjects at baseline or cycle 2, 1997–2000, by vitamin B12 status Vitamin B12 status

Characteristics of participants

Probable deficiency (n ⴝ 73)*

Adequate (n ⴝ 443)

Proportion female

65.7

58.7

82 ⫾ 6 [70, 98]

Age (y)† Proportion black†

28.8 13.3 ⫾ 3.7

Education (y)‡ Proportion with elevated serum creatinine§

79 ⫾ 6 [69, 96] 48.1

17.8

12.8 ⫾ 3.5 13.2

Proportion currently smoking

12.3

10.0

Proportion with anemia¶

17.8

23.8

0.18 ⫾ 0.69 [0.28]

Global cognitive score‡

0.18 ⫾ 0.65 [0.23]

Reported supplement user (%) Folate

25.0

34.5

Vitamin B12

27.4

36.1

Multivitamins

28.8

37.8

264.6 ⫾ 44.9 [275.0]

487.7 ⫾ 164.1 [457.0]

Serum measures* Vitamin B12 (pg/mL) ‡
Homocysteine (␮mol/L)‡


15.1 ⫾ 5.6 [13.6]

10.9 ⫾ 4.4 [10.2]

Methylmalonic acid (nmol/L)‡


488.7 ⫾ 290.0 [385.0]

244.4 ⫾ 113.6 [224.0]

Cystathionine (nmol/L)‡

299.3 ⫾ 131.5 [262.0]

299.6 ⫾ 350.5 [231.0]

2-Methylcitric acid (nmol/L)‡


239.3 ⫾ 92.6 [212.0]

205.0 ⫾ 92.0 [189.0]

*Probable vitamin deficiency was defined as serum vitamin B12 concentrations ⬍258 pmol/L, methylmalonic acid concentrations ⬎271 nmol/L, and methylmalonic acid ⬎ 2-methylcitric acid. †Values reflect means ⫾ SD (minimum, maximum). ‡Values reflect means ⫾ SD [medians]. § Elevated creatinine concentrations were defined as ⱖ133 ␮mol/L for men and ⱖ115 ␮mol/L for women. ¶ Anemia defined by hemoglobin less than 13 g/dL for men and for women, less than 12 g/dL.
Values are significantly different (p ⬍ 0.01) from one another based on either chi-square test for categorical variables or Wilcoxon rank sum for other cases.

and multiple adjusted models (␤ ⫽ ⫺0.00036, SE ⫽ 0.0001, p ⫽ 0.01) (table 3). Over the 6-year interval, higher concentrations of serum vitamin B12 were associated with slower rates of decline (␤ ⫽ ⫹0.00011, SE ⬍ 0.0001, p ⫽ 0.01), and higher concentrations of methylmalonic acid were associated with faster rates of cognitive decline (␤ ⫽ ⫺0.00017, SE ⫽ 0.0001, p ⫽ 0.002) in basic models. Estimates of effect did not change materially with further adjustment for smoking, alcohol use, or intakes of fats, fish, and vitamins E and C and niacin. Circulating concentrations of homocysteine, 2-methylcitric acid, or cystathionine were not predictive of cognitive change in basic or multiple adjusted models. When all three biomarkers were incorporated in the models simultaneously, serum methylmalonic acid remained predictive of cognitive decline for the basic model (␤ ⫽ ⫺0.000149, SE ⫽ 0.0001, p ⫽ 0.01) and for the 364

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fully adjusted model (␤ ⫽ ⫺0.000136, SE ⫽ 0.0001, p ⫽ 0.03). Serum vitamin B12 was not significantly associated with cognitive change in the basic model (␤ ⫽ ⫹0.000078, SE ⬍ 0.0001, p ⫽ 0.12), but with adjustment for additional confounding factors, the effect estimate increased substantially and attained statistical significance (␤ ⫽ ⫹0.000103, SE ⫽ 0.0001, p ⫽ 0.04). In further analyses of methylmalonic acid and cognitive decline, we observed effect modification by sex (␤ ⫽ ⫺0.000259, SE ⫽ 0.0001, p ⫽ 0.01), but not by age (␤ ⫽ ⫺0.000012, SE ⬍ 0.0001, p ⫽ 0.14) or race (␤ ⫽ ⫹0.000061, SE ⫽ 0.0001, p ⫽ 0.61). When stratified by sex, the inverse estimate of the relation between methylmalonic acid concentrations and cognitive decline was of stronger magnitude among CHAP men (␤ ⫽ ⫺0.00030, SE ⫽ 0.0001, p ⫽ 0.0002) as compared with CHAP women (␤ ⫽ ⫺0.00006, SE ⫽ 0.0001, p ⫽ 0.39). There were no remarkable differences in the distributions of methylmalonic acid concentrations of men in contrast to those for women. We explored the possibility that cognitive decline may result from increases in serum homocysteine concentrations as previously reported5,6 through an examination of the repeat biochemical markers in 174 sample participants. Nearly three quarters (70.5%) of subjects experienced an increase in serum homocysteine concentrations from cycle 2 to cycle 3; all increases exceeded 3 ␮mol/L. However, there was no association between the indicator variable for increased serum homocysteine concentration from cycle 2 to cycle 3 and cycle 3 cognitive score (␤ ⫽ ⫺0.08, SE ⫽ 0.08, p ⫽ 0.36) in the basic model. DISCUSSION In this biracial study of older adults, higher serum concentrations of vitamin B12 were associated with a slower rate of cognitive decline and higher concentrations of methylmalonic acid were associated with a faster rate over a 6-year interval (table 3). Serum homocysteine concentrations were not significantly related to cognitive change. Inadequate vitamin B12 nutriture in the elderly may occur with conditions (e.g., atrophic gastritis) or drugs that reduce absorption (e.g., metformin).22 Thus, while few CHAP participants reported inadequate intakes of vitamin B12, 14.2% showed evidence of metabolic or preclinical deficiency. There is no widely accepted cutoff for marginal or preclinical vitamin B12 deficiency.23,24 Use of several blood indicators in addition to vitamin B12 may improve differential diagnosis.7,9 Methylmalonic acid concentration reflects intracellular vitamin stores and exhibits higher specificity for low vitamin B12 status than any other metabolite including homocysteine.9 However,

Table 3

Estimated effects (␤ coefficients) of serum vitamin B12 indicators on global cognitive scores at baseline (cross-sectional) and on rate of change in global cognitive scores over 6 years based on adjusted mixed models among 516 sample participants of the Chicago Health and Aging Project*† Cross-sectional associations

Cognitive change

All (n ⴝ 516), basic model,‡ ␤ (SE); p value

All (n ⴝ 498), multiple adjusted,§ ␤ (SE); p value

All (n ⴝ 516), basic model,‡ ␤ (SE); p value

All (n ⴝ 498), multiple adjusted,§ ␤ (SE); p value

Vitamin B12 (pg/mL)

⫹0.00016 (0.0001); 0.26

⫹0.00009 (0.0001); 0.49

⫹0.00011 (0.00001); 0.01

⫹0.00013 (⬍0.0001); 0.005

Homocysteine (␮mol/L)

⫺0.011 (0.0065); 0.09

⫺0.010 (0.0063); 0.12

⫺0.00125 (0.0036); 0.73

⫺0.00188 (0.0036); 0.60

Methylmalonic acid (nmol/L )

⫺0.00033 (0.0002); 0.03

⫺0.00036 (0.0001); 0.01

⫺0.00017 (0.0001); 0.002

⫺0.00016 (0.0001); 0.004

2-Methylcitric acid (nmol/L)

⫹0.00008 (0.0004); 0.83

⫺0.00020 (0.0004); 0.60

⫺0.000017 (0.0001); 0.90

⫺0.000021 (0.0001); 0.88

Cystathionine (nmol/L)

⫺0.00010 (0.0001); 0.38

⫺0.00011 (0.0001); 0.32

⫹0.000019 (⬍0.0001); 0.65

⫹0.000004 (⬍0.0001); 0.93

Serum indicators

*Values arepresented as ␤ or regression coefficient (standard error of the mean) and the p value with each marker added separately. Values reflect the rates of cognitive change after basic model or multiple model adjustment using linear mixed models. †Significant modification of the association of methylmalonic acid concentrations with cognitive change by sex was observed (␤ ⫽ ⫺0.000259, SE ⫽ 0.0001, p ⫽ 0.01). ‡Basic model includes age, sex, race, education, frequency of cognitive activities, and serum creatinine concentrations. § Multiple adjusted model includes the basic model components and smoking, alcohol use, calorie adjusted intakes of saturated fat (g/day), trans unsaturated fat intake (g/day), vitamin E in food (mg/day), niacin in food (mg/day), total vitamin C (mg/day), and fish intake (times/week).

this indicator adds considerable cost when compared to the screening measure, serum vitamin B12. Serum vitamin B12 concentrations have not been consistently associated with cognitive change in prospective analyses.25-29 Few groups examined cognition in relation to measures that reflect preclinical or metabolic vitamin B12 deficiency. In a cross-sectional UK survey of 1,000 individuals aged 75 years or older, cognitive impairment (defined as a MiniMental State Examination score ⬍22) was more strongly associated with holotranscobalamin, a tissue transport protein for vitamin B12, homocysteine, and methylmalonic acid than with serum vitamin B12.30 In a recent prospective UK study of elders in whom three or more cognitive assessments were obtained, both methylmalonic acid and holotranscobalamin concentrations were predictive of cognitive decline.7 In these studies, serum vitamin B12 concentrations were lower (mean ⫾ SD, 274 ⫾ 139 pmol/L [370 ⫾ 188 pg/mL, 2003 sample]) than those observed in either the present CHAP incident sample (n ⫽ 842) or subsample (n ⫽ 516) (table 1). Serum methylmalonic acid (390 ⫾ 390 nmol/L) and homocysteine (16.5 ⫾ 6.2 ␮mol/L) concentrations in the United Kingdom were also higher than those observed for our CHAP subjects. In a representative postfortification US sample of older adults, homocysteine levels ranged from 8 to 10.7 ␮mol/L31; in two prospective studies of older adults,28,33 values were similar to those reported in the present study, which spans a pre- to perifortification period. An interaction between serum concentrations of vitamin B12 and folate on cognitive score was observed in a large cross-sectional survey of 1,302

NHANES 1999 –2002 participants aged 60 years or more.3 Those with low vitamin B12 status and high serum folate concentrations (⬎59 nmol/L) were at greater risk of cognitive impairment (odds ratio [OR] ⫽ 2.6, 95% confidence interval [CI] 1.1– 6.1) when compared to those with low vitamin B12 status and normal serum folate concentrations. In contrast, among those seniors with normal vitamin B12 status, high serum folate concentrations were associated with less cognitive impairment (OR ⫽ 0.4, 95% CI 0.2– 0.9) when compared to those with normal serum folate concentrations. These findings partially support an earlier CHAP report in which a faster rate of cognitive decline was observed among participants with high folate intakes (⬎400 ␮g/day) from either supplements or food.4 In a multiple adjusted model that included folate intakes, we observed a positive interaction (p ⫽ 0.009) between total vitamin B12 intakes with older age on cognitive decline in CHAP.4 Rates of cognitive decline for the average 80-year-old who consumed 20 ␮g per day of vitamin B12 were 25% slower than rates of a similar 80-yearold who consumed the recommended daily allowance of 2.4 ␮g. For the average 70-year-old, rates of decline did not vary with such widely different vitamin B12 intakes.4 In the present study, although we measured several serum markers of vitamin B12 status, we did not determine serum folate concentrations. Thus, the interaction of serum folate concentrations with biochemical indicators of vitamin B12 deficiency on cognitive function/decline could not be investigated. In the present study, serum homocysteine concentrations were not associated with cognitive perforNeurology 72

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mance or with cognitive decline. Nor did CHAP participants with increases in serum homocysteine concentrations over a 3-year period manifest significant cognitive decline. An association may not have been observed because subjects may have had adequate folate status but confirmation by measurements of serum or erythrocyte folate concentrations is needed. Serum homocysteine concentrations were not predictive of cognitive decline among the Leiden 85-Plus study participants26 nor the 70- to 79-yearold MacArthur Studies of Successful Aging participants.28 Elevated homocysteine concentrations were associated with declines among Framingham study participants but at a time prior to mandatory folic fortification,6 in select cognitive domains of French older persons33 and among aging male veterans.29 Among Mexican American seniors from 1997 to 1999, homocysteine concentrations were associated with greater risk of dementia and cognitive impairment, but this was modified by serum vitamin B12 concentrations; rates of decline were greater for those with lower vitamin B12 concentrations (⬍340 pg/ mL) (HR ⫽ 1.61, p for interaction ⫽ 0.04) as compared to those with higher concentrations (⬎340 pg/mL but ⱕ498 pg/mL).32 Clinical trial evidence supportive of a role for homocysteine and cognitive decline is still equivocal. Most trials were performed where folate fortification has not been mandated, and in subjects with adequate serum vitamin B12 concentrations.34-36 In many, the intervention was a combination of B vitamins. In the longest trial (3 years), a large sample and a single vitamin intervention (800 ␮g folic acid daily), folate supplements significantly improved memory, information processing speed, and sensorimotor speed among Dutch adults.34 Although some cross-sectional evidence exists for a methylmalonic acid and cognition association,30,37-40 to our knowledge, there is limited study of its relation to cognitive decline. In the Oxford Healthy Aging Project, greater cognitive decline (over 10 years) was associated with lower holotranscobalamin and higher methylmalonic acid concentrations after adjustment for a number of vitamin markers.7 In our study, we observed a similar relationship— cognitive decline remained significantly associated with serum concentrations of methylmalonic and vitamin B12 after adjustment for vitamin markers. Thus, there is evidence for subtle vitamin B12 deficiency in two large prospective cohorts of elders in whom deleterious changes in cognition were related to sensitive markers for vitamin B12 inadequacy. Strengths of the present study include the prospective design, a biracial community sample, and use of a number of biochemical indicators of B vitamin status and of multiple tests to measure cognitive 366

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function. Moreover, the present analyses were adjusted for many dietary and lifestyle confounders. As stated previously, a limitation of the present study is the lack of serum folate determinations. Because of the observational study design, we must caution against a causal interpretation of findings. Further study of these complex interrelationships between vitamin B12, folate, and cognitive changes is warranted, but multiple biochemical indices of folate and vitamin B12 should be determined. Greater attention must be paid to plausibility of subtle vitamin B12 deficiency among our senior citizens, especially when higher folate intakes are possible. ACKNOWLEDGMENT The authors thank Drs. Robert Allen and Sally Stabler for their expertise and vitamin B12 metabolite determinations. They also thank Cheryl Bibbs for study coordination and Todd Beck for programming and the CHAP interviewers and participants.

Received July 11, 2008. Accepted in final form October 15, 2008.

REFERENCES 1. Pfeiffer CM, Caudill SP, Gunter EW, Osterloh J, Sampson EJ. Biochemical indicators of B vitamin status in the US population after folic acid fortification: results from the National Health and Nutrition Examination Survey 19992000. Am J Clin Nutr 2005;82:442–450. 2. Department of Health. London: Scientific Advisory Committee on Nutrition; 2006. 3. Morris MS, Jacques PF, Rosenberg IH, Selhub J. Folate and vitamin B-12 status in relation to anemia, macrocytosis, and cognitive impairment in older Americans in the age of folic acid fortification. Am J Clin Nutr 2007;85: 193–200. 4. Morris MC, Evans DA, Bienias JL, et al. Dietary folate and vitamin B12 intake and cognitive decline among community-dwelling older persons. Arch Neurol 2005;62: 641–645. 5. Ravaglia G, Forti P, Maioli F, et al. Homocysteine and folate as risk factors for dementia and Alzheimer disease. Am J Clin Nutr 2005;82:636–643. 6. Seshadri S, Beiser A, Selhub J, et al. Plasma homocysteine as a risk factor for dementia and Alzheimer’s disease. N Engl J Med 2002;346:476–483. 7. Clarke R, Birks J, Nexo E, et al. Low vitamin B-12 status and risk of cognitive decline in older adults. Am J Clin Nutr 2007;86:1384–1391. 8. Bienias JL, Beckett LA, Bennett DA, Wilson RS, Evans DA. Design of the Chicago Health and Aging Project (CHAP). J Alzheimer Dis 2003;5:349–355. 9. Allen RH, Stabler SP, Savage DG, Lindenbaum J. Metabolic abnormalities in cobalamin (vitamin B12) and folate deficiency. FASEB J 1993;7:1344–1353. 10. Allen RH, Stabler SP, Savage DG, Lindenbaum J. Elevation of 2-methylcitric acid I and II levels in serum, urine, and cerebrospinal fluid of patients with cobalamin deficiency. Metabolism 1993;42:978–988. 11. Stabler SP, Lindenbaum J, Savage DG, Allen RH. Elevation of serum cystathionine levels in patients with cobalamin and folate deficiency. Blood 1993;81:3404–3413.

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Albert MS, Smith LA, Scherr PA. Use of brief cognitive tests to identify individuals in the community with clinically-diagnosed Alzheimer’s disease. Intl J Neurosci 1991;57:167–178. Folstein MF, Folstein SE, McHugh PR. “Mini-mental state.” A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975;12:189– 198. Smith A. Symbol Digit Modalities Test Manual—Revised. Los Angeles, CA: Western Psychological;1984. Wilson RS, Bennett DA, Beckett LA, et al. Cognitive activity in older persons from a geographically defined population. J Gerontol B Psychol Sci Soc Sci 1999;54: P155–P160. Morris MC, Colditz GA, Evans DA. Response to a mail nutritional survey in an older bi-racial community population. Ann Epidemiol 1998;8:342–346. Willett WC. Total energy intake and nutrient composition: dietary recommendations for epidemiologists. Int J Cancer 1990;46:770–771. Laird NM, Ware JH. Random effects models for longitudinal data. Biometrics 1982;38:963–974. Morris MC, Evans DA, Tangney CC, Bienias JL, Wilson RS. Fish consumption and cognitive decline with age in a large community study. Arch Neurol 2005;62: 1849–1853. Morris MC, Evans DA, Bienias JL, et al. Dietary niacin and the risk of incident Alzheimer’s disease and of cognitive decline. J Neurol Neurosurg Psychiatry 2004;75:1093– 1099. Morris MC, Evans DA, Bienias JL, Tangney CC, Wilson RS. Dietary fat intake and 6-year cognitive change in an older biracial community population. Neurology 2004;62: 1573–1579. Nilsson-Ehle H. Age-related changes in cobalamin (vitamin B12) handling: implications for therapy. Drugs Aging 1998;12:277–292. Stabler S, Lindenbaum J, Allen R. Vitamin B-12 deficiency in the elderly: current dilemmas. Am J Clin Nutr 1997;66:741–749. Saperstein DS, Wolfe GI, Gronseth GS, et al. Challenges in the identification of cobalamin-deficiency polyneuropathy. Arch Neurol 2003;60:1296–1301. Martin DC, Francis J, Protetch J, Huff FJ. Time dependency of cognitive recovery with cobalamin replacement: report of a pilot study. J Am Geriatr Soc 1992;40:168– 172. Mooijaart SP, Gussekloo J, Frolich M, et al. Homocysteine, vitamin B-12, and folic acid and the risk of cognitive decline in old age: the Leiden 85-Plus study. Am J Clin Nutr 2005;82:866–871. Kang JH, Irizarry MC, Grodstein F. Prospective study of plasma folate, vitamin B12, and cognitive function and decline. Epidemiology 2006;17:650–657.

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Kado DM, Karlamangla AS, Huang MH, et al. Homocysteine versus the vitamins folate, B6, and B12 as predictors of cognitive function and decline in older highfunctioning adults: MacArthur Studies of Successful Aging. Am J Med 2005;118:161–167. 29. Tucker KL, Qiao N, Scott T, Rosenberg I, Spiro A, 3rd. High homocysteine and low B vitamins predict cognitive decline in aging men: the Veterans Affairs Normative Aging Study. Am J Clin Nutr 2005;82:627–635. 30. Hin H, Clarke R, Sherliker P, et al. Clinical relevance of low serum vitamin B12 concentrations in older people: the Banbury B12 study. Age Ageing 2006;35:416–422. 31. Pfeiffer CM, Osterloh JD, Kennedy-Stephenson J, et al. Trends in circulation concentrations of total homocysteine among US adolescents and adults: findings from the 1991–1994 and 1999 –2004 National Health and Nutrition Examination Surveys. Clin Chem 2008;54:1–12. 32. Haan MN, Miller JW, Aiello AE, et al. Homocysteine, B vitamins, and the incidence of dementia and cognitive impairment: results from the Sacramento Area Latino Study on Aging. Am J Clin Nutr 2007;85:511–517. 33. Dufouil C, Alperovitch A, Ducros V, Tzourio C. Homocysteine, white matter hyperintensities, and cognition in healthy elderly people. Ann Neurol 2003;53:214–221. 34. Durga J, van Boxtel MP, Schouten EG, et al. Effect of 3-year folic acid supplementation on cognitive function in older adults in the FACIT trial: a randomised, double blind, controlled trial. Lancet 2007;369:208–216. 35. Stott DJ, MacIntosh G, Lowe GD, et al. Randomized controlled trial of homocysteine lowering vitamin treatment in elderly patients with vascular disease. Am J Clin Nutr 2005;82:1320–1326. 36. McMahon JA, Green TJ, Skeaff CM, Knight RG, Mann JI, Williams SM. A controlled trial of homocysteine lowering and cognitive performance. N Engl J Med 2006;354: 2764–2772. 37. Lewerin C, Matousek M, Steen G, Johanssen B, Steen B, Nilsson-Ehle H. Significant correlations of plasma homocysteine and serum methylmalonic acid with movement. Am J Clin Nutr 2005;81:155–162. 38. McCracken C, Hudson P, Ellis R, McCaddon A. Medical Research Council Cognitive Function and Ageing Study: methylmalonic acid and cognitive function in the Medical Research Council Cognitive Function and Ageing Study. Am J Clin Nutr 2006;84:1406–1411. 39. Lewis MS, Miller LS, Johnson MA, Dolce EB, Allen RH, Stabler SP. Elevated methylmalonic acid is related to cognitive impairment in older adults enrolled in an elderly nutrition program. J Nutr Elderly 2005;24:47–65. 40. Garcia AA, Haron Y, Evans LR, Smith MG, Freedman M, Roman GC. Metabolic markers of cobalamin deficiency and cognitive function in normal older adults. J Am Geriatr Soc 2004;52:66–71.

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VIEWS & REVIEWS

Vascular risk factors and dementia How to move forward?

Anand Viswanathan, MD, PhD Walter A. Rocca, MD, MPH Christophe Tzourio, MD, PhD

Address correspondence and reprint requests to Dr. Christophe Tzourio, INSERM, Unit 708, Hoˆpital de la Salpeˆtrie`re, 47, boulevard de l’Hopital, 75651 Paris Cedex 13, France [email protected] or Dr. Anand Viswanathan, Stroke Service and Memory Disorders Unit, Neurology Clinical Trial Unit, 175 Cambridge Street, Suite 300, Boston, MA 02114 [email protected]

ABSTRACT

In recent years, accumulating evidence has suggested that vascular risk factors contribute to Alzheimer disease (AD). Vascular dementia had been traditionally considered secondary to stroke and vascular disease. It has been traditionally distinguished from AD, considered to be a purely neurodegenerative form of dementia. However, in light of this more recent literature, it appears that there is a spectrum: ranging from patients with pure vascular dementia to patients with pure AD and including a large majority of patients with contributions from both Alzheimer and vascular pathologies. In this article, we discuss the impact of vascular risk factors on AD and its consequences at the individual level and at the population level by highlighting the concept of attributable risk. We then discuss the key questions and next steps involved in designing a therapeutic trial to control vascular risk factors for the prevention of dementia. Neurology® 2009;72:368–374 GLOSSARY AD ⫽ Alzheimer disease; VaD ⫽ vascular dementia; WMH ⫽ white matter hyperintensities.

Over the past 10 years, a growing body of literature, including several large population-based clinicopathologic or clinicoradiologic studies, has highlighted the important contribution of vascular risk factors (hypertension and diabetes as primary examples) in Alzheimer disease (AD).1-4 In the Rotterdam study, one of the first large studies that called attention to this issue, dementia was associated with the presence of atherosclerosis and this association applied to subjects clinically diagnosed with vascular-type dementia as well as those with AD.2 An association between high blood pressure and the risk of AD was also reported in other cohort studies with a 15- to 21-year follow-up.1,3 Diabetes, a high level of cholesterol, tobacco smoking, as well as other vascular risk factors have also been associated with a higher risk of AD.5-7 Furthermore, atrial fibrillation, hypertension, and angina have been shown to be associated with a greater rate of decline in patients with AD.8 Apart from the occurrence of a clinical stroke, the mechanisms by which vascular factors increase the risk of AD or accelerate cognitive deterioration among patients with AD are not yet fully elucidated. Most of these factors have been shown to be associated with subcortical lesions seen on brain MRI: white matter hyperintensities (WMH),9-12 lacunar infarctions,13-15 or cerebral microhemorrhages.16 There is also evidence to suggest that lowering blood pressure may stop or delay the progression of WMH.17 The extent of WMH has been clearly linked both to cognitive impairment and the risk of incident dementia in several population-based studies.11,18-20 Further, small, clinically silent brain infarctions appear to be at least as strong a risk for subsequent dementia21 as larger, clinically evident strokes.22,23 It is, however, likely that these lesions do not fully explain the impact of vascular factors on the brain and that there exist other more subtle structural changes that may have consequences related to cognition and dementia. From the Department of Neurology and Clinical Trials Unit (A.V.), Massachusetts General Hospital and Harvard Medical School, Boston; Division of Epidemiology (W.A.R.), Department of Health Sciences Research and Department of Neurology, College of Medicine, Mayo Clinic, Rochester, MN; INSERM (C.T.), Unit 708 Neuroepidemiology, Paris; UPMC Univ Paris6 (C.T.); and Department of Neurology (C.T.), Hoˆpital Lariboisie`re, Paris, France. Supported by ARNEVA (Association de Recherche en Neurologie Vasculaire), Hoˆpital Lariboisie`re, Paris, France. Disclosure: The authors report no disclosures.

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Copyright © 2009 by AAN Enterprises, Inc.

Figure

Reconsidering the classification of dementia

Schematic diagram of common dementias depicts proposed alternative classification of dementia. Alzheimer disease (AD) and vascular dementia (VaD) fall on a continuous spectrum of disease, composed of a gradient of features of both AD and VaD (center panel; see text for detailed discussion). Neurodegenerative mechanisms play a greater role on the left side of the spectrum (upper panel). The impact of subcortical lesions of cerebral small-vessel disease increases to the right of the spectrum (lower panel). Note white matter hyperintensities on FLAIR sequences (left), lacunar lesions on T1-weighted sequences (arrowheads, center), and cerebral microhemorrhages on gradient-echo sequences (arrowheads, right). These silent brain lesions may, in part, mediate the risk of dementia associated with vascular risk factors.

The discovery of the association between vascular risk factors and AD does not question nor negate the presumed degenerative mechanisms thought to underlie pure AD. It can be hypothesized that vascular and degenerative mechanisms actually develop in parallel. A small burden of cerebral ischemic or hemorrhagic lesions caused by vascular factors may disclose the expression of plaques and tangles associated with AD in a patient with latent dementia. In other words, vascular brain injury could act additively or synergistically with concomitant AD pathology to produce more severe cognitive dysfunction than either process alone. This interpretation is supported by extensive clinical–pathologic data indicating that subjects with both vascular disease and AD pathology show either more severe cognitive impairment during life than those with pure AD24-26 or require less severe AD pathology to produce the same amount of cognitive impairment.27-30 Most of the vascular lesions described in these studies were lacunar infarcts or microinfarcts rather than large hemispheric infarctions, supporting the importance of small vascular lesions also

noted in population-based clinical–radiographic studies.21,31 To summarize, the important question is no longer whether vascular factors contribute to dementia, but to determine their relative weight in contribution to all types of dementia in the general population. There is strong evidence to suggest that there is a spectrum: on one end, those with relatively pure dementia of vascular type, on the other end, those with relatively pure AD, and in-between there is a contribution from both AD and vascular pathologies, most likely representing the largest group (figure).32-34 RE-EXAMINATION OF THE CLASSIFICATION OF DEMENTIAS Since the 1970s, the concept of

vascular dementia (VaD), a type of dementia secondary to stroke and vascular disease, has been distinguished from the purely neurodegenerative form of dementia (AD). Since then, many clinical, neuropsychological, radiologic, and pathologic criteria have been proposed in an attempt to distinguish these entities35-38 in order to identify a homogenous group of patients who supposedly all share a common specific underlying mechanism of dementia. Thus, in principle, mechanism-specific therapies can then be designed for this homogenous group of patients, thereby maximizing potential therapeutic benefit. Neurology 72

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Unfortunately, no classification method to date has achieved this theoretical goal. Despite continuing attempts, there is no consensus on how to separate these two entities. As a consequence, the relative frequency of VaD has been estimated in a range going from 0 to 85% of all patients with dementia.32,39 Further, medications for the symptomatic treatment of AD have also been shown to be beneficial in cases of VaD.40-44 Recent data on the role of vascular risk factors in AD discussed above provide an explanation for our failure so far to achieve this goal: if indeed there exists a spectrum of patients ranging from those with pure AD to those with pure VaD, distinguishing a subgroup of patients within this spectrum relies highly on where the threshold is set. In other words, apart from the ends of the spectrum where pure VaD or pure AD lie, the majority of patients cannot be easily classified as being in one group or the other. Because in most patients, clinical dementia is a mixture of neurodegenerative and vascular features which may be impossible to untangle, it seems urgent to reconsider our current classification scheme. The existing classification strategy imposes reductionist thinking that could be misleading for understanding the underlying mechanisms of various types of dementia, for treating individual patients, or for devising strategies of prevention at the population level (figure). IMPACT OF VASCULAR FACTORS IN DEMENTIA AT THE POPULATION LEVEL The main con-

sequence of this uncertainty concerning this reappraisal of the classification of dementias at the population level is a dramatic reevaluation of the impact of vascular risk factors on the risk of dementia. This reevaluation depends on the key difference between relative risk and population attributable risk. Elevated blood pressure or diabetes does not spectacularly increase the risk of AD in individual patients with either condition (relative risk).45 By contrast, as hypertension and diabetes are common conditions with a relatively high prevalence, this modest increase in risk translates into an elevated attributable risk at the population level. For example, based on results from the Honolulu-Asia Aging Study,46 the population attributable risk of dementia for untreated hypertension can be estimated at approximately 40%. It would therefore be higher than the estimated 20% population attributable risk of the ␧4 allele of the APOE genotype, a potent genetic risk factor for dementia with a high relative risk of about 2 to 3 for ␧3/4 genotype and 11 to 12 for ␧4/4 genotype.47,48 In other words, the impact of a risk factor can be considerable on a population if it is common, even 370

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though the increased risk of disease at the individual level is relatively low. The importance of vascular risk factors should therefore not be uniquely estimated in the context of dementias that are strongly associated with these factors (such as subcortical ischemic vascular dementia or poststroke dementia) but for the spectrum of all dementias including AD. Indeed this perspective would be reasonable from a population point of view: what is important in the broadest public health sense is not the relative proportion of one type of dementia or another, but the global clinical impact and morbidity associated with all dementias. In this context of uncertain nosologic frontiers between different types of diseases, we should aim to have an overall estimation of the role of risk factors independently of classifications. Not doing so may cause a large underestimation of the impact of shared risk factors, and may result in a missed opportunity for the prevention of the most common forms of dementia. Defining the exact role of these vascular risk factors on all dementias including AD is particularly important from the perspective of defining a robust strategy for prevention. Because the most common forms of dementia affect the old or very old, even a modest delay in the appearance or worsening of cognitive deterioration could translate into a large reduction of the incidence of disease as these subjects would die from other causes before entering an overt stage of dementia. Indeed it is estimated that among the 106 million cases of AD expected globally by the year 2050, about 23 million could be avoided completely if it was possible to delay the start of disease by 2 years starting in the year 2010.49 A DIFFERENT VISION OF THE CLASSIFICATION OF DEMENTIA FOR BETTER PATIENT CARE The concept of attributable risk and its conse-

quences should also be considered at the individual patient level. Given the considerable amount of evidence, we feel that clinicians should abandon the overly simplistic dichotomous classification of these disorders and accept the possibility of including multiple etiologies when taking care of patients with dementia. This is with the understanding that each patient lies somewhere along the spectrum of dementias mentioned above. In practice, this means that a clinician treating a patient with AD should acknowledge that the patient’s symptoms could be due in part or could be precipitated by vascular risk factors. In a similar fashion, in patients with vascular-related dementia, accompanying neurodegenerative pathology could, at least in part, explain the clinical presentation. We suggest that clinicians should take into account the respective influences of both vascular

risk factors and neurodegenerative pathologies. For example, if vascular risk factors are present in a patient with probable AD, clinicians should identify these factors to patients and caregivers and emphasize their relative contribution to the patient’s cognitive impairment. The advantages of this alternative conception are self-evident. Rather than placing patients in one diagnostic category or another, which implicitly assigns a putative and unique mechanism of disease causation, this method would permit the clinician to consider other factors which could play a role, albeit modest, in the initial manifestation or worsening of the symptoms. In the absence of an etiology-based therapy for dementia, an important therapeutic goal is to maximize the cognitive capacity of the patient and increase the period of dementia-free living. Aggressively treating vascular risk factors such as elevated blood pressure or poorly controlled diabetes could potentially avoid cognitive deterioration and its major consequences for patient autonomy, dignity, as well as caregiver and societal burden. This goal, although apparently modest, should not be underestimated. A delay of several months of the onset of more severe stages of dementia is precious for the patient and his or her loved ones. Furthermore, the individual variability on the impact of these vascular lesions is likely to be important and, in certain patients, treatment of these factors could potentially have a large effect and help to slow down or halt cognitive deterioration for several years. However, although available observational data from numerous epidemiologic studies are concordant, they do not allow one to evaluate the efficacy of treatment of vascular risk factors on the prevention of dementia. Neither do they allow one to determine which patients would potentially best respond to such treatments. In order to initiate preventive strategies for dementia, physicians must rely on the results from randomized trials. TOWARD THE DESIGN OF A DEMENTIA PREVENTION STUDY It has not yet been convincingly

shown in a therapeutic trial that controlling vascular factors reduces the risk of AD. The main reason is that, to date, no trial has been specifically designed with the prevention of dementia as the primary endpoint. Several trials using blood pressure lowering drugs in hypertensive subjects50-52 or in patients with a history of stroke53 have included dementia as a secondary endpoint. Their results remain inconclusive but they usually have poorly addressed the central issues of type of cognitive testing, duration of followup, calculation of study power based on cognitive events, type of patients included, and inclusion of

neuroimaging criteria. The Syst-Eur study, the only trial to date that has shown that a blood pressure lowering treatment reduces the risk of AD, was based on only 32 cases of dementia in a cohort of 2,418 patients.51 An open extension of the follow-up of patients enrolled in that trial confirmed the results of the main study with a doubling of the number of cases but with the limitations of open studies.54 One of the most important questions in designing a prevention trial is the role of age on the relationship between vascular factors and the risk of dementia. Observational studies suggest that the relative risk of dementia associated with elevated blood pressure diminishes with age,55 a pattern that is also seen for stroke. Although this observed risk attenuation does not have an unequivocal explanation, it raises the issue of the efficacy of lowering blood pressure on the risk of dementia in older subjects. An alternative strategy would be to conduct a therapeutic trial on slightly younger subjects, between ages 65 and 75, for example. The major limitation of this type of trial is that the risk of dementia is relatively low in this age group. Thus, to demonstrate a clinically significant effect of blood pressure lowering, one would have to increase the number of subjects or the duration of follow-up (perhaps 10 years or more), which could be challenging in terms of the infrastructural and financial resources required to conduct such a trial. The question of optimal age range is part of broader reflections on the definition of the optimal target population for therapeutic intervention. Cardiovascular studies published to date have recruited patients with certain vascular risk factors, such as hypertension or previous vascular event. A therapeutic prevention study of dementia should be done in patients with cognitive deterioration at risk for but who do not meet the criteria for dementia. The identification of this group of patients is more complicated than identifying subjects with vascular risk factors— this could be done by recruiting patients with cognitive complaints and a confirmed deficit on validated neuropsychological tests. As vascular pathologies may have greater impact on non-memory cognitive domains such as executive dysfunction and processing speed,56 inclusion criteria should not be restricted to only those with memory impairment but be broadened to individuals with deficits in any defined cognitive domain. The possibility of selecting subjects at high vascular risk within this group (patients with clinical risk factors or lesions due to small-vessel disease on neuroimaging) also becomes an important consideration. Another major question concerns the type of workup required and the endpoint to be measured. MR imaging seems essential for selecting patients for Neurology 72

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the trial, for validating the impact of vascular factor reduction on the brain, and for understanding the variability of this effect across categories of patients. However, this type of evaluation may be difficult to achieve for large numbers of patients due to logistic considerations and the inherent high costs. Furthermore, the clinical endpoint in such a study also needs to be carefully defined. Using a continuous measure of cognitive function in addition to a specific threshold (which may only represent an arbitrary cutpoint) would provide a clinically meaningful and complementary quantitative measure of the effect of treatment. Even a fundamental question such as the type of therapeutic intervention remains open. In the literature, there is no definitive argument to choose one type of intervention over another or to prefer one type of drug. Should one treat only one risk factor, or should a trial attempt an intervention on multiple risk factors? Should one treat subjects based on a threshold of risk, or should the intervention be given to all patients regardless of their estimated vascular risk? In subjects with high vascular risk, should the intervention replace or be added to their current treatment? Should one limit interventions to medication therapies or should non-medication intervention also be considered (e.g., exercise or diet)? These set of questions, by no means exhaustive, demonstrate the complexities of designing such a trial. Options should be considered after careful reflection among experts as definitive scientific evidence for these options is lacking. However, one cannot be certain these choices will necessarily avoid reaching an inconclusive result, even in a carefully designed trial. Before launching a large therapeutic trial of long duration, it may be a reasonable option to conduct several smaller proof of concept studies on a limited number of precisely defined subjects such as those individuals at highest risk for dementia associated with vascular risk factors. This was done, for example, in a recently published trial of patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, a model of subcortical vascular dementia.41 Similar trials could potentially be designed in high risk populations such as these which then could be then tested in broader populations if initial results provide promise. Such potential approaches represent the important initial steps that must be taken in order to prevent the common forms of dementia in years to come. CONTRIBUTORS C.T. planned the outline of the paper; A.V. and C.T. wrote the first draft; all authors contributed to the final version. 372

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ACKNOWLEDGMENT The authors thank Drs. Annick Alpe´rovitch, Steven M. Greenberg, and Joe¨l Me´nard for helpful discussions during the preparation of this manuscript.

Received July 1, 2008. Accepted in final form October 13, 2008. REFERENCES 1. Kivipelto M, Helkala EL, Laakso MP, et al. Midlife vascular risk factors and Alzheimer’s disease in later life: longitudinal, population based study. BMJ 2001;322:1447–1451. 2. Hofman A, Ott A, Breteler M, et al. Atherosclerosis, apolipoprotein E, and prevalence of dementia and Alzheimer’s disease in the Rotterdam Study. Lancet 1997;349:151– 154. 3. Skoog I, Lernfelt B, Landahl S, et al. 15-year longitudinal study of blood pressure and dementia. Lancet 1996;347: 1141–1145. 4. Chui HC, Zarow C, Mack WJ, et al. Cognitive impact of subcortical vascular and Alzheimer’s disease pathology. Ann Neurol 2006;60:677–687. 5. Biessels GJ, Deary IJ, Ryan CM. Cognition and diabetes: a lifespan perspective. Lancet Neurol 2008;7:184–190. 6. Luchsinger JA, Tang MX, Stern Y, Shea S, Mayeux R. Diabetes mellitus and risk of Alzheimer’s disease and dementia with stroke in a multiethnic cohort. Am J Epidemiol 2001;154:635–641. 7. Luchsinger JA, Reitz C, Honig LS, Tang MX, Shea S, Mayeux R. Aggregation of vascular risk factors and risk of incident Alzheimer disease. Neurology 2005;65:545–551. 8. Mielke MM, Rosenberg PB, Tschanz J, et al. Vascular factors predict rate of progression in Alzheimer disease. Neurology 2007;69:1850–1858. 9. de Leeuw FE, deGroot JC, Oudkerk M, et al. A follow-up study of blood pressure and cerebral white matter lesions. Ann Neurol 1999;46:827–833. 10. Liao DP, Cooper L, Cai JW, et al. The prevalence and severity of white matter lesions, their relationship with age, ethnicity, gender, and cardiovascular disease risk factors: The ARIC study. Neuroepidemiology 1997;16:149–162. 11. Longstreth WT, Manolio TA, Arnold A, et al. Clinical correlates of white matter findings on cranial magnetic resonance imaging of 3301 elderly people: The cardiovascular health study. Stroke 1996;27:1274–1282. 12. Veldink JH, Scheltens P, Jonker C, Launer LJ. Progression of cerebral white matter hyperintensities on MRI is related to diastolic blood pressure. Neurology 1998;51:319–320. 13. Bernick C, Kuller L, Dulberg C, et al. Silent MRI infarcts and the risk of future stroke: The cardiovascular health study. Neurology 2001;57:1222–1229. 14. Fisher CM. Lacunar strokes and infarcts: a review. Neurology 1982;32:871–876. 15. Kazui S, Levi CR, Jones EF, Quang L, Calafiore P, Donnan GA. Risk factors for lacunar stroke: a case-control transesophageal echocardiographic study. Neurology 2000;54:1385– 1387. 16. Viswanathan A, Chabriat H. Cerebral microhemorrhage. Stroke 2006;37:550–555. 17. Dufouil C, Chalmers J, Coskun O, et al. Effects of blood pressure lowering on cerebral white matter hyperintensities in patients with stroke: the PROGRESS (Perindopril Protection Against Recurrent Stroke Study) Magnetic Resonance Imaging Substudy. Circulation 2005;112:1644–1650.

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Clinical/Scientific Notes

S. Shalaby, MD Y.K. Hayashi, MD, PhD I. Nonaka, MD, PhD S. Noguchi, PhD I. Nishino, MD, PhD

NOVEL FHL1 MUTATIONS IN FATAL AND BENIGN REDUCING BODY MYOPATHY

Reducing body myopathy (RBM) is a rare disorder characterized pathologically by the presence of intracytoplasmic inclusions strongly stained by menadioneNBT (nitroblue tetrazolium) staining in the absence of the substrate ␣-glycerophosphate. The causative gene for RBM was recently identified as FHL1 on chromosome Xq27 encoding four and a half LIM domains 1.1 FHL1 is a 32 kDa protein, composed of four LIM domains preceded by a single N-terminal zinc finger. FHL1 is highly expressed in skeletal muscle and heart. Here, we searched for FHL1 mutations in three sporadic cases2-4 and one familial case5 of RBM we previously reported. Methods. All clinical materials used in this study were obtained for diagnostic purpose with informed consent. Patient 1 and patient 2 have fatal infantile form,2,3 and patient 3 has adult-onset form.4 Patients 4 (son) and 5 (his mother) had familial cases.5 We directly sequenced all exons and their flanking intronic regions of FHL1 in the five RBM patients and 250 Japanese controls. Frozen muscle specimens were examined by immunohistochemistry and immunoblotting using standard technique.

Supplemental data at www.neurology.org

Results. We identified four novel mutations in FHL1: a heterozygous missense mutation of c.449G⬎A (p.C150Y) in patient 1 and c.302G⬎T (p.C101F) in patient 2, an in-frame 9 bp deletion at c.304312delAAGGGGTGC (p.102-104delKFC) in patient 3, and a hemizygous mutation c.310T⬎C (p.C104R) in patient 4. The mother (patient 5) had the same mutation in heterozygous mode. All mutations we identified are located in the second LIM domain of FHL1 (figure e-1 on the Neurology® Web site at www.neurology.org). Immunohistochemical analysis of patients’ muscles showed strong immunoreactive depositions of FHL1, ␣5-integrin, myosin heavy chain-slow (MyHC-slow), ribosomal proteins, and nucleolar protein coilin (figure). Protein amount of FHL1 was significantly reduced in patients 2 and 4 with less reduction in patient 5 after normalization to actin level. In contrast, patient 3 showed mild increase in FHL1 (figure).

Discussion. All our RBM patients, with a wide range of clinical phenotypes, fatal infantile (patient 1 and 2), benign childhood (patient 4), and adultonset (patients 3 and 5), had novel FHL1 mutations, confirming the recent report that FHL1 is the causative gene for RBM.1 All the mutations identified in RBM patients affects the cysteine or histidine residues located within the second LIM domain of FHL1, indicating their irreplaceable role in stabilizing FHL1 (figure e-1). Phenotypic severity may depend on how the altered residue affects the zinc binding sites and resulting disruption of the structure and function of the LIM domain. In this study, clinical severity is correlated with the amount of the FHL1 protein. Nevertheless, previously reported fatal RBM patients show increased FHL1 amount.1 Since RBM shows asymmetric muscle involvement and focal pathologic changes in the same muscle specimen (figure), the decrease or increase of FHL1 amount may depend on the degree of affection of the biopsied part of the muscle. We should also consider the degree of protein degradation/ turnover. Here we showed that MyHC-slow is aggregated in patient muscles. It was reported that both overexpression and underexpression of FHL1 were associated with the failure of myosin to assemble into thick filaments. Aggregation of myosin was also noted in FHL1 knockdown cells. In RBM muscles, mislocalization of myosin filaments and the sarcomeric disassembly may be caused by FHL1 dysfunction. Surprisingly, ␣5-integrin was also highly aggregated in RBM patients although normally ␣5-integrin is expressed in myoblasts and during primary myogenesis, and is downregulated in mature muscle. FHL1 was reported to induce ␣5␤1-integrin-dependent myocyte elongation. Whether or not there is a correlation between ␣5-integrin aggregation and the suggested role of FHL1 in integrin signaling and regulation of cytoskeletal dynamics during muscle differentiation is not clear. To date, only 6 families and 16 sporadic patients with RBM have been reported. However, RBM patients may be overlooked and underestimated, since reducing bodies can be observed in selective parts of the muscle, as shown in the figure. Furthermore, menadioneNeurology 72

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Figure

Immunohistochemical and immunoblotting analyses

NBT staining without substrate is not performed unless RBM is suspected. FHL1 mutations have also been reported as the cause of X-linked scapuloperoneal myopathy (SPM)6 and X-linked myopathy with postural atrophy (XMPMA).7 Certainly, RBM, SPM, and XPMPA share common clinicopathologic features such as scapuloperoneal dominant muscle involvement, asymmetric muscle weakness, rigid spine, myofibers with core-like appearance on NADH, and rimmed vacuoles, and this finding raises a possibility that they may be a single entity. In addition, reducing bodies detected in a SPM patient strengthens this idea (unpublished data). Further studies together with the identification of more RBM patients may help refine the diagnostic criteria for RBM and may explain the pathomechanism underlying the formation of reducing bodies which is unclear. From the Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan. Supported by a Grant-in-Aid for Scientific Research and a Grant-in-Aid for Exploratory Research from Japan Society for the Promotion of Science; by Research on Psychiatric and Neurological Diseases and Mental Health of Health Labor Sciences Research Grants and the Research Grant for Nervous and Mental Disorders from the Ministry of Health, Labor, and Welfare; by Research on Publicly Essential Drugs and Medical Devices from the Japanese Health Sciences Foundation; and by the Program for Promotion of Fundamental Studies in Health Sciences of the National Institute of Biomedical Innovation (NIBIO). Disclosure: The authors report no disclosures. Received May 21, 2008. Accepted in final form August 19, 2008. Address correspondence and reprint requests to Dr. Yukiko K. Hayashi, Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 OgawaHigashi, Kodaira, Tokyo 187-8502, Japan; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4. (A–E) Immunohistochemical analysis of patient 3 was performed using antibodies against FHL1 (AVIVA), ␣5-integrin (Chemicon), slow myosin heavy chain (MyHC-slow; Novocastra), ribosomal protein L28 (Santa Cruz), coilin (Sigma), and lamin C (see reference e-1 at www. neurology.org). Abnormal accumulation of FHL1 (A), ␣5-integrin (B), MyHC-slow (C), and ribosomal proteins (D) are seen. Double immunostaining of coilin (green) and lamin C (orange) revealed intracytoplasmic and perinuclear accumulation of coilin (E). These findings may be characteristic for reducing body myopathy (RBM) as it was observed in patients 2, 4, and 5 (fatal and benign RBM) but not seen in muscle specimens from a healthy control or diseased controls. Because of the limited amounts of the specimens, we could not examine in patient 1. Bar ⫽ 50 ␮m. (F) Modified Gomori-trichrome staining from patient 3 shows focal involvement in the muscle section. Bar ⫽ 50 ␮m. (G) Immunoblotting analysis of FHL1 in muscle specimens from patients 2, 3, 4, and 5 show variable amount of FHL1. Patients 2, 4, and 5 show significant reduction in FHL1 amount. Patient 4 (son) shows more reduction in FHL1 amount than patient 5 (his mother). Patient 3 shows slight increase in FHL1. Relative amount of FHL1 was calculated and normalized to actin (Nichirei).

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5. 6.

7.

Schessl J, Zou Y, McGrath MJ, et al. Proteomic identification of FHL1 as the protein mutated in human reducing body myopathy. J Clin Invest 2008;118:904–912. Kiyomoto BH, Murakami N, Kobayashi Y, et al. Fatal reducing body myopathy: ultrastructural and immunohistochemical observations. J Neurol Sci 1995;128:58–65. Kobayashi Y, Nihei K, Kuwajima K, Nonaka I. [Reducing body myopathy: a case report.] Rinsho Shinkeigaku 1992; 32:62–67. Kiyomoto BH, Murakami N, Kishibayashi J, et al. Reducing bodies in distal myopathy with rimmed vacuole formation. Acta Neuropathol 1995;89:109–111. Ohsawa M, Liewluck T, Ogata K, et al. Familial reducing body myopathy. Brain Dev 2007;29:112–116. Quinzii CM, Vu TH, Min KC, et al. X-linked dominant scapuloperoneal myopathy is due to a mutation in the gene encoding four-and-a-half-LIM protein 1. Am J Hum Genet 2008;82:208–213. Windpassinger C, Schoser B, Straub V, et al. An X-linked myopathy with postural muscle atrophy and generalized hypertrophy, termed XMPMA, is caused by mutations in FHL1. Am J Hum Genet 2008;82:88–99.

H.H. Schaumburg, MD C. Gellido, MD S.W. Smith, MD L.S. Nelson, MD R.S. Hoffman, MD

ELEMENTAL MERCURY NEUROTOXICITY FROM SELF-INJECTION

We describe a Guyanese diabetic man who developed an elevation in body burdens of mercury following repeated self-injection of elemental mercury. His early signs of neurotoxicity responded to excision of the injection sites and chelation therapy. Case report. A 61-year-old diabetic man presented with burning pain in the feet and tremor of the hands. During his 20 years of insulin-dependent diabetes, his most common insulin injection sites were the forearms and abdominal wall. About 4 to 6 years earlier, he first experienced burning discomfort in the feet, attributed initially to his diabetes. This intensified, and a tremor appeared shortly thereafter, which had gradually become disabling. His handwriting steadily progressed to illegibility, and it was difficult for him to drink from a glass without spillage. In the past 4 years he also noticed the appearance of raised black protuberant scars over his volar forearms and abdomen at the usual injection sites. Examination disclosed numerous raised, firm keloids over both forearms (figure, A). Mental status examination revealed normal cognitive function. There was a mild fine rapid tremor of the fingers at rest that became intense on movement. There was no rigidity, bradykinesia, or cogwheeling. Tendon reflexes were 2/4 in the upper limbs, absent in the low-

Figure

Preoperative images from the left forearm

(A) Photograph of keloid following polar biopsy (before radical excision). (B) X-ray showing radiopaque subcutaneous deposition of mercury.

ers. Sensory abnormalities were confined to the distal lower limbs and were consistent with diabetic symmetric neuropathy. Nerve conduction studies disclosed absent sural, radial, median, and ulnar responses and reduced motor amplitudes in peroneal and tibial nerves. Psychiatric consultation revealed no psychiatric or cognitive disorders. A polar biopsy of one of the forearm lesions was unexpectedly consistent with a mercury granuloma. Subsequent radiographs of the forearm (figure, B) and abdomen radiograph demonstrated radiopaque densities consistent with mercury deposition. A 24-hour urine mercury and whole blood mercury concentration (WBMC) were 321 ␮g/L (normal ⬍20 ␮g/L) and 230 ␮g/L (normal ⬍10 ␮g/L); whole blood lead was undetectable. IM dimercaprol (British anti-Lewisite) was administered pre- and post- surgical excision of the forearm and abdominal lesions. Oral succimer (2,3-dimercaptosuccinic acid) was provided postoperatively for 19 days. Further therapy was declined. At a 2-week follow-up examination, his tremor was diminished, his handwriting legible, and WBMC had fallen to 92 ␮g/L. Nine months later, the tremor had disappeared, the sensory (diabetic?) neuropathy was unchanged, and WBMC was 7 ␮g/L. Discussion. Upper limb tremor is commonly the heralding symptom of elemental mercury neurotoxicity and improves pari passu with significant reduction in body burden.1 Elemental mercury intoxication of sufficient magnitude to affect the adult CNS is usually associated with occupational inhalation of vapor.2 While chelation removes very little mercury deposited in tissue, BAL followed by succimer was administered in this case due to the potential for extensive intraoperative mobilization.3 Self-administration of elemental mercury is usually associated with ointments, accidents, suicide attempts,4 alternative medicine therapy, or tattoo augmentation. There is also a widespread belief in Far Eastern and Central and South American countries that mercury injection will increase limb and penile strength or ward off evil.5,6 Elemental mercury is sold in urban religious stores (botanicas) for use in Esperitismo, Santeria, and voodoo magicoreligious practices, as well as for self-medication. A 1996 survey found 38 of 41 surveyed New York City botanicas sold capsules or vials of elemental mercury.7 Despite warnings from public health advocates, pediatricians, and toxicologists, there is still no ban on the sale of elemental mercury. This should be pursued as clearly consequential misuse continues. From the Department of Neurology (H.H.S., C.G.), Albert Einstein College of Medicine, Bronx, NY; and New York City Poison ConNeurology 72

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trol Center and Department of Emergency Medicine (S.W.S., L.S.N., R.S.H.), New York University School of Medicine, NY.

2.

Disclosure: The authors report no disclosures. Received May 20, 2008. Accepted in final form August 20, 2008. Address correspondence and reprint requests to Dr. Herbert H. Schaumburg, Departments of Neurology and Pathology (Neuropathology), Albert Einstein College of Medicine, 1300 Morris Park, Bronx, NY 10461-1602; [email protected]

3. 4.

5.

Copyright © 2009 by AAN Enterprises, Inc. 1.

Bassel F. Shneker, MD Peggy D. Baylin, PharmD Michael E. Nakhla, PharmD

Markowitz L, Schaumburg HH. Successful treatment of inorganic mercury neurotoxicity with n-acetyl penicillamine despite an adverse reaction. Neurology 1980;39: 1000–1003.

LINEZOLID INDUCING COMPLEX PARTIAL STATUS EPILEPTICUS IN A PATIENT WITH EPILEPSY

Many antibiotics can worsen seizures in patients with epilepsy and provoke seizures in patients without epilepsy. The agents most commonly associated with this adverse effect include penicillin and other ␤-lactams, imipenem-cilastatin, and quinolones.1 The mechanism by which antibiotics can induce seizures can be related to lowering seizure threshold by affecting neurotransmitters or by decreasing the efficacy of antiepileptic drugs (AEDs).2,3 Linezolid (Zyvox) is the first agent in a new class of antibiotics known as oxazolidinones. Oxazolidinones act primarily against Gram-positive bacteria by inhibiting protein synthesis. The most common side effects from linezolid are nausea, headache, and diarrhea.4 Serious adverse effects such as reversible myelosuppression have been reported.4,5 Linezolid may increase the risk of serotonin syndrome when taken with other serotonergic agents.4,6 Seizures have been reported as side effects in the package insert in children4; however, no case reports of linezolid-induced seizures exist in the medical literature. We report a patient with epilepsy who experienced complex partial status epilepticus (CPSE) upon receiving linezolid. Case report. The patient is a 45-year-old lefthanded woman with a history of epilepsy since childhood. She has been followed in the Epilepsy Clinic at The Ohio State University (OSU) for more than 10 years. She has rare tonic-clonic seizures, frequent (3 per day) simple partial (right-sided dystonic posture for a few seconds), and frequent (2 per day) complex partial seizures (extension of both legs and clonic movements of right side lasting for less than a minute). Her seizures have been intractable despite trying all approved AEDs, vagus nerve stimulator, and two resective brain surgeries (left frontal lobe) that resulted in right-sided weakness. Her past medi-

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6. 7.

Clarkson TW, Magos L, Myers GJ. The toxicology of mercury-current exposures and clinical manifestations. N Engl J Med 2003;349:1731–1737. Hill DM. Self-administration of mercury by subcutaneous injection. BMJ 1967;1:342–343. Ragothaman M, Kulkarni G, Ashraf VV, et al. Elemental mercury poisoning probably causes cortical myoclonus. Mov Disord 2007;22:1964–1968. Oh KJ, Park K, Kang TW, et al. Subcutaneous metallic mercury injection for penile augmentation. Urology 2007; 69:185.e3–185.e4. Prasad VL. Subcutaneous injection of mercury: “warding off evil.” Eviron Health Persp 2004;13:1326–1328. Zayas LH, Ozuah PO. Mercury use in espiritismo: a survey of botanicas. Am J Public Health 1996;86:111–112.

cal history is significant for postictal psychosis and depression. Her medications included zonisamide, clonazepam, acetazolamide, aripiprazole, and lorazepam as needed. She had no history of unusual reaction to any medication. On April 10, 2008, she underwent an excision of a painful wart-like growth on her right knee. Her wound did not heal well and a wound infection was suspected. Wound cultures on April 22, 2008, were consistent with nonpathologic skin flora. On April 24, 2008, she underwent debridement of her wound and was placed on IV vancomycin, then switched to IV linezolid on April 25, 2008, receiving one dose. She was discharged home on April 26, 2008, on oral linezolid. Two doses were taken. In the evening of April 26, 2008, her habitual complex partial seizures became more frequent and longer in duration. Oral lorazepam did not help. The seizures became almost constant. She was admitted to OSU Medical Center with a diagnosis of CPSE. She was intubated, placed on a propofol drip, and given IV levetiracetam in addition to her home AEDs. IV vancomycin was started in place of linezolid. Continuous EEG monitoring showed initially frequent seizures of left fronto-central onset that subsided with treatment. On the morning of April 28, 2008, propofol was stopped and she was successfully extubated. Her seizures were back to baseline (few daily seizures). Her workup ruled out any acute systemic or neurologic process. She was febrile at presentation; however, no source of infection was found. On April 29, 2008, all IV medications were switched to oral formulations with plans to complete a 7-day course of antibiotics. Oral linezolid was restarted on April 30, 2008. Late that morning, she started to have prolonged and frequent seizures. She received benzodiazepines and her levetiracetam was increased. Seizures became more frequent. On the morning of May 1, 2008, linezolid was stopped after a total of three doses. She was loaded with IV fosphenytoin. Within 18 hours, the

patient’s seizure frequency improved dramatically and she seemed to be at her baseline. She was discharged home on May 2, 2008.

Pharmacy (P.D.B.), The Ohio State University Medical Center, Columbus. Disclosure: The authors report no disclosures. Received June 5, 2008. Accepted in final form August 25, 2008.

Discussion. Our patient developed CPSE and had worsening of her seizures. The patient had no acute neurologic or systemic illness to explain the worsening of her seizures. She has no history of status epilepticus in the past. Historically, she is a very compliant patient. Although we cannot be definite about the exact cause, the chronological correlation suggests that linezolid was the cause. Our patient was given linezolid on two separate occasions. On each occasion, within less than 24 hours of starting linezolid, she had significant worsening of her seizures. Seizures improved dramatically within 24 hours of stopping linezolid. The mechanism by which linezolid worsened our patient’s seizures is not clear. A review of the patient’s concomitant medication list did not reveal any possible drug– drug interactions with linezolid. Unfortunately, the levels of zonisamide and clonazepam were not checked to determine if linezolid affected either one. Linezolid should be administered cautiously in patients with a history of epilepsy. From the Department of Neurology (B.F.S.) and College of Pharmacy (M.E.N.), The Ohio State University; and Department of

Address correspondence and reprint requests to Dr. Bassel F. Shneker, Assistant Professor, The Ohio State University, Department of Neurology, 1654 Upham Drive, 411 Means Hall, Columbus, OH 43210; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4. 5. 6.

Granowitz EV, Brown RB. Antibiotic adverse reactions and drug interactions. Crit Care Clin 2008;24:421– 442. Sugimoto M, Uchida I, Mashimo T, et al. Evidence for the involvement of GABA(A) receptor blockade in convulsions induced by cephalosporins. Neuropharmacology 2003;45:304–314. Coves-Orts FJ, Borras-Blasco J, Navarro-Ruiz A, MurciaLopez A, Palacios-Ortega F. Acute seizures due to a probable interaction between valproic acid and meropenem. Ann Pharmacother 2005;39:533–537. Available at: http://media.pfizer.com/files/products/uspi_ zyvox.pdf. Accessed June 5, 2008. Moellering RC. Linezolid: The first oxazolidinone antimicrobial. Ann Intern Med 2003;138:135–142. Morales-Molina JA, Mateu-de Antonio J, Marin-Casino M, Grau S. Linezolid-associated serotonin syndrome: What we can learn from cases reported so far. J Antimicrob Chemother 2005;56:1176–1178.

Neurology 72

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Clinical/Scientific Notes

S. Shalaby, MD Y.K. Hayashi, MD, PhD I. Nonaka, MD, PhD S. Noguchi, PhD I. Nishino, MD, PhD

NOVEL FHL1 MUTATIONS IN FATAL AND BENIGN REDUCING BODY MYOPATHY

Reducing body myopathy (RBM) is a rare disorder characterized pathologically by the presence of intracytoplasmic inclusions strongly stained by menadioneNBT (nitroblue tetrazolium) staining in the absence of the substrate ␣-glycerophosphate. The causative gene for RBM was recently identified as FHL1 on chromosome Xq27 encoding four and a half LIM domains 1.1 FHL1 is a 32 kDa protein, composed of four LIM domains preceded by a single N-terminal zinc finger. FHL1 is highly expressed in skeletal muscle and heart. Here, we searched for FHL1 mutations in three sporadic cases2-4 and one familial case5 of RBM we previously reported. Methods. All clinical materials used in this study were obtained for diagnostic purpose with informed consent. Patient 1 and patient 2 have fatal infantile form,2,3 and patient 3 has adult-onset form.4 Patients 4 (son) and 5 (his mother) had familial cases.5 We directly sequenced all exons and their flanking intronic regions of FHL1 in the five RBM patients and 250 Japanese controls. Frozen muscle specimens were examined by immunohistochemistry and immunoblotting using standard technique.

Supplemental data at www.neurology.org

Results. We identified four novel mutations in FHL1: a heterozygous missense mutation of c.449G⬎A (p.C150Y) in patient 1 and c.302G⬎T (p.C101F) in patient 2, an in-frame 9 bp deletion at c.304312delAAGGGGTGC (p.102-104delKFC) in patient 3, and a hemizygous mutation c.310T⬎C (p.C104R) in patient 4. The mother (patient 5) had the same mutation in heterozygous mode. All mutations we identified are located in the second LIM domain of FHL1 (figure e-1 on the Neurology® Web site at www.neurology.org). Immunohistochemical analysis of patients’ muscles showed strong immunoreactive depositions of FHL1, ␣5-integrin, myosin heavy chain-slow (MyHC-slow), ribosomal proteins, and nucleolar protein coilin (figure). Protein amount of FHL1 was significantly reduced in patients 2 and 4 with less reduction in patient 5 after normalization to actin level. In contrast, patient 3 showed mild increase in FHL1 (figure).

Discussion. All our RBM patients, with a wide range of clinical phenotypes, fatal infantile (patient 1 and 2), benign childhood (patient 4), and adultonset (patients 3 and 5), had novel FHL1 mutations, confirming the recent report that FHL1 is the causative gene for RBM.1 All the mutations identified in RBM patients affects the cysteine or histidine residues located within the second LIM domain of FHL1, indicating their irreplaceable role in stabilizing FHL1 (figure e-1). Phenotypic severity may depend on how the altered residue affects the zinc binding sites and resulting disruption of the structure and function of the LIM domain. In this study, clinical severity is correlated with the amount of the FHL1 protein. Nevertheless, previously reported fatal RBM patients show increased FHL1 amount.1 Since RBM shows asymmetric muscle involvement and focal pathologic changes in the same muscle specimen (figure), the decrease or increase of FHL1 amount may depend on the degree of affection of the biopsied part of the muscle. We should also consider the degree of protein degradation/ turnover. Here we showed that MyHC-slow is aggregated in patient muscles. It was reported that both overexpression and underexpression of FHL1 were associated with the failure of myosin to assemble into thick filaments. Aggregation of myosin was also noted in FHL1 knockdown cells. In RBM muscles, mislocalization of myosin filaments and the sarcomeric disassembly may be caused by FHL1 dysfunction. Surprisingly, ␣5-integrin was also highly aggregated in RBM patients although normally ␣5-integrin is expressed in myoblasts and during primary myogenesis, and is downregulated in mature muscle. FHL1 was reported to induce ␣5␤1-integrin-dependent myocyte elongation. Whether or not there is a correlation between ␣5-integrin aggregation and the suggested role of FHL1 in integrin signaling and regulation of cytoskeletal dynamics during muscle differentiation is not clear. To date, only 6 families and 16 sporadic patients with RBM have been reported. However, RBM patients may be overlooked and underestimated, since reducing bodies can be observed in selective parts of the muscle, as shown in the figure. Furthermore, menadioneNeurology 72

January 27, 2009

375

Figure

Immunohistochemical and immunoblotting analyses

NBT staining without substrate is not performed unless RBM is suspected. FHL1 mutations have also been reported as the cause of X-linked scapuloperoneal myopathy (SPM)6 and X-linked myopathy with postural atrophy (XMPMA).7 Certainly, RBM, SPM, and XPMPA share common clinicopathologic features such as scapuloperoneal dominant muscle involvement, asymmetric muscle weakness, rigid spine, myofibers with core-like appearance on NADH, and rimmed vacuoles, and this finding raises a possibility that they may be a single entity. In addition, reducing bodies detected in a SPM patient strengthens this idea (unpublished data). Further studies together with the identification of more RBM patients may help refine the diagnostic criteria for RBM and may explain the pathomechanism underlying the formation of reducing bodies which is unclear. From the Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan. Supported by a Grant-in-Aid for Scientific Research and a Grant-in-Aid for Exploratory Research from Japan Society for the Promotion of Science; by Research on Psychiatric and Neurological Diseases and Mental Health of Health Labor Sciences Research Grants and the Research Grant for Nervous and Mental Disorders from the Ministry of Health, Labor, and Welfare; by Research on Publicly Essential Drugs and Medical Devices from the Japanese Health Sciences Foundation; and by the Program for Promotion of Fundamental Studies in Health Sciences of the National Institute of Biomedical Innovation (NIBIO). Disclosure: The authors report no disclosures. Received May 21, 2008. Accepted in final form August 19, 2008. Address correspondence and reprint requests to Dr. Yukiko K. Hayashi, Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 OgawaHigashi, Kodaira, Tokyo 187-8502, Japan; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4. (A–E) Immunohistochemical analysis of patient 3 was performed using antibodies against FHL1 (AVIVA), ␣5-integrin (Chemicon), slow myosin heavy chain (MyHC-slow; Novocastra), ribosomal protein L28 (Santa Cruz), coilin (Sigma), and lamin C (see reference e-1 at www. neurology.org). Abnormal accumulation of FHL1 (A), ␣5-integrin (B), MyHC-slow (C), and ribosomal proteins (D) are seen. Double immunostaining of coilin (green) and lamin C (orange) revealed intracytoplasmic and perinuclear accumulation of coilin (E). These findings may be characteristic for reducing body myopathy (RBM) as it was observed in patients 2, 4, and 5 (fatal and benign RBM) but not seen in muscle specimens from a healthy control or diseased controls. Because of the limited amounts of the specimens, we could not examine in patient 1. Bar ⫽ 50 ␮m. (F) Modified Gomori-trichrome staining from patient 3 shows focal involvement in the muscle section. Bar ⫽ 50 ␮m. (G) Immunoblotting analysis of FHL1 in muscle specimens from patients 2, 3, 4, and 5 show variable amount of FHL1. Patients 2, 4, and 5 show significant reduction in FHL1 amount. Patient 4 (son) shows more reduction in FHL1 amount than patient 5 (his mother). Patient 3 shows slight increase in FHL1. Relative amount of FHL1 was calculated and normalized to actin (Nichirei).

376

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5. 6.

7.

Schessl J, Zou Y, McGrath MJ, et al. Proteomic identification of FHL1 as the protein mutated in human reducing body myopathy. J Clin Invest 2008;118:904–912. Kiyomoto BH, Murakami N, Kobayashi Y, et al. Fatal reducing body myopathy: ultrastructural and immunohistochemical observations. J Neurol Sci 1995;128:58–65. Kobayashi Y, Nihei K, Kuwajima K, Nonaka I. [Reducing body myopathy: a case report.] Rinsho Shinkeigaku 1992; 32:62–67. Kiyomoto BH, Murakami N, Kishibayashi J, et al. Reducing bodies in distal myopathy with rimmed vacuole formation. Acta Neuropathol 1995;89:109–111. Ohsawa M, Liewluck T, Ogata K, et al. Familial reducing body myopathy. Brain Dev 2007;29:112–116. Quinzii CM, Vu TH, Min KC, et al. X-linked dominant scapuloperoneal myopathy is due to a mutation in the gene encoding four-and-a-half-LIM protein 1. Am J Hum Genet 2008;82:208–213. Windpassinger C, Schoser B, Straub V, et al. An X-linked myopathy with postural muscle atrophy and generalized hypertrophy, termed XMPMA, is caused by mutations in FHL1. Am J Hum Genet 2008;82:88–99.

H.H. Schaumburg, MD C. Gellido, MD S.W. Smith, MD L.S. Nelson, MD R.S. Hoffman, MD

ELEMENTAL MERCURY NEUROTOXICITY FROM SELF-INJECTION

We describe a Guyanese diabetic man who developed an elevation in body burdens of mercury following repeated self-injection of elemental mercury. His early signs of neurotoxicity responded to excision of the injection sites and chelation therapy. Case report. A 61-year-old diabetic man presented with burning pain in the feet and tremor of the hands. During his 20 years of insulin-dependent diabetes, his most common insulin injection sites were the forearms and abdominal wall. About 4 to 6 years earlier, he first experienced burning discomfort in the feet, attributed initially to his diabetes. This intensified, and a tremor appeared shortly thereafter, which had gradually become disabling. His handwriting steadily progressed to illegibility, and it was difficult for him to drink from a glass without spillage. In the past 4 years he also noticed the appearance of raised black protuberant scars over his volar forearms and abdomen at the usual injection sites. Examination disclosed numerous raised, firm keloids over both forearms (figure, A). Mental status examination revealed normal cognitive function. There was a mild fine rapid tremor of the fingers at rest that became intense on movement. There was no rigidity, bradykinesia, or cogwheeling. Tendon reflexes were 2/4 in the upper limbs, absent in the low-

Figure

Preoperative images from the left forearm

(A) Photograph of keloid following polar biopsy (before radical excision). (B) X-ray showing radiopaque subcutaneous deposition of mercury.

ers. Sensory abnormalities were confined to the distal lower limbs and were consistent with diabetic symmetric neuropathy. Nerve conduction studies disclosed absent sural, radial, median, and ulnar responses and reduced motor amplitudes in peroneal and tibial nerves. Psychiatric consultation revealed no psychiatric or cognitive disorders. A polar biopsy of one of the forearm lesions was unexpectedly consistent with a mercury granuloma. Subsequent radiographs of the forearm (figure, B) and abdomen radiograph demonstrated radiopaque densities consistent with mercury deposition. A 24-hour urine mercury and whole blood mercury concentration (WBMC) were 321 ␮g/L (normal ⬍20 ␮g/L) and 230 ␮g/L (normal ⬍10 ␮g/L); whole blood lead was undetectable. IM dimercaprol (British anti-Lewisite) was administered pre- and post- surgical excision of the forearm and abdominal lesions. Oral succimer (2,3-dimercaptosuccinic acid) was provided postoperatively for 19 days. Further therapy was declined. At a 2-week follow-up examination, his tremor was diminished, his handwriting legible, and WBMC had fallen to 92 ␮g/L. Nine months later, the tremor had disappeared, the sensory (diabetic?) neuropathy was unchanged, and WBMC was 7 ␮g/L. Discussion. Upper limb tremor is commonly the heralding symptom of elemental mercury neurotoxicity and improves pari passu with significant reduction in body burden.1 Elemental mercury intoxication of sufficient magnitude to affect the adult CNS is usually associated with occupational inhalation of vapor.2 While chelation removes very little mercury deposited in tissue, BAL followed by succimer was administered in this case due to the potential for extensive intraoperative mobilization.3 Self-administration of elemental mercury is usually associated with ointments, accidents, suicide attempts,4 alternative medicine therapy, or tattoo augmentation. There is also a widespread belief in Far Eastern and Central and South American countries that mercury injection will increase limb and penile strength or ward off evil.5,6 Elemental mercury is sold in urban religious stores (botanicas) for use in Esperitismo, Santeria, and voodoo magicoreligious practices, as well as for self-medication. A 1996 survey found 38 of 41 surveyed New York City botanicas sold capsules or vials of elemental mercury.7 Despite warnings from public health advocates, pediatricians, and toxicologists, there is still no ban on the sale of elemental mercury. This should be pursued as clearly consequential misuse continues. From the Department of Neurology (H.H.S., C.G.), Albert Einstein College of Medicine, Bronx, NY; and New York City Poison ConNeurology 72

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377

trol Center and Department of Emergency Medicine (S.W.S., L.S.N., R.S.H.), New York University School of Medicine, NY.

2.

Disclosure: The authors report no disclosures. Received May 20, 2008. Accepted in final form August 20, 2008. Address correspondence and reprint requests to Dr. Herbert H. Schaumburg, Departments of Neurology and Pathology (Neuropathology), Albert Einstein College of Medicine, 1300 Morris Park, Bronx, NY 10461-1602; [email protected]

3. 4.

5.

Copyright © 2009 by AAN Enterprises, Inc. 1.

Bassel F. Shneker, MD Peggy D. Baylin, PharmD Michael E. Nakhla, PharmD

Markowitz L, Schaumburg HH. Successful treatment of inorganic mercury neurotoxicity with n-acetyl penicillamine despite an adverse reaction. Neurology 1980;39: 1000–1003.

LINEZOLID INDUCING COMPLEX PARTIAL STATUS EPILEPTICUS IN A PATIENT WITH EPILEPSY

Many antibiotics can worsen seizures in patients with epilepsy and provoke seizures in patients without epilepsy. The agents most commonly associated with this adverse effect include penicillin and other ␤-lactams, imipenem-cilastatin, and quinolones.1 The mechanism by which antibiotics can induce seizures can be related to lowering seizure threshold by affecting neurotransmitters or by decreasing the efficacy of antiepileptic drugs (AEDs).2,3 Linezolid (Zyvox) is the first agent in a new class of antibiotics known as oxazolidinones. Oxazolidinones act primarily against Gram-positive bacteria by inhibiting protein synthesis. The most common side effects from linezolid are nausea, headache, and diarrhea.4 Serious adverse effects such as reversible myelosuppression have been reported.4,5 Linezolid may increase the risk of serotonin syndrome when taken with other serotonergic agents.4,6 Seizures have been reported as side effects in the package insert in children4; however, no case reports of linezolid-induced seizures exist in the medical literature. We report a patient with epilepsy who experienced complex partial status epilepticus (CPSE) upon receiving linezolid. Case report. The patient is a 45-year-old lefthanded woman with a history of epilepsy since childhood. She has been followed in the Epilepsy Clinic at The Ohio State University (OSU) for more than 10 years. She has rare tonic-clonic seizures, frequent (3 per day) simple partial (right-sided dystonic posture for a few seconds), and frequent (2 per day) complex partial seizures (extension of both legs and clonic movements of right side lasting for less than a minute). Her seizures have been intractable despite trying all approved AEDs, vagus nerve stimulator, and two resective brain surgeries (left frontal lobe) that resulted in right-sided weakness. Her past medi-

378

Neurology 72

January 27, 2009

6. 7.

Clarkson TW, Magos L, Myers GJ. The toxicology of mercury-current exposures and clinical manifestations. N Engl J Med 2003;349:1731–1737. Hill DM. Self-administration of mercury by subcutaneous injection. BMJ 1967;1:342–343. Ragothaman M, Kulkarni G, Ashraf VV, et al. Elemental mercury poisoning probably causes cortical myoclonus. Mov Disord 2007;22:1964–1968. Oh KJ, Park K, Kang TW, et al. Subcutaneous metallic mercury injection for penile augmentation. Urology 2007; 69:185.e3–185.e4. Prasad VL. Subcutaneous injection of mercury: “warding off evil.” Eviron Health Persp 2004;13:1326–1328. Zayas LH, Ozuah PO. Mercury use in espiritismo: a survey of botanicas. Am J Public Health 1996;86:111–112.

cal history is significant for postictal psychosis and depression. Her medications included zonisamide, clonazepam, acetazolamide, aripiprazole, and lorazepam as needed. She had no history of unusual reaction to any medication. On April 10, 2008, she underwent an excision of a painful wart-like growth on her right knee. Her wound did not heal well and a wound infection was suspected. Wound cultures on April 22, 2008, were consistent with nonpathologic skin flora. On April 24, 2008, she underwent debridement of her wound and was placed on IV vancomycin, then switched to IV linezolid on April 25, 2008, receiving one dose. She was discharged home on April 26, 2008, on oral linezolid. Two doses were taken. In the evening of April 26, 2008, her habitual complex partial seizures became more frequent and longer in duration. Oral lorazepam did not help. The seizures became almost constant. She was admitted to OSU Medical Center with a diagnosis of CPSE. She was intubated, placed on a propofol drip, and given IV levetiracetam in addition to her home AEDs. IV vancomycin was started in place of linezolid. Continuous EEG monitoring showed initially frequent seizures of left fronto-central onset that subsided with treatment. On the morning of April 28, 2008, propofol was stopped and she was successfully extubated. Her seizures were back to baseline (few daily seizures). Her workup ruled out any acute systemic or neurologic process. She was febrile at presentation; however, no source of infection was found. On April 29, 2008, all IV medications were switched to oral formulations with plans to complete a 7-day course of antibiotics. Oral linezolid was restarted on April 30, 2008. Late that morning, she started to have prolonged and frequent seizures. She received benzodiazepines and her levetiracetam was increased. Seizures became more frequent. On the morning of May 1, 2008, linezolid was stopped after a total of three doses. She was loaded with IV fosphenytoin. Within 18 hours, the

patient’s seizure frequency improved dramatically and she seemed to be at her baseline. She was discharged home on May 2, 2008.

Pharmacy (P.D.B.), The Ohio State University Medical Center, Columbus. Disclosure: The authors report no disclosures. Received June 5, 2008. Accepted in final form August 25, 2008.

Discussion. Our patient developed CPSE and had worsening of her seizures. The patient had no acute neurologic or systemic illness to explain the worsening of her seizures. She has no history of status epilepticus in the past. Historically, she is a very compliant patient. Although we cannot be definite about the exact cause, the chronological correlation suggests that linezolid was the cause. Our patient was given linezolid on two separate occasions. On each occasion, within less than 24 hours of starting linezolid, she had significant worsening of her seizures. Seizures improved dramatically within 24 hours of stopping linezolid. The mechanism by which linezolid worsened our patient’s seizures is not clear. A review of the patient’s concomitant medication list did not reveal any possible drug– drug interactions with linezolid. Unfortunately, the levels of zonisamide and clonazepam were not checked to determine if linezolid affected either one. Linezolid should be administered cautiously in patients with a history of epilepsy. From the Department of Neurology (B.F.S.) and College of Pharmacy (M.E.N.), The Ohio State University; and Department of

Address correspondence and reprint requests to Dr. Bassel F. Shneker, Assistant Professor, The Ohio State University, Department of Neurology, 1654 Upham Drive, 411 Means Hall, Columbus, OH 43210; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4. 5. 6.

Granowitz EV, Brown RB. Antibiotic adverse reactions and drug interactions. Crit Care Clin 2008;24:421– 442. Sugimoto M, Uchida I, Mashimo T, et al. Evidence for the involvement of GABA(A) receptor blockade in convulsions induced by cephalosporins. Neuropharmacology 2003;45:304–314. Coves-Orts FJ, Borras-Blasco J, Navarro-Ruiz A, MurciaLopez A, Palacios-Ortega F. Acute seizures due to a probable interaction between valproic acid and meropenem. Ann Pharmacother 2005;39:533–537. Available at: http://media.pfizer.com/files/products/uspi_ zyvox.pdf. Accessed June 5, 2008. Moellering RC. Linezolid: The first oxazolidinone antimicrobial. Ann Intern Med 2003;138:135–142. Morales-Molina JA, Mateu-de Antonio J, Marin-Casino M, Grau S. Linezolid-associated serotonin syndrome: What we can learn from cases reported so far. J Antimicrob Chemother 2005;56:1176–1178.

Neurology 72

January 27, 2009

379

Clinical/Scientific Notes

S. Shalaby, MD Y.K. Hayashi, MD, PhD I. Nonaka, MD, PhD S. Noguchi, PhD I. Nishino, MD, PhD

NOVEL FHL1 MUTATIONS IN FATAL AND BENIGN REDUCING BODY MYOPATHY

Reducing body myopathy (RBM) is a rare disorder characterized pathologically by the presence of intracytoplasmic inclusions strongly stained by menadioneNBT (nitroblue tetrazolium) staining in the absence of the substrate ␣-glycerophosphate. The causative gene for RBM was recently identified as FHL1 on chromosome Xq27 encoding four and a half LIM domains 1.1 FHL1 is a 32 kDa protein, composed of four LIM domains preceded by a single N-terminal zinc finger. FHL1 is highly expressed in skeletal muscle and heart. Here, we searched for FHL1 mutations in three sporadic cases2-4 and one familial case5 of RBM we previously reported. Methods. All clinical materials used in this study were obtained for diagnostic purpose with informed consent. Patient 1 and patient 2 have fatal infantile form,2,3 and patient 3 has adult-onset form.4 Patients 4 (son) and 5 (his mother) had familial cases.5 We directly sequenced all exons and their flanking intronic regions of FHL1 in the five RBM patients and 250 Japanese controls. Frozen muscle specimens were examined by immunohistochemistry and immunoblotting using standard technique.

Supplemental data at www.neurology.org

Results. We identified four novel mutations in FHL1: a heterozygous missense mutation of c.449G⬎A (p.C150Y) in patient 1 and c.302G⬎T (p.C101F) in patient 2, an in-frame 9 bp deletion at c.304312delAAGGGGTGC (p.102-104delKFC) in patient 3, and a hemizygous mutation c.310T⬎C (p.C104R) in patient 4. The mother (patient 5) had the same mutation in heterozygous mode. All mutations we identified are located in the second LIM domain of FHL1 (figure e-1 on the Neurology® Web site at www.neurology.org). Immunohistochemical analysis of patients’ muscles showed strong immunoreactive depositions of FHL1, ␣5-integrin, myosin heavy chain-slow (MyHC-slow), ribosomal proteins, and nucleolar protein coilin (figure). Protein amount of FHL1 was significantly reduced in patients 2 and 4 with less reduction in patient 5 after normalization to actin level. In contrast, patient 3 showed mild increase in FHL1 (figure).

Discussion. All our RBM patients, with a wide range of clinical phenotypes, fatal infantile (patient 1 and 2), benign childhood (patient 4), and adultonset (patients 3 and 5), had novel FHL1 mutations, confirming the recent report that FHL1 is the causative gene for RBM.1 All the mutations identified in RBM patients affects the cysteine or histidine residues located within the second LIM domain of FHL1, indicating their irreplaceable role in stabilizing FHL1 (figure e-1). Phenotypic severity may depend on how the altered residue affects the zinc binding sites and resulting disruption of the structure and function of the LIM domain. In this study, clinical severity is correlated with the amount of the FHL1 protein. Nevertheless, previously reported fatal RBM patients show increased FHL1 amount.1 Since RBM shows asymmetric muscle involvement and focal pathologic changes in the same muscle specimen (figure), the decrease or increase of FHL1 amount may depend on the degree of affection of the biopsied part of the muscle. We should also consider the degree of protein degradation/ turnover. Here we showed that MyHC-slow is aggregated in patient muscles. It was reported that both overexpression and underexpression of FHL1 were associated with the failure of myosin to assemble into thick filaments. Aggregation of myosin was also noted in FHL1 knockdown cells. In RBM muscles, mislocalization of myosin filaments and the sarcomeric disassembly may be caused by FHL1 dysfunction. Surprisingly, ␣5-integrin was also highly aggregated in RBM patients although normally ␣5-integrin is expressed in myoblasts and during primary myogenesis, and is downregulated in mature muscle. FHL1 was reported to induce ␣5␤1-integrin-dependent myocyte elongation. Whether or not there is a correlation between ␣5-integrin aggregation and the suggested role of FHL1 in integrin signaling and regulation of cytoskeletal dynamics during muscle differentiation is not clear. To date, only 6 families and 16 sporadic patients with RBM have been reported. However, RBM patients may be overlooked and underestimated, since reducing bodies can be observed in selective parts of the muscle, as shown in the figure. Furthermore, menadioneNeurology 72

January 27, 2009

375

Figure

Immunohistochemical and immunoblotting analyses

NBT staining without substrate is not performed unless RBM is suspected. FHL1 mutations have also been reported as the cause of X-linked scapuloperoneal myopathy (SPM)6 and X-linked myopathy with postural atrophy (XMPMA).7 Certainly, RBM, SPM, and XPMPA share common clinicopathologic features such as scapuloperoneal dominant muscle involvement, asymmetric muscle weakness, rigid spine, myofibers with core-like appearance on NADH, and rimmed vacuoles, and this finding raises a possibility that they may be a single entity. In addition, reducing bodies detected in a SPM patient strengthens this idea (unpublished data). Further studies together with the identification of more RBM patients may help refine the diagnostic criteria for RBM and may explain the pathomechanism underlying the formation of reducing bodies which is unclear. From the Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan. Supported by a Grant-in-Aid for Scientific Research and a Grant-in-Aid for Exploratory Research from Japan Society for the Promotion of Science; by Research on Psychiatric and Neurological Diseases and Mental Health of Health Labor Sciences Research Grants and the Research Grant for Nervous and Mental Disorders from the Ministry of Health, Labor, and Welfare; by Research on Publicly Essential Drugs and Medical Devices from the Japanese Health Sciences Foundation; and by the Program for Promotion of Fundamental Studies in Health Sciences of the National Institute of Biomedical Innovation (NIBIO). Disclosure: The authors report no disclosures. Received May 21, 2008. Accepted in final form August 19, 2008. Address correspondence and reprint requests to Dr. Yukiko K. Hayashi, Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 OgawaHigashi, Kodaira, Tokyo 187-8502, Japan; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4. (A–E) Immunohistochemical analysis of patient 3 was performed using antibodies against FHL1 (AVIVA), ␣5-integrin (Chemicon), slow myosin heavy chain (MyHC-slow; Novocastra), ribosomal protein L28 (Santa Cruz), coilin (Sigma), and lamin C (see reference e-1 at www. neurology.org). Abnormal accumulation of FHL1 (A), ␣5-integrin (B), MyHC-slow (C), and ribosomal proteins (D) are seen. Double immunostaining of coilin (green) and lamin C (orange) revealed intracytoplasmic and perinuclear accumulation of coilin (E). These findings may be characteristic for reducing body myopathy (RBM) as it was observed in patients 2, 4, and 5 (fatal and benign RBM) but not seen in muscle specimens from a healthy control or diseased controls. Because of the limited amounts of the specimens, we could not examine in patient 1. Bar ⫽ 50 ␮m. (F) Modified Gomori-trichrome staining from patient 3 shows focal involvement in the muscle section. Bar ⫽ 50 ␮m. (G) Immunoblotting analysis of FHL1 in muscle specimens from patients 2, 3, 4, and 5 show variable amount of FHL1. Patients 2, 4, and 5 show significant reduction in FHL1 amount. Patient 4 (son) shows more reduction in FHL1 amount than patient 5 (his mother). Patient 3 shows slight increase in FHL1. Relative amount of FHL1 was calculated and normalized to actin (Nichirei).

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5. 6.

7.

Schessl J, Zou Y, McGrath MJ, et al. Proteomic identification of FHL1 as the protein mutated in human reducing body myopathy. J Clin Invest 2008;118:904–912. Kiyomoto BH, Murakami N, Kobayashi Y, et al. Fatal reducing body myopathy: ultrastructural and immunohistochemical observations. J Neurol Sci 1995;128:58–65. Kobayashi Y, Nihei K, Kuwajima K, Nonaka I. [Reducing body myopathy: a case report.] Rinsho Shinkeigaku 1992; 32:62–67. Kiyomoto BH, Murakami N, Kishibayashi J, et al. Reducing bodies in distal myopathy with rimmed vacuole formation. Acta Neuropathol 1995;89:109–111. Ohsawa M, Liewluck T, Ogata K, et al. Familial reducing body myopathy. Brain Dev 2007;29:112–116. Quinzii CM, Vu TH, Min KC, et al. X-linked dominant scapuloperoneal myopathy is due to a mutation in the gene encoding four-and-a-half-LIM protein 1. Am J Hum Genet 2008;82:208–213. Windpassinger C, Schoser B, Straub V, et al. An X-linked myopathy with postural muscle atrophy and generalized hypertrophy, termed XMPMA, is caused by mutations in FHL1. Am J Hum Genet 2008;82:88–99.

H.H. Schaumburg, MD C. Gellido, MD S.W. Smith, MD L.S. Nelson, MD R.S. Hoffman, MD

ELEMENTAL MERCURY NEUROTOXICITY FROM SELF-INJECTION

We describe a Guyanese diabetic man who developed an elevation in body burdens of mercury following repeated self-injection of elemental mercury. His early signs of neurotoxicity responded to excision of the injection sites and chelation therapy. Case report. A 61-year-old diabetic man presented with burning pain in the feet and tremor of the hands. During his 20 years of insulin-dependent diabetes, his most common insulin injection sites were the forearms and abdominal wall. About 4 to 6 years earlier, he first experienced burning discomfort in the feet, attributed initially to his diabetes. This intensified, and a tremor appeared shortly thereafter, which had gradually become disabling. His handwriting steadily progressed to illegibility, and it was difficult for him to drink from a glass without spillage. In the past 4 years he also noticed the appearance of raised black protuberant scars over his volar forearms and abdomen at the usual injection sites. Examination disclosed numerous raised, firm keloids over both forearms (figure, A). Mental status examination revealed normal cognitive function. There was a mild fine rapid tremor of the fingers at rest that became intense on movement. There was no rigidity, bradykinesia, or cogwheeling. Tendon reflexes were 2/4 in the upper limbs, absent in the low-

Figure

Preoperative images from the left forearm

(A) Photograph of keloid following polar biopsy (before radical excision). (B) X-ray showing radiopaque subcutaneous deposition of mercury.

ers. Sensory abnormalities were confined to the distal lower limbs and were consistent with diabetic symmetric neuropathy. Nerve conduction studies disclosed absent sural, radial, median, and ulnar responses and reduced motor amplitudes in peroneal and tibial nerves. Psychiatric consultation revealed no psychiatric or cognitive disorders. A polar biopsy of one of the forearm lesions was unexpectedly consistent with a mercury granuloma. Subsequent radiographs of the forearm (figure, B) and abdomen radiograph demonstrated radiopaque densities consistent with mercury deposition. A 24-hour urine mercury and whole blood mercury concentration (WBMC) were 321 ␮g/L (normal ⬍20 ␮g/L) and 230 ␮g/L (normal ⬍10 ␮g/L); whole blood lead was undetectable. IM dimercaprol (British anti-Lewisite) was administered pre- and post- surgical excision of the forearm and abdominal lesions. Oral succimer (2,3-dimercaptosuccinic acid) was provided postoperatively for 19 days. Further therapy was declined. At a 2-week follow-up examination, his tremor was diminished, his handwriting legible, and WBMC had fallen to 92 ␮g/L. Nine months later, the tremor had disappeared, the sensory (diabetic?) neuropathy was unchanged, and WBMC was 7 ␮g/L. Discussion. Upper limb tremor is commonly the heralding symptom of elemental mercury neurotoxicity and improves pari passu with significant reduction in body burden.1 Elemental mercury intoxication of sufficient magnitude to affect the adult CNS is usually associated with occupational inhalation of vapor.2 While chelation removes very little mercury deposited in tissue, BAL followed by succimer was administered in this case due to the potential for extensive intraoperative mobilization.3 Self-administration of elemental mercury is usually associated with ointments, accidents, suicide attempts,4 alternative medicine therapy, or tattoo augmentation. There is also a widespread belief in Far Eastern and Central and South American countries that mercury injection will increase limb and penile strength or ward off evil.5,6 Elemental mercury is sold in urban religious stores (botanicas) for use in Esperitismo, Santeria, and voodoo magicoreligious practices, as well as for self-medication. A 1996 survey found 38 of 41 surveyed New York City botanicas sold capsules or vials of elemental mercury.7 Despite warnings from public health advocates, pediatricians, and toxicologists, there is still no ban on the sale of elemental mercury. This should be pursued as clearly consequential misuse continues. From the Department of Neurology (H.H.S., C.G.), Albert Einstein College of Medicine, Bronx, NY; and New York City Poison ConNeurology 72

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377

trol Center and Department of Emergency Medicine (S.W.S., L.S.N., R.S.H.), New York University School of Medicine, NY.

2.

Disclosure: The authors report no disclosures. Received May 20, 2008. Accepted in final form August 20, 2008. Address correspondence and reprint requests to Dr. Herbert H. Schaumburg, Departments of Neurology and Pathology (Neuropathology), Albert Einstein College of Medicine, 1300 Morris Park, Bronx, NY 10461-1602; [email protected]

3. 4.

5.

Copyright © 2009 by AAN Enterprises, Inc. 1.

Bassel F. Shneker, MD Peggy D. Baylin, PharmD Michael E. Nakhla, PharmD

Markowitz L, Schaumburg HH. Successful treatment of inorganic mercury neurotoxicity with n-acetyl penicillamine despite an adverse reaction. Neurology 1980;39: 1000–1003.

LINEZOLID INDUCING COMPLEX PARTIAL STATUS EPILEPTICUS IN A PATIENT WITH EPILEPSY

Many antibiotics can worsen seizures in patients with epilepsy and provoke seizures in patients without epilepsy. The agents most commonly associated with this adverse effect include penicillin and other ␤-lactams, imipenem-cilastatin, and quinolones.1 The mechanism by which antibiotics can induce seizures can be related to lowering seizure threshold by affecting neurotransmitters or by decreasing the efficacy of antiepileptic drugs (AEDs).2,3 Linezolid (Zyvox) is the first agent in a new class of antibiotics known as oxazolidinones. Oxazolidinones act primarily against Gram-positive bacteria by inhibiting protein synthesis. The most common side effects from linezolid are nausea, headache, and diarrhea.4 Serious adverse effects such as reversible myelosuppression have been reported.4,5 Linezolid may increase the risk of serotonin syndrome when taken with other serotonergic agents.4,6 Seizures have been reported as side effects in the package insert in children4; however, no case reports of linezolid-induced seizures exist in the medical literature. We report a patient with epilepsy who experienced complex partial status epilepticus (CPSE) upon receiving linezolid. Case report. The patient is a 45-year-old lefthanded woman with a history of epilepsy since childhood. She has been followed in the Epilepsy Clinic at The Ohio State University (OSU) for more than 10 years. She has rare tonic-clonic seizures, frequent (3 per day) simple partial (right-sided dystonic posture for a few seconds), and frequent (2 per day) complex partial seizures (extension of both legs and clonic movements of right side lasting for less than a minute). Her seizures have been intractable despite trying all approved AEDs, vagus nerve stimulator, and two resective brain surgeries (left frontal lobe) that resulted in right-sided weakness. Her past medi-

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6. 7.

Clarkson TW, Magos L, Myers GJ. The toxicology of mercury-current exposures and clinical manifestations. N Engl J Med 2003;349:1731–1737. Hill DM. Self-administration of mercury by subcutaneous injection. BMJ 1967;1:342–343. Ragothaman M, Kulkarni G, Ashraf VV, et al. Elemental mercury poisoning probably causes cortical myoclonus. Mov Disord 2007;22:1964–1968. Oh KJ, Park K, Kang TW, et al. Subcutaneous metallic mercury injection for penile augmentation. Urology 2007; 69:185.e3–185.e4. Prasad VL. Subcutaneous injection of mercury: “warding off evil.” Eviron Health Persp 2004;13:1326–1328. Zayas LH, Ozuah PO. Mercury use in espiritismo: a survey of botanicas. Am J Public Health 1996;86:111–112.

cal history is significant for postictal psychosis and depression. Her medications included zonisamide, clonazepam, acetazolamide, aripiprazole, and lorazepam as needed. She had no history of unusual reaction to any medication. On April 10, 2008, she underwent an excision of a painful wart-like growth on her right knee. Her wound did not heal well and a wound infection was suspected. Wound cultures on April 22, 2008, were consistent with nonpathologic skin flora. On April 24, 2008, she underwent debridement of her wound and was placed on IV vancomycin, then switched to IV linezolid on April 25, 2008, receiving one dose. She was discharged home on April 26, 2008, on oral linezolid. Two doses were taken. In the evening of April 26, 2008, her habitual complex partial seizures became more frequent and longer in duration. Oral lorazepam did not help. The seizures became almost constant. She was admitted to OSU Medical Center with a diagnosis of CPSE. She was intubated, placed on a propofol drip, and given IV levetiracetam in addition to her home AEDs. IV vancomycin was started in place of linezolid. Continuous EEG monitoring showed initially frequent seizures of left fronto-central onset that subsided with treatment. On the morning of April 28, 2008, propofol was stopped and she was successfully extubated. Her seizures were back to baseline (few daily seizures). Her workup ruled out any acute systemic or neurologic process. She was febrile at presentation; however, no source of infection was found. On April 29, 2008, all IV medications were switched to oral formulations with plans to complete a 7-day course of antibiotics. Oral linezolid was restarted on April 30, 2008. Late that morning, she started to have prolonged and frequent seizures. She received benzodiazepines and her levetiracetam was increased. Seizures became more frequent. On the morning of May 1, 2008, linezolid was stopped after a total of three doses. She was loaded with IV fosphenytoin. Within 18 hours, the

patient’s seizure frequency improved dramatically and she seemed to be at her baseline. She was discharged home on May 2, 2008.

Pharmacy (P.D.B.), The Ohio State University Medical Center, Columbus. Disclosure: The authors report no disclosures. Received June 5, 2008. Accepted in final form August 25, 2008.

Discussion. Our patient developed CPSE and had worsening of her seizures. The patient had no acute neurologic or systemic illness to explain the worsening of her seizures. She has no history of status epilepticus in the past. Historically, she is a very compliant patient. Although we cannot be definite about the exact cause, the chronological correlation suggests that linezolid was the cause. Our patient was given linezolid on two separate occasions. On each occasion, within less than 24 hours of starting linezolid, she had significant worsening of her seizures. Seizures improved dramatically within 24 hours of stopping linezolid. The mechanism by which linezolid worsened our patient’s seizures is not clear. A review of the patient’s concomitant medication list did not reveal any possible drug– drug interactions with linezolid. Unfortunately, the levels of zonisamide and clonazepam were not checked to determine if linezolid affected either one. Linezolid should be administered cautiously in patients with a history of epilepsy. From the Department of Neurology (B.F.S.) and College of Pharmacy (M.E.N.), The Ohio State University; and Department of

Address correspondence and reprint requests to Dr. Bassel F. Shneker, Assistant Professor, The Ohio State University, Department of Neurology, 1654 Upham Drive, 411 Means Hall, Columbus, OH 43210; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4. 5. 6.

Granowitz EV, Brown RB. Antibiotic adverse reactions and drug interactions. Crit Care Clin 2008;24:421– 442. Sugimoto M, Uchida I, Mashimo T, et al. Evidence for the involvement of GABA(A) receptor blockade in convulsions induced by cephalosporins. Neuropharmacology 2003;45:304–314. Coves-Orts FJ, Borras-Blasco J, Navarro-Ruiz A, MurciaLopez A, Palacios-Ortega F. Acute seizures due to a probable interaction between valproic acid and meropenem. Ann Pharmacother 2005;39:533–537. Available at: http://media.pfizer.com/files/products/uspi_ zyvox.pdf. Accessed June 5, 2008. Moellering RC. Linezolid: The first oxazolidinone antimicrobial. Ann Intern Med 2003;138:135–142. Morales-Molina JA, Mateu-de Antonio J, Marin-Casino M, Grau S. Linezolid-associated serotonin syndrome: What we can learn from cases reported so far. J Antimicrob Chemother 2005;56:1176–1178.

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REFLECTIONS: NEUROLOGY AND THE HUMANITIES

Poems

Section Editor Michael H. Brooke, MD

Arthur Ginsberg, MD

Address correspondence and reprint requests to Dr. Arthur Ginsberg, 10470 Meridian Avenue N, Seattle, WA 98133 [email protected]

380

CONSCIOUSNESS

SPINE

floats in the delicate ether of butterflies, brain spilt into itself, warbling through a garden of grey matter, an unmistakable interiority that does not emote, gabble or quack, is pre-syntax and babble, reigns like a cloud over the birth of flowers, gazes across a moat into the forest of pheromones and photons, the din of decibels, and into the reservoir of itself; a pool of unshattered meniscus, untouched by the tongue that comes out of the mouth, flicking the surface like trout. Mind sifts the pre-syllabic library in every ridge and rut, lifts on muslin wings beyond the circuitry, and waits for the anesthesia of sleep, when consciousness fibrillates, set free to orbit in the galaxy of Galileo’s imagery. Without it, worlds that men propose, reality or dream, would be unmindfully comatose.

you have held me in all matters of gravity; extended, flexed and bowed

Copyright © 2009 by AAN Enterprises, Inc.

as a reed in the wind. Between sculpted blocks, viscous pillows absorb contortion and shock. All my goods are hung upon your gallows, viscera suspended like avocados from a bough, the muscles stitched to knobby rack, a ridge like Stegosaurus, and dropping down, the pelvis wed to sacroiliac. Bottom end, vestigial bone of my tail; perched on top, the locked box of my soul. With Newtonian zeal you have served my dance and line with hubris and strut, priest of the bipedal romp. There will be pain as my plumb-line bends, white-hot Camelias sprouting from ligaments. In time you will be my memory when mortality’s stripped off the rack, you will shiver and rattle through earth’s cold bite, the last witness intact.

NEUROIMAGES

Open-ring peripherally enhancing lesion of the cervical spine

Figure

Sagittal STIR (A) and axial gadolinium enhanced T1-weighted (B) images demonstrate a 3.6-cm expansile lesion of the cervical spine extending from the C2 through C4 level with abnormal STIR signal and associated open-ring peripheral enhancement suggestive of active demyelination

A 26-year-old woman presented with progressive difficulty ambulating and upper and lower extremity numbness. Clinical examination showed dysesthesia and an allodynia sensation in the bilateral upper and lower extremities. She also demonstrated primary dysmetria and incoordination especially on finger to nose testing. Reflexes were extremely brisk and the gait was ataxic and unstable. CSF analysis revealed increased IgG synthesis rate and oligoclonal banding consistent with multiple sclerosis. To our knowledge, the association between open-ring peripherally enhancing lesions of the spine (figure) in patients with multiple sclerosis has been previously described only once in the Japanese literature.1 Wilson Pyle, MD, Khurshed Dastur, MD, Moshin Rahman, MD, and Jawad Tsay, MD, Pittsburgh, PA Disclosure: The authors report no disclosures. Address correspondence and reprint requests to Dr. Wilson Pyle, Department of Radiology, UPMC Mercy Hospital, 1400 Locust St., Pittsburgh, PA 15219; [email protected] 1.

Dohi N, Ishikawa S, Kamijyo Y, et al. Multiple sclerosis with open-ring enhancement in the cerebrum and spinal cord. Intern Med 2003;42:273–276.

Copyright © 2009 by AAN Enterprises, Inc.

381

RESIDENT & FELLOW SECTION Section Editor Mitchell S.V. Elkind, MD, MS

L.A. Schuh, MD J.C. Adair, MD O. Drogan, MS B.M. Kissela, MD J.C. Morgenlander, MD J.R. Corboy, MD

Address correspondence and reprint requests to Dr. Lori Schuh, Department of Neurology, Henry Ford Hospital, 2799 West Grand Blvd., Detroit, MI 48202 [email protected]

Education Research: Neurology residency training in the new millennium ABSTRACT

Objective: To survey adult neurology program directors (ANPD) to identify their most pressing needs at a time of dramatic change in neurology resident education.

Methods: All US ANPD were surveyed in 2007 using an instrument adjusted from a 1999 survey instrument. The goal was to characterize current program content, the institution and evaluation of the core competencies, program director characteristics, program director support, the institution of work duty hour requirements, resident support, and the curriculum needs of program directors and programs.

Results: A response rate of 82.9% was obtained. There is a significant disconnect between administration time spent by ANPD and departmental/institutional support of this, with ANPD spending approximately 35% of a 50-hour week on administration with only 16.7% salary support. Rearrangement of rotations or services has been the most common mode for ANPD to deal with work duty hour requirements, with few programs employing mid level providers. Most ANPD do not feel work duty hour reform has improved resident education. More residents are entering fellowships following graduation than documented in the past. Curriculum deficiencies still exist for ANPD to meet all Neurology Program Requirements, especially for nontraditional neurology topics outside the conventional bounds of clinical neurology (e.g., practice management). Nearly one quarter of neurology residency programs do not have a meeting or book fund for every resident in the program.

Conclusions: Adult neurology program directors (ANPDs) face multiple important financial and organizational hurdles. At a time of increasing complexity in medical education, ANPDs need more institutional support. Neurology® 2009;72:e15–e20 GLOSSARY AAN ⫽ American Academy of Neurology; ACGME ⫽ Accreditation Council for Graduate Medical Education; ANPDs ⫽ adult neurology program directors; CNPD ⫽ Consortium of Neurology Program Directors; GES ⫽ Graduate Education Subcommittee; NPR ⫽ Neurology Program Requirements; NRC ⫽ Neurology Review Committee; PA ⫽ program administrator.

Supplemental data at www.neurology.org

Neurology residency training has experienced unprecedented change in the new millennium with the introduction of the Accreditation Council for Graduate Medical Education’s (ACGME) Outcome Project and the institution of work hour requirements.1,2 In the first two phases of the Outcome Project (July 2001–June 2006), learning opportunities in the six core competencies were integrated into residents’ didactic and clinical educational experiences and programs were required to improve evaluation of resident performance in all competency domains. In the third phase (July 2006 –June 2011), programs are expected to provide evidence of data driven residency program improvements with resident performance data becoming the basis for program improvement and evidence for accreditation review. External measures such as clinical quality indicators, patient surveys, and graduate surveys are being used to verify performance. In this same time frame, the ACGME mandated Resident Work Duty Hour Requirements limiting the total number of hours per shift and per week, and setting the

Editorial, page 302 From the Department of Neurology (L.A.S.), Henry Ford Hospital, Detroit, MI; Department of Neurology (J.C.A.), University of New Mexico School of Medicine, Albuquerque; American Academy of Neurology Staff (O.D.), St. Paul, MN; Department of Neurology (B.M.K.), University of Cincinnati, OH; Department of Medicine (J.C.M.), Duke University Medical Center, Durham, NC; and Denver Veterans Affairs Medical Center and Department of Neurology (J.R.C.), University of Colorado Health Sciences Center, Denver. Disclosure: L.A. Schuh has received an AAN Education Research Grant. J.C. Adair, B.M. Kissela, J.C. Morgenlander, and J.R. Corboy have none relevant to this article. O. Drogan is a salaried employee of the AAN. Copyright © 2009 by AAN Enterprises, Inc.

e15

Table 1

Program director work duties

Duty

Mean hours per week

Median hours per week

Minimum hours per week

Maximum hours per week

Clinical duties (n ⴝ 98)

25.5

20.0

5

70

Teaching–residency (n ⴝ 95)

7.7

6.0

2

40

Administrative–residency (n ⴝ 98)

9.6

9.0

1

30

Education research (n ⴝ 46)

2.5

1.5

0

20

Teaching–other (n ⴝ 73)

3.8

2.0

0

20

Administrative–other (n ⴝ 70)

7.2

5.0

0

25

Research–other (n ⴝ 70)

7.4

5.0

0

50

n ⫽ number of respondents.

minimum hours between shifts and number of days off per week. These changes have dramatically altered neurology residency curricula and the role and administrative workload of program directors. In light of these challenges, the Graduate Education Subcommittee (GES) and Consortium of Neurology Program Directors (CNPD) of the American Academy of Neurology (AAN) conducted a survey of adult neurology program directors (ANPD) to ascertain the state of neurology training. The goal was to characterize current program content, the evaluation of the core competencies, program director characteristics and support, the effects of work hour requirements, resident support, and the curriculum needs of programs. Results were compared to those from a prior survey completed in 1999.3 We wanted to identify the most pressing needs of ANPD in this changing educational environment. METHODS The GES and CNPD designed a 46-question survey modified from a 1999 survey of ANPD to address the issues described above.3 Questions were determined over the course of several GES meetings and through e-mail communication. In January 2007, a draft was submitted to the AAN Member Demographics Subcommittee for review and to obtain suggestions for improvement. The final survey was sent to all ANPD with active status in the AAN as of February 21, 2007. Directors of child neurology programs and Canadian programs were excluded. Responses were confidential, although AAN staff could track nonrespondents. Staff sent four reminders to nonresponders and members of the CNPD and GES called nonresponders encouraging the return of the survey the week before data collection was closed (April 16, 2007). Data were analyzed by Oksana Drogan, AAN staff. Subset data analysis was performed by program type: state university, private university, or community program; by program size: small (1–9 residents), medium (10 –16 residents), and large (ⱖ17 residents); and by e16

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level of support: those with funding from the department or institution for role of program director or other administrative work vs no funding for administration.

The survey was sent to 123 ANPD. A total of 102 surveys were returned for a response rate of 82.9%.

RESULTS

Program characteristics. Forty-six percent of respondents were from state universities, 35% from private universities, 17% community programs with or without a university affiliation, and 2% military programs. A mean of 14.0 (range 3– 41) residents trained at each program. The majority (67.0%) of programs had voluntary unpaid clinical faculty participating in resident teaching. Community programs were more likely to rely on a significant percentage of teaching from voluntary faculty (mean 56.1%) compared to state (mean 7.2%) or private university programs (mean 15.4%). Program director demographics. The majority (81%) of ANPD were men. About half of all ANPD were in a “clinician-educator” track (54.7%). Of the remainder, this track was not available to 65% at their institution. The academic ranks of ANPD tended to be advanced with 32.7% professors, 44.9% associate professors, and only 21.4% assistant professors. ANPD served a mean of 6.7 years as program director and many had other administrative duties (11% preclinical neuroscience course director, 18% student clerkship director, 22% fellowship director, 27% department chair or section chief, and 12% vice-chair). ANPD support. ANPD spent approximately 17.3 hours per week (35% of a 50-hour work week) on duties related to teaching and administration, while a mean of 16.7% of their salaries came from departmental or institutional funds earmarked for these activities (ables 1 and 2). Nearly 25% received no departmental or institutional support for residency work. The time required solely for administering the residency program increased proportional to program size. ANPD of small programs devoted on average 7.7 hours per week, compared to medium programs (9.0 hours) and large programs (12.5 hours). ANPD from community programs spent a greater amount of time per week providing clinical care (mean 36.6 hours) than ANPD of state (23.5 hours) or private universities (24.8 hours). Eighty percent of all ANPD have attended a CNPD meeting, with 97% of ANPD from private universities and 70% of ANPD from state university or community programs attending. Nearly 36% of ANPD from small neurology programs have never attended a CNPD meeting. Many are encouraged by their chair to attend

Table 2

Salary sources for adult neurology program directors (n ⴝ 98)

Source

Mean %

Median %

Minimum %

Maximum %

Clinical income

to a fixed number of positions, has limited the ability of 49.5% of ANPD to offer their residents external rotations.

51.7

50

0

100

Resident research. Ten percent of neurology resi-

Research grants

5.8

0

0

75

Education grants

0.9

0

0

25

Endowment

1.0

0

0

35

10.7

0

0

50

Departmental funding for other administrative work

4.2

0

0

75

Institutional funding for program director

6.0

0

0

50

Institutional funding for other administrative work

7.7

0

0

100

dency programs include a research requirement for every resident with dedicated research rotations, while 53% required research but afforded trainees no specific rotation. Research rotations last 1–3 months with about half equally split between 1 and 2 months. Fifty percent of programs with a dedicated research rotation did not need to alter resident schedules to accommodate the rotation as they always required such training, while 30% reduced elective time, 10% reduced ward service, and 10% reduced other rotations.

Departmental funding for program director

(75.3%), with 44.4% receiving financial support to attend both CNPD meetings each year, and 31.1% receiving no support to attend either meeting. About half (53.9%) employed a full-time program administrator (PA), while 38.2% employed a part-time PA. Large programs were more likely to have a full-time PA (74%) compared to medium (43%) or small programs (46%). About a quarter of programs designated an assistant or associate program director (26.5%). A full or part-time secretary was available to 8.8% and 19.6% of programs. Few programs employed departmental information technologists or PhD educators (5.9% and 3.9%). Most ANPD (90.2%) favored sending PAs to professional development courses. Likewise, ANPD supported developing medical education workshops separate from the Annual AAN Clerkship and Residency Program Director’s Conference: 74.7% favored attaching workshops to the AAN annual meeting, 32.3% favored workshops at the American Neurological Association annual meeting, and 31.3% would attend any time, including a completely unattached meeting. Resident support. Seventy-eight percent of residency

programs provided a book fund for every resident in the program, with an average annual amount of $510.70 per resident. Nearly a quarter of residency programs provided no meeting expense funds for each trainee (24.0%). For programs that provide meeting expense funds for every resident, the average annual amount was $897.20. Of those programs that provide meeting expense funds to every resident, 45.3% offered funds every year of training, 33.3% during 1 year of training, and 56.0% when residents presented abstracts at national meetings. Small and medium-sized programs were more likely to fund residents to attend meetings every year of training (small 53%, medium 49%, large 28%). The institution of the Medicare “Cap,” which strictly limits funding of residency training

Work duty hours. Programs most commonly rear-

ranged services and rotations to accommodate work hour requirements. Table e-1 on the Neurology® Web site at www.neurology.org lists other adaptations instituted by ANPD. Fifteen percent of programs used mid-level providers to deal with work hour reform. Thirty-two percent of ANPD track duty hours with electronic or written time records on a continuous basis, while 41.0% track hours intermittently. Very few ANPD believe that implementation of duty hour limits has improved patient care (8.1%) or resident education (15%). The majority of ANPD believe the rules have improved resident quality of life (80%) but increased faculty work load (61.6%). Graduate information. ANPD reported a mean of

76.9% of their program graduates from the prior 3 years entered fellowships, while 22.6% went directly into practice. Most (71.3%) entered ACGME approved clinical fellowships, while 24.5% entered nonACGME approved clinical fellowships; 1.6% entered basic science fellowships, and 2.6% entered a mixed clinical and basic science program. More graduates from small programs entered practice (41.4%) than their counterparts in medium (18.4%) and large programs (11.6%). Curriculum. The ACGME Neurology Program Requirements (NPR) outline the topics which must be covered during residency training. The ANPD were polled about the availability of specialists in 36 areas specifically listed in the program requirements, including whether faculty were available within or outside their department, and whether the educational experience was an internal rotation, external rotation, or didactic experience (table 3). Data demonstrate programs are more likely to lack faculty in highly specialized areas (neurointensive care, neurology of aging, neuro-oncology, neuro-otology, and Neurology 72

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Program content (n ⴝ 102)

Table 3

Faculty within department

Faculty outside department

No faculty available

Neurophysiology

89.1

20.8

4.0

Neuropharmacology

40.6

51.5

13.9

Neuropathology

41.2

66.7

0

Neuroimmunology

68.7

19.2

15.2

Neurogenetics

52.0

40.0

16.0

Neuroepidemiology

36.0

38.0

Neuroradiology

40.2

Pediatric neurology

80.2

Neurointensive care EEG-epilepsy

Internal rotation

Outside rotation

Didactic lecture(s) or course

Neurosciences 37.6

4.0

49.5

3.0

2.0

49.5

41.2

12.7

42.2

16.2

3.0

45.5

7.0

6.0

46.0

28.0

3.0

3.0

42.0

73.5

2.0

48.0

3.9

42.2

28.7

0

47.5

10.9

42.6

65.7

26.5

14.7

34.3

10.8

31.4

98.0

4.9

0

53.9

2.9

47.1

EMG-neuromuscular

98.0

4.9

0

53.9

2.9

47.1

Evoked potentials

99.0

2.0

0

36.3

2.0

40.2

Vascular neurology

98.0

3.9

1.0

47.1

1.0

50.0

Psychiatry

23.5

85.3

0

45.1

5.9

39.2

Neurosurgery

15.8

86.1

0

30.7

4.0

30.7

Neuroanatomy

60.8

50.0

5.9

5.9

2.0

53.9

Behavioral neurology

78.4

19.6

8.8

25.5

3.9

46.1

Movement disorders

88.2

6.9

6.9

34.3

8.8

47.1

Pain management

43.1

57.8

8.8

16.7

10.8

40.2

Neurology of aging

70.6

22.5

14.7

12.7

3.9

35.3

Headache

91.2

5.9

4.9

21.6

2.9

47.1

Neuro-oncology

50.0

37.0

17.0

25.0

8.0

44.0

Neuro-ophthalmology

45.5

59.4

5.0

32.7

7.9

44.6

Neuro-otology

21.8

66.3

13.9

10.9

5.0

38.6

Neurorehabilitation

35.0

65.0

4.0

21.0

17.0

35.0

Sleep disorders

65.7

40.2

4.9

29.4

6.9

49.0

Neuroinfectious disease

42.6

46.5

14.9

5.9

4.0

47.5

End-of-life/palliative care

44.1

56.9

8.8

4.9

2.9

52.0

Ethics

49.0

56.9

5.9

2.0

1.0

55.9

Practice management

48.5

33.7

19.8

2.0

0

45.5

Statistics/epidemiology

46.1

54.9

9.8

1.0

2.0

45.1

Medicolegal

22.5

47.1

29.4

1.0

0

39.2

Outcomes research

38.4

42.4

24.2

1.0

0

32.3

Recognition and management of abuse

17.8

59.4

22.8

1.0

1.0

34.7

Cost-effective care

42.0

37.0

24.0

1.0

0

36.0

Effects of sleep deprivation

50.0

35.3

13.7

2.0

0

48.0

Clinical topics

Values are percentages. Percentages add up to greater than 100 because departments may have expertise both within and outside the department, and may have rotations and didactic experiences.

neuroinfectious disease). About 6 –30% of programs have no faculty teaching nontraditional topics outside the conventional bounds of clinical neurology (e.g., ethics, practice management, end-of-life/palliative care, medicolegal issues, effects of sleep deprivation, and recognition and management of physical/sexual abuse). e18

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When ANPD prioritized their preference for distance learning educational supplements for residency training, from the list of 36 educational components the top five priorities related to these topics were statistics/epidemiology, practice management, medicolegal issues, ethics, and neuropharmacology (in descending order).

Table 4

Length of rotations for a typical neurology resident (n ⴝ 92)

Rotation

Mean number of months (range)

Inpatient adult wards/consults

13.3 (8–20)

Outpatient clinics (include continuity clinic)

5.3 (0–10)

Pediatric neurology

3.1 (2–6)

Neuroradiology

1.0 (0–5)

Psychiatry

1.0 (0–3)

Neurosurgery

0.4 (0–2)

Neuropathology

1.3 (0–3)

EEG

1.5 (0–4)

EMG

1.9 (0–4)

Epilepsy unit (if separate from adult wards)

0.5 (0–3)

Research

0.3 (0–2)

Electives

4.3 (0–11)

Neurorehabilitation

0.4 (0–4)

Neurointensive care (if separate from adult wards)

0.6 (0–4)

Neuro-ophthalmology

0.3 (0–2)

Entries totaling more than 36 months were excluded from the analysis.

There continues to be a wide variety of rotation experiences offered in different programs, as seen in table 4. Twenty-five percent of program directors polled would increase the duration of neurology residency training by 1 year. ANPD have incorporated multiple methods to evaluate the six core competencies (table e-2). Most programs use a global rating scale to evaluate all core competencies, a written examination to evaluate medical knowledge, and multisource/360 degree assessments of interpersonal and communication skills and professionalism. This survey provides important insight into the needs of ANPD and residency training programs in this unprecedented time of change in training. These results demonstrate a striking disconnect between ANPD administration and teaching time commitment in residency programs and the level of support for these activities. These findings are basically unchanged compared to the 1999 survey. Support includes not only ANPD salary and dedicated time, but support for a dedicated PA, and faculty development through subsidizing attendance at CNPD meetings. These results also demonstrate less than adequate support of residents in about a quarter of programs as evidenced by the absence of a book or travel fund. From this survey, small communitybased programs are the most likely to lack sufficient

DISCUSSION

support. Program requirements of other nonsurgical specialties (dermatology, emergency medicine, family medicine, internal medicine, pediatrics, psychiatry, and diagnostic radiology) were reviewed; only neurology and dermatology fail to specifically require salary support or minimum protected time for program directors.4 Many ANPD also desire career development with more education-oriented workshops than are currently available at the AAN annual meeting. ANPD accommodate work hour requirements with a variety of program changes. Compared to neurosurgery, mid-level providers have not filled the gap for neurology programs.5 This is not surprising given the differences in clinical income between the surgical and nonsurgical specialties. It is also likely that physician extenders are better suited to neurosurgery for the portion of their service which provides care to medically well patients admitted for elective procedures in which standardized clinical pathways can be employed. Institution of a night float system has not been common except in large neurology programs where nearly half have such systems. According to ANPD work hour reform has not improved resident education or patient care, and there is increasing stress on academic physicians to, in part, make up for time residents are not available. While these statements remain to be independently verified, they are basically unchanged from the opinions of a limited number of ANPD surveyed in 2004 immediately after institution of duty hour reform.6 Multiple areas of curricular deficiency in residency programs were identified. A trend continues toward increased outpatient clinic rotations compared to 1999, with a reduction in the months on neuropathology, EMG, EEG, and electives.3 Despite increased outpatient clinic time, the 2007 respondents reported a mean of 5.3 months in the outpatient clinic setting, whereas ACGME NPR mandate a minimum of 6 months. Respondents may have failed to include longitudinal clinic experiences, despite instructions to include all clinic experiences, or simply reported inaccurate data. Compared to 1999, slightly more programs have no faculty to teach traditional topics such as neuropharmacology and neuroimmunology.3 Nontraditional education components (ethics, end-of-life/palliative care, statistics and epidemiology, practice management) are also NPR but only 32– 63% of programs provide a didactic experience in these areas. Despite these deficiencies, the authors are optimistic that innovation can help ANPD meet these needs. For example, the AAN offers a basic science curriculum for residents including neuropharmacology at the annual meeting. ANPD can already access the Neurology 72

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AAN’s case-based curriculum, “Ethical Dimensions of Neurologic Practice,” currently being updated by the AAN Ethics, Law and Humanities Committee (personal communication, Tyler Reimschisel, MD). The AAN’s Evidence Based Medicine Toolkit includes didactics on basic statistics and epidemiology and became available to ANPD in 2008. Web-based curricula covering traditional neurology topics (e.g., headache and epilepsy) have also been developed.7,8 The reliability and validity of these curricula and tools have not yet been determined. Validated educational tools and curricula in end-of-life/palliative care are also available to ANPD, and have been adopted successfully in some programs.9,10 This survey has provided a set of priorities for the development of supplemental educational materials for residency use. Statistics/epidemiology was the first priority followed by practice management, medicolegal issues, and ethics. High priority should be placed on the development of a practice management and a medicolegal educational resource as it is unlikely these needs will be met at each individual program site. This may be accomplished through a Web-based tool or development of educational modules for local program use. It is interesting that ANPD recognize deficiencies in teaching nontraditional topics such as end-of-life/palliative care and recognizing the effects of sleep deprivation but these were not highly ranked as priorities for the development of supplemental educational materials for residency use. We hope this survey becomes an instrument of change. The survey results have been shared with ANPD, the GES, and the ACGME Neurology Review Committee (NRC). One purpose of this survey was to provide important benchmarking information for ANPD. Despite fiscal challenges to residency programs, all wish to recruit the best possible candidates. This information may assist ANPD in highlighting their program’s strengths and in advocating for curriculum change or resident support to enhance their program’s attractiveness to applicants. The results of this survey highlight the need for revising the NPR to address important issues of salary and professional development support for ANPD, administrative support with a PA, and resident travel and book

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fund support. Indeed, the GES and CNPD formally asked the NRC to require several of these items and the updated NPR will include new requirements for minimum ANPD salary support, support for ANPD attendance at one education meeting per year, and support for resident attendance at one national meeting during training. The survey’s limitations are clear. The information obtained cannot be externally verified. Furthermore, data from child neurology and fellowship program directors were not obtained. Their input into neurology education needs is also vital and should be addressed by future surveys. ACKNOWLEDGMENT The authors thank Lucy Persaud for administrative help and the members of the Graduate Education Subcommittee of the AAN for comments and direction.

REFERENCES 1. ACGME Outcome Project. Available at: http://www.acgme. org/outcome/project/timeline/TIMELINE_index_frame. htm. Accessed July 14, 2008. 2. ACGME Resident Duty Hours. Available at: http://www. acgme.org/acWebsite/dutyHours/dh_Lang703.pdf. Accessed July 14, 2008. 3. Corboy JR, Boudreau E, Morgenlander JC, Rudnicki S, Coyle PK. Neurology residency training at the millennium. Neurology 2002;58:1454–1460. 4. ACGME Review Committees, Program Requirements. Available at: http://www.acgme.org/acWebsite/home/ home.asp. Accessed July 19, 2008. 5. Cohen-Gadol AA, Piepgras DG, Krishnamurthy S, Fessler RD. Resident duty hours reform: results of a national survey of the program directors and residents in neurosurgery training programs. Neurosurgery 2005;56:398–403. 6. Watson JC. Impact of the ACGME Work Hour Requirements: a neurology resident and program director survey. Neurology 2005;64:E11–E15. 7. American Headache Society Neurology Residency Program. Available at: http://www.ahs-cbl.com/cbl/default. aspx. Accessed July 23, 2008. 8. American Epilepsy Society Epilepsy Education Program. Available at: http://www.aesnet.org/go/professionaldevelopment/educational-opportunities/epilepsy-educationprogram/epilepsy-education-program. Accessed July 23, 2008. 9. End-of-Life/Palliative Education Resource Center. Available at: http://www.eperc.mcw.edu/. Accessed July 19, 2008. 10. Schuh LA, Biondo A, An A, et al. Neurology resident learning in an end-of-life/palliative care course. J Palliat Med 2007;10:178–181.

PATIENT PAGE Section Editors David C. Spencer, MD Steven Karceski, MD

Kathleen A. WelshBohmer, PhD Charles L. White III, MD

Alzheimer disease What changes in the brain cause dementia?

When scientists look under the microscope at the brains of very elderly patients who have died, some confusing patterns are seen. Some patients who had healthy memory and thinking show many of the findings often seen in patients with Alzheimer disease (AD). These are called plaques and tangles. This is confusing because plaques and tangles are not always seen in normal patients but are more common in patients with AD. At the same time, some patients with significant dementia have very few of these brain changes. Brain researchers wonder how memory and brain function stay healthy in patients even though their brains show problems seen in AD. A new study reported by Erten-Lyons and coauthors tries to answer this question (Neurology 2009; 72:354 –360). They compared the brains of patients with AD to another group that had similar findings under the microscope but had normal thinking and memory. They asked, “What protects those patients whose thinking remains normal?” The investigators looked for differences in the medical histories and brain examinations of these two groups. They also looked at differences in the size of some brain areas using MRI scans that were taken when the patient was living. Along with the MRIs, other changes were considered, like age, sex, and timing of the MRIs. The authors’ idea was that plaques and tangles might be necessary to cause AD, but that there might be some important reasons why some patients did not get AD. They thought that patients with healthy brains might be able to lose some brain function but have enough reserve that these changes did not result in dementia. The authors were also interested in other factors that might show why these patients seemed to be protected. Surprisingly, the two groups were not very different in their medical histories, ages, or education. They looked similar

WHAT WAS THE MAIN FINDING?

on an important gene test. In addition, their brain studies did not show more signs of small strokes or other differences that might explain why one group had more memory and thinking problems and the other did not. However, the groups were different when the size of some brain areas was compared. Those people with plaques and tangles who did not show thinking and memory problems had larger overall brain size than the group that had dementia. In addition, the brain structure that is important for new learning and memory, the hippocampus, was also larger in the healthy group. Importantly, these brain size differences were seen even after the researchers carefully considered a number of other factors. These factors included the time between brain MRI and death, age, and number of plaques and tangles in the brain. HOW DOES THIS HELP EXPLAIN WHY SOME PEOPLE GET AD AND SOME DO NOT? The

findings are interesting and suggest that there is not a direct link between the presence of plaques and tangles and dementia. It has been long suspected, and proven here, that it is possible to survive into old age without developing dementia, even with many plaques and tangles in the brain. The results raise the important possibility that healthy brain aging requires healthy brain cells and a high number of brain cell connections (synapses). This is consistent with the cognitive reserve idea, which suggests that larger brain size and greater cognitive abilities beginning early in life may be important for later protection against dementia. Whether or not this idea is true, the findings indicate that brain size measurements may show if someone is at risk of developing dementia. Studies like this may point the way toward better prevention of dementia. Finding ways to actively prevent dementia is a very important approach, since our ability to treat AD, once it has started, is currently very limited.

Copyright © 2009 by AAN Enterprises, Inc.

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PATIENT PAGE Section Editors David C. Spencer, MD Steven Karceski, MD

About Alzheimer disease

AD is a progressive neurologic disorder associated with aging. It is common, now affecting more than 5.2 million Americans. AD begins with great difficulty in new learning and memory, which leads to forgetfulness of recent events. AD worsens over time, usually over many years, leading to difficulty remembering new events, problems in finding words and reasoning, difficulty completing normal activities, relying on others to function, and ultimately death. At autopsy, when the brain of a patient with AD is examined under a microscope, there are abnormal cells and cell structures in the brain, particularly in portions of the brain related to memory. These parts of the brain include the entorhinal cortex and hippocampus. Under the microscope, a researcher is likely to see atrophy, or shrinkage, in this region. There also may be more generalized shrinkage in the outer gray matter or cerebral cortex, resulting in reduced brain weight and visible brain shrinkage. The key diagnostic neuropathologic features of the disease are senile plaques, a buildup of a protein called amyloid. It is surrounded by dead or dying neurons and inflammatory cells. In addition, the other features are neurofibrillary tangles, which are present in significant numbers throughout the memory structures and cerebral cortex. Amyloid of senile plaques are outside the cell. Tangles are intracellular—inside the cell—and are a buildup of an abnormal form of another protein, tau. Tau is in the neurons and neurons are the cells that assist in all brain functions (such as thinking and memory). The presence of neurofibrillary tangles signals an interruption of cell transport properties that are important for neuronal survival and function. This type of interruption leads to synapse contacts and results in weakened communication between cells in the brain.

WHAT IS ALZHEIMER DISEASE?

WHAT IS COGNITIVE RESERVE? Cognitive reserve has been suggested as a concept to explain the differences among individuals in coping with the neuropathologic changes, plaques and tangles, of AD. The notion is that the ability of the mature brain to sustain normal function in the face of significant disease or injury is a function of its reserve capacity. The cognitive reserve capacity is set early in e22

Copyright © 2009 by AAN Enterprises, Inc.

life and gradually declines as the nervous system ages. As individuals age, those with a greater reserve capacity will have a lower risk of dementia than individuals with less cognitive reserve. The impact of brain diseases or injuries will be less apparent in those with a greater reserve capacity, as healthy brain functions are able to accommodate for the cell loss. However, in those where cognitive reserve capacity is low, the effects of the same injury will be more readily apparent as the limited resources available in this situation become expended more quickly. WHERE DO WE GO FROM HERE IN APPLYING THESE FINDINGS TO ENHANCE CLINICAL DIAGNOSIS AND TREATMENT? The challenge

presented by these findings is to determine the biologic factors that support larger brain volumes that will protect against cognitive decline. Knowing these factors will assist in the prevention of cognitive decline and in efforts to maintain brain function even if there is brain disease. Several possibilities can be explored that could affect care. First, some investigators have suggested that larger brain sizes reflect the limits of our inherited hardware. If correct, this suggests that our brain reserve is set early in brain development and that protection against disease during later aging is a result of the proportion of healthy cells to those affected by disease.1 The goal would be maintaining healthy cellular function throughout life. However, other investigators believe that it is not necessarily the number of cells people have but rather the activity of specific neural circuits and synapses, and the efficient use of alternative brain networks that play a role in cognitive resiliency. This suggests that habits or lessons learned early in life may help to keep the brain active and healthy into old age. This highlights the importance of keeping the brain active. Still another idea is that despite what we inherit and how we use these capacities, environmental factors may hinder cell death and influence the development of AD symptoms. This hypothesis focuses more on cell mechanisms and suggests that there are many events that lead to clinically expressed symptoms of AD. These events can possibly be changed, turned on or delayed, by factors such as high educa-

tion, exercise, nutrition, and absence of cerebral vascular disease. It is possible that all of these are correct. Good cognitive function may be related to starting capacity and continued efficient neural processing, but it may also be due to inherited genes and how these genes are changed by other health conditions, lifestyle habits, and other factors. Because many of the factors suggested to enhance cognitive resiliency are also important for cardiovascular and cerebrovascular health, attention to healthy diet and lowering cardiovascular risk conditions, such as controlling weight, blood pressure, and diabetes, will be important for

both heart and brain health. The treatment for AD will depend on uncovering the cellular mechanisms responsible for the expression of dementia and the early memory symptoms. Plaques and tangles are a part of the story but may not be the entire picture. For more information, see your local chapter of the Alzheimer’s Association or go to www.alz.org

FOR MORE INFORMATION

REFERENCE 1. Scarmeas N, Stern Y. Cognitive reserve: implications for diagnosis and prevention of Alzheimer’s disease. Curr Neurol Neurosci Rep 2004;4:374–380.

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Correspondence

PRACTICE PARAMETER: ASSESSING PATIENTS IN A NEUROLOGY PRACTICE FOR RISK OF FALLS (AN EVIDENCE-BASED REVIEW): REPORT OF THE QUALITY STANDARDS SUBCOMMITTEE OF THE AMERICAN ACADEMY OF NEUROLOGY

To the Editor: Although some falls in patients with neurologic disorders can be prevented, I have discovered that in Parkinson disease (PD), many cannot. I observed that a number of patients with PD fall frequently, and despite being aware that they are at risk and can ably describe the situations in which they fall they continue to fall on a frequent basis. I prospectively collected information on fall frequency in every patient I saw and personally diagnosed with idiopathic PD, using UK Brain Bank criteria, in a 5-week period during the winter of 2008. My definition of falls required the patient to contact the ground. This is not the definition employed by Thurman et al.,1 and generally used in studies of falls,2 which defines a fall as coming to rest on the ground or a lower position. I believe patients are more likely to allow themselves to fall onto a sofa or into a chair if they are losing balance near a soft resting place so that my definition is more restrictive and underestimates the frequency.3 Of 160 patients evaluated, 72 were stage 3 or greater. Of these 72, 27 reported falls since their last visit or in the preceding 3 months if a new patient. Four of the 27 patients fell only on ice or snow, hence not really a fall.1 Therefore 23 admitted falls, of whom 4 had frequent falls. The frequent fallers fell at least once daily, while the others generally fell less than once per month, with a single exception of once per week. There was a sharp divide in falling frequency. Of the frequent fallers, two were Hoehn-Yahr stage 4 and one was stage 3. One was stage 5 in the office but 4 at home. Two of these were demented by DSM criteria, one had mild cognitive impairment, and one was cognitively intact. All fell while walking. In addition to these fallers, one stage 4 patient with dementia slipped out of her wheelchair at least once daily, and one stage 4 patient with dementia frequently slipped to the ground when exiting her bed (unknown number). The problem of daily falls in PD is challenging because these patients, despite their cognitive impairments, are able to describe their falls and the situa382

Neurology 72

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tions producing them yet do not take preventive steps.4 It is difficult to devise effective safety interventions under these circumstances. Joseph H. Friedman, Barrington, RI Disclosure: The author reports no disclosures.

To the Editor: We were pleased to see the Practice Parameter addressing the fall risk among neurologic patients.1 We believe that these guidelines will help improve the safety and quality of life of patients. We would like to emphasize the role of visual field deficits as an important neurologic cause of fall-related morbidity. Neurologic disorders frequently cause visual loss, especially visual field defects, and visual loss is common in the elderly. Loss of visual acuity or visual field has been associated with an increased risk of falls.5,6 A recent, prospective population cohort study of 2,520 older adults found that visual field loss was the most important component of vision related to increased fall risk.6 In this study, there was 8% higher odds of falling for each 10% loss in binocular visual field the patient experienced. This risk remained after adjustment for other factors, including several neurologic conditions including poor balance, Parkinson disease, stroke, and decreased grip strength. A homonymous hemianopia (a 50% loss of binocular visual field) increased a patient’s odds of falling by 47%, comparable to the increased odds of falling conveyed by poor balance (35%) or stroke (57%) in the same study. It has been shown that most patients with homonymous hemianopia secondary to stroke are not aware of the visual field defect, suggesting that homonymous visual field defects are often overlooked, both in patients with and without associated neurologic defects.7,8 As neurologists, we need to be alert to these deficits and their contribution to our patients’ fall risk. Patients with recurrent or unexplained falls should be referred for assessment of their visual acuity and visual field. Beau B. Bruce, Vale´rie Biousse, Nancy J. Newman, Atlanta, GA Disclosure: The authors report no disclosures.

Reply from the Authors: We appreciate the comments of Dr. Friedman and those of Drs. Bruce, Biousse, and Newman.

Dr. Friedman’s observations describe the difficulty of trying to prevent falls among patients with PD. Unfortunately, similar limitations are also described in the more general population of older adults, where multifactorial screening and intervention programs have been found on average to reduce the incidence of falls by only about 20%.9 While such measures are partially effective and thus important, further treatment options need to be investigated. Dr. Friedman’s other observations underscore additional findings of our review that the risk of falls is amplified in people with more advanced PD and in people with multiple risk factors. Dr. Bruce and colleagues emphasize that visual field defects are important risk factors for falls. We identified vision loss in general as a risk factor, although most of the studies we reviewed did not adequately address visual field defects. We therefore welcome this additional information and fully agree with the conclusions offered. Both of these letters highlight the need for more study of specific neurologic conditions that contribute to the risk of falls and of specific interventions to more effectively reduce these risks. David J. Thurman, MD, MPH, Judy A. Stevens, PhD, Jaya K. Rao, MD, MHS, Atlanta, GA Disclosure: The authors report no disclosures. Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4.

5.

6.

7.

8.

9.

Thurman DJ, Stevens JA, Rao JK. Practice Parameter: Assessing patients in a neurology practice for risk of falls (an evidence-based review). Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2008;70:473– 479. Gibson MJ, Andres RO, Isaacs B, et al. The prevention of falls in later life: a report of the Kellogg International Work Group on the prevention of falls by the elderly. Danish Medical Bull 1987;34(suppl 4):1–24. Pickering RM, Grimbergen YA, Rigney U, et al. A metaanalysis of six prospective studies of falling in Parkinson’s disease. Mov Disord 2007;22:1892–1900. Bloem BR, Brimbergen YA, van Dijk JG, Munneke M. The “posture second” strategy: a review of wrong priorities in Parkinson’s disease. J Neurol Sci 2006;248:196 –204. Coleman AL, Stone K, Ewing SK, et al. Higher risk of multiple falls among elderly women who lose visual acuity. Ophthalmology 2004;111:857– 862. Freeman AE, Mun˜oz B, Rubin G, West SK. Visual field loss increases the risk of falls in older adults: the Salisbury Eye Evaluation. Invest Ophthalmol Vis Sci 2007;48: 4445– 4450. Gilhotra JS, Mitchell P, Healey PR, Cumming RG, Currie J. Homonymous visual field defects and stroke in an older population. Stroke 2002;33:2417–2420. Zhang X, Kedar S, Lynn MJ, Newman NJ, Biousse V. Homonymous hemianopias: clinical-anatomic correlations in 904 cases. Neurology 2006;66:906 –910. Gillespie LD, Gillespie WJ, Robertson MC, Lamb SE, Cumming RG, Rowe BH. Interventions for preventing falls in elderly people. Cochrane Database Syst Rev 2003; (4):CD000340.

A RANDOMIZED, PLACEBO-CONTROLLED TRIAL OF REPEATED IV ANTIBIOTIC THERAPY FOR LYME ENCEPHALOPATHY PROLONGED LYME DISEASE TREATMENT: ENOUGH IS ENOUGH

To the Editor: For transparent results, randomized, placebo-controlled clinical trials optimally evaluate a primary outcome of treatment efficacy with a simple, well-defined statistical test. Fallon et al.1 chose a linear mixed model with factors of group, time, and cognitive domain as their primary analysis. Model fitting involved selecting correlation structure and assessing significant two- and three-way interactions. Model selection procedures are, by definition, data-driven and are generally considered appropriate for exploratory analyses rather than for evaluating treatment efficacy in confirmatory randomized trials.2 Interpreting p values as if the selected model had been hypothesized a priori is frequently overly optimistic and underestimates p values.3,4 Using the same data for model selection and parameter estimation can also substantially bias parameter estimates, particularly if the number of model parameters is large relative to the number of subjects.3 The primary conclusion involves the interaction between treatment and time, interpreted as a beneficial effect of IV ceftriaxone at 12 weeks that disappears by 24 weeks. Given the potentially optimistic error rates, too much emphasis is given to the borderline p value of 0.053 for the comparison in cognitive improvement between antibiotic and placebo at 12 weeks. Attaching a strong conclusion to them particularly when the results are not clearcut is unwarranted as they were post hoc comparisons. Inclusion of a group of healthy controls who do not directly inform the drug vs placebo comparison also raises the question of how the overall tests of significance might reflect differences between healthy subjects and patients, rather than drug vs placebo. The lower index score in the antibiotic group at baseline raises the question whether part of the difference in gains between the two groups was introduced by a regression towards the mean (RTM) effect. That is, whether by chance the antibiotic group had more individuals with worse test scores that drifted closer to the overall mean at the next time point. The authors do not mention the significant interaction between group and cognitive domain in the primary omnibus analysis. The randomized, placebo-controlled trial design allows for straightforward statistical analysis of the primary outcome. Fallon et al.1 made it difficult to interpret the results by choosing as their primary analysis a complicated model chosen by a data-driven model selection process. Neurology 72

January 27, 2009

383

Nevertheless, the Fallon et al. study joins other randomized, double-blind trials that failed to provide convincing evidence that additional antibiotic therapy is a beneficial strategy for patients with postLyme disease symptoms.5 Other management approaches need to be studied. A. Marques, MD, P. Shaw, PhD, Bethesda, MD; C.H. Schmid, PhD, A. Steere, MD, Boston, MA; R.F. Kaplan, PhD, Farmington, CT; A. Hassett, PsyD, New Brunswick, NJ; E. Shapiro, MD, New Haven, CT; G.P. Wormser, MD, Valhalla, NY Disclosure: The authors report no disclosures.

Supplemental data at www.neurology.org

384

Reply from the Authors: Marques et al. call for the use of a “simple well-defined statistical test” without specifying their test of preference. The analysis of clinical trials requires statistical approaches that adequately handle missing data. Mixed effects models (MEM) produce valid inferences under the “missing at random” (MAR) assumption in contrast to the more restrictive “missing completely at random” assumption required for simple tests.6 –9 The validity of the likelihood approach (MEM) under MAR is based on correctly specifying the covariance structure. The small sample size prevented the specification of the completely unrestricted covariance,10 which would have circumvented modeling it. Testing whether the effect is the same for all cognitive domains (three-way interaction) before assessing an overall treatment effect (two-way interaction) is an established procedure that is not post hoc. Patient groups did not differ significantly on baseline cognition. In addressing RTM, the authors do not specify the reference population. Is it 1) the healthy control or 2) the study patient population? In either case, RTM is not selective and should impact both drug and placebo groups. In case 1, RTM should affect patients in each group similarly, since each had cognitive index scores well below the control mean at baseline. The placebo group exhibited gradual cognitive improvement consistent with a practice effect at a rate parallel to the controls (see figure e-1 on the Neurology威 Web site at www. neurology.org) and no evidence for RTM. The antibiotic group’s trajectory for improvement steeply increased to week 12 and then, contrary to RTM, decreased to week 24. In case 2, since the placebo group was above the overall patient mean, RTM should have brought the placebo mean down, which it did not. The logical explanation for the pattern of improvement followed by worsening in the antibiotic group is a treatment effect in the first 12 weeks and loss of the effect after treatment discontinuation. Healthy controls were included in the study Neurology 72

January 27, 2009

design to enable parcellation of the practice, placebo, and drug effects. The significant group by cognitive domain interaction was not surprising, as patients with Lyme encephalopathy have a differing pattern of cognitive strengths and weaknesses than healthy controls. Because of the small sample size, we emphasized confidence intervals rather than p values. Finally, although acute benefits were seen, the risks of IV treatment and lack of sustained benefits in cognition underline the need for other treatments for persistent Lyme encephalopathy that are safe, effective, and durable. Brian A. Fallon, MD, Eva Petkova, PhD, John G. Keilp, PhD, Iordan Slavov, PhD, New York, NY Disclosure: Roche Pharmaceuticals supplied ceftriaxone free of charge for this study but were not involved in any other aspect of the study. Dr. Fallon has given expert testimony at hearings related to Lyme disease and its treatment. The other authors report no disclosures.

To the Editor: Fallon et al.1 report results from a carefully constructed ceftriaxone trial for Lyme encephalopathy demonstrating that patients responded well to additional treatment but failed to sustain the response when treatment was withdrawn. The study makes several important points that contradict the conventional wisdom about Lyme disease. Although mainstream experts assert that objective findings are rare post-treatment,11 73% of the patients of Fallon et al. had sensory abnormalities an average of 7 years after the initial diagnosis and treatment of Lyme disease. The accompanying editorial suggests that long-term antibiotic therapy is ineffective.12 The study suggests that 10 weeks of treatment with ceftriaxone may be insufficient to eradicate a pleomorphic bacterium like Borrelia burgdorferi, the Lyme spirochete. Cell-wall drugs promote transformation to the “cystic” form, which is unaffected by cell-wall agents, such as cephalosporins and penicillins, tetracyclines and macrolides.13 Once the antibiotic threat passes, these cystic forms may revert to the motile state. The spirochete can invade a variety of human cell types14 and intracellular pathogens require longer treatment courses utilizing suitable antibiotics. It is possible that ceftriaxone alone, regardless of treatment duration, may fail to eradicate a well established Lyme infection. That ceftriaxone therapy works in many patients underscores the need to better understand the variables of the host response in this illness. The patients entering this study were symptomatic despite a mean of 2.5 months of IV and 7.9 months of oral antibiotics. Additional ceftriaxone was able to induce clinical improvements as seen at week 12. However, as a sin-

gle therapeutic agent, it was unable to sustain these gains when treatment was withdrawn. In this select group of patients, more of the same proved to be insufficient. Proponents of long-term treatment believe that antibiotic therapy must address the multiple mechanisms supporting survival of the Lyme spirochete. Enough is only enough when it is the “right stuff.” Elizabeth L. Maloney, MD, Wyoming, MN Disclosure: The author reports no disclosures.

Reply from the Editorialist: I am grateful to Dr. Maloney for the opportunity to address several points. First, she asserts that objective neurologic abnormalities are common after treatment, pointing out that 27 of the study’s patients had sensory abnormalities. Although this is 73% of the study subjects, the 37 patients in the study were selected from among 3,368 patients screened. During the study’s recruitment period, the CDC Web site indicated there were approximately 85,000 new cases of Lyme disease. Observations in such an extraordinarily selected population are meaningless epidemiologically but certainly cannot be used to conclude that objective abnormalities are common. Second, the statement that “The accompanying editorial suggests that long-term antibiotic therapy is ineffective” misattributes this conclusion. It is the data in the study that demonstrate only a marginally statistically significant and unsustained difference between patients receiving ceftriaxone and those given placebo. Concluding that this supports the use of even longer courses of antibiotics is contrary to what we understand about the biology of organisms such as B burgdorferi, and ignores the significant morbidity associated with this approach. Allusions to “pleomorphic” “cell wall-free” “cystic forms” of this bacterium are frequently repeated. There is no evidence that this occurs in vivo or is of any clinical significance. The conclusion that B burgdorferi would be “unaffected by cell-wall agents, such as cephalosporins and penicillins, tetracyclines and macrolides” is unfortunately misguided since tetracyclines and macrolides act on intracellular protein synthesis, not on the cell wall. It is difficult for a patient-centered, evidencebased clinician to justify prolonged antibiotic therapy in patients with Lyme disease or post-Lyme disease symptoms given concordant observations1,15,16 that this treatment poses substantial risks and provides minimal or no benefit.

Dr. Halperin holds equity in Abbott, Bristol Myers Squibb, Johnson & Johnson, Schering Plough and Vasogen.

Reply from the Author: Persistent symptoms after standard courses of antibiotic treatment for Lyme disease may occur for several reasons. These include persistence of infection, a postinfectious process, or incorrect diagnosis. If infection persists, then the cause may be due to either the immune evading survival strategies of the B burgdorferi (Bb) spirochete or the failure of antibiotics to eradicate the organism.17 Dr. Maloney argues that ceftriaxone may not be sufficient to eliminate the Bb spirochete which at least in vitro has been shown to exist intracellularly and may not be effective against cyst-like forms. That viable Bb may persist despite treatment was recently demonstrated in a mouse study in which Bb were cultured after ceftriaxone therapy when the mice were subsequently given anti-tumor necrosis factor-␣.18 Persistence of symptoms, however, may also be explained by a postinfectious process, which includes autoimmune phenomena, neurotransmitter changes triggered by the initial infection, or damage. It is clear that the group of patients with posttreatment Lyme disease symptoms is heterogeneous. While some patients improve in response to antibiotic retreatment, showing either short-term moderate improvement in cognition or longer term improvement in fatigue, pain, and physical dysfunction,1,14 other patients do not.14,15 In order to avoid exposing patients unnecessarily to the serious risks associated with antibiotic therapy, particularly when given intravenously, biomarkers of active infection need to be identified. These biomarkers will allow physicians to distinguish patients most likely to benefit from antibiotic retreatment from those where other symptom-reduction strategies should be used. The care of patients with chronic persistent symptoms would be advanced by increased research into the heterogeneous etiology of symptom persistence and studies that seek to identify safe, effective, and specific treatments targeted to the mechanism of persistent symptoms in discrete patient groups. Brian A. Fallon, MD, New York, NY Disclosure: The following disclosures relate to the study to which this Correspondence refers. This study was funded by a grant from NINDS to Dr. Fallon (R01-NS38636). Roche Pharmaceuticals supplied ceftriaxone free of charge for this study but were not involved in any other aspect of the study. Dr. Fallon has given expert testimony at hearings related to Lyme disease and its treatment. The other authors report no disclosures.

John J. Halperin, MD, Summit, NJ Disclosure: Dr. Halperin has served as a defense expert in cases alleging failure to diagnose or treat nervous system Lyme disease.

To the Editor: I was interested in Dr. Halperin’s reply to Dr. Maloney concerning the cell-wall defiNeurology 72

January 27, 2009

385

cient forms of Borrelia burgdorferi and the site of action of antibiotics. Having seen Dr. Maloney’s presentation on Lyme borreliosis and other tick-borne disorders, I am confident that she is well aware that the tetracyclines and macrolides impact protein synthesis, and that the cephalosporins and penicillins impact the cell wall. It would seem that an unfortunate punctuation placement and perhaps the editing of words of clarification may account for the confusion of the statement. I am concerned that the discounting of this line of thought on that grammatic stumble does a disservice to the interesting possibilities it holds. Of course, in vivo evidence is harder to demonstrate, but does not most science progress from both in vitro and in vivo observations?

3.

4. 5.

6. 7.

Beatrice M. Szantyr, MD, Lincoln, ME Disclosure: The author reports no disclosures.

8.

Reply from the Author: There is little one can do with the punctuation of the statement “cell-wall agents, such as cephalosporins and penicillins, tetracyclines and macrolides” to interpret it other than as suggesting tetracyclines and macrolides are cell wall agents. However, the reason for discounting this interesting hypothesis was not a grammatical error, but the fact that there is no in vivo evidence that cell wall-free or cystic forms play any role in Lyme borreliosis.

9. 10.

11.

12. 13.

John J. Halperin, MD, Summit, NJ Disclosure: Dr. Halperin holds equity in Abbott, Bristol Myers Squibb, Johnson & Johnson, Schering Plough and Vasogen. He has served as an expert witness in medical malpractice actions.

To the Editor: It was my intent that the statement regarding Borrelia burgdorferi’s pleomorphism would read as follows: Cell-wall drugs promote transformation to the “cystic” form, which is unaffected by cellwall agents (such as cephalosporins and penicillins), tetracyclines, and macrolides. Pleomorphism may be one mechanism to explain persistent infection, as demonstrated by Hodzic et al.19

14.

15.

16.

17.

Elizabeth Maloney, MD, Wyoming, MN Disclosure: The author reports no disclosures.

18.

Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

386

Fallon BA, Keilp JG, Corbera KM, et al. A randomized, placebo-controlled trial of repeated IV antibiotic therapy for Lyme encephalopathy. Neurology 2008;70:992–1003. Guidance for Industry. E9 Statistical principles for clinical trials. US Department of Health and Human Services

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19.

Food and Drug Administration Federal Register on September 16, 1998 (63 FR 49583). Available at: http:// www.fda.gov/cder/guidance/index.htm. Accessed February 7, 2008. Burnham KP, Anderson DR. Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach. Springer: New York; 1998. Ye J. On measuring and correcting the effects of data mining and model selection. J Am Stat Assoc 1998;120 –131. Wormser GP, Dattwyler RJ, Shapiro ED, et al. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis 2006;43:1089 –1134. Little RJA. A class of pattern mixture models for normal incomplete data. Biometrika 1994;81:471– 483. Siddiqui O, Ali MW. A comparison of the random-effects pattern-mixture model with last-observation-carriedforward (LOCF) analysis in longitudinal clinical trials with dropouts. J Biopharm Stat 1998;8:545–563. Everitt BS. Analysis of longitudinal data: beyond MANOVA. Br J Psychiatry 1998;172:7–10. Molenberghs G, Kenward MG. Missing Data in Clinical Studies. Chichester, UK: Wiley & Sons Inc.; 2007. Mallinckrodt CH, Clark WS, Stacy RD. Accounting for dropout bias using mixed effects models. J Biopharm Stat 2001;11:9 –21. Halperin J, Bever C, Belman A, et al. Practice Parameter: treatment of nervous system Lyme disease (an evidencebased review). Neurology 2007;69:91–102. Halperin J. Prolonged Lyme disease treatment: enough is enough. Neurology 2008;70:986 –987. Kersten A, Poitschek C, Rauch S, Aberer E. Effects of penicillin, ceftriaxone, and doxycycline on morphology of Borrelia burgdorferi. Antimicrob Agents Chemother 1995;39: 1127–1133. Livengood JA, Gilmore RD Jr. Invasion of human neuronal and glial cells by an infectious strain of Borrelia burgdorferi. Microbes Infect 2006;8:2832–2840. Krupp LB, Hyman LG, Grimson R, et al. Study and treatment of post Lyme disease (STOP-LD): a randomized double masked clinical trial. Neurology 2003;60:1923– 1930. Klempner M, Hu LT, Evans J, et al. Two controlled trials of antibiotic treatment in patients with persistent symptoms and a history of Lyme disease. N Engl J Med 2001; 345:85–92. Embers ME, Ramamoorthy R, Philipp MT. Survival strategies of Borrelia burgdorferi, the etiologic agent of Lyme disease. Microbes Infect 2004;6:312–318. Yrjanainen H, Hytonen J, Song XY, Oksi J, Hartiala K, Viljanen MK. Anti-tumor necrosis factor-alpha treatment actives Borrelia burgdorferi spirochetes 4 weeks after ceftriaxone treatment in C3H/He mice. J Infect Dis 2007;195:1489–1496. Hodzic E, Feng S, Holden K, Freet K, Barthold S. Persistence of Borrelia burgdorferi following antibiotic treatment in mice. Antimicrob Agents Chemother 2008;52:1728 – 1736.

Correspondence

PRACTICE PARAMETER: ASSESSING PATIENTS IN A NEUROLOGY PRACTICE FOR RISK OF FALLS (AN EVIDENCE-BASED REVIEW): REPORT OF THE QUALITY STANDARDS SUBCOMMITTEE OF THE AMERICAN ACADEMY OF NEUROLOGY

To the Editor: Although some falls in patients with neurologic disorders can be prevented, I have discovered that in Parkinson disease (PD), many cannot. I observed that a number of patients with PD fall frequently, and despite being aware that they are at risk and can ably describe the situations in which they fall they continue to fall on a frequent basis. I prospectively collected information on fall frequency in every patient I saw and personally diagnosed with idiopathic PD, using UK Brain Bank criteria, in a 5-week period during the winter of 2008. My definition of falls required the patient to contact the ground. This is not the definition employed by Thurman et al.,1 and generally used in studies of falls,2 which defines a fall as coming to rest on the ground or a lower position. I believe patients are more likely to allow themselves to fall onto a sofa or into a chair if they are losing balance near a soft resting place so that my definition is more restrictive and underestimates the frequency.3 Of 160 patients evaluated, 72 were stage 3 or greater. Of these 72, 27 reported falls since their last visit or in the preceding 3 months if a new patient. Four of the 27 patients fell only on ice or snow, hence not really a fall.1 Therefore 23 admitted falls, of whom 4 had frequent falls. The frequent fallers fell at least once daily, while the others generally fell less than once per month, with a single exception of once per week. There was a sharp divide in falling frequency. Of the frequent fallers, two were Hoehn-Yahr stage 4 and one was stage 3. One was stage 5 in the office but 4 at home. Two of these were demented by DSM criteria, one had mild cognitive impairment, and one was cognitively intact. All fell while walking. In addition to these fallers, one stage 4 patient with dementia slipped out of her wheelchair at least once daily, and one stage 4 patient with dementia frequently slipped to the ground when exiting her bed (unknown number). The problem of daily falls in PD is challenging because these patients, despite their cognitive impairments, are able to describe their falls and the situa382

Neurology 72

January 27, 2009

tions producing them yet do not take preventive steps.4 It is difficult to devise effective safety interventions under these circumstances. Joseph H. Friedman, Barrington, RI Disclosure: The author reports no disclosures.

To the Editor: We were pleased to see the Practice Parameter addressing the fall risk among neurologic patients.1 We believe that these guidelines will help improve the safety and quality of life of patients. We would like to emphasize the role of visual field deficits as an important neurologic cause of fall-related morbidity. Neurologic disorders frequently cause visual loss, especially visual field defects, and visual loss is common in the elderly. Loss of visual acuity or visual field has been associated with an increased risk of falls.5,6 A recent, prospective population cohort study of 2,520 older adults found that visual field loss was the most important component of vision related to increased fall risk.6 In this study, there was 8% higher odds of falling for each 10% loss in binocular visual field the patient experienced. This risk remained after adjustment for other factors, including several neurologic conditions including poor balance, Parkinson disease, stroke, and decreased grip strength. A homonymous hemianopia (a 50% loss of binocular visual field) increased a patient’s odds of falling by 47%, comparable to the increased odds of falling conveyed by poor balance (35%) or stroke (57%) in the same study. It has been shown that most patients with homonymous hemianopia secondary to stroke are not aware of the visual field defect, suggesting that homonymous visual field defects are often overlooked, both in patients with and without associated neurologic defects.7,8 As neurologists, we need to be alert to these deficits and their contribution to our patients’ fall risk. Patients with recurrent or unexplained falls should be referred for assessment of their visual acuity and visual field. Beau B. Bruce, Vale´rie Biousse, Nancy J. Newman, Atlanta, GA Disclosure: The authors report no disclosures.

Reply from the Authors: We appreciate the comments of Dr. Friedman and those of Drs. Bruce, Biousse, and Newman.

Dr. Friedman’s observations describe the difficulty of trying to prevent falls among patients with PD. Unfortunately, similar limitations are also described in the more general population of older adults, where multifactorial screening and intervention programs have been found on average to reduce the incidence of falls by only about 20%.9 While such measures are partially effective and thus important, further treatment options need to be investigated. Dr. Friedman’s other observations underscore additional findings of our review that the risk of falls is amplified in people with more advanced PD and in people with multiple risk factors. Dr. Bruce and colleagues emphasize that visual field defects are important risk factors for falls. We identified vision loss in general as a risk factor, although most of the studies we reviewed did not adequately address visual field defects. We therefore welcome this additional information and fully agree with the conclusions offered. Both of these letters highlight the need for more study of specific neurologic conditions that contribute to the risk of falls and of specific interventions to more effectively reduce these risks. David J. Thurman, MD, MPH, Judy A. Stevens, PhD, Jaya K. Rao, MD, MHS, Atlanta, GA Disclosure: The authors report no disclosures. Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4.

5.

6.

7.

8.

9.

Thurman DJ, Stevens JA, Rao JK. Practice Parameter: Assessing patients in a neurology practice for risk of falls (an evidence-based review). Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2008;70:473– 479. Gibson MJ, Andres RO, Isaacs B, et al. The prevention of falls in later life: a report of the Kellogg International Work Group on the prevention of falls by the elderly. Danish Medical Bull 1987;34(suppl 4):1–24. Pickering RM, Grimbergen YA, Rigney U, et al. A metaanalysis of six prospective studies of falling in Parkinson’s disease. Mov Disord 2007;22:1892–1900. Bloem BR, Brimbergen YA, van Dijk JG, Munneke M. The “posture second” strategy: a review of wrong priorities in Parkinson’s disease. J Neurol Sci 2006;248:196 –204. Coleman AL, Stone K, Ewing SK, et al. Higher risk of multiple falls among elderly women who lose visual acuity. Ophthalmology 2004;111:857– 862. Freeman AE, Mun˜oz B, Rubin G, West SK. Visual field loss increases the risk of falls in older adults: the Salisbury Eye Evaluation. Invest Ophthalmol Vis Sci 2007;48: 4445– 4450. Gilhotra JS, Mitchell P, Healey PR, Cumming RG, Currie J. Homonymous visual field defects and stroke in an older population. Stroke 2002;33:2417–2420. Zhang X, Kedar S, Lynn MJ, Newman NJ, Biousse V. Homonymous hemianopias: clinical-anatomic correlations in 904 cases. Neurology 2006;66:906 –910. Gillespie LD, Gillespie WJ, Robertson MC, Lamb SE, Cumming RG, Rowe BH. Interventions for preventing falls in elderly people. Cochrane Database Syst Rev 2003; (4):CD000340.

A RANDOMIZED, PLACEBO-CONTROLLED TRIAL OF REPEATED IV ANTIBIOTIC THERAPY FOR LYME ENCEPHALOPATHY PROLONGED LYME DISEASE TREATMENT: ENOUGH IS ENOUGH

To the Editor: For transparent results, randomized, placebo-controlled clinical trials optimally evaluate a primary outcome of treatment efficacy with a simple, well-defined statistical test. Fallon et al.1 chose a linear mixed model with factors of group, time, and cognitive domain as their primary analysis. Model fitting involved selecting correlation structure and assessing significant two- and three-way interactions. Model selection procedures are, by definition, data-driven and are generally considered appropriate for exploratory analyses rather than for evaluating treatment efficacy in confirmatory randomized trials.2 Interpreting p values as if the selected model had been hypothesized a priori is frequently overly optimistic and underestimates p values.3,4 Using the same data for model selection and parameter estimation can also substantially bias parameter estimates, particularly if the number of model parameters is large relative to the number of subjects.3 The primary conclusion involves the interaction between treatment and time, interpreted as a beneficial effect of IV ceftriaxone at 12 weeks that disappears by 24 weeks. Given the potentially optimistic error rates, too much emphasis is given to the borderline p value of 0.053 for the comparison in cognitive improvement between antibiotic and placebo at 12 weeks. Attaching a strong conclusion to them particularly when the results are not clearcut is unwarranted as they were post hoc comparisons. Inclusion of a group of healthy controls who do not directly inform the drug vs placebo comparison also raises the question of how the overall tests of significance might reflect differences between healthy subjects and patients, rather than drug vs placebo. The lower index score in the antibiotic group at baseline raises the question whether part of the difference in gains between the two groups was introduced by a regression towards the mean (RTM) effect. That is, whether by chance the antibiotic group had more individuals with worse test scores that drifted closer to the overall mean at the next time point. The authors do not mention the significant interaction between group and cognitive domain in the primary omnibus analysis. The randomized, placebo-controlled trial design allows for straightforward statistical analysis of the primary outcome. Fallon et al.1 made it difficult to interpret the results by choosing as their primary analysis a complicated model chosen by a data-driven model selection process. Neurology 72

January 27, 2009

383

Nevertheless, the Fallon et al. study joins other randomized, double-blind trials that failed to provide convincing evidence that additional antibiotic therapy is a beneficial strategy for patients with postLyme disease symptoms.5 Other management approaches need to be studied. A. Marques, MD, P. Shaw, PhD, Bethesda, MD; C.H. Schmid, PhD, A. Steere, MD, Boston, MA; R.F. Kaplan, PhD, Farmington, CT; A. Hassett, PsyD, New Brunswick, NJ; E. Shapiro, MD, New Haven, CT; G.P. Wormser, MD, Valhalla, NY Disclosure: The authors report no disclosures.

Supplemental data at www.neurology.org

384

Reply from the Authors: Marques et al. call for the use of a “simple well-defined statistical test” without specifying their test of preference. The analysis of clinical trials requires statistical approaches that adequately handle missing data. Mixed effects models (MEM) produce valid inferences under the “missing at random” (MAR) assumption in contrast to the more restrictive “missing completely at random” assumption required for simple tests.6 –9 The validity of the likelihood approach (MEM) under MAR is based on correctly specifying the covariance structure. The small sample size prevented the specification of the completely unrestricted covariance,10 which would have circumvented modeling it. Testing whether the effect is the same for all cognitive domains (three-way interaction) before assessing an overall treatment effect (two-way interaction) is an established procedure that is not post hoc. Patient groups did not differ significantly on baseline cognition. In addressing RTM, the authors do not specify the reference population. Is it 1) the healthy control or 2) the study patient population? In either case, RTM is not selective and should impact both drug and placebo groups. In case 1, RTM should affect patients in each group similarly, since each had cognitive index scores well below the control mean at baseline. The placebo group exhibited gradual cognitive improvement consistent with a practice effect at a rate parallel to the controls (see figure e-1 on the Neurology威 Web site at www. neurology.org) and no evidence for RTM. The antibiotic group’s trajectory for improvement steeply increased to week 12 and then, contrary to RTM, decreased to week 24. In case 2, since the placebo group was above the overall patient mean, RTM should have brought the placebo mean down, which it did not. The logical explanation for the pattern of improvement followed by worsening in the antibiotic group is a treatment effect in the first 12 weeks and loss of the effect after treatment discontinuation. Healthy controls were included in the study Neurology 72

January 27, 2009

design to enable parcellation of the practice, placebo, and drug effects. The significant group by cognitive domain interaction was not surprising, as patients with Lyme encephalopathy have a differing pattern of cognitive strengths and weaknesses than healthy controls. Because of the small sample size, we emphasized confidence intervals rather than p values. Finally, although acute benefits were seen, the risks of IV treatment and lack of sustained benefits in cognition underline the need for other treatments for persistent Lyme encephalopathy that are safe, effective, and durable. Brian A. Fallon, MD, Eva Petkova, PhD, John G. Keilp, PhD, Iordan Slavov, PhD, New York, NY Disclosure: Roche Pharmaceuticals supplied ceftriaxone free of charge for this study but were not involved in any other aspect of the study. Dr. Fallon has given expert testimony at hearings related to Lyme disease and its treatment. The other authors report no disclosures.

To the Editor: Fallon et al.1 report results from a carefully constructed ceftriaxone trial for Lyme encephalopathy demonstrating that patients responded well to additional treatment but failed to sustain the response when treatment was withdrawn. The study makes several important points that contradict the conventional wisdom about Lyme disease. Although mainstream experts assert that objective findings are rare post-treatment,11 73% of the patients of Fallon et al. had sensory abnormalities an average of 7 years after the initial diagnosis and treatment of Lyme disease. The accompanying editorial suggests that long-term antibiotic therapy is ineffective.12 The study suggests that 10 weeks of treatment with ceftriaxone may be insufficient to eradicate a pleomorphic bacterium like Borrelia burgdorferi, the Lyme spirochete. Cell-wall drugs promote transformation to the “cystic” form, which is unaffected by cell-wall agents, such as cephalosporins and penicillins, tetracyclines and macrolides.13 Once the antibiotic threat passes, these cystic forms may revert to the motile state. The spirochete can invade a variety of human cell types14 and intracellular pathogens require longer treatment courses utilizing suitable antibiotics. It is possible that ceftriaxone alone, regardless of treatment duration, may fail to eradicate a well established Lyme infection. That ceftriaxone therapy works in many patients underscores the need to better understand the variables of the host response in this illness. The patients entering this study were symptomatic despite a mean of 2.5 months of IV and 7.9 months of oral antibiotics. Additional ceftriaxone was able to induce clinical improvements as seen at week 12. However, as a sin-

gle therapeutic agent, it was unable to sustain these gains when treatment was withdrawn. In this select group of patients, more of the same proved to be insufficient. Proponents of long-term treatment believe that antibiotic therapy must address the multiple mechanisms supporting survival of the Lyme spirochete. Enough is only enough when it is the “right stuff.” Elizabeth L. Maloney, MD, Wyoming, MN Disclosure: The author reports no disclosures.

Reply from the Editorialist: I am grateful to Dr. Maloney for the opportunity to address several points. First, she asserts that objective neurologic abnormalities are common after treatment, pointing out that 27 of the study’s patients had sensory abnormalities. Although this is 73% of the study subjects, the 37 patients in the study were selected from among 3,368 patients screened. During the study’s recruitment period, the CDC Web site indicated there were approximately 85,000 new cases of Lyme disease. Observations in such an extraordinarily selected population are meaningless epidemiologically but certainly cannot be used to conclude that objective abnormalities are common. Second, the statement that “The accompanying editorial suggests that long-term antibiotic therapy is ineffective” misattributes this conclusion. It is the data in the study that demonstrate only a marginally statistically significant and unsustained difference between patients receiving ceftriaxone and those given placebo. Concluding that this supports the use of even longer courses of antibiotics is contrary to what we understand about the biology of organisms such as B burgdorferi, and ignores the significant morbidity associated with this approach. Allusions to “pleomorphic” “cell wall-free” “cystic forms” of this bacterium are frequently repeated. There is no evidence that this occurs in vivo or is of any clinical significance. The conclusion that B burgdorferi would be “unaffected by cell-wall agents, such as cephalosporins and penicillins, tetracyclines and macrolides” is unfortunately misguided since tetracyclines and macrolides act on intracellular protein synthesis, not on the cell wall. It is difficult for a patient-centered, evidencebased clinician to justify prolonged antibiotic therapy in patients with Lyme disease or post-Lyme disease symptoms given concordant observations1,15,16 that this treatment poses substantial risks and provides minimal or no benefit.

Dr. Halperin holds equity in Abbott, Bristol Myers Squibb, Johnson & Johnson, Schering Plough and Vasogen.

Reply from the Author: Persistent symptoms after standard courses of antibiotic treatment for Lyme disease may occur for several reasons. These include persistence of infection, a postinfectious process, or incorrect diagnosis. If infection persists, then the cause may be due to either the immune evading survival strategies of the B burgdorferi (Bb) spirochete or the failure of antibiotics to eradicate the organism.17 Dr. Maloney argues that ceftriaxone may not be sufficient to eliminate the Bb spirochete which at least in vitro has been shown to exist intracellularly and may not be effective against cyst-like forms. That viable Bb may persist despite treatment was recently demonstrated in a mouse study in which Bb were cultured after ceftriaxone therapy when the mice were subsequently given anti-tumor necrosis factor-␣.18 Persistence of symptoms, however, may also be explained by a postinfectious process, which includes autoimmune phenomena, neurotransmitter changes triggered by the initial infection, or damage. It is clear that the group of patients with posttreatment Lyme disease symptoms is heterogeneous. While some patients improve in response to antibiotic retreatment, showing either short-term moderate improvement in cognition or longer term improvement in fatigue, pain, and physical dysfunction,1,14 other patients do not.14,15 In order to avoid exposing patients unnecessarily to the serious risks associated with antibiotic therapy, particularly when given intravenously, biomarkers of active infection need to be identified. These biomarkers will allow physicians to distinguish patients most likely to benefit from antibiotic retreatment from those where other symptom-reduction strategies should be used. The care of patients with chronic persistent symptoms would be advanced by increased research into the heterogeneous etiology of symptom persistence and studies that seek to identify safe, effective, and specific treatments targeted to the mechanism of persistent symptoms in discrete patient groups. Brian A. Fallon, MD, New York, NY Disclosure: The following disclosures relate to the study to which this Correspondence refers. This study was funded by a grant from NINDS to Dr. Fallon (R01-NS38636). Roche Pharmaceuticals supplied ceftriaxone free of charge for this study but were not involved in any other aspect of the study. Dr. Fallon has given expert testimony at hearings related to Lyme disease and its treatment. The other authors report no disclosures.

John J. Halperin, MD, Summit, NJ Disclosure: Dr. Halperin has served as a defense expert in cases alleging failure to diagnose or treat nervous system Lyme disease.

To the Editor: I was interested in Dr. Halperin’s reply to Dr. Maloney concerning the cell-wall defiNeurology 72

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cient forms of Borrelia burgdorferi and the site of action of antibiotics. Having seen Dr. Maloney’s presentation on Lyme borreliosis and other tick-borne disorders, I am confident that she is well aware that the tetracyclines and macrolides impact protein synthesis, and that the cephalosporins and penicillins impact the cell wall. It would seem that an unfortunate punctuation placement and perhaps the editing of words of clarification may account for the confusion of the statement. I am concerned that the discounting of this line of thought on that grammatic stumble does a disservice to the interesting possibilities it holds. Of course, in vivo evidence is harder to demonstrate, but does not most science progress from both in vitro and in vivo observations?

3.

4. 5.

6. 7.

Beatrice M. Szantyr, MD, Lincoln, ME Disclosure: The author reports no disclosures.

8.

Reply from the Author: There is little one can do with the punctuation of the statement “cell-wall agents, such as cephalosporins and penicillins, tetracyclines and macrolides” to interpret it other than as suggesting tetracyclines and macrolides are cell wall agents. However, the reason for discounting this interesting hypothesis was not a grammatical error, but the fact that there is no in vivo evidence that cell wall-free or cystic forms play any role in Lyme borreliosis.

9. 10.

11.

12. 13.

John J. Halperin, MD, Summit, NJ Disclosure: Dr. Halperin holds equity in Abbott, Bristol Myers Squibb, Johnson & Johnson, Schering Plough and Vasogen. He has served as an expert witness in medical malpractice actions.

To the Editor: It was my intent that the statement regarding Borrelia burgdorferi’s pleomorphism would read as follows: Cell-wall drugs promote transformation to the “cystic” form, which is unaffected by cellwall agents (such as cephalosporins and penicillins), tetracyclines, and macrolides. Pleomorphism may be one mechanism to explain persistent infection, as demonstrated by Hodzic et al.19

14.

15.

16.

17.

Elizabeth Maloney, MD, Wyoming, MN Disclosure: The author reports no disclosures.

18.

Copyright © 2009 by AAN Enterprises, Inc. 1.

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Fallon BA, Keilp JG, Corbera KM, et al. A randomized, placebo-controlled trial of repeated IV antibiotic therapy for Lyme encephalopathy. Neurology 2008;70:992–1003. Guidance for Industry. E9 Statistical principles for clinical trials. US Department of Health and Human Services

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Food and Drug Administration Federal Register on September 16, 1998 (63 FR 49583). Available at: http:// www.fda.gov/cder/guidance/index.htm. Accessed February 7, 2008. Burnham KP, Anderson DR. Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach. Springer: New York; 1998. Ye J. On measuring and correcting the effects of data mining and model selection. J Am Stat Assoc 1998;120 –131. Wormser GP, Dattwyler RJ, Shapiro ED, et al. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis 2006;43:1089 –1134. Little RJA. A class of pattern mixture models for normal incomplete data. Biometrika 1994;81:471– 483. Siddiqui O, Ali MW. A comparison of the random-effects pattern-mixture model with last-observation-carriedforward (LOCF) analysis in longitudinal clinical trials with dropouts. J Biopharm Stat 1998;8:545–563. Everitt BS. Analysis of longitudinal data: beyond MANOVA. Br J Psychiatry 1998;172:7–10. Molenberghs G, Kenward MG. Missing Data in Clinical Studies. Chichester, UK: Wiley & Sons Inc.; 2007. Mallinckrodt CH, Clark WS, Stacy RD. Accounting for dropout bias using mixed effects models. J Biopharm Stat 2001;11:9 –21. Halperin J, Bever C, Belman A, et al. Practice Parameter: treatment of nervous system Lyme disease (an evidencebased review). Neurology 2007;69:91–102. Halperin J. Prolonged Lyme disease treatment: enough is enough. Neurology 2008;70:986 –987. Kersten A, Poitschek C, Rauch S, Aberer E. Effects of penicillin, ceftriaxone, and doxycycline on morphology of Borrelia burgdorferi. Antimicrob Agents Chemother 1995;39: 1127–1133. Livengood JA, Gilmore RD Jr. Invasion of human neuronal and glial cells by an infectious strain of Borrelia burgdorferi. Microbes Infect 2006;8:2832–2840. Krupp LB, Hyman LG, Grimson R, et al. Study and treatment of post Lyme disease (STOP-LD): a randomized double masked clinical trial. Neurology 2003;60:1923– 1930. Klempner M, Hu LT, Evans J, et al. Two controlled trials of antibiotic treatment in patients with persistent symptoms and a history of Lyme disease. N Engl J Med 2001; 345:85–92. Embers ME, Ramamoorthy R, Philipp MT. Survival strategies of Borrelia burgdorferi, the etiologic agent of Lyme disease. Microbes Infect 2004;6:312–318. Yrjanainen H, Hytonen J, Song XY, Oksi J, Hartiala K, Viljanen MK. Anti-tumor necrosis factor-alpha treatment actives Borrelia burgdorferi spirochetes 4 weeks after ceftriaxone treatment in C3H/He mice. J Infect Dis 2007;195:1489–1496. Hodzic E, Feng S, Holden K, Freet K, Barthold S. Persistence of Borrelia burgdorferi following antibiotic treatment in mice. Antimicrob Agents Chemother 2008;52:1728 – 1736.

Section Editors Christopher J. Boes, MD Kenneth J. Mack, MD, PhD

Book Review

THE FATAL SLEEP: AFRICA’S KILLER DISEASE THAT WENT UNDISCOVERED FOR CENTURIES

edited by Peter Kennedy, 264 pp., Edinburgh, Luath Press, 2007, $30 An article in the August 2008 issue of Annals of Neurology provides neurologists with a comprehensive update of human African trypanosomiasis (sleeping sickness), a disease transmitted by the bite of the tsetse fly. Sleeping sickness is a major threat to 60 million people in sub-Saharan Africa. The pathogenesis of disease, particularly CNS involvement, is well described and details are given about the drugs used to treat sleeping sickness, including the fact that the most effective drug, melarsoprol, kills 5% of patients who receive it. The importance of pharmaceutical industry investment in new drug discovery is emphasized. Peter Kennedy, the author of the article, has also written a book for clinicians, scientists, and nonscientists about the history and profound importance of sleeping sickness. One of the book’s attractions is that Kennedy, a clinician-scientist, has studied both the scientific and social aspects of the disease based on repeated journeys to Africa (18 visits over a 31year period since his medical student days). This popular science book conveys the magnitude of disease produced by sleeping sickness, combined with the adventure and challenges of learning about the

disease in “the dark continent.” Kennedy elegantly details his sojourns into Africa, with its rich fabric of physical beauty, people, spirit, and mystery that quickly enthralls the reader. The scientific details of sleeping sickness and its ravishing effects are interwoven with accounts of the dangers Kennedy himself faced, ranging from reckless drivers and seedy accommodations to eating food and water contaminated with multiple pathogenic microorganisms to the threats posed by crocodiles, swamps, and malaria during his repeated excursions into “the bush.” The pathogenesis of disease is explained, including a mouse model of sleeping sickness, mixed with details about the beauty of African life and the clarity of stars visible in the night’s sky and not seen in the large, polluted cities of industrialized nations. The book has broad appeal, containing science, medicine, politics, economics, and geography. It closes with challenges and a call for organizational support to eradicate this disease. The reader would do well to allot a block of uninterrupted time for this relatively short book (just over 200 pages), because once started, it is hard to put down. It is a book you will want to share with family, friends, and colleagues. Reviewed by Donald H. Gilden, MD Disclosure: The author reports no disclosures. Copyright © 2009 by AAN Enterprises, Inc.

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Calendar

2009 Neurology® publishes short announcements of meetings and courses related to the field. Items must be received at least 6 weeks before the first day of the month in which the initial notice is to appear. Send Calendar submissions to Calendar, Editorial Office, Neurology®, Suite 214, 20 SW 2nd Ave., P.O. Box 178, Rochester, MN 55903 [email protected]

JAN. 16 –18 AAN Winter Conference will be held at Disney Contemporary Resort in Orlando, FL. American Academy of Neurology: tel (800) 879-1960; www.aan.com/winter. FEB. 9 –11 Case Studies in Epilepsy Surgery will be held at the Silver Tree and Snowmass Conference Center in Snowmass, CO. Contact Martha Tobin at (216) 445-3449 or (800) 2232273, ext 53449, or at [email protected] for seminar details. FEB. 9 –13 The 22nd Annual Practicing Physician’s Approach to the Difficult Headache Patient will be held at the Camelback Inn, Scottsdale, AZ. Approved for AMA PRA Category 1 credit. Diamond Headache Clinic Research & Educational Foundation: tel (877) 706-6363 or (733) 883-2062; [email protected]; www.dhc-fdn.org. FEB. 16 –17 Fifth Annual Update Symposium on Clinical Neurology and Neurophysiology will be held in Tel Aviv, Israel. Presented by Weill Cornell Medical College, Department of Neurology, and Tel Aviv University, Adams Brain Supercenter. www.neurophysiology-symposium.com. FEB. 20 –22 International Symposium on Stereotactic Body Radiation Therapy and Stereotactic Radiosurgery will be held at the Floridian Resort & Spa in Lake Buena Vista, FL. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. APR. 2– 4 The Innsbruck Colloquium on Status Epilepticus 2009 will be held at the Congress Innsbruck, Austria. [email protected]; www.innsbruck-SE2009.eu. APR. 3 5th Annual Contemporary Issues in Pituitary: Casebase Management Update will be held at the Cleveland Clinic Lerner Research Institute in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. APR. 20 –22 Leksell Gamma Knife® Perfexion™ Upgrade Course will be held at the Gamma Knife Center in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 2232273, ext 53449, or at [email protected] for seminar details. APR. 25–MAY 2 AAN Annual Meeting will be held in Seattle, Washington State Convention & Trade Center, WA. American Academy of Neurology: tel (800) 879-1960; www.aan.com/am. MAY 3– 6 2nd International Epilepsy Colloquium, Pediatric Epilepsy Surgery Cite´ Internationale will be held in Lyon, France. http://epilepsycolloquium2009ams.fr.

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MAY 6 –10 International SFEMG Course and Xth Quantitative EMG conference will be held in Venice, Italy. tel 39041-951112; [email protected]; www.congressvenezia.it. MAY 8 The Office of Continuing Medical Education at the University of Michigan Medical School is sponsoring a CME conference entitled: Movement Disorders: A Practical Approach. It is located at The Inn at St. John’s in Plymouth, Michigan. tel (734) 763-1400; fax (734) 936-1641. MAY 11–12 Music and the Brain will be held at the InterContinental Hotel & Bank of America Conference Center in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. MAY 15–17 The Fifth International Conference on Alzheimer’s Disease and Related Disorders in the Middle East will be held in Limassol, Cyprus. www.worldeventsforum.com/alz. MAY 28 –30 6th International Headache Seminary. Focus on Headaches: New Frontier in Mechanisms and Management will be held at the Grand Hotel des Iles Borromees in Stresa (Italy); tel/fax 02 7063 8067; [email protected]. JUN. 8 –12 Leksell Gamma Knife® Perfexion™ Introductory Course will be held at the Gamma Knife Center in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. JUN. 12 Mellen Center Regional Symposium on Multiple Sclerosis will be held at the InterContinental Hotel & Bank of America Conference Center in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. JUN. 19 –24 Epileptology Symposium will be held at the InterContinental Hotel & Bank of America Conference Center, in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. JUL. 7–10 SickKids Centre for Brain & Behaviour International Symposium. [email protected]; www.sickkids.ca/ learninginstitute. JUL. 16 –18 Mayo Clinic Neurology in Clinical Practice2009 will be held at the InterContinental Hotel, Chicago, IL. Mayo CME: tel: (800) 323-2688; [email protected]; http:// www.mayo.edu/cme/neurology-neurologic-surgery.html. JUL. 21–27 Cleveland Spine Review 2009 will be held at the Embassy Suites Cleveland–Rockside Hotel in Independence, OH. Contact Martha Tobin at (216) 445-3449 or (800) 2232273, ext 53449, or at [email protected] for seminar details.

AUG. 17–19 Leksell Gamma Knife® Perfexion™ Upgrade Course will be held at the Gamma Knife Center in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. SEP. 12–15 13th Congress of the European Federation of Neurological Societies will be held in Florence, Italy. For more information: tel ⫹41 22 908 0488; http://www.kenes.com/efns2009/ index.asp; [email protected]. SEP. 25 Practical Pearls in Neuro-Ophthalmology–International Symposium in Honour of Dr. James Sharpe will be held on September 25, 2009 at the University of Toronto Conference Centre, Toronto, Ontario. For further information contact the Office of Continuing Education & Professional Development, Faculty of Medicine, University of Toronto: tel (416) 978-2719; (888) 5128173; fax (416) 946-7028; [email protected]; http:// events.cmetoronto.ca/website/index/OPT0907. OCT. 8 –11 The Third World Congress on Controversies in Neurology. Full information is available at: ComtecMed - Medical Congresses, PO Box 68, Tel-Aviv, 61000 Israel; tel ⫹972– 3-5666166; fax ⫹972–3-5666177; [email protected]; www.comtecmed.com/cony.

OCT. 24 –30 19th World Congress of Neurology, WCN 2009, will be held in Bangkok, Thailand. www.wcn2009bangkok.com. NOV. 19 –22 The Sixth International Congress on Vascular Dementia will be held Barcelona, Spain. For further details, please contact: Kenes International 17 Rue du Cendrier, P.O. Box 1726, CH-1211, Geneva 1, Switzerland; tel ⫹41 22 908 0488; fax ⫹41 22 732 2850; [email protected]; http://www. kenes.com/vascular. DEC. 3– 6 Neuromodulation 2009 Encore will be held at Wynn Las Vegas in NV. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. DEC. 7–11 Leksell Gamma Knife® Perfexion™ Introductory Course will be held at the Gamma Knife Center in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details.

2010 MAY 2–7 11th International Child Neurology Congress will be held in Cairo, Egypt; http://www.icnc2010.com/.

Save These Dates for AAN CME Opportunities! Mark these upcoming dates on your calendar for these exciting continuing education opportunities, where you can catch up on the latest neurology information. AAN Annual Meetings ● April 25—May 2, 2009, Seattle, Washington State Convention & Trade Center ● April 10 –17, 2010, Toronto, Ontario, Canada, Toronto Convention Centre

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In the next issue of Neurology® Volume 72, Number 5, February 3, 2009 www.neurology.org THE MOST WIDELY READ AND HIGHLY CITED PEER-REVIEWED NEUROLOGY JOURNAL

THIS WEEK IN Neurology®

399

461

Executive dysfunction in frontotemporal dementia and corticobasal syndrome E.D. Huey, E.N. Goveia, S. Paviol, M. Pardini, F. Krueger, G. Zamboni, M.C. Tierney, et al.

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Educational attainment and cognitive decline in old age R.S. Wilson, L.E. Hebert, P.A. Scherr, L.L. Barnes, C.F. Mendes de Leon, and D.A. Evans

Highlights of the February 3 issue

EDITORIALS

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Natalizumab: Bound to rebound? Nicoline Schiess and Peter A. Calabresi Cortical malformations: Looking behind the cortex Harvey B. Sarnat

ARTICLES

CLINICAL/SCIENTIFIC NOTES

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Immunologic, clinical, and radiologic status 14 months after cessation of natalizumab therapy O. Stu ¨ve, P.D. Cravens, E.M. Frohman, J.T. Phillips, G.M. Remington, G. von Geldern, S. Cepok, et al.

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Ocular motor and lid apraxia as initial symptom of anti-Ma1/Ma2-associated encephalitis J. Wagner, C. Schankin, T. Birnbaum, G. Po ¨pperl, and A. Straube

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Effect of plasma exchange in accelerating natalizumab clearance and restoring leukocyte function B.O. Khatri, S. Man, G. Giovannoni, A.P. Koo, J.-C. Lee, B. Tucky, F. Lynn, S. Jurgensen, et al.

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Conventional MRI and Notch3 gene screening in sporadic CADASIL M. Liguori, R. Mazzei, C. Ungaro, I.L. Simone, A. Gambardella, I. Plasmati, F. Fera, et al.

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Midbrain– hindbrain involvement in lissencephalies P. Jissendi-Tchofo, S. Kara, and A.J. Barkovich

Atypical voluntary nystagmus R.F. Lewis, A.S. Traish, and S. Lessell

NEUROIMAGES

Direct visualization of remyelination in multiple sclerosis using T2-weighted high-field MRI K. Schmierer, H.G. Parkes, and P.-W. So

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Assessment of potential drug interactions in patients with epilepsy: Impact of age and sex B.E. Gidal, J.A. French, P. Grossman, and G. Le Teuff

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Automatic detection of preclinical neurodegeneration: Presymptomatic Huntington disease S. Klo ¨ppel, C. Chu, G.C. Tan, et al., PREDICT-HD Investigators of the Huntington Study Group

RESIDENT & FELLOW SECTION

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International Issues: Of saints and sickness: A neurology elective in India Sarah I. Sheikh

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Incidence and remaining lifetime risk of Parkinson disease in advanced age J.A. Driver, G. Logroscino, J.M. Gaziano, and T. Kurth

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Teaching NeuroImage: Idiopathic hypertrophic spinal pachymeningitis Max R. Lowden and David Gill

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Randomized, double-blind, placebo-controlled study of XP13512/GSK1838262 in patients with RLS C.A. Kushida, P.M. Becker, A.L. Ellenbogen, D.M. Canafax, et al., the XP052 Study Group

CORRESPONDENCE

Clinical and electrodiagnostic correlates of peroneal intraneural ganglia N.P. Young, E.J. Sorenson, R.J. Spinner, and J.R. Daube

FUTURE ISSUES

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481 484

ALS/PDC syndrome and the cycad hypothesis Is it time for neurohospitalists?

Abstracts In the Next Issue of Neurology®

Subject to change.

THE OFFICIAL JOURNAL OF THE AMERICAN ACADEMY OF NEUROLOGY