EDITOR’S NOTE
Prescription for Change Edelle C. Field-Fote, PT, PhD
[email protected]
I
t’s funny how thoughts take their seemingly random path and carry you along, making connections among concepts that were otherwise unconnected. Beginning to make plans for the American Physical Therapy Association (APTA) Annual Meeting in Boston, MA, got me thinking about that city. Who can think of Boston without thinking of the Boston Tea Party and beginnings of our nation? It is an interesting coincidence that in 1922 the First Annual Conference of the American Women’s Physical Therapeutic Association was held in Boston (where members voted to change the name of the organization to the American Physiotherapy Association). Both these historical events are examples of small groups of people committing themselves to an idea; one a ragtag group of patriots who envisioned a great nation and mobilized to make it so, and the other a group of women, led by Mary McMillan, who were committed to a professional society that focused on restoration of physical function. Thinking about these events, it occurs to me that most significant social changes start this way, with a small group of individuals committed to an idea, who grow into a larger group and that idea becomes a movement. Our own profession has numerous examples of positive changes that began with an idea and the efforts of a small group of individuals united in a cause such as the development of board certified clinical specialties, the establishment of the Physical Therapy Fund (later the Foundation for Physical Therapy), and the efforts for direct access to physical therapist services in all states. The movement toward evidence-based practice is surely a significant effort on par with these. During the past two decades, the Neurology Section has, through JNPT, efforts of the Special Interest Groups efforts, and Combined Sections Meeting programming and regional course offerings, been assisting members in translating evidence into practice and facilitating the link between clinicians and researchers. Other Sections and the APTA have made similar efforts. Despite the best efforts of the APTA and the Sections, there remains a recognized gap between typical practice and the research evidence, but a new effort is afoot that represents the culmination of forces quietly at work for many years. On December 2–4, 2009, in Philadelphia, PA (not Boston, darn, there goes that thread), the APTA sponsored a workshop entitled Creating a Culture of Collaboration: Vitalizing Practice Through Research and Research Through Practice. The concept of the conference had evolved during the past two years with the guidance of a planning group under the direction of Marc Goldstein, APTA’s Director of Research. Conference participants applied to attend and, in their letters of application, addressed ways in which their efforts and experiences supported the conference goal of “developing a structure that will foster research collaborations between physical therapist researchers and clinicians in ways that will lead to enhanced patient care.” Among the 54 participants selected to contribute to the conference, the Neurology Section was well represented by many long-time section leaders. All the presentations related to this conference are available for viewing by APTA members on the APTA Communities Web site at: http://www.apta.org/AM/Template.cfm? Section ⫽ Home&TEMPLATE ⫽/CM/ContentDisplay.cfm&CONTENTID ⫽ 67119. These presentations offer examples of real-world approaches currently in place in clinical and academic settings in various parts of the United States, wherein a true reciprocal relationship exists between practice and research. In these settings, physical therapist practice is informed by research and informs research in turn. These innovative ways of combining research and practice have resulted in high levels of both expert practice and patient satisfaction. Conference participants worked in breakout groups to develop practical ideas for fostering a collaborative relationship among clinicians and researchers. The climax of the conference was an exhilarating presentation by each of the breakout groups wherein the ideas generated in the brainstorming sessions were shared. The conference culminated in the drafting of recommenJNPT • Volume 34, March 2010
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Editor’s Note
dations for tangible steps our profession might to bring these ideas to fruition. The draft list of recommendations is proffered in the Appendix. That everything changes is a well-worn cliche´, as the Greek philosopher Heraclitus said in the 5th century BC: “There is nothing permanent except change.” Although we have little choice about whether there will be change, we do have a choice about the direction in which that change will take us. In his popular book The Tipping Point: How Little Things Can Make a Big Difference, Gladwell1 argues that “context”—small but influential changes in the environment—is one of the principal factors that determines whether an idea will flourish. We are at an exciting time when the state of clinical practice, research, healthcare market forces, and technology are all coalescing into a context that will push us toward new models of patient care. We will all be part of the changes that come, but what are the ways that we can shape these changes and the future of practice? Grol2 describes a model for implementing change that seems to be well suited to moving forward in a direction of best possible practice. The model begins with developing a concrete proposal for changing clinical practice and identifying obstacles to change. Substantive ideas that are consistent with this model were presented at the research conference. I encourage you to visit the Web site and avail yourself of the conference materials. In the language of Gladwell,1 many of the ideas presented at this conference represent the practice of “innovators” and the first step in getting to the tipping point that will dramatically change physical therapists practice for the better. Each of us has the opportunity to be among the “early adopters” of a model of practice that offers our patients the best possible care by bringing together exceptional clinical practice and research and that brings out the best clinical scientist in each of us. REFERENCES 1. Gladwell M. The Tipping Point: How Little Things Can Make a Big Difference. New York: Little, Brown and Company; 2000. 2. Grol R. Beliefs and evidence in changing clinical practice. BMJ. 1997;315:418 – 421.
APPENDIX. Draft List of Recommendations for Creating a Culture of Collaboration To create a culture of collaboration, it is recommended that the profession: - Identify mechanisms to discern conditions amenable to the development of clinical practice guidelines. - Develop demonstration projects for integrating and optimizing treatment approaches - Assemble a core set of outcome measurements, which span the patient lifespan and domains of ability/disability, for each of the specialty areas of physical therapist practice - Explore and implement all mechanisms of extramural funding to facilitate communication between research and clinical communities - Advocate within research funding agencies to create funding mechanisms, which will bridge research gaps that limit development of evidence-based treatment protocols. - Coordinate with APTA and the Sections to develop a clinical data registry that includes a minimum data set - Develop incentives for physical therapists collecting data that conforms to the minimum data set to contribute to the clinical registry - Work with federal and private agencies to adopt evidence based-processes of patient care - Define protocols for key practice areas to determine the value of physical therapy when the practitioner adheres to evidence-based treatment protocols - Define changes in education, including but not limited to clinical residency, clinical instructor training, and changes to continuing education, that would facilitate a better understanding and increased use of evidence-based practice - Develop a new specialty in clinical research - Create incentives for clinician/researcher partnerships, and promote these so that they may serve as models for collaboration - Support the development of didactic and clinical models that build the skills of faculty and students, which will enhance collaboration between researchers and clinicians - Utilize decision support systems that can be used across a variety of digital media platforms
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© 2010 Neurology Section, APTA
ARTICLE
A Small-Group Functional Balance Intervention for Individuals with Alzheimer Disease: A Pilot Study Julie D. Ries, PT, PhD, Jamie Michelle Drake, PT, DPT, and Christopher Marino, PT, DPT
Background and Purpose: Individuals with Alzheimer disease (AD) have a higher risk of falls than their cognitively intact peers. This pilot study was designed to assess the feasibility and effectiveness of a small-group balance exercise program for individuals with AD in a day center environment. Methods: Seven participants met the inclusion criteria: diagnosis of AD or probable AD, medical stability, and ability to walk (with or without assistive device). We used an exploratory pre- and post-test study design. Participants engaged in a functional balance exercise program in two 45-minute sessions each week for eight weeks. Balance activities were functional and concrete, and the intervention was organized into constant, blocked, massed practice. Outcome measures included Berg Balance Scale (BBS), Timed Up and Go (TUG), and gait speed (GS; self-selected and fast assessed by an instrumented walkway). Data were analyzed by comparing individual change scores with previously identified minimal detectable change scores at the 90% confidence level (MDC90). Results: Pre- and post-test data were acquired for five participants (two participants withdrew). The BBS improved in all five participants, and improved ⱖ6.4 points (the MDC90 for the BBS in three participants. Four participants improved their performance on the TUG, and three participants improved ⱖ4.09 seconds (the MDC90 for the TUG). Self-selected GS increased ⱖ9.44 cm/sec (the MDC90 for gait speed) in three participants. Two participants demonstrated post-test self-selected GS comparable with their pretest fast GS. Discussion and Conclusions: This pilot study suggests that a small-group functional balance intervention for individuals with AD is feasible and effective. Although participants had no explicit memory of the program, four of five improved in at least two outcome measures. Larger scale functional balance intervention studies with individuals with AD are warranted. Key words: Alzheimer disease, balance, exercise (JNPT 2010;34: 3–10)
Department of Physical Therapy, Marymount University, Arlington, Virginia. Address correspondence to: Julie D. Ries, E-mail:
[email protected] Copyright © 2010 Neurology Section, APTA ISSN: 1557-0576/10/3401-0003 DOI: 10.1097/NPT.0b013e3181d00f2e
JNPT • Volume 34, March 2010
INTRODUCTION
A
lzheimer disease (AD) affects 5.3 million individuals in the United States, and with the aging of the US population, this number will continue to increase.1 Historically, individuals with AD were excluded from research studies and exercise programs intended to improve physical and functional performance in older adults. More recently, researchers have begun to evaluate the feasibility and the effectiveness of these exercise programs for individuals with AD and other forms of dementia. Although there are conflicting reports about the effectiveness of exercise programs for older individuals with cognitive impairment,2–5 the feasibility of individuals with dementia participating in organized exercise programs has been demonstrated by numerous studies.6 –12 In their 2008 Cochrane Review on physical activity programs for persons with dementia, Forbes et al13 concluded that “There is insufficient evidence to determine the effectiveness of activity programs in managing or improving cognition, function, behavior, depression, and mortality in people with dementia.” Individuals with AD have a higher risk of falls than their age-matched peers,14 –17 and they experience greater morbidity and mortality associated with falls.18 –20 Balance exercise programs have been shown to be effective in reducing falls in cognitively intact older adults21–23; however, there is limited evidence of the effectiveness of balance exercise programs for individuals with AD. An exercise program that leads to improved performance on balance and mobility tests in individuals with AD could mean a reduced incidence of falls in this population. This could have a positive impact on quality of life and delay the need to move from a day-care environment to an assisted living or skilled nursing facility. Maintaining the individual with AD in the least restrictive environment while decreasing morbidity and healthcare costs related to the sequelae of falls can save healthcare dollars and have a positive effect on a major public health issue.18,20 Individuals with AD represent a unique challenge in motor learning. Although the ability for declarative memory formation and learning is lost with AD, the ability to use procedural memory and learning systems seems to remain intact.24 –26 Individuals with AD maintain some ability for learning and relearning of motor skills through the use of procedural memory and learning. These individuals learn best under constant, consistent practice conditions; they learn best with practice of a specific, relevant task and may have difficulty generalizing the skills practiced.24,25,27 For the best
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possible outcome, it seems essential to integrate these principles when creating an exercise program for individuals with AD. Based on the evidence in the motor learning literature,24,25,27 characteristics of an effective balance intervention for individuals with AD would include a program that is functional, relevant, familiar, and designed with appropriate constant, blocked, massed practice conditions to facilitate optimal learning. Constant (as opposed to variable) practice refers to repetition under consistent and specific task conditions, blocked (as opposed to random) practice indicates that a block of task trials is completed before moving to another task, and massed (as opposed to distributed) practice indicates more practice than rest in a practice session.28 Another consideration in working with individuals with AD is to choose appropriate outcome measures. The study of outcome measures for use with individuals with AD and other dementias is a recent addition to the rehabilitation literature.29 –31 Reliability and validity of specific outcome measures for this population, and minimal detectable change (MDC) scores, which can help to determine whether individuals are making “true” changes in performance over time, are now available. The purpose of this pilot study was to assess the feasibility and effectiveness of a small-group balance exercise program for individuals in an AD day program. It was hypothesized that this functionally based balance intervention would improve balance, as defined by performance on balance and gait outcome measures.
METHODS This was an exploratory pilot study using a pre- and post-test design. The project was approved by the Marymount University Institutional Review Board.
Participants Seven individuals at a local adult day center were recruited to participate in this pilot study. The facility administrator identified appropriate participants based on the inclusion and exclusion criteria and approached participants and guardians on behalf of the researchers to make initial contact. Inclusion criteria consisted of diagnosis of AD or probable AD per primary care physician, medical stability, ability to walk with or without assistive device without the physical assistance of another person, and ability to follow one-step commands. Individuals were excluded from the study if they had any neurologic or musculoskeletal comorbidity that might affect their gait or balance (eg, cerebral vascular accident, Parkinson disease, recent orthopedic surgery), limiting cardiac or pulmonary condition or if they were a new participant (within past three weeks) of the adult day center. Informed consent was provided by proxy decision makers for all participants. Assent forms were offered, but all proxy decision makers opted not to have participants sign the assent forms.
Procedures Data were collected from each participant’s facility health record, including birth date and age, sex, height and weight, home environment, social and family history (to allow researchers to establish rapport by discussing familiar
4
people and activities), medications, medical history, ambulation status, and assistive device requirement. The professional literature is rich with practical tips on optimal interaction and communication with individuals with AD, and every effort was made to integrate these concepts into the study protocol to maximize success of interactions. A personal connection between patient and caregiver is deemed necessary for optimal social interaction and engagement of participants32–34; thus, the collection of personal information allowed researchers to establish rapport with participants. Many authors cite the importance of a low-stress environment and working in a familiar place with familiar people as key factors to facilitating optimal performance in individuals with AD.35–39 The progression of cuing was another component of the protocol that was clearly outlined for the administration of pretests and posttests and for the exercise activities. The progression of cuing began with verbal instruction with concurrent visual cue, followed by gesturing or demonstration, followed by tactile guidance, and, finally, physical assistance.40,41 These general guidelines were used across all activities within the study and are represented in Table 1. The week before beginning the exercise program, participants were administered a Mini-Mental Status Examination (MMSE)42 by the principal investigator and were rated
TABLE 1. Achieving Optimal Performance in Individuals with Alzheimer Disease Characteristics of Interaction Individual perceives a personal connection with the tester/ researcher/clinician Individual perceives the environment to be low stress Interpersonal interaction is perceived as friendly, nonthreatening, clear in purpose
The optimal progression of cuing is followed
Suggested Mechanisms of Attainment Individual is oriented to their own personal history Individual is talked through a “reminiscence” before the activity There are no distracting stimuli The setting is a familiar place The people are familiar Tester/researcher/clinician uses direct, friendly eye contact and facial expression Clinician sits (does not stand) across from patient to explain the task at hand in simple terms Clinician uses pleasant but firm voice commands (not questions) when trying to elicit a physical response or activity Clinician gives commands one step at a time Clinician gives meaningful goals vs actions Begin with verbal instruction with concurrent visual cue. Allow 10 sec for response. If no response, provide gesturing and demonstration. Allow 10 sec for response. If no response, provide tactile guidance. Allow 10 sec for response. If no response, provide physical assistance
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with the Functional Assessment STaging (FAST) tool,43,44 with the assistance of a staff informant. These tools were used to classify the level of dementia. The FAST is a functionally oriented tool used by the Alzheimer’s Association to educate about the progression of AD; scores range from 1 (normal adult with no cognitive or functional decrement) to 7 (severe AD), with levels 6 and 7 having subscores A through E, giving the tool 15 levels. The functional nature of the tool is evident in the descriptors of each stage. For instance, stage 4 (mild AD) is defined as “assistance required in complex tasks (handling finances, marketing, or planning dinner for guests).” Stage 5 (moderate AD) is defined as “assistance required in choosing proper clothing.” The MMSE scores range from 0 to 30, with lower scores representing more profound cognitive impairment. Use of the MMSE allowed for general comparison of level of cognitive function of participants in this study with other published studies, as this is a widely used cognitive screening tool. A score of ⱕ23 on the MMSE is the generally accepted indicator of cognitive impairment, with 18 to 23 indicating mild impairment and 0 to 17 indicating severe impairment.45 Participants performed pretests of three clinical measures of balance and gait on the same day. The outcome measures chosen were Timed Up and Go (TUG), Berg Balance Scale (BBS) score, and gait speed (GS) as measured by the GAITRite walkway (CIR Systems, Inc., Havertown, PA). Both self-selected GS (SSGS) and fast GS (FGS) were assessed. For the TUG,46 participants began seated in a chair with arm rests, and on the instruction “Go,” the participant stood, walked 3 m, circled around a cone, walked back to the chair, and sat down. The participants were instructed to go as fast as they comfortably could. They performed this activity twice after a practice trial, and the time for the trial began when the participant’s bottom left the chair and ended when the bottom contacted the chair. This modified protocol of beginning the stop watch on movement initiation as opposed to command for movement has been previously documented.29 This approach was adopted to capture only the mobility component of the TUG and not the time required for progression of cuing strategies before movement. Participants also frequently needed prompting cues during the test (eg, “go around the cone” and “sit in that chair”). The outcome score was the mean of two performances. The TUG has been evaluated for use with individuals with AD and other dementias and found to have excellent test-retest reliability (intraclass correlation coefficient [ICC] ⫽ 0.92– 0.99).29,47,48 The BBS49 –52 consists of 14 different balance activities, ranging in difficulty from sitting unsupported in a chair to picking up an object from the floor or turning in a circle while standing. The activities are function oriented, and each item is scored from 0 (unable to perform) to 4 (proficient performance). The BBS has been used with older adults with cognitive deficits, and test-retest reliability has been found to be excellent (ICC ⫽ 0.97).31,47 The SSGS was assessed using the GAITRite walkway and software system. Participants walked twice (after one practice walk) across the 12-foot walkway instrumented with sensors that recorded the temporal and spatial parameters of gait; the walkway was arranged to allow the acceleration and deceleration periods of the walk © 2010 Neurology Section, APTA
Balance Intervention in Individuals with AD
to occur before the start and after the end of the mat, respectively. The GAITRite walkway has been found to have excellent validity and reliability for GS53,54 and has been used with individuals with AD with high test-retest reliability (ICC ⫽ 0.96 – 0.977).29,30 Mean GS of two passes on the mat at SSGS gave the SSGS score and mean GS of two passes on the mat at FGS gave the FGS score. The balance exercise intervention was an eight-week, twice-weekly class with 45 minutes for each session. The program was performed in the therapy room of the adult day center. The class was held at consistent times and days each week. The ratio of participants to instructor was never greater than 2:1, and the same licensed physical therapist and student physical therapists supervised the classes each week. The structure of the exercise program was based on available literature concerning motor learning in individuals with AD. The program was designed to be functional and relevant and to include tasks that would be familiar to the participants. It was organized with constant, blocked, massed practice conditions to facilitate optimal learning in the participants. Balance is defined as maintaining the center of gravity (COG) over the base of support (BOS). Thus, justification for the majority of exercises is related to changes in COG or BOS within a functional context. Although some of the exercises might also be appropriate as strengthening, coordination, or flexibility interventions, they were chosen primarily as challenges to balance. The exercise activities included in the program and their justifications are included in Table 2. The exact same activities were not performed each session, although the underlying principles of maintaining balance during changes to the COG and BOS and the functional nature of the exercises were consistent throughout all sessions. Whenever participants were trying an activity for the first time, they were provided with 1:1 supervision. The low participant-toinstructor ratio also allowed individual attention to performance and appropriate adaptation or progression of activities for each participant. Depending on the activity and the day, some tasks were performed in the larger group, and some were performed at stations, either in pairs or individually with an instructor. An attendance log was maintained to monitor attendance and participation. Individuals got credit for participation if they engaged in 50% or more of a given exercise class. Recording in a narrative log after each session allowed class instructors to summarize their perceptions of participant engagement and performance. The week after the final exercise session, each participant again underwent the series of three balance and mobility outcome measures outlined previously. Testing occurred in the same place, at the same general time of day, and in the same order as the pretests, and the posttesting session was scored by the same examiner as the pretesting session.
Data Analysis Data were analyzed for each participant by comparing changes in performance between pretest and posttest (ie, individual change score) with pre-established MDC scores at the 90% confidence interval (MDC90) for the chosen outcome measures for this population. When an individual change
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TABLE 2. Balance Exercises and Justification Exercise Activity Sit to stand and stand to sit
One-leg stance Toe-touching in standing and return to upright Heel raises and toe-walking Overhead and side-to-side reaching Rotating right and left while standing and rotating while walking Tandem standing and walking on line Fast walking Slow walking
Obstacle avoidance Stop and go and turning on command Navigation of uneven terrain High stepping or marching Backward walking Side stepping Picking up objects from different heights or levels and placing them on different heights or levels Heel walking
Ramp ascent or descent
Stair or curb ascent or descent
Walking while carrying objects of different sizes and weights Catching and throwing ball or soft object Kicking ball Sport and leisure activities: putting golf ball, playing bocci ball, swinging tennis racket at tossed ball
Justification for Exercise Activity Moves COG over a stable BOS; strengthening to lower extremity extensors in concentric and eccentric fashion; functional activity Decreases BOS; functional for single limb support during gait and stair climbing Moves COG over stable BOS; hamstring stretch; eccentric and concentric hip extension activity Decreases BOS in dynamic context; strengthening to plantar flexors Changes COG in direction of reach; dynamic control of weight shifting within a functional activity Changes COG over stable and then dynamically changing BOS; functional activity Narrows BOS in static and dynamic context Rapidly changing BOS in functional context Eliminates benefit of forward momentum of COG during gait, increasing balance demand Dynamic functional activity; requires adaptation to environmental demand Dynamic functional activity Dynamic functional activity; requires adaptation to environmental demand Changes BOS, prolongs single limb stance Dynamic functional activity Dynamic functional activity Dynamic functional activity; requires adaptation to environmental demand
Alters BOS; strengthening to anterior compartment and stretching to posterior compartment of lower leg Dynamic functional activity; requires adaptation to environmental demand; increases demand for ankle range of motion Changing BOS; requires unilateral lower extremity strength and coordination to successfully elevate or lower body weight Changes COG; dynamic functional activity; involves dual tasking Requires anticipatory and reactive balance mechanisms Changing BOS with dynamic shift in COG; requires single limb stance Dynamic functional activities; recreational
Abbreviations: COG, center of gravity; BOS, base of support.
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score exceeds the MDC90 score, this represents a “true” change in performance, beyond what would be expected from individual variability and measurement error for the chosen outcome measure. The pre-established MDC90 score used for the TUG was 4.09 seconds,29 for the SSGS was 9.44 cm/ sec,29 and for the BBS score was 6.4.31 There are no established MDC90 scores for FGS, and for this reason, it is not considered one of the primary outcome measures for this study.
RESULTS Of the seven individuals recruited, five completed the exercise program and pretesting and posttesting. One individual was relocated to an inpatient facility after pretesting and attending one exercise class. A second participant engaged in pretesting and attended the first three weeks of exercise classes, but refused to attend subsequent classes. The characteristics of the five participants who completed the protocol are summarized in Table 3. There were no documented falls at the facility for any of the participants before or during the study; however, data related to history of falls outside of the facility were not available. The BBS scores improved in all five participants, with three participants having scores that improved by ⬎6.4 of the pre-established MDC90. Four participants improved in TUG performance time, with three participants improving their time by ⬎4.09 seconds of the pre-established MDC90. Three participants improved in SSGS, with all of them improving their speed by ⬎9.44 cm/sec of the pre-established MDC90. Three participants showed improvements in FGS, whereas two participants demonstrated a decline in FGS performance. Two participants improved their SSGS to the extent that their post-test SSGS was comparable with their pretest FGS (within 7.1 cm/sec for participant 3 and within 1.3 cm/sec for participant 5). Individual pre- and posttest scores and change scores are given in Table 4.
TABLE 3. Participant Characteristics Participants
Sex Diagnosis MMSE score FAST score Age (yr) Comorbiditiesa Assistive device Attendance (%) Participationb (%)
1
2
3
4
5
F AD 18 5 93 a, b None 100 100
F Prob AD 24 5 87 b, c, d None 100 88
F AD 26 4 84 a, e RW 100 100
F AD 24 4 81 a, e None 94 88
M Prob AD 24 4 87 a, b, c, f RW 75 69
a Comorbidities: a, cardiovascular disease or hypertension; b, visual impairment (glaucoma, cataracts, or macular degeneration); c, peripheral vascular disease; d, thyroid disorder; e, osteoporosis; f, depression. b Participation ⫽ percentage of exercise classes in which subject engaged or participated. Abbreviations: AD, Alzheimer disease; Prob AD, probable Alzheimer disease; MMSE, Mini-Mental Status Examination; FAST, Functional Assessment Staging Tool (4, mild AD; 5, moderate AD); RW, rolling walker.
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TABLE 4.
Balance Intervention in Individuals with AD
Results of the Study Participants 1
2
3
4
5
Change Change Change Change Change Pretest Post-Test Score Pretest Post-Test Score Pretest Post-Test Score Pretest Post-Test Score Pretest Post-Test Score Berg Balance Scale score Timed Up and Go (sec) Self-selected gait speed (cm/sec) Fast-selected gait speed (cm/sec)
48 11.25
54 6.97
6
38
39
4.28a
13.48
16.45
1
8a
31
39
48
(2.97)
27.71
17.03
10.68a
15.68
55 9.93
7a
37
48
5.75a
16.72
13.55
11a 3.17
86.9
101.8
14.9a
94.3
75.2
(19.1)
40.9
57.3
16.4a
71.5
61.9
(9.6)
48.0
69.3
21.3a
144.0
180.9
36.9
114.1
83.8
(30.3)
64.4
84.3
19.9
112.4
90.7
(21.7)
70.6
106.0
35.4
Parenthetical values represent degradation of performance. a Exceeds predetermined minimal detectable change score at the 90% confidence interval.
DISCUSSION The five participants who completed the exercise intervention demonstrated excellent attendance and very good participation. There were no changes in medical status or medications for any of the participants during the study. Routinely, participants who came to class engaged in all class activities; however, there were a few occasions in which individuals were present but unable or unwilling to participate. Reasons for lack of participation included general fatigue, headache, foot pain, disinterest, or agitation. No individual missed more than one session for the same reason. Except participant 2, all participants who completed the program made significant improvement in at least two of the three primary outcome measures, as determined by change scores greater than MDC90. Participant 3, who had 100% participation, showed significant improvement in all three outcome measures. Participant 2 did not seem to put forth her best effort on the day of post-testing because she verbalized general health concerns (as was a common behavior for her) and complaints of vague lower extremity discomfort throughout all testing activities. Her constant verbalizations were not conducive to capturing her best performance on post-tests. Efforts to reschedule the post-testing were unsuccessful. Participant 4, who showed significant gains in BBS score and TUG, offered a poor effort on SSGS and FGS, as evidenced by walking with hands in pockets and scuffing feet along the mat during post-testing. She was frustrated with the posttest session by the time of the third and final tests (SSGS and FGS). Participant 5, whose participation level was lowest (69%), showed significant gains in both BBS score and SSGS. Both participants 3 and 5 increased their SSGS such that their post-test SSGS were comparable with their pretest FGS. Worthy of mention is the attrition of two of the original seven program participants. One participant had been awaiting placement in an inpatient facility, and a bed was available during the first week of the exercise intervention. This individual was an 83-year-old man with an MMSE score of 16 and FAST score of 5 (moderate AD). The other individual © 2010 Neurology Section, APTA
had been experiencing an increase in agitated behavior before the initiation of the exercise program. He participated in pretesting and the first six exercise classes without incident; however, he became agitated on invitation to join the class on subsequent days, and he was ultimately withdrawn from the study. This individual was a 90-year-old man with an MMSE score of 18 and FAST score of 6D (moderately severe AD). Of the seven participants initially recruited, the two individuals who withdrew from the study represented the most cognitively impaired (MMSE score of 16) and the most functionally impaired (FAST score of 6) participants. Although no conclusions can be drawn from this observation, consideration of dementia level may be an important component in the implementation of an exercise intervention. Kenny et al,55 in examining predictors of transition from dementia-specific assisted living facilities to skilled nursing facilities, identified that GS and balance (as determined by a modified BBS) were significant predictors of movement to an increased level of care. They suggested that interventions geared toward improving balance and GS and minimizing fall risk in this population, could potentially affect the high transfer rate to skilled nursing facilities. This is convincing justification for designing an efficacious balance intervention. The feasibility of group exercise interventions with some focus on balance training for individuals with AD and other dementias has been well established,8,11,12,56 and a few studies have provided some evidence of effectiveness of interventions in improving balance and gait performance or attenuating loss of function.8,11,56 Toulotte et al11 studied the effects of a general exercise program on measures of balance in older adults with cognitive impairment of various etiologies (mean MMSE, 16.3 ⫾ 6.5). They found that the exercise group showed significant gains in balance (TUG and SSGS) after the 16-week, twice-weekly exercise program compared with a control group. However, there was an apparent difference in the two groups before the intervention in balance performance, and this is not addressed by the authors. Santana-Sosa et al57 reported findings from a controlled study of
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a 12-week, three times per week exercise intervention for individuals with AD (mean MMSE [training group], 20.1 ⫾ 2.3; mean MMSE [control group], 19.9 ⫾ 1.7), which demonstrated significant improvement in balance and gait (using Tinetti scale) in the training group, with no significant change in the control group. This was a small (eight subjects in each group) but well-designed study demonstrating the balance benefits of a generalized (resistance, flexibility, and coordination) exercise program in individuals with AD. In examining an intervention of longer duration, Rolland et al8 demonstrated the attenuation of decline in activities of daily living and improvement in GS compared with a control group, in nursing home residents with AD (mean MMSE, 8.8 ⫾ 6.6) who participated in a 12-month exercise program. Christofoletti et al56 compared six months of motor interventions across three randomized groups of individuals with dementia. Group 1 (mean MMSE, 18.7 ⫾ 1.7) received interdisciplinary treatment (individualized physical therapy, group occupational therapy, and group physical education totaling two hours per day, five days per week); Group 2 (mean MMSE, 12.7 ⫾ 2.1) received individualized physical therapy three times per week for one hour; and Group 3 (mean MMSE, 14.6 ⫾ 1.2) received no motor intervention (control). Although the authors concluded that individuals in both Groups 1 and 2 “improved” their balance, this may be somewhat overstated because there was no evidence that performance scores on the chosen outcome measures (TUG and BBS score) are significantly different from preintervention to postintervention; a decline in performance was observed in the control group. A recent study by Kwak et al58 identified the beneficial effect on balance of a one-year group exercise program in individuals with senile dementia, but the authors did not define how balance was assessed in the study, making interpretation of results difficult. In each of these previous studies, balance is one of the many components in the exercise programs, not the primary focus. In this study, upright balance training was the principal purpose of the exercise intervention. Basic exercise principles of specificity of training- and task-oriented activities informed the design of the exercise program used in this study. Littbrand et al12 confirmed that impaired cognitive function does not negatively affect the feasibility of participating in a high-intensity weight-bearing exercise program (primarily upright standing and walking activities), although given the design of their study, the authors could not draw conclusions about the effectiveness of their intervention. Netz et al59 demonstrated that older adults with dementia did not benefit from a seated, low-intensity exercise program; however, when the same group participated in a more rigorous exercise program performed while standing or walking, they showed improvement in TUG performance. Accordingly, the majority of activities within the exercise intervention in this study were upright static or dynamic activities. Another unique aspect of this study was the deliberate design of the intervention to address the motor learning needs of individuals with AD. None of the authors of the reviewed studies offered extensive comment on the design of the exercise programs used in their protocols. The use of constant, blocked, massed practice and the low instructor-to-
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participant ratio, which allowed individualized progression of tasks to appropriately challenge participants, were considered key to the success of the intervention in this study. Participants generally enjoyed the exercise program, as evidenced by their mood during the majority of exercise sessions. With the exception of participant 5, individuals had no explicit memory of engaging in the exercise program from session to session. They greeted researchers as if for the first time during every session, and when questioned whether they recalled participating in an exercise class, they responded that they did not. Given that individuals with AD may have intact procedural (implicit) motor learning capacity,24,25 the improvement observed in this study demonstrates motor memory of the activities practiced during the exercise program, despite the lack of declarative (explicit) memory (ie, ability to recall participation in the class). The BBS items on which the subjects showed the most improvement were items that were practiced often in the context of the exercise class (eg, turn to look behind, standing with one leg in front, standing on one foot), reinforcing the idea that specificity of training is important for this population. Toward the end of the intervention, staff at the adult day center provided unsolicited comments on the improved abilities of the participants.
Limitations Drawing definitive conclusions from this exploratory pilot study would be premature. The small sample size and lack of a control group are considerable limitations; however, the results of this study reveal the need for future research, including larger studies and randomized controlled trials, to assess the effectiveness of carefully designed small-group balance interventions to improve balance and potentially to decrease the risk of falls in individuals with AD. Considerations for further study might include the level of dementia of participants, “dosage” of exercise intervention, instructor-toparticipant ratio, and identification of minimally clinically important difference scores (in relation to MDC scores) in these individuals.
CONCLUSIONS This pilot study confirmed the feasibility of a smallgroup upright balance exercise program for individuals with AD in a day-care setting. The eight-week, twice weekly exercise intervention was designed with attention to the evidence available in the motor learning literature on individuals with AD. Constant, blocked, massed practice was used, and specific guidelines were followed for communication and cuing with the participants. This exercise program seemed to be effective in improving balance in individuals with mild to moderate AD. Further research is warranted. REFERENCES 1. Alzheimer’s Association. 2009 Alzheimer’s disease facts and figures. Alzheimers Dement. 2009;5:234 –270. 2. Perez CA, Cancela Carral JM. Benefits of physical exercise for older adults with Alzheimer’s disease. Geriatr Nurs. 2008;29:384 –391. 3. Hauer K, Becker C, Lindemann U, et al. Effectiveness of physical training on motor performance and fall prevention in cognitively impaired older persons: a systematic review. Am J Phys Med Rehabil. 2006;85:847– 857.
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4. Heyn P, Abreu BC, Ottenbacher KJ. The effects of exercise training on elderly persons with cognitive impairment and dementia: a meta-analysis. Arch Phys Med Rehabil. 2004;85:1694 –1704. 5. Rolland Y, Abellan van Kan G, Vellas B. Physical activity and Alzheimer’s disease: from prevention to therapeutic perspectives. J Am Med Dir Assoc. 2008;9:390 – 405. 6. Arkin SM. Student-led exercise sessions yield significant fitness gains for Alzheimer’s patients. Am J Alzheimers Dis Other Demen. 2003;18: 159 –170. 7. Binder E. Implementing a structured exercise program for frail nursing home residents with dementia: issues and challenges. J Aging Phys Activity. 1995;3:383–395. 8. Rolland Y, Pillard F, Klapouszczak A, et al. Exercise program for nursing home residents with Alzheimer’s disease: a 1-year randomized, controlled trial. J Am Geriatr Soc. 2007;55:158 –165. 9. Rolland Y, Rival L, Pillard F, et al. Feasibility of regular physical exercise for patients with moderate to severe Alzheimer disease. J Nutr Health Aging. 2000;4:109 –113. 10. Thomas VS, Hageman PA. Can neuromuscular strength and function in people with dementia be rehabilitated using resistance-exercise training? Results from a preliminary intervention study. J Gerontol A Biol Sci Med Sci. 2003;58:746 –751. 11. Toulotte C, Fabre C, Dangremont B, et al. Effects of physical training on the physical capacity of frail, demented patients with a history of falling: a randomised controlled trial. Age Ageing. 2003;32:67–73. 12. Littbrand H, Rosendahl E, Lindelof N, et al. A high-intensity functional weight-bearing exercise program for older people dependent in activities of daily living and living in residential care facilities: evaluation of the applicability with focus on cognitive function. Phys Ther. 2006;86:489 – 498. 13. Forbes D, Forbes S, Morgan DG, et al. Physical activity programs for persons with dementia. Cochrane Database Syst Rev. 2008;3: CD006489. 14. Alexander NB, Mollo JM, Giordani B, et al. Maintenance of balance, gait patterns, and obstacle clearance in Alzheimer’s disease. Neurology. 1995;45:908 –914. 15. Chong RK, Horak FB, Frank J, et al. Sensory organization for balance: specific deficits in Alzheimer’s but not in Parkinson’s disease. J Gerontol A Biol Sci Med Sci. 1999;54:M122–M128. 16. Pettersson AF, Engardt M, Wahlund LO. Activity level and balance in subjects with mild Alzheimer’s disease. Dement Geriatr Cogn Disord. 2002;13:213–216. 17. Allan LM, Ballard CG, Rowan EN, et al. Incidence and prediction of falls in dementia: a prospective study in older people. PLoS One. 2009;4:e5521. 18. Frytak JR, Henk HJ, Zhao Y, et al. Health service utilization among Alzheimer’s disease patients: evidence from managed care. Alzheimers Dement. 2008;4:361–367. 19. Larson EB, Shadlen MF, Wang L, et al. Survival after initial diagnosis of Alzheimer disease. Ann Intern Med. 2004;140:501–509. 20. Zhao Y, Kuo TC, Weir S, et al. Healthcare costs and utilization for Medicare beneficiaries with Alzheimer’s. BMC Health Serv Res. 2008; 8:108. 21. Gillespie LD, Gillespie WJ, Robertson MC, et al. Interventions for preventing falls in elderly people [Review]. Cochrane Database Syst Rev. 2003;4:CD000340. 22. Hauer K, Rost B, Rutschle K, et al. Exercise training for rehabilitation and secondary prevention of falls in geriatric patients with a history of injurious falls. J Am Geriatr Soc. 2001;49:10 –20. 23. Steadman J, Donaldson N, Kalra L. A randomized controlled trial of an enhanced balance training program to improve mobility and reduce falls in elderly patients. J Am Geriatr Soc. 2003;51:847– 852. 24. Harrison BE, Son GR, Kim J, et al. Preserved implicit memory in dementia: a potential model for care. Am J Alzheimers Dis Other Demen. 2007;22:286 –293. 25. van Halteren-van Tilborg IA, Scherder EJ, Hulstijn W. Motor-skill learning in Alzheimer’s disease: a review with an eye to the clinical practice. Neuropsychol Rev. 2007;17:203–212. 26. Vidoni ED, Boyd LA. Achieving enlightenment: what do we know about the implicit learning system and its interaction with explicit knowledge? J Neurol Phys Ther. 2007;31:145–154.
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27. Dick MB, Hsieh S, Dick-Muehlke C, et al. The variability of practice hypothesis in motor learning: does it apply to Alzheimer’s disease? Brain Cogn. 2000;44:470 – 489. 28. Shumway-Cook A, Woollacott MH. Motor Control: Translating Research into Clinical Practice. 3rd ed. Baltimore, MD: Lippincott Williams & Wilkins; 2007. 29. Ries JD, Echternach JL, Nof L, et al. Test-retest reliability and minimal detectable change scores for the timed “up & go” test, the six-minute walk test, and gait speed in people with Alzheimer disease. Phys Ther. 2009;89:569 –579. 30. Wittwer JE, Webster KE, Andrews PT, et al. Test-retest reliability of spatial and temporal gait parameters of people with Alzheimer’s disease. Gait Posture. 2008;28:392–396. 31. Conradsson M, Lundin-Olsson L, Lindelof N, et al. Berg balance scale: intrarater test-retest reliability among older people dependent in activities of daily living and living in residential care facilities. Phys Ther. 2007;87:1155–1163. 32. Staples S. Alzheimer’s disease: modifying instructions and approach to enhance performance. Presented at: Combined Sections Meeting of the American Physical Therapy Association, New Orleans, LA, February 23–27, 2005. 33. Haak NJ. Maintaining connections: understanding communication from the perspective of the person with dementia. Alzheimer Care Quart. 2002;3:116 –131. 34. Kovach CR, Henschel H. Planning activities for patients with dementia: a descriptive study of therapeutic activities on special care units. J Gerontol Nurs. 1996;22:33–38. 35. Patterson JT, Wessel J. Strategies for retraining functional movement in persons with Alzheimer disease: a review. Physiother Canada. 2002;54: 274 –280. 36. Auer SR, Sclan SG, Yaffee RA, et al. The neglected half of Alzheimer disease: cognitive and functional concomitants of severe dementia. J Am Geriatr Soc. 1994;42:1266 –1272. 37. Davis CM. The role of the physical and occupational therapist in caring for the victim of Alzheimer’s disease. Phys Occup Ther Geriatr. 1986; 4:15–28. 38. Ellis SM. Health professionals’ guide to managing patients with Alzheimer’s disease and their families. Can Pharm J. 1983;116:132–133. 39. Hoppes S, Davis LA, Thompson D. Environmental effects on the assessment of people with dementia: a pilot study. Am J Occup Ther. 2003;57:396 – 402. 40. Vogelpohl TS, Beck CK, Heacock P, et al. “I can do it!” Dressing: promoting independence through individualized strategies. J Gerontol Nurs. 1996;22:39 – 42. 41. Beck CK, Heacock P, Rapp CG, et al. Assisting cognitively impaired elders with activities of daily living. Am J Alzheimer Care Relat Disord Res. 1993;8:11–20. 42. 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. 43. Reisberg B, Ferris SH, Anand R, et al. Functional staging of dementia of the Alzheimer type. Ann NY Acad Sci. 1984;435:481– 483. 44. Reisberg B, Ferris SH, Franssen E. An ordinal functional assessment tool for Alzheimer’s-type dementia. Hosp Commun Psychiatr. 1985;36: 593–595. 45. Tombaugh TN, McIntyre NJ. The mini-mental state examination: a comprehensive review. J Am Geriatr Soc. 1992;40:922–935. 46. Podsiadlo D, Richardson S. The timed “Up & Go”: a test of basic functional mobility for frail elderly persons. J Am Geriatr Soc. 1991; 39:142–148. 47. van Iersel MB, Benraad CE, Rikkert MG. Validity and reliability of quantitative gait analysis in geriatric patients with and without dementia. J Am Geriatr Soc. 2007;55:632– 634. 48. Nordin E, Rosendahl E, Lundin-Olsson L. Timed “Up & Go” test: reliability in older people dependent in activities of daily living—focus on cognitive state. Phys Ther. 2006;86:646 – 655. 49. Berg K, Norman KE. Functional assessment of balance and gait. Clin Geriatr Med. 1996;12:705–723. 50. Berg K, Wood-Dauphinee S, Williams JI. The Balance Scale: reliability assessment with elderly residents and patients with an acute stroke. Scand J Rehabil Med. 1995;27:27–36.
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51. Berg KO, Maki BE, Williams JI, et al. Clinical and laboratory measures of postural balance in an elderly population. Arch Phys Med Rehabil. 1992;73:1073–1080. 52. Berg KO, Wood-Dauphinee SL, Williams JI, et al. Measuring balance in the elderly: validation of an instrument. Can J Public Health. 1992; 83(Suppl 2):S7–S11. 53. McDonough AL, Batavia M, Chen FC, et al. The validity and reliability of the GAITRite system’s measurements: a preliminary evaluation. Arch Phys Med Rehabil. 2001;82:419 – 425. 54. Menz HB, Latt MD, Tiedemann A, et al. Reliability of the GAITRite walkway system for the quantification of temporo-spatial parameters of gait in young and older people. Gait Posture. 2004;20:20 –25.
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55. Kenny AM, Bellantonio S, Fortinsky RH, et al. Factors associated with skilled nursing facility transfers in dementia-specific assisted living. Alzheimer Dis Assoc Disord. 2008;22:255–260. 56. Christofoletti G, Oliani MM, Gobbi S, et al. A controlled clinical trial on the effects of motor intervention on balance and cognition in institutionalized elderly patients with dementia. Clin Rehabil. 2008;22:618 – 626. 57. Santana-Sosa E, Barriopedro MI, Lopez-Mojares LM, et al. Exercise training is beneficial for Alzheimer’s patients. Int J Sports Med. 2008;29:845– 850. 58. Kwak YS, Um SY, Son TG, et al. Effect of regular exercise on senile dementia patients. Int J Sports Med. 2008;29:471– 474. 59. Netz Y, Axelrad S, Argov E. Group physical activity for demented older adults feasibility and effectiveness. Clin Rehabil. 2007;21:977–986.
© 2010 Neurology Section, APTA
ARTICLE
Effects of Medication on Turning Deficits in Individuals with Parkinson’s Disease Minna Hong, PT, PhD, and Gammon M. Earhart, PT, PhD
Background and Purpose: People with Parkinson’s disease often have difficulty executing turns. To date, most studies of turning have examined subjects ON their anti-Parkinson medications. No studies have examined what specific aspects of turning are modified or remain unchanged when medication is administered. The purpose of this study was to determine how anti-Parkinson medications affect temporal and spatial features of turning performance in individuals with Parkinson’s disease. Methods: We examined turning kinematics in 10 people with Parkinson’s disease who were assessed both OFF and ON medication. For both conditions, participants were evaluated with the Unified Parkinson’s Disease Rating Scale motor subscale, rated how well their medication was working on a visual analog scale, and performed straight-line walking and 180-degree in-place turns. We determined the average walking velocity, time and number of steps to execute turns, sequence of yaw rotation onsets of the head, trunk, and pelvis during turns, and amplitudes of yaw rotation of the head, trunk, and pelvis during turns. Results: Medication significantly improved the Unified Parkinson’s Disease Rating Scale scores (P ⫽ 0.02), visual analog scale ratings (P ⫽ 0.03), and walking velocity (P ⫽ 0.02). Although improvements in turning were not statistically significant, medication did reduce the time and number of steps required to turn, slightly increased the amplitudes of yaw rotation of the various segments, and increased the rotation of the head relative to the other segments. Medication did not improve the timing of segment rotations, which showed en bloc turn initiation in both the OFF and ON medication conditions. Discussion and Conclusion: These results suggest that only certain aspects of turning may be responsive to anti-Parkinson medications. As such, additional rehabilitative approaches to address turning are needed because turning may not be effectively addressed by pharmacologic approaches. These results should be interpreted cautiously given the small sample size.
Program in Physical Therapy and Departments of Neurology and Anatomy and Neurobiology (G.M.E.), Washington University School of Medicine, St. Louis, Missouri Spinal Cord Injury Center (M.H.), VA Palo Alto Health Care System, Palo Alto, CA. Supported by NIH grants 1 K01 HD048437-05 and 1 F31 NS056653, and PODS II from the Foundation for Physical Therapy. Address correspondence to: Gammon M. Earhart, E-mail: earhartg@wusm. wustl.edu Copyright © 2010 Neurology Section, APTA ISSN: 1557-0576/10/3401-0011 DOI: 10.1097/NPT.0b013e3181d070fe
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Key words: Parkinson’s disease, walking, turning (JNPT 2010;34: 11–16)
INTRODUCTION
I
mpaired turning affects a large percentage of people with Parkinson disease (PD) and is often present before the onset of other gait abnormalities.1,2 Turning impairment hinders activities of daily living, is associated with falls, and has a significant effect on the quality of life.1,3– 6 Previous studies have noted several deficits in turning. Individuals with PD have been repeatedly noted to require more steps and more time to complete a turn compared with age-matched controls.6 –9 Individuals with PD also demonstrate altered timing of turn initiation with near simultaneous onset of rotation of the head, trunk, and pelvis.2,7,10 –12 This pattern of simultaneous rotation onsets together with reduced relative rotations between the segments is commonly referred to as en bloc turning.7 Control subjects turn with a top-down sequence of rotation onsets, with the head rotating first followed by the trunk and then the pelvis.7 In addition to alterations in timing of yaw rotation (a turn about the vertical axis) onsets, reductions in the amount of relative rotation between the body segments and in the peak velocity of yaw rotation during turning have also been reported for those with PD.7,8,12,13 To our knowledge, no studies have examined the specific effects of anti-Parkinson medication on turning performance, and only a single study examined turning performance in individuals OFF medication.7 The purpose of this study was to determine whether and how anti-Parkinson medications alter the temporal and spatial features of turning in a small pilot sample of people with PD. Various hypotheses have been put forth regarding the nature of turning impairment, including the possibility that turning problems are related to axial rigidity, disrupted interlimb coordination, asymmetry of disease effects, and difficulty modifying the ongoing motor program.6,12,14,15 Information about what aspects of turning difficulties may or may not be effectively targeted by pharmacologic interventions could provide insights into the role of the basal ganglia in certain aspects of motor control and help to guide interventions to address problems that remain unresolved with medication. We hypothesized that medication would reduce the time to turn and number of steps to turn. We further hypothesized that medication would enhance spatial aspects of turning (ie, amplitude of segment rotations), more than temporal aspects of turning (ie, relative timing of segment rotations).
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TABLE 1. Subject Demographics Age (yr)
Sex
Time Since PD Diagnosis (yr)
UPDRS Score OFF Medications
1
76
M
8
47
2 3
78 60
M M
2 8
22 22
4 5 6 7 8 9 10
68 66 74 57 63 71 58
F M M M M F M
3 8 6 8 21 10 6
26 32 39 31 37 48 31
Subject
Anti-Parkinson Medication Sinemet 10/100 mg (2 tab qid), amantadine 100 mg (1 tab tid), pramipexole 1 mg (0.5 tab tid) Sinemet 25/100 mg (3 tab qid), requip 3 mg (2 tab qhs) Sinemet 25/100 mg (2 tab tid), amantadine 100 mg (1 tab tid), pramipexole 0.25 mg (0.5 tab tid) Sinemet 25/250 mg (2.75 tab qid), tolcapone 200 mg (1 tab tid) Sinemet 25/100 mg (1.5 tab tid) Sinemet 25/100 mg (1 tab tid), sinemet CR 50/200 mg (1 tab tid) Sinemet 25/100 mg (3 tab 6 times/day) Sinemet 25/100 mg (1.25 tab 6 times/day) Sinemet 25/10 mg (2 tab 7 times/day) Sinemet 25/100 mg (1.5 tab 7 times/day), pramipexole 1 mg (1 tab qid)
Abbreviations: PD, Parkinson disease; sinemet, Carbidopa-Levodopa; requip, ropinirole; UPDRS, Unified Parkinson’s Disease Rating Scale; tab, tablet; qid, four times daily; tid, three times daily; qhs, every night.
METHODS Participants Ten participants with idiopathic PD diagnosed according to standard clinical criteria16 participated (see Table 1 for subject demographics). Exclusionary criteria included history or evidence of orthopedic or neurologic condition (other than PD) and presence of dyskinesia. All participants responded positively when asked whether they had turning difficulty, and all had normal vision or corrected to normal vision. In addition, each had been noted to turn en bloc during evaluations conducted by movement disorders neurologists on routine clinical examination before this study, and turning difficulty had been noted in each individual’s medical record. En bloc turning was defined as turning the head, trunk, and pelvis as a unit rather than turning the segments in a top-down sequence as is seen in healthy controls.7 Participants were tested after overnight withdrawal of anti-Parkinson medications (OFF condition, average off time ⫽ 13.7 ⫾ 0.7 hours). After completing the protocol, participants took their medications, waited one hour, and were retested (ON condition). Testing first OFF and then ON medications was performed to permit all measurements on a single day because many participants traveled long distances and were unable to come for two visits. All testing was performed without shoes on a linoleum floor in a fully illuminated room. Participants provided written informed consent before participation, and the protocol was approved by the Human Research Protection Office at Washington University School of Medicine.
Protocol The Unified Parkinson’s Disease Rating Scale (UPDRS) subscale III was administered by a trained physical therapist. Participants rated how well their medication was working using a 10-cm visual analog scale. Responses could range from 0% if they thought medications were not working at all to 100% if they thought they were getting maximum benefit. We used an eight-camera three-dimensional motion capture system (Motion Analysis Corp., Santa Rosa, CA), accurate to within 1 mm, that was calibrated before each
12
session. Thirty-three reflective markers were used: four on the head (top of head, left ear, right ear, and a head offset marker placed in an arbitrary position on one side of the head to create an asymmetrical marker set to assist with automatic identification of markers using the motion capture software), five on the trunk (left and right acromions, right scapula, 12th thoracic vertebra, and sternal notch), four on the pelvis (left and right anterior superior iliac spines, left posterior superior iliac spine, and sacrum), and 10 on each leg (greater trochanter, anterior thigh, femoral condyle, fibular head, middle tibia, lateral malleolus, calcaneus, navicular, fifth metatarsal head, and great toe). Markers were left in place throughout testing period to minimize shifts in marker position from OFF to ON. There were two components to the study: a walking component and a turning component. For the walking component, participants walked at self-selected pace across a 10-m walkway three times. For the turning component, all turns were made from quiet stance and were 180 degrees in amplitude. This procedure has been used in previous studies and was selected for this study because turns of this nature are used in everyday activities and can be consistently elicited without providing an external cue to indicate the desired turn amplitude.7 Participants were given the instruction “turn and face the wall behind you whenever you are ready.” Each participant performed turns to the left and to the right, completing practice trials in each direction to verify that they understood the instructions. Data were then collected for 10 trials, with each participant turning five times in each direction in random order (determined in advance by random number generator). Order of task performance, walking or turning, was also randomized. Participants were allowed to rest as long as needed between trials.
Analysis There were no differences between turns toward and away from the most affected side; thus, we combined data from the two directions for analysis. Results were averaged across walking trials and across turning trials. Walking velocity was the velocity of the T12 marker across the middle © 2010 Neurology Section, APTA
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Effects of Medication on Turning Deficits in PD
3 m of the walkway. We determined (1) turn duration; (2) number of steps used to turn; (3) sequence of yaw rotation onsets for the head, trunk, and pelvis at turn initiation; (4) amplitude of angular rotation for each segment in the yaw plane during the first stride of the turn; and (5) amplitude of relative rotation angles between different segments for the first stride of the turn (Kintrak; Motion Analysis Corp.). Turn duration was defined as the time from liftoff of the foot used to initiate the turn to touchdown of the foot taking the final step of the turn. These times were clearly identifiable because turns were made from quiet stance, and subjects resumed quiet stance on completion of each turn. Yaw rotation was defined as rotation in the horizontal plane and in the direction of the turn. Relative rotation angles were defined as the maximum rotation present between two segments and were assessed across the entire period of the first stride. Values for head rotation relative to the trunk were obtained by subtracting trunk values from head values, for the trunk relative to pelvis were obtained by subtracting pelvis values from trunk values, and for the head relative to pelvis were obtained by subtracting pelvis values from head values. The sequence of rotation onsets was determined relative to start of the first step of the turn and expressed as a percentage of the gait cycle for the first stride. The beginning and end of the first step of each turn were identified in Kintrak and visually confirmed. The first stride was defined as the time from first liftoff of the foot used to initiate the turn to the next liftoff of that same foot. Amplitudes of angular rotation of each segment were determined relative to laboratory axes. We compared OFF and ON conditions using paired t tests, or Wilcoxon tests if data were not normally distributed (P ⱕ 0.05; SigmaStat, Systat Software Inc., Richmond, CA). Corrections for multiple t tests were not used, given the exploratory and pilot nature of this study. Effect sizes were also calculated.
RESULTS In the medicated state, participants had significantly lower (ie, better) UPDRS-III scores (Table 2). Participants
also walked significantly faster when ON medication, although their walking velocity remained well below that reported previously for age-matched controls.7 Participants reported significantly greater benefit from medication in the ON compared with the OFF medication condition (Table 2) as noted by the visual analog scale. The number of steps to turn and time to turn also improved with medication, although not significantly (Table 2). With medication, the timing of yaw rotation onsets of the various segments relative to liftoff of the first foot occurred earlier in time, and further from control values (Fig. 1). The relative timing between segments was not altered by medication, and PD subjects showed nearly simultaneous onset of head, trunk, and pelvis rotation in both the OFF and ON medication conditions (Table 2). The amplitudes of absolute rotation of the head, trunk, and pelvis all increased slightly, although not significantly, and remained well below values previously reported for age-matched controls (Fig. 2). The relative rotation between the head, trunk, and pelvis increased with medication, although not significantly (Table 2). There was no evidence of systematic differences in responses of individuals with short versus long course of disease or lower versus higher UPDRS scores.
DISCUSSION This study is, to our knowledge, the first to examine the effects of anti-Parkinson medications on specific aspects of turning in people with PD. Medication had a statistically significant impact on UPDRS scores and walking velocities, demonstrating that participants did generally have an overall benefit from medication. Although turning performance was not significantly altered, there was evidence of improvements, particularly with respect to the amplitudes of relative rotation between segment rotations, with effect sizes ranging from 0.42 to 0.70. In contrast, there was no improvement in the timing of rotation onsets of the different segments relative to one another (effect sizes all ⬍0.15). Our results suggest that only certain features of impaired turning may be respon-
TABLE 2. Effects of Medication Variable UPDRS subscale III motor ratingb,c Medication VASb,c Straight walking velocity (m/s)b,c Time to turn (sec) Steps to turn Head re: trunk rotation onset time (% gait cycle) Trunk re: pelvis rotation onset time (% gait cycle) Head re: pelvis rotation onset time (% gait cycle) Head re: trunk rotation amplitude (degree) Trunk re: pelvis rotation amplitude (degree) Head re: pelvis rotation amplitude (degree)
OFF Medication
ON Medication
Effect Sizea
P
35.14 ⫾ 3.23 25.09 ⫾ 7.16 0.63 ⫾ 0.11 7.45 ⫾ 1.38 13.30 ⫾ 3.14 ⫺3.41 ⫾ 5.03 ⫺2.61 ⫾ 3.17 ⫺0.79 ⫾ 2.67 11.83 ⫾ 1.95 4.19 ⫾ 0.37 13.52 ⫾ 2.08
29.95 ⫾ 3.51 56.18 ⫾ 7.83 0.82 ⫾ 0.10 7.18 ⫾ 1.50 11.15 ⫾ 1.99 ⫺0.69 ⫾ 3.46 ⫺2.20 ⫾ 4.85 1.51 ⫾ 2.64 15.67 ⫾ 2.49 5.45 ⫾ 0.67 16.51 ⫾ 2.38
0.58 1.31 0.58 0.31 0.25 ⫺0.09 ⫺0.02 ⫺0.13 0.53 0.70 0.42
0.02 0.03 0.02 0.32 0.28 0.60 0.93 0.60 0.08 0.07 0.09
Values are mean ⫾ standard error. a Negative effect sizes denote changes in a direction away from control values, whereas positive effect sizes denote changes that are considered improvements (ie, toward control values). b Significant difference OFF versus ON. c Mann-Whitney U test. Abbreviations: UPDRS, Unified Parkinson’s Disease Rating Scale; VAS, visual analog scale; re, relative to.
© 2010 Neurology Section, APTA
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A
ES = -0.35, p = 0.36
ES = 0.22, p = 0.34
10
10
9
9
8
8
7
7
Subject Number
Subject Number
A
6 5 4 3
1
-60
-40
5 4 3
OFF ON OFFAverage ON Average CTRLAverage
2
6
2 1
-20
0
0
20
20
40
B
B
ES = -0.47, p = 0.31 10
80
100
120
80
100
120
80
100
120
ES = 0.31, p = 0.25 10
9
9
8
8
7
7
Subject Number
Subject Number
60
Head Rotation (deg)
Head Onset Time
6 5 4
6 5 4
3
3
2
2
1
1
0 -60
-40
-20
0
20
0
20
Trunk Onset Time
ES = -0.72, p = 0.13
10
9
9
8
8
7
7
6 5 4
6 5 4
3
3
2
2
1
1
-40
-20
0
20
Pelvis Onset Time
FIGURE 1. Onsets of yaw rotation for the head (A), trunk (B), and pelvis (C) for each individual. Onset times are expressed as percentage of the gait cycle, with 0% representing the time of liftoff for the first step of the turn. Filled circles show values when OFF medication and open circles are ON medication. The group average OFF medication is shown with the solid vertical line and ON medication with the dashed vertical line. The dotted vertical line shows normative values previously reported for age-matched controls.7 ES ⫽ effect size. P values are for paired t tests comparing ON with OFF.
14
ES = 0.39, p = 0.11
10
-60
60
Trunk Rotation (deg)
C
Subject Number
Subject Number
C
40
0
20
40
60
Pelvis Rotation (deg)
FIGURE 2. Amplitudes of absolute rotation of the head (A), trunk (B), and pelvis (C) during the first stride of the turn for each individual. Filled circles show values when OFF medication and open circles are ON medication. The group average OFF medication is shown with the solid vertical line and ON medication with the dashed vertical line. The dotted vertical line shows normative values previously reported for agematched controls.7 ES ⫽ effect size. P values are for paired t tests comparing ON with OFF.
© 2010 Neurology Section, APTA
JNPT • Volume 34, March 2010
sive to anti-Parkinson medication. Future work with larger sample sizes is needed to confirm or refute this speculation. We acknowledge that this study is limited by the small sample size, high variability, and lack of correction for multiple tests, given the pilot nature of the work. In addition, the differences between subjects in terms of dose and frequency of medication across participants could have contributed to the lack of differences observed. Despite these limitations, turning has been shown by others to be less responsive than other behaviors to intervention in PD. Turning deficits do not improve with auditory cues known to enhance straight walking.17 This line of evidence also highlights a potential difference in responsiveness of turning versus straight walking to interventions. At present, it is unclear why interventions, such as cues, which enhance straight walking may not similarly enhance turning or why certain aspects of turn performance may respond to medication, and others do not. Although the mechanisms underlying turning difficulty remain unclear, it is apparent that individuals with PD have difficulty turning and that, like other axial symptoms of PD, including postural stability and freezing of gait, turning may not be adequately addressed by medication alone. The improvements noted in amplitudes of rotation without improvements in timing of rotation onsets are in keeping with other studies showing that medication can improve movement velocity without improving timing of muscle activity. Robichaud et al18 noted improvements in elbow flexion velocity and in the amplitude of muscle activity with medication, but noted no improvements in timing of muscle activity. Despite the improvements observed in velocity and amplitudes during turning, these parameters were generally still quite different from those of age-matched controls as previously reported.7 Similar medication effects on arm and leg movements have been reported. Vaillancourt et al19,20 reported improvements in movement velocity and amplitude and failure of medication to fully normalize these features because deficits in amplitude scaling and temporal patterns remained even after administration of medication. O’Sullivan et al21 noted that medication improved gait velocity and stride length without concomitant improvements in cadence. This again suggests the potentially greater effectiveness of levodopa in improving velocity and amplitude as compared with timing of movements. Individuals with PD who have difficulty turning are likely to have difficulty with many everyday activities.6 Although we did not note any directional asymmetry in turning in this study, this has been recently reported in other work.6 This discrepancy may be due to our smaller sample size or differences in level of PD symptom asymmetry between the samples of the two studies. Other than this discrepancy, our findings are in keeping with those of previous studies with respect to time to turn, number of steps, reduced amplitudes of yaw rotation, and both spatial and temporal alterations in intersegmental rotations.
Limitations The results of this study must be considered in light of the small sample size and lack of statistical correction for © 2010 Neurology Section, APTA
Effects of Medication on Turning Deficits in PD
multiple tests. Between-subject differences in medication dose and frequency could have been a factor in the high variability that we observed in the measures, and this may have contributed to an inability to detect differences.
CONCLUSIONS Turning impairments associated with PD are not being fully addressed by medication. In particular, medication may enhance spatial features of turning to a greater extent than temporal features. This is in keeping with other work noting improvements in amplitude but not the timing of arm and leg movements.18 –21 Given the lack of improvement in temporal aspects of turning, additional nonpharmacologic approaches to address turning difficulty are needed because impaired turning can interfere with activities of daily living and can place individuals with PD at risk of falls during turning.
ACKNOWLEDGMENTS The authors thank Joshua Funk, Michael Falvo, Karen Stringer, and Callie Mosiman for their assistance in data analysis. REFERENCES 1. Bloem BR, Grimbergen YA, Cramer M, et al. Prospective assessment of falls in Parkinson’s disease. J Neurol. 2001;248:950 –958. 2. Crenna P, Carpinella I, Rabuffetti M, et al. The association between impaired turning and normal straight walking in Parkinson’s disease. Gait Posture. 2007;26:172–178. 3. Giladi N, McMahon D, Przedborski S. Motor blocks in Parkinson’s disease. Neurology. 1992;42:333–339. 4. Stack E, Ashburn A. Fall-events described by people with Parkinson’s disease: implication for clinical interviewing and the research agenda. Physiotherapy. 1999;4:190 –200. 5. Rahman S, Griffin HJ, Quinn NP, et al. Quality of life in Parkinson’s disease: the relative importance of the symptoms. Mov Disord. 2008; 23:1428 –1434. 6. Stack E, Ashburn A. Dysfunctional turning in Parkinson’s disease. Disabil Rehabil. 2008;30:1222–1229. 7. Hong M, Perlmutter JS, Earhart GM. A kinematic and electromyographic analysis of turning in people with Parkinson disease. Neurorehabil Neural Repair. 2009;23:166 –176. 8. Carpinella I, Crenna P, Calabrese E, et al. Locomotor function in the early stage of Parkinson’s disease. IEEE Trans Neural Syst Rehabil Eng. 2007;15:543–551. 9. Stack EL, Ashburn AM, Jupp KE. Strategies used by people with Parkinson’s disease who report difficulty turning. Parkinsonism Relat Disord. 2006;12:87–92. 10. Huxham F, Baker R, Morris ME, et al. Head and trunk rotation during walking turns in Parkinson’s disease. Mov Disord. 2008;23:1391– 1397. 11. Huxham F, Baker R, Morris ME, et al. Footstep adjustments used to turn during walking in Parkinson’s disease. Mov Disord. 2008;23: 817– 823. 12. Ferrarin M, Carpinell I, Rabuffetti M, et al. Locomotor disorders in patients at early stages of Parkinson’s disease: a quantitative analysis. Conf Proc IEEE Eng Med Biol Soc. 2006;1:1224 –1227. 13. Visser JE, Voermans NC, Oude Nijhuis LB, et al. Quantification of trunk rotations during turning and walking in Parkinson’s disease. Clin Neurophysiol. 2007;118:1602–1606. 14. Boonstra TA, van der Kooij H, Munneke M, et al. Gait disorders and balance disturbances in Parkinson’s disease: clinical update and pathophysiology. Curr Opin Neurol. 2008;21:461– 471. 15. Mak MK, Patla A, Hui-Chan C. Sudden turning during walking is impaired in people with Parkinson’s disease. Exp Brain Res. 2008;190: 43–51.
15
Hong and Earhart
16. Racette BA, Rundle M, Parsian A, et al. Evaluation of a screening questionnaire for genetic studies of Parkinson’s disease. Am J Med Genet. 1999;88:539 –543. 17. Willems AM, Nieuwboer A, Chavret F, et al. Turning in Parkinson’s disease patients and controls: the effect of auditory cues. Mov Disord. 2007;22:1871–1878. 18. Robichaud JA, Pfann KD, Comella CL, et al. Effect of medication on EMG patterns in individuals with Parkinson’s disease. Mov Disord. 2002;17:950 –960. 19. Vaillancourt DE, Prodoehl J, Verhagen Metman L, et al. Effects of deep
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brain stimulation and medication on bradykinesia and muscle activation in Parkinson’s disease. Brain. 2004;127(Pt 3):491–504. 20. Vaillancourt DE, Prodoehl J, Sturman MM, et al. Effects of deep brain stimulation and medication on strength, bradykinesia, and electromyographic patterns of the ankle joint in Parkinson’s disease. Mov Disord. 2006;21:50 –58. 21. O’Sullivan JD, Said CM, Dillon LC, et al. Gait analysis in patients with Parkinson’s disease and motor fluctuations: influence of levodopa and comparison with other measures of motor function. Mov Disord. 1998;13:900 –906.
© 2010 Neurology Section, APTA
REVIEW ARTICLE
Trends in Inpatient Rehabilitation Stroke Outcomes Before and After Advent of the Prospective Payment System: A Systematic Review Suzanne Rinere O’Brien, PT, NCS, MS
Background and Purpose: The purpose of this systematic review was to examine quality care indicators for inpatient stroke rehabilitation, trends for length of stay (LOS), functional outcomes, and discharge destination. In order to examine the influence of the prospective payment system (PPS), which was instituted in 2002, particular attention was paid to the pre-PPS to post-PPS period. This is the first review of literature to examine the quality of stroke care provided in inpatient rehabilitation facilities in the United States. Methods: A search of Ovid Medline and Ovid Cumulative Index of Nursing and Allied Health databases was performed for articles published between 1990 and 2007. Search terms included treatment outcome, outcome assessment, activities of daily living, exercise, rehabilitation, cerebrovascular accident, LOS, and rehabilitation centers. Results: Twelve articles met the criteria for review. A trend for shorter LOS was evident in the literature up until the time of implementation of PPS. An insufficient amount of literature was available to confirm whether this trend continued after the implantation of PPS. The most recent data indicated that average LOS in inpatient rehabilitation facilities for stroke was ⬍20 days. Functional Independence Measure (FIM) discharge scores remained stable through the 1990s. After the implementation of PPS, discharge FIM scores may be decreasing, but revisions to the FIM tool may confound interpretation of post-PPS findings. Data for discharge to noninstitutional settings after stroke rehabilitation were inconclusive pre-PPS. There may be indications that discharges to institutional settings are increasing post-PPS. Conclusions: The impact of PPS on quality care indicators for inpatient stroke rehabilitation, trends for LOS, and trends for functional outcomes are insufficiently documented in the medical literature. Further research is needed to understand the influence of LOS on functional outcomes and discharge destination. More information is needed on post-PPS outcomes to substantiate the benefit of inpatient rehabilitation for individuals with stroke. Key words: stroke, rehabilitation, outcomes, Prospective Payment System, length of stay, Functional Independence Measure, discharge destination (JNPT 2010;34: 17–23) University of Rochester Medical Center, School of Nursing, Rochester, New York. Address correspondence to: Suzanne Rinere O’Brien, E-mail: suzanner_
[email protected] Copyright © 2010 Neurology Section, APTA ISSN: 1557-0576/10/3401-0017 DOI: 10.1097/NPT.0b013e3181cfd3ac
JNPT • Volume 34, March 2010
INTRODUCTION
I
npatient rehabilitation is often necessary after stroke for individuals to recover from and learn to compensate for the associated deficits resulting from stroke. Of the ⬃780,000 people who have a first stroke or a recurrent stroke each year in the United States,1 ⬃247, 000 require inpatient stroke rehabilitation, in either an acute inpatient rehabilitation facility (IRF) or skilled nursing facility. According to the Centers for Disease Control and Prevention, ⬃140,000 people will receive care in an IRF each year.2 Inpatient rehabilitation is the setting of choice for those most at risk of chronic functional disability. Individuals who receive rehabilitation in an IRF experience a comprehensive, multidisciplinary approach to care.3 It is expensive to provide this level of care, but there is evidence that IRF stroke units provide better outcomes than noncomprehensive types of care, such as rehabilitation received in a skilled nursing facility.4 – 6 The advent of the prospective payment system (PPS), the system used by the Centers for Medicare and Medicaid7 to reimburse the healthcare providers, was a significant occurrence for IRF care. Passed in the Balanced Budget Act of 1997 and implemented in 2002, this change had two purposes: (1) to decrease the cost of rehabilitation services to Medicare, the largest payer for IRF rehabilitation8,9 and (2) to adjust reimbursement according to the presence of comorbidities and stroke severity, so that care for those with more comorbidities and more severe strokes would be reimbursed at higher rates.8 –10 The reimbursement formula began with a fixed amount based on the diagnosis, and this rate was adjusted based on the qualifiers for age and previous chronic medical problems, if applicable.8 –10 The standardized reimbursement rates in PPS created incentives to reduce the costs of care to maximize profit. During the period from 1990 to 2007, IRFs sought to cut costs, typically by decreasing length of stay (LOS).11 Little is known about the effect of reduced LOS on outcomes after inpatient rehabilitation. Because IRF care is needed by large numbers of individuals each year, it is important to examine the possibility of less favorable outcomes with shorter LOS. No reviews have been published on this subject. The purposes of this systematic review were to examine the trend for LOS at IRFs for individuals with stroke, to determine whether there were trends for outcomes during this time period, and to compare the pre-PPS and post-PPS
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periods for effects on LOS and outcomes. At every level of healthcare, whether the insurance system, the delivery system, or the reimbursement system, the US healthcare system is unlike those in most other countries, and equitable comparisons cannot be made between the United States and most other countries.12 As a result, this review was limited to stroke rehabilitation provided by IRFs in the United States.
METHODS Search and Screening Strategy To complete this review, the author searched three electronic databases: Ovid Medline, Ovid Cumulative Index of Nursing and Allied Health, and Physiotherapy Evidence Database. Search terms included treatment outcome, outcome assessment, activities of daily living, exercise, rehabilitation, cerebrovascular accident, LOS, and rehabilitation centers. The search strategy included the use of scope notes to ensure an inclusive list of terminology and key words. Only Englishlanguage articles published during the period of January1990 to July 2008 were included. The author examined a total of 242 abstracts for inclusion. An article was excluded if the
focus of the article was limited to (1) treatment and not outcomes, (2) IRFs outside the United States, (3) a subtype of stroke, for example, posterior cerebral artery, or (4) Veterans Health Administration hospitals. Flowcharts of the search strategy and results for the Medline and Cumulative Index of Nursing and Allied Health searches are illustrated in Figure 1. A flowchart for the Physiotherapy Evidence Database search was not included because no new citations were recovered from that database. Articles included in this review met the following criteria: (1) reported data of patients with stroke from IRFs in the United States, (2) measured outcomes using the Functional Independence Measure (FIM) or discharge destination, and (3) reported LOS data.21 Twelve articles describing 10 studies (one study was described in three articles) met the inclusion criteria. All 12 articles were original reports. Articles included in the review are listed in Table 1.
Data Collection The following characteristics were abstracted from each article: sample size of patients and size of IRFs, study design, type and location of the facility, type of data, years
FIGURE 1. Search strategy flowcharts.
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Rehabilitation Outcome Trends Before and After PPS
TABLE 1. Articles Included in the Review
Reference Source
Sample Size (Subjectsa/ IRFsb)
Bode and Heinemann 200213 Bode et al, 200414
129a,c/8
DeJong et al, 20058d,e
Deutsch et al, 20064 Gillen et al, 20079
Study Design
Type of Data
Years of Data Collection
Outcomes Collected
Type of Analysis
Objectives Met
Prospective
UDSmr facilities
IRF records
1994–1998 LOS, FIM
Descriptive statistics, Rasch model
1
198/8
Observational
IRF records
1993–1998 LOS, FIM
Rasch model, regression
1
539/3
Prospective, observational, cohort
1 VA, for-profit and not-for profit East coast, West coast, Middle US, academic IRFs UDSmr facilities IRF and SNF Northeastern US
IRF records
2001–2003 LOS, FIM change scores, DD
Ordinary least squares, logistic regression
1, 2, 3
Logistic regression, multiple regression ANCOVA, logistic regression
2, 3
Descriptive statistics, FIM items average scores Descriptive statistics, 2, t test, multiple regression Fisher exact, 2, t test
1, 2
54,914/631 Retrospective, records review 945/1 Descriptive, retrospective, observational
Hamilton and 27,034a/114 Descriptive, retrospective Granger, 199415 Horn et al, 830/5 Prospective, 200516d,e observational, cohort McNaughton 1161/6 Prospective, et al, observational, 200517d,e cohort Murakami 67,235/g Descriptive and Inouye, 200218d Ottenbacher 48,055a/744 Retrospective, et al, cohort 200411 Schlenker et 483/27 Quasiexperimental, al, 19975a,b longitudinal Ruff et al, 199919
Facility or Location
113/1
Quasiexperimental
UDSmr facilities
UDSmr, MedPARf 1996–1997 FIM, DD records IRF records 1997–2005 LOS, FIM, DD, cognition, depression UDSmr records 1992 LOS, FIM, DD
Large, urban IRFs IRF records throughout US
2001–2003 FIM, DD
Large, urban IRFs IRF records throughout US
2001–2003 LOS, FIM, DD
UDSmr facilities
UDSmr records
UDSmr facilities
UDSmr records
Urban, represent IRF records, all regions of Medicare only the US Not-for-profit IRF IRF records
1998
LOS, FIM, DD
1994–2001 LOS, FIM, DD 1991–1994 LOS
—g
LOS, FIM, patient preference
1, 2, 3
2, 3
1, 2, 3
Mean FIM/LOS
1, 2
Descriptive, statistics, repeated measures ANCOVA Multiple regression
1, 2
One-way ANOVA
1, 2
1
a
Only data for patients with stroke. Studies may have included additional diagnoses groups, which is not included. Only data for IRFs. Studies may have included additional levels of care, which is not included. Eliminated subjects with atypical stays (⬍2 wks and ⬎6 wks). d Only data for US patients included. e These studies are from Post-stroke Rehabilitation Outcomes Project. Full report using all data is McNaughton et al, 2005.17 f Contains stay information for Medicare fee-for-service beneficiaries. g Not reported. Abbreviations: IRFs, inpatient rehabilitation facilities; UDSmr, Uniform Data System for Medical Rehabilitation; LOS, length of stay; FIM, Functional Independence Measure; VA, Veterans Administration hospital; US, United States; DD, discharge destination; SNF, skilled nursing facility; MedPAR, Medicare Provider and Analysis and Review files; ANCOVA, analysis of covariance; ANOVA, analysis of variance. b c
data were collected, outcomes measured, type of analysis conducted by the authors, and which of the three objectives of this review was met by the article.
Data Sources and Measures The Uniform Data System for Medical Rehabilitation (UDSmr), which receives reports from nearly 70% of the IRFs in the United States,20 is a major source of data on IRF care used in several of the analyses discussed in this review. The UDSmr database contains information related to the following © 2010 Neurology Section, APTA
variables: patient characteristics, LOS, total charges, and functional status. These data were designed to describe the realm of rehabilitation for clinical and research purposes.21 In this review, LOS was defined as the number of days in the IRF. LOS is considered an important indicator of the process of care, and for the potential amount of improvement a patient can achieve during the rehabilitation stay.22 The number of days of therapy actually received was not differentiated from total LOS in the studies in this review. The
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outcome of care was defined as the indicator of quality from the cumulative effects of interventions received by the patients.22 Outcomes after care in an IRF can be measured in two ways, each having the potential to reflect the quality of care. The first, mean discharge FIM scores or mean FIM change scores, denotes the functional progress made by patients from all the interventions received in the IRF. The second, discharge destination, identifies the setting where the patient lives after the IRF intervention. Discharge to the community or home, instead to an institution, is often viewed as an important quality benchmark for IRFs. During the period of interest of this review, the FIM was the measurement tool used nearly universally by IRFs to assess functional status. The FIM is a scale that is scored by clinicians at admission, at regular intervals (typically weekly) during the rehabilitation stay, and at discharge. This tool was designed to measure basic global functional status, the burden of care, quality of care, and the effectiveness of care.21,23 The original version of the FIM included scores for 18 different motor and cognitive tasks, with each task having a lowest possible score of 1 (dependent) and a maximal score of 7 (independent without need for an assistive device). Total FIM scores range from 18 to 126 points.21,23 The FIM has been in existence for ⬃20 years, and a large body of literature is available regarding the psychometric properties of this tool in patients, including those with stroke, who are undergoing physical rehabilitation. The FIM has two dimensions, motor and cognitive, with all 18 items functioning similarly across diagnoses, and across LOS.24 –28 Test-retest reliability of the FIM has been shown to be high during both short durations (seven to 10 days; intraclass correlation coefficient [ICC] ⫽ 0.99) and long durations (four to six weeks; ICC ⫽ 0.92).29 Reliability of the FIM has been found to be greater when used by examiners trained in its use (ICCs from 0.97 to 0.99) in comparison with examiners at IRFs who did not train personnel in its use (ICCs from 0.89 to 0.96).30 Concurrent validity of the FIM has been supported during the course of the rehabilitation stay through correlations with Barthel Index.31 FIM scores have been found to predict the burden of care after stroke.25 Using hypothesis testing, construct validity of the FIM was affirmed by the finding that higher scores were achieved by younger patients, patients with fewer comorbidities, and patients who were discharged home.32 With the advent of PPS, the FIM underwent several revisions. One significant revision was to the FIM scoring system, to which a low score of 0 was added. Using the UDSmr database, one study examined the psychometric properties of the revised FIM.23 Item functioning was found to be very similar to the original FIM, but the revised FIM may provide lower scores compared with the original version. None of the articles included in the present review took into consideration how FIM revisions may have altered reported scores.
20
RESULTS Trends for LOS Studies reporting data from the 1990s showed a trend toward shorter LOS for IRF stroke rehabilitation.5,11,13–15,17–19 Data arranged by year of data collection, rather than by year of publication, are illustrated in Table 2 to present the data in chronologic order. This arrangement of studies suggested a descending trend for LOS from the early to late 1990s. This apparent trend was clearly demonstrated in a retrospective, longitudinal study of a nationally representative database of 744 IRFs using the UDSmr database from 1994 to 2001, which confirmed the downward trend during the 1990s and showed that it continued through 2001. During the course of this study, average LOS decreased significantly from 24 days to 16 days (P ⬍ 0.001).11 The study included patients from five diagnosis groups, but only data related to stroke have been reported in this review. A separate longitudinal study of a smaller sample of six IRFs in the United States used data from 2001 to 200317 and reported average LOS to be 18.6 days.
Trends in Outcomes: FIM Scores and Discharge Destination Despite decreasing LOS, discharge FIM scores remained steady throughout the 1990s. As illustrated in Table 3, patients with stroke were consistently achieving discharge FIM scores between 83 and 87 out of 126 points.11,15,17,18 Bode and Heinemann13 stratified patients with stroke by the number of weeks (from two through six weeks) spent in rehabilitation and monitored FIM outcome by each stratum. They compared patients with stroke (n ⫽ 129), brain injury, and spinal cord injury, although only the data for patients with stroke were included in this review. Patients with more severe strokes remained in IRF care for a greater number of weeks and achieved lower FIM scores at discharge, but change in FIM scores from admission to discharge did not TABLE 2. Trend for IRF LOS for Stroke, 1990 –2007a,b Study Hamilton and Granger, 199415 Schlenker et al, 19975 Bode and Heinemann, 200213c Bode et al, 200414 Ruff et al, 199919 Murakami and Inouye, 200218d Ottenbacher et al, 200411 McNaughton et al, 200517
Year(s) of Data Collection
LOS (d)
1992 1991–1994 1994–1998 1993–1998 NR 1998
28 26 26c 24 20 20
1994–2001 2001–2003
24–16e 18.6
a Only data for patients with stroke. Studies may have included additional diagnoses groups, which were not included. b Only data for IRFs. Studies may have included additional levels of care, which were not included. c Study eliminated subjects with atypical stays (less than two weeks and more than six weeks). d Only data for US patients included. e LOS trend from beginning to end of study. Abbreviations: IRF, inpatient rehabilitation facility; LOS, length of stay; US, United States.
© 2010 Neurology Section, APTA
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Rehabilitation Outcome Trends Before and After PPS
TABLE 3. Trends for Outcome I: Mean Discharge FIM Scores From 1990 to 2002a,b Source
Year(s) of Data Collection
Mean Discharge FIM Score
1992 1998 1994–2001 2001–2003
85.9 86.9 86.5 87.2
Hamilton and Granger, 199415 Murakami and Inouye, 200218c Ottenbacher et al, 200411 McNaughton et al, 200517
a Only data for patients with stroke. Studies may have included additional diagnoses groups, which were not included. b Only data for IRFs. Studies may have included additional levels of care, which were not included. c Only data for US patients included. Abbreviations: FIM, Functional Independence Measure; IRF, inpatient rehabilitation facility; US, United States.
differ by stroke severity. In other words, patients with more severe strokes did not reach the same FIM scores as those with less severe strokes, but made the same amount of change as those with less severe strokes, although over a longer period of time. In this literature, discharge destination was typically reported as rates of community discharge. There were no clear trends for this quality marker across studies in the review, possibly because of fewer studies reporting this variable. As can be seen in Table 4, rates of community discharges reported after IRF stroke rehabilitation ranged from 74% to 81%.11,12,17,18
Comparison of LOS and Outcomes Before and After PPS Two studies specifically compared outcomes in the pre-PPS time period with those in the post-PPS time period.7,8 These studies can be instructive because longitudinal methodology provides a reliable approach to study outcomes across a particular time period. Each study was derived from a relatively small database compared with the studies based on the larger UDSmr database, and included three IRFs and one IRF, respectively. DeJong et al8 noted that although LOS did not change, a significant decrease of 2.9 points (P ⫽ 0.034) in average FIM change scores occurred during the period beginning one year before PPS and ending one year after PPS. According to the authors, decreased scores for the TABLE 4. Trends for Outcome II: Rates of Community Dischargesa,b Source Hamilton and Granger, 199415 Murakami and Inouye, 200218c Ottenbacher et al, 200411 McNaughton et al, 200517
Year(s) of Data Collection
Mean Rate (%)
1992 1998 1994–2001 2001–2003
74 76 81 78
a Only data for patients with stroke. Studies may have included additional diagnoses groups, which were not included. b Only data for IRFs. Studies may have included additional levels of care, which were not included. c Only data for US patients included. Abbreviations: IRF, inpatient rehabilitation facility; US, United States.
© 2010 Neurology Section, APTA
moderately impaired and severely impaired groups accounted for the overall decrease, despite an average increase in discharge FIM scores in the mildly impaired group during the pre-PPS period to post-PPS period. Over the course of the three-year study, the authors reported trends toward decreasing discharge to home across the mild, moderate, and severe stroke groups of 7.1%, 3.1% and 2.0%, respectively, but none of these trends were significant. Gillen et al9 compared the impact of PPS over a longer period, from five years before to 3.5 years after PPS implementation. In this larger data set, these authors reported a 4.5-day decrease in LOS (P ⬍ 0.001), a decrease in mean discharge FIM score from 92.75 to 87.7 points (P ⬍ 0.001), and an accompanying 10% decrease in those discharged home after PPS (P ⬍ 0.001).
DISCUSSION The purpose of this review was to identify the trends over time for stroke outcomes in IRFs in the United States, with special attention to the critical period when IRF reimbursement was altered in 2002. Three factors reflecting the process and outcomes of IRF care, such as LOS, FIM scores, and discharge destination, were examined for trends present from 1990 through 2008. The findings of this review provide mostly consistent data on the continuing trend toward shorter LOS for IRFs, which began well before the implementation of the PPS. Well before the implementation of the PPS, IRFs were decreasing patients’ LOS. However, studies specifically examined the pre-PPS period to post-PPS period reported conflicting trends in LOS data post-PPS. Further research is necessary to determine whether LOS has continued to decrease since the advent of PPS. If such a trend has continued, then there is potential for a negative impact on outcomes, FIM scores, and discharge destination after stroke rehabilitation at IRFs. FIM scores at discharge reflect functional outcomes after IRF care and can help clinicians ascertain the postdischarge needs of patients. Discharge FIM scores were not shown to decrease until after PPS was implemented, after which two studies7,8 identified significant decreases in discharge FIM scores. This finding is confounded by the fact that the FIM tool was revised with the advent of PPS. Neither study reported took into account revisions to the tool during analysis of FIM score data. Granger et al23 recently reported that the new post-PPS version of the FIM functions somewhat differently from the original version. Future investigations should control for the different FIM versions during analysis to ensure the accurate evaluation of outcomes. The trends in FIM scores reported in this review give reason for a positive outlook. Interventions that patients with stroke receive from therapists in IRFs may have enabled FIM scores to remain stable despite shorter LOS. Across the studies included in this review, patients with differing levels of stroke severity, ages, and LOS who received care at IRFs all made significant functional gains with rehabilitation. Further studies to determine which interventions promote the greatest functional gain, and in which subgroups of individuals with stroke, should continue. Many possibilities for subgroup analyses exist, including severity of stroke, type of
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lesion or stroke syndrome, or specific demographic factors, such as sex, which may alter responses to rehabilitation interventions. Another outcome, discharge destination, did not demonstrate consistent changes in IRF performance over time. Trends for discharge to home remained stable before PPS, but there may be worsening outcomes for post-PPS discharge destination. Although post-PPS discharge destination did not reach significance in the analysis by DeJong et al,8 detrimental trends were observed, most surprisingly in the mild stroke group, which was found to have the largest increase in discharges to institutional settings, with the moderate stroke and severe stroke groups also increasingly being discharged to institutional settings. Within a longer period of observation, Gillen et al9 found significantly more patients discharged to institutional settings. More study is needed to analyze these potential trends.
Limitations There are several limitations to this review. First, there is a paucity of research, and no randomized controlled trials, on the relationship between payment system and rehabilitation outcomes. Further studies are needed to elucidate the functioning of patients with stroke after IRF care and also to elucidate the functioning of IRFs that treat such patients. Second, FIM revisions have complicated comparisons of studies from the pre-PPS period with the post-PPS period. Any future study of this literature should describe which version of the FIM was used to measure function. Third, studies included a wide variety of sample sizes at the IRF level and at the patient level, resulting in potential problems with generalizability. Larger studies would improve generalizability, but authors should carefully describe the characteristics of the IRFs and the patients. The available literature was satisfactory for describing patient characteristics, but more detailed information regarding IRF factors is needed. Factors such as IRF size, location, and ownership could provide novel information about how these characteristics influence LOS and outcomes. Finally, factors that affect the decision-making process regarding discharge destination were not discussed in this literature. Decisions made at the time of discharge are not typically made simply based on the FIM score. Other factors must be considered by clinicians to ensure safety after discharge. For instance, in some cases, the home must be wheelchair accessible, and in other cases, supervision or assistance will be required for the patient. No study reviewed included controls for these factors. Schlenker et al5 cautioned that PPS could provide incentives to shorten LOS to maximize IRF reimbursement. Evidence may be emerging that a threshold has been crossed and that rehabilitation stays are too short to allow patients to return to the home after care in the IRF setting. Further research is needed to improve the understanding of these phenomena and to protect the quality outcomes for which IRF stroke rehabilitation is known.
CONCLUSIONS IRF care has undergone at least two major changes since 1990: decreasing LOS and altered reimbursement. The
22
effects of LOS changes are unclear, but some research suggests cause for concern about the outcomes of care being provided under these conditions. If further research determines that outcomes are indeed deteriorating, action must be taken to prevent worsening function, increased disability, increased institutional discharges, and higher costs for the US healthcare system. REFERENCES 1. American Heart Association. Heart Disease and Stroke Statistics—2008 Update. Dallas, TX: American Heart Association; 2008. 2. Centers for Disease Control and Prevention. Public health and aging: hospitalizations for stroke among adults ⬎65 years—United States, 2000. MMWR Morb Mortal Wkly Rep. 2003;52:586 –589. 3. Centers for Medicare and Medicaid. IRF classification criteria. http://www. cms.hhs.gov/InpatientRehabFacPPS/03_Criteria.asp. Accessed December 1, 2007. 4. Deutsch A, Granger CV, Heinemann AW, et al. Poststroke rehabilitation: outcomes and reimbursement of inpatient rehabilitation facilities and subacute rehabilitation programs. Stroke. 2006;37:1477–1482. 5. Schlenker RE, Kramer AM, Hrincevich CA, et al. Rehabilitation costs: implications for prospective payment. Health Services Res. 1997;32: 651– 668. 6. Langhorne P, Duncan P. Does the organization of postacute stroke care really matter? Stroke. 2001;32:268 –274. 7. Centers for Medicare and Medicaid Services. Prospective payment system. http://www.cms.hhs.gov/ProspMedicareFeeSvcPmtGen/. Accessed December 1, 2007. 8. DeJong G, Horn SD, Smout RJ, et al. The early impact of the inpatient rehabilitation facility prospective payment system on stroke rehabilitation case mix, practice patterns, and outcomes. Arch Phys Med Rehabil. 2005;86(Suppl 2):93–100. 9. Gillen R, Tennen H, McKee T. The impact of the inpatient rehabilitation facility prospective payment system on stroke program outcomes. Am J Phys Med Rehabil. 2007;86:356 –363. 10. McCue MJ, Thompson JM. Early effects of the prospective payment system on inpatient rehabilitation hospital performance. Arch Phys Med Rehabil. 2006;87:198 –202. 11. Ottenbacher KJ, Smith PM, Illig SB, et al. Trends in length of stay, living setting, functional outcome, and mortality following medical rehabilitation. JAMA. 2004;292:1687–1695. 12. Shi L, Singh DA. Delivering Healthcare in America: A Systems Approach. 4th ed. Boston, MA: Jones and Bartlett; 2008. 13. Bode RK, Heinemann AW. Course of functional improvement after stroke, spinal cord injury, and traumatic brain injury. Arch Phys Med Rehabil. 2002;83:100 –106. 14. Bode RK, Heinemann AW, Semik P, et al. Relative importance of rehabilitation therapy characteristics on functional outcomes for persons with stroke. Stroke. 2004;35:2537–2542. 15. Hamilton BB, Granger CV. Disability outcomes following inpatient rehabilitation for stroke. Phys Ther. 1994;74:494 –503. 16. Horn SD, DeJong G, Smout RJ, et al. Stroke rehabilitation patients, practice and outcomes: is earlier and more aggressive therapy better? Arch Phys Med Rehabil. 2005;86(Suppl 2):101–114. 17. McNaughton H, DeJong G, Smout RJ, et al. A comparison of stroke rehabilitation practice and outcomes between New Zealand and United States facilities. Arch Phys Med Rehabil. 2005;86(Suppl 2):115–120. 18. Murakami M, Inouye M. Stroke rehabilitation outcome study: a comparison of Japan with the United States. Am J Phys Med Rehabil. 2002;81:279 –282. 19. Ruff RM, Yarnell S, Marinos JM. Are stroke patients discharged sooner if in-patient rehabilitation services are provided seven v six days per week? Am J Phys Med Rehabil. 1999;78:143–146. 20. Uniform Data System for Medical Rehabilitation Web site. http:// udsmr.org. Accessed October 18, 2008. 21. Hamilton BB, Granger CV, Sherwin FS, et al. A uniform national data system for medical rehabilitation. In: Fuhrer MJ, ed. Rehabilitation Outcomes: Analysis and Measurement.. Baltimore, MD: Paul H. Brookes Publishing; 1987:137–147.
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22. Donabedian A. The quality of medical care. Science. 1978;200:856 – 864. 23. Granger CV, Deutsch A, Linn RT. Modifications of the FIM instrument under the inpatient rehabilitation facility prospective payment system. Am J Phys Med Rehabil. 2007;86:883– 892. 24. Chang WC, Chan C. Rasch analysis for outcomes measures: some methodological considerations. Arch Phys Med Rehabil. 1995;76:934 – 939. 25. Granger CV, Cotter AC, Hamilton BB, et al. Functional assessment scales: a study of persons after stroke. Arch Phys Med Rehabil. 1993; 74:133–138. 26. Heinemann AW, Linacre JM, Wright BD, et al. Relationships between impairment and physical disability as measured by the functional independence measure. Arch Phys Med Rehabil. 1993;74:566 –573. 27. Linacre JM, Heinemann AW, Wright BD, et al. The structure and stability of the functional independence measure. Arch Phys Med Rehabil. 1994;75:127–132.
Rehabilitation Outcome Trends Before and After PPS
28. Stineman MG, Shea JA, Jette A, et al. The functional independence measure: tests of scaling assumptions, structure, and reliability across 20 diverse impairment categories. Arch Phys Med Rehabil. 1996;77:1101– 1108. 29. Ottenbacher KJ, Mann WC, Granger CV, et al. Inter-rater agreement and stability of functional assessment in the community-based elderly. Arch Phys Med Rehabil. 1994;75:1297–1301. 30. Hamilton BB, Laughlin JA, Fiedler RC, et al. Interrater reliability of the 7-level functional independence measure (FIM). Scand J Rehabil Med. 1994;26:115–119. 31. Roth E, Davidoff G, Haughton J, et al. Functional assessment in spinal cord injury: a comparison of the modified Barthel index and the ‘adapted’ functional independence measure. Clin Rehabil. 1990;4:277– 285. 32. Dodds TA, Martin DP, Stolov WC, et al. A validation of the functional independence measure and its performance among rehabilitation patients. Arch Phys Med Rehabil. 1993;74:531–536.
olden Synapse Award G e h T THE AWARD RECOGNIZES THE MOST OUTSTANDING ARTICLE PUBLISHED IN JNPT EACH YEAR The decision is made by the JNPT Reviewers and Associate Editors and is based on the article’s conceptualization, execution, presentation and contribution to physical therapy practice.
The Effects of Exercise on Balance in Persons with Parkinson’s Disease: A Systematic Review across the Disablement Spectrum authored by Lee Dibble, PT, PhD, ATC, Odessa Addison, PT, DPT, and Evan Papa, MS. The article was published in the March 2009 issue of JNPT (Volume 33, Number 1, pp. 14 – 26). The authors were recognized and awarded plaques at the Neurology Section Business Meeting in San Diego, CA
© 2010 Neurology Section, APTA
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22. Donabedian A. The quality of medical care. Science. 1978;200:856 – 864. 23. Granger CV, Deutsch A, Linn RT. Modifications of the FIM instrument under the inpatient rehabilitation facility prospective payment system. Am J Phys Med Rehabil. 2007;86:883– 892. 24. Chang WC, Chan C. Rasch analysis for outcomes measures: some methodological considerations. Arch Phys Med Rehabil. 1995;76:934 – 939. 25. Granger CV, Cotter AC, Hamilton BB, et al. Functional assessment scales: a study of persons after stroke. Arch Phys Med Rehabil. 1993; 74:133–138. 26. Heinemann AW, Linacre JM, Wright BD, et al. Relationships between impairment and physical disability as measured by the functional independence measure. Arch Phys Med Rehabil. 1993;74:566 –573. 27. Linacre JM, Heinemann AW, Wright BD, et al. The structure and stability of the functional independence measure. Arch Phys Med Rehabil. 1994;75:127–132.
Rehabilitation Outcome Trends Before and After PPS
28. Stineman MG, Shea JA, Jette A, et al. The functional independence measure: tests of scaling assumptions, structure, and reliability across 20 diverse impairment categories. Arch Phys Med Rehabil. 1996;77:1101– 1108. 29. Ottenbacher KJ, Mann WC, Granger CV, et al. Inter-rater agreement and stability of functional assessment in the community-based elderly. Arch Phys Med Rehabil. 1994;75:1297–1301. 30. Hamilton BB, Laughlin JA, Fiedler RC, et al. Interrater reliability of the 7-level functional independence measure (FIM). Scand J Rehabil Med. 1994;26:115–119. 31. Roth E, Davidoff G, Haughton J, et al. Functional assessment in spinal cord injury: a comparison of the modified Barthel index and the ‘adapted’ functional independence measure. Clin Rehabil. 1990;4:277– 285. 32. Dodds TA, Martin DP, Stolov WC, et al. A validation of the functional independence measure and its performance among rehabilitation patients. Arch Phys Med Rehabil. 1993;74:531–536.
olden Synapse Award G e h T THE AWARD RECOGNIZES THE MOST OUTSTANDING ARTICLE PUBLISHED IN JNPT EACH YEAR The decision is made by the JNPT Reviewers and Associate Editors and is based on the article’s conceptualization, execution, presentation and contribution to physical therapy practice.
The Effects of Exercise on Balance in Persons with Parkinson’s Disease: A Systematic Review across the Disablement Spectrum authored by Lee Dibble, PT, PhD, ATC, Odessa Addison, PT, DPT, and Evan Papa, MS. The article was published in the March 2009 issue of JNPT (Volume 33, Number 1, pp. 14 – 26). The authors were recognized and awarded plaques at the Neurology Section Business Meeting in San Diego, CA
© 2010 Neurology Section, APTA
23
ARTICLE
Assessment of Postural Muscle Strength in Sitting: Reliability of Measures Obtained with Hand-Held Dynamometry in Individuals with Spinal Cord Injury Cathy A. Larson, PT, PhD, Wynne Dawley Tezak, PT, Meghan Sheppard Malley, PT, and William Thornton, PT
Background and Purpose: Muscle weakness frequently impairs the ability to maintain upright sitting in individuals with spinal cord injury (SCI). The primary purpose of this study was to examine the intrarater and interrater reliability of hand-held dynamometry to assess postural muscle strength for maintaining upright sitting in individuals with SCI. We also assessed reliability of forces measured in four directions of force application and of measures obtained by experienced versus student physical therapist examiners. Methods: Twenty-nine individuals with SCI (mean age, 32.4 ⫾ 11.0 years; injury level C4 –L1; American Spinal Injury Association Impairment Scale (AIS) classification A–D) participated in this study. The raters were two experienced physical therapists and two student physical therapists. Force was applied to the anterior, posterior, and right and left lateral trunk. Values were acquired in a group of participants who did not require upper extremity support for sitting (n ⫽ 22) and a group who did require upper extremity support (n ⫽ 7). Results: Intrarater reliability was good to excellent (intraclass correlation coefficients, 0.80 – 0.98 [unsupported]; 0.79 – 0.99 [supported]) for all raters in the four directions of force application. Interrater reliability was excellent (intraclass correlation coefficients, 0.97– 0.99 [unsupported]; 0.96 – 0.98 [supported]) for all directions. There were no significant differences among peak forces obtained among the four directions of force application or by experienced raters compared with student raters. Discussion and Conclusion: The use of hand-held dynamometry to assess postural muscle strength for maintaining upright sitting in individuals with SCI has high intrarater and interrater reliability. The direction of force application and experience of the rater did not influence the level of reliability. Future research is needed to identify the minimum muscle strength required to maintain the seated posture and to understand how this measure relates to seated postural control and balance. Rehabilitation Institute of Michigan (C.A.L., W.T.), Center for Spinal Cord Injury Recovery, Detroit, Michigan; and School of Health Sciences (W.D.T., M.S.M.), Program in Physical Therapy, Oakland University, Rochester, Michigan. Supported by Rehabilitation Institute of Michigan’s Del Harder grant. Address correspondence to: Cathy A. Larson, E-mail:
[email protected] Copyright © 2010 Neurology Section, APTA ISSN: 1557-0576/10/3401-0024 DOI: 10.1097/NPT.0b013e3181cf5c49
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Key words: spinal cord injury, sitting strength, reliability, handheld dynamometer, trunk strength (JNPT 2010;34: 24–31)
INTRODUCTION
L
oss of motor function and muscle weakness due to spinal cord injury (SCI) may impair the ability to maintain an upright sitting posture. An outcome measure that objectively measures postural muscle strength during upright sitting would be useful when documenting improvements due to intervention. In previous studies in individuals with SCI,1,2 stroke,3–5 and brain injury,3 a hand-held dynamometer (HHD) has been used to quantify peak force while subjects attempted to maintain a sitting posture. To assess trunk strength, force was applied anteriorly to the midsternum,1,2,4,5 posteriorly on the interscapular area,1,2 or laterally on the shoulders3–5; no study has examined all four directions of force application in the same subject pool. Although sitting posture is primarily maintained by the trunk muscles, pelvic, hip, and lower extremity muscles also assist in maintaining upright sitting in individuals without disability and those with chronic low back pain.6 In individuals with SCI, muscles used to maintain upright sitting are dependent on the level of injury. In the absence of abdominal muscles, an individual with SCI may use neck and upper trunk muscles or recruit available arm muscles to maintain the sitting position. For example, individuals with paraplegia used “nonpostural” muscles, including the latissimus dorsi, trapezius, and pectoralis major, in addition to their innervated abdominal and paraspinal muscles, to maintain the sitting position.7–11 In individuals with SCI, maintaining an active, upright sitting position against an external force cannot accurately be described as testing only trunk muscle strength. Therefore, the outcome measure examined in this study will be more generally described as postural muscle strength in the sitting position with or without bilateral upper extremity (UE) support. Testing strength in upright sitting using HHD has several advantages over other methods, such as isokinetic dynamometry6,12–14 or manual muscle testing (MMT).15,16 When using an isokinetic dynamometer to test trunk flexion and extension strength, an individual may be required to move as little as 20 degrees to as much as 70 degrees at velocities of 30 to 180 degrees/sec, which may be impossible JNPT • Volume 34, March 2010
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for individuals with SCI.6,12–14 In addition, an isokinetic dynamometer may not be available in many clinical settings because of the high cost and space requirements, or not used because of the time-consuming nature of the test procedures. Performance of the specific movements required by standardized MMT procedures15,16 may be problematic for individuals with SCI.17 For example, testing the strength of the abdominal muscles requires performance of a partial sit-up from the supine position along with active stabilization of the pelvis and legs, a maneuver that is frequently impossible for individuals with SCI. Key trunk flexor muscles include the rectus, internal and external oblique abdominis, and iliopsoas muscles, and key trunk extension muscles include the iliocostalis, longissimus, spinalis, multifidi, gluteus maximus, and hamstrings muscles.12,18 Testing all of these muscles is time consuming, and it is often difficult for individuals with SCI to assume the required test positions. In particular, many individuals with SCI do not tolerate the prone position because of respiratory compromise. In addition, MMT scales are nonlinear, ordinal, and relatively insensitive to change in muscle strength during the course of rehabilitation.19 –22 MMT scores have been reported to plateau, whereas handheld dynamometry measurements continued to increase over time after SCI.19 An MMT grade of 4/5 may be assigned with as little as 10% of predicted muscle strength and may be associated with forces that range from 10 to 250 N.19 –21 Hand-held dynamometry is a more objective method of recording strength and is more sensitive to change over time.19 Finally, for the majority of individuals with SCI, functional activities such as dressing, hygiene, eating, transfers, and wheelchair mobility are typically performed in the sitting position. This makes documentation of the forcegenerating capacity of the postural muscles during sitting a functionally relevant approach. In the clinical setting, assessment of the postural muscle strength in sitting is typically performed by applying manual force and offering a subjective description of the amount of force (minimal, moderate, or maximal) that the individual can resist; or using a four- or five-point ordinal scale for which psychometric properties of the scoring systems are not known.3,23,24 To our knowledge, the reliability and validity of these scoring systems have never been documented. HHD provides an objective means of quantifying forces generated by the postural muscles in the upright sitting posture. Before the use of HHD can be recommended for the assessment of postural muscle strength in sitting, information must be obtained about reliability of this measure in different directions of force application and under different UE support conditions, as well as the possible influence of rater experience. Numerous studies have reported good to excellent intrarater and interrater reliability when using HHD to measure strength of the extremity muscles.25–29 We identified only a single study that used hand-held dynamometry to obtain test-retest measurements of lateral trunk muscle strength in sitting within a single session; the study participants were 11 individuals who had sustained a stroke or traumatic brain injury.3 In addition, a majority of the studies have used testers who were experienced in using the HHD. © 2010 Neurology Section, APTA
Assessment of Postural Muscle Strength in Sitting
Test-retest,28 intrarater,30 and interrater29 reliabilities have been reported to be good to excellent for novice examiners using HHD to test elbow30 or hip, knee, and shoulder28 muscle strength. None of these studies examined the influence of the level of experience of the rater on reliability of the hand-held dynamometry strength values obtained. The primary purpose of this study was to examine the intrarater and interrater reliability of hand-held dynamometry for the assessment of postural muscle strength during sitting in individuals with SCI. We also compared forces generated in each of the four directions of force application and values obtained by experienced versus student physical therapist examiners. Strength was operationally defined as peak force recorded with a hand-held dynamometer.
METHODS The study was approved by the Wayne State University’s Human Investigating Committee and Oakland University’s Institutional Review. Twenty-nine individuals with SCI (five women, 24 men; mean age, 32.4 ⫾ 11.0 years; range, 19 – 69 years) who were participating in an outpatient rehabilitation program took part in this study. Participants had sustained spinal cord injuries injury level between C4 and the cauda equina (19 with tetraplegia and 10 with paraplegia). American Spinal Injury Association Impairment Scale31 (AIS) scores of the 29 participants included were as follows: 12 AIS A, 10 AIS B, five AIS C, and two AIS D. The mean time since injury was 4.5 ⫾ 4.6 years (range, 0.5–19 years). Exclusion criteria included being dependent on a ventilator, medical instability, or having musculoskeletal impairments that could confound results of the study. Before participation in the outpatient therapy program, all individuals who had SCI for ⬎1.5 years were routinely screened for osteoporosis as measured by bone density scan of the spine and femur; individuals identified as having osteoporosis, defined as having T scores ⱕ⫺3.0, were excluded from the study. The four raters were two experienced physical therapists and two student physical therapists. Of the two licensed physical therapists, one had 25 years of experience and the other had five years of clinical experience. The two student physical therapists were enrolled in the second year of an entry-level doctorate of physical therapy program. Before the start of the study, all four raters were trained in the procedures outlined below by the primary investigator during a one-hour session, and then practiced the test procedures on a minimum of four individuals with SCI.
Procedures After signing the institute-approved informed consent forms and Health Insurance Portability and Accountability Act form, demographic information was obtained through interview or medical record examination. Participants were positioned in sitting on a height-adjustable table, with feet flat on the floor, with hips and knees at 90 degrees, and with the popliteal fossa against the mat edge to maximize thigh contact with the support surface and provide a stable base of support (BOS). Participants were instructed to sit in a posture that was as erect as possible. A back support was not used because it was previously reported that individuals with SCI
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FIGURE 1. Positioning for lateral force application. The handheld dynamometer was placed over the proximal tip of the acromion; force was applied perpendicular to the long axis of the trunk while the examiner maintained horizontal forearm alignment.
tilt the pelvis posteriorly and use the backrest of a chair for passive support to compensate for instability of the pelvis and lower spine.9 If the participant was able to assume an erect seated posture without UE support (with shoulders in neutral and elbows flexed to 90 degrees) and maintain this posture and for at least five seconds, then the test was conducted without UE support (unsupported condition). However, if the participant was unable to maintain an erect seated posture without UE support, then the UEs were placed in the best position (as judged by both the participant and examiner; typically, with shoulders extended ⬃15 degrees and externally rotated, elbows and wrists fully extended, and fingers flexed) for the individual to maintain the seated UE-supported position (supported condition). Participants who required UE support for sitting were neither encouraged nor discouraged from using their UEs to assist in the test. A MicroFet2 HHD (Hoggan Inc., West Jordan, UT) was used to measure peak force. The device was at low threshold setting capable of measuring peak force from 0.36 to 68.04 kg (0.8 –150 lb) with a sensitivity of 0.045 kg (0.1 lb). The HHD device was placed between the examiner’s hand and the participant’s body with the force applied perpendicular to the trunk while the examiner maintained horizontal forearm alignment (Fig. 1). The examiner applied force to the trunk in four directions by placing the HHD in four different locations: anterior, over the mid-sternum; posterior, over the thoracic spine midway between the superior and inferior angles of the scapula; and right and left lateral, over the lateral aspect of the acromial process. The proximal tip of the acromion was used to avoid confounding the data if the participant used shoulder abduc-
26
tion balance reactions (Fig. 1). Instructions were either “hold, do not let me move you” or “push, push as hard as you can.” The examiner gradually built up force over a three- to four-second period to allow time for the participants to respond and produce their maximal force.17 The test concluded when the participant was displaced ⬃2.5 cm (1 in) in the direction in which force was being applied (visually estimated by linear trunk movement). Force was released gradually to avoid protective responses or substantially disrupting the participant’s sitting posture. The peak force registered by the HDD was recorded for that trial. Two practice and three actual trials were performed for each direction of force application with rest periods of ⬃15 seconds between trials. Two practice trials were used to allow the participant to develop a strategy for maximum force generation, whereas no more than three actual test trials were performed to avoid fatigue. The order of testing was randomized for direction of force application. A second person was available to both record the force values and guard the participant for safety purposes. To determine interrater reliability, all participants were tested by all four raters (randomized order) on the same day or within one to two days. To test intrarater reliability, the participants were tested again within a one-week time interval by all four raters. Raters were blinded to the force measures obtained by the other raters.
Data Analysis Using SPSS version 13.0 (SPSS, Chicago, IL), demographic descriptive statistics were generated. Intrarater and interrater reliability was determined using intraclass correlation coefficients (ICC; two-way, mixed model, absolute agreement). When examining interrater reliability, data were pooled across the two test sessions. When examining the peak force data for the unsupported and supported conditions, 2 (test 1, test 2) ⫻ 4 (raters) analyses of variances with repeated measures and Bonferroni post hoc tests were performed for the four directions of force application. Variability was determined using coefficients of variation (COV) (standard deviation [SD]/mean ⫻ 100%). Means, SDs, and 99% confidence intervals were generated for data obtained from each of the four trunk locations at which the HDD was positioned, for data obtained from subjects tested in the supported and the unsupported conditions. Multivariate, general linear-model analyses of variances were used to determine whether forces measured were different for experienced versus student raters. To obtain preliminary insights into the relationship between balance and postural muscle strength in sitting, participants were categorized into one of the three (modified) balance categories3,23,24 based on the ability to maintain upright sitting position: poor (maintains upright sitting for 5–15 seconds), fair (maintains upright sitting for 15– 60 seconds, holds against minimal resistance), and good (maintains upright sitting and holds against moderate to maximum resistance without UE support).
RESULTS Twenty-two participants were able to perform the test without UE support, and seven participants performed the test with UE support during the first session (test 1). Because of © 2010 Neurology Section, APTA
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TABLE 1. Intrarater Reliability (Intraclass Correlation Coefficients) Rater 1: Experienced Unsupported sitting: without UE support, n Anterior Posterior Right lateral Left lateral Supported sitting: with UE support, n Anterior Posterior Right lateral Left lateral
19
Rater 2: Student 17
Rater 3: Student
Rater 4: Experienced
16
17
0.97 0.92 0.90 0.93 7
0.90 0.97 0.94 0.87 6
0.87 0.94 0.86 0.80 6
0.98 0.97 0.97 0.92 7
0.99 0.91 0.95 0.92
0.87 0.83 0.95 0.86
0.91 0.91 0.85 0.86
0.92 0.95 0.79 0.84
Abbreviation: UE, upper extremity.
FIGURE 2. Forces generated by postural muscles in sitting without upper extremity support. Mean ⫾ 1 SD force (kg) for test 1 (T1; white) and test 2 (T2; gray), for the four raters (R1–R4 in consecutive order) for the anterior, posterior, right lateral, and left lateral force-application locations.
TABLE 2. Interrater Reliability (Intraclass Correlation Coefficients): Tests 1 and 2 Pooled
Anterior Posterior Right lateral Left lateral
Unsupported Sitting (Without UE Support), n ⴝ 22
Supported Sitting (With UE Support), nⴝ7
0.98 0.99 0.97 0.97
0.98 0.98 0.96 0.97
Abbreviation: UE, upper extremity.
scheduling difficulties, not all participants were retested during session 2 (test 2; see sample sizes [n] in Tables 1 and 2).
Reliability of Postural Muscles Strength Tested in Sitting: Without UE Support Force measures acquired in participants who could sit without UE support had good to excellent intrarater reliability; ICCs were 0.80 to 0.98 for all four raters for the four force-application locations (Table 1). Interrater reliability was excellent, with ICCs ranging from 0.97 to 0.99 for the four force-application locations (Table 2). For sitting without UE support, mean ⫾ 1 SD peak forces generated by the participants for anterior, posterior, right lateral, and left lateral force-application locations are illustrated in Figure 2. Within each force-application direction, mean peak force obtained by raters 1 to 4 (R1, R2, R3, and R4) for tests 1 and 2 (T1, T2) are consecutively presented (Fig. 2). For all four force-application locations, there were no significant differences in peak force between tests 1 and 2 (P ⫽ 0.32– 0.68) or between the four raters (P ⫽ 0.32– 0.80), with no significant interactions between the parameters. There were no differences among the peak forces generated for the four forceapplication locations (F3,604 ⫽ 0.36; P ⫽ 0.64). Betweensubject force COVs were 11%, 10%, 9%, and 10% for the © 2010 Neurology Section, APTA
FIGURE 3. Forces generated by postural muscles in sitting with upper extremity support. Mean ⫾ 1 SD force (kg) for test 1 (T1; white) and test 2 (T2; gray), for the four raters (R1–R4 in consecutive order) for the anterior, posterior, right lateral, and left lateral force-application locations.
anterior, posterior, right lateral, and left lateral force-application locations, respectively, for the four raters.
Reliability of Postural Muscles Strength Tested in Sitting: With UE Support When testing postural muscle strength in participants who required UE support for sitting, intrarater reliability was good to excellent; ICCs were 0.79 to 0.99 for all four raters in the four force-application locations (Table 1). Interrater reliability was excellent, with ICCs ranging from 0.96 to 0.98 for the four force-application locations (Table 2). For sitting with UE support, mean ⫾ 1 SD peak forces generated by the participants for anterior, posterior, right lateral, and left lateral force-application locations obtained by raters 1 to 4 for tests 1 and 2 are displayed in Figure 3. For all four forceapplication locations, there were no significant differences in
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TABLE 3. Sitting Strength Partitioned by Balance Categorya Unsupported: without UE support Anterior Posterior Right lateral Left lateral Supported: with UE support Anterior Posterior Right lateral Left lateral
Poor
Fair
Good
4.3 ⫾ 2.1 (9.4 ⫾ 4.7) 3.5–5.0 (7.8–11.0) 4.4 ⫾ 1.5 (9.6 ⫾ 3.4) 3.8–4.9 (8.4–10.8) 6.0 ⫾ 2.0 (13.2 ⫾ 4.5) 5.3–6.7 (11.7–14.8) 5.6 ⫾ 2.2 (12.4 ⫾ 4.9) 4.9–6.4 (10.7–14.1)
7.4 ⫾ 4.0 (16.4 ⫾ 8.9) 5.8–9.1 (12.8–20.1) 9.8 ⫾ 9.0 (21.7 ⫾ 19.9) 6.1–13.5 (13.5–29.8) 9.0 ⫾ 4.7 (19.8 ⫾ 10.4) 7.0–10.9 (15.5–24.0) 8.3 ⫾ 3.4 (18.3 ⫾ 7.4) 6.9–9.7 (15.3–21.4)
12.4 ⫾ 4.1 (27.3 ⫾ 9.1) 10.7–14.0 (23.7–30.8) 12.2 ⫾ 6.2 (26.8 ⫾ 13.7) 9.8–14.6 (21.5–32.1) 10.9 ⫾ 2.9 (24.0 ⫾ 6.4) 9.8–12.0 (21.5–26.4) 11.1 ⫾ 3.6 (24.4 ⫾ 8.0) 9.7–12.5 (21.3–27.5)
4.4 ⫾ 1.5 (9.8 ⫾ 3.3) 3.4–5.6 (7.4–12.3) 4.3 ⫾ 0.8 (9.4 ⫾ 1.7) 3.7–4.9 (8.1–10.7) 6.0 ⫾ 1.7 (13.3 ⫾ 3.8) 4.8–7.3 (10.5–16.1) 6.6 ⫾ 3.2 (14.5 ⫾ 7.1) 4.2–9.0 (9.3–19.8)
8.2 ⫾ 5.9 (18.1 ⫾ 12.9) 5.6–10.7 (12.4–23.7) 8.7 ⫾ 5.0 (19.2 ⫾ 11.1) 6.5–10.9 (14.3–24.1) 9.3 ⫾ 5.1 (20.4 ⫾ 11.3) 7.0–11.5 (15.4–25.4) 8.8 ⫾ 4.7 (19.3 ⫾ 10.4) 6.7–10.8 (14.7–23.9)
— — — — — — — —
a Values are expressed as mean ⫾ 1 SD peak force, in kg and lb, with a 99% confidence interval, in kg and lb in the next row. Abbreviation: UE, upper extremity.
peak force between tests 1 and 2 (P ⫽ 0.66 – 0.94; intrarater reliability) or between the four raters (P ⫽ 0.71– 0.94; interrater reliability) with no significant interactions between the parameters. There were no differences among the peak forces generated in the four force-application locations (F3,216 ⫽ 0.77; P ⫽ 0.51). Between-subject peak force COVs were 14%, 9%, 8%, and 10% for the anterior, posterior, right lateral, and left lateral force-application locations, respectively, for the four raters.
Postural Muscles Strength Tested in Sitting: Experienced Versus Student Raters Overall, peak force variability was 9% to 14%. There were no significant differences among the peak forces obtained in the sitting without UE support condition when participants were examined by experienced compared with student raters for the anterior (F1,157 ⫽ 0.06; P ⫽ 0.81), posterior (F1,157 ⫽ 1.24; P ⫽ 0.27), right lateral (F1,157 ⫽ 1.3; P ⫽ 0.26), or left lateral (F1,157 ⫽ 0.2.4; P ⫽ 0.12) force-application locations. Likewise, there were no significant differences among the peak forces obtained in the sitting with UE support condition when participants were examined by experienced compared with student raters for the anterior (F1,54 ⫽ 0.04; P ⫽ 0.84), posterior (F1,54 ⫽ 0.07; P ⫽ 0.79), right lateral (F1,54 ⫽ 0.05; P ⫽ 0.83), or left lateral (F1,54 ⫽ 0.22; P ⫽ 0.64) force-application locations.
Muscle Forces, UE Support, and Balance For participants who did not require UE support for sitting, mean ⫾ 1 SD peak forces and 99% confidence intervals for the four force-application locations were determined based on their balance category (poor, fair, and good balance; Table 3). Generally, those participants who could sit without UE support were categorized as having poor, fair,
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and good balance generated mean peak forces in the 3.5 to 6.7, 5.8 to 13.5, and 9.7 to 14.6 kg (7.8 –14.8, 12.8 –29.8, and 21.3–32.1 lb) ranges, respectively. When examining the 99% confidence interval results, a criterion estimate for the minimum strength required to maintain the sitting position without UE support for five to 15 seconds was 3.5 kg (7.8 lb), 3.8 kg (8.4 lb), 5.3 kg (11.7 lb), and 4.9 kg (10.7 lb) at the anterior, posterior, right lateral, and left lateral force-application locations, respectively. Of the three balance categories, participants who did require UE support for sitting fell into either the poor or the fair balance category. Mean ⫾ 1 SD peak forces and 99% confidence interval for the four force-application locations were determined for participants in each of these two categories (Table 3). Because there were no significant differences among the force-application locations, the data for all locations were pooled. Those participants with poor balance generated forces in the range of 3.4 to 9.0 kg (7.4 –19.8 lb), whereas participants with fair balance generated forces in the range of 5.6 to 11.5 kg (12.4 –25.4 lb).
DISCUSSION Test of Postural Muscle Strength in Sitting: Intrarater and Interrater Reliability The use of HHD to assess postural muscle strength in sitting (defined as peak force generated in upright sitting with or without UE support) showed good to excellent intrarater and interrater reliability as applied in this study. This provides preliminary evidence to suggest that HHD used in this manner is a reliable measure in individuals with SCI. These findings support and extend the reliability of strength testing with handheld dynamometry findings reported by past studies examining © 2010 Neurology Section, APTA
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trunk strength in individuals with stroke or traumatic brain injury3 and examining extremity strength in healthy adults25,27,28 and individuals with a variety of pathologies.4,26,29 There were no differences obtained in measures of postural muscle strength in sitting for the experienced physical therapists compared with student physical therapists. It is likely that the high level of rater agreement is attributable to standardization of the testing procedure because before beginning the study all examiners participated in a training session and practiced the procedures. Previous studies reported training durations of as little as one practice test for one muscle for a single healthy individual29 to as much as three to five hours of practice using the HHD.28,30 A number of seemingly minor technical factors can influence the data acquired during hand-held dynamometry; among these are patient position, examiner position, force application and velocity, and instructions given to the patient.6,13,17 To facilitate acquisition of reliable and repeatable hand-held dynamometry measurements of postural muscle strength in sitting, standardized procedures for testing and practice by the examiners are recommended. The verbal instructions used during strength testing were intended to reflect what typically occurs in the clinical setting. The raters’ instructions were either “hold, do not let me move you” (break test) or “push, push as hard as you can” (make test). Break tests elicit an eccentric contraction in which the examiner applies resistance sufficient enough to overcome the maximal effort of the subject,17 causing the subject to move in the opposite direction.29 When performing a make test, if the examiner has sufficient strength to resist movement by the subject, then an isometric contraction is generated; otherwise, a concentric contraction is produced. It has been suggested that, given high reliability, there is no clear reason to choose one test over another29; however, others have stated that because the make-and-break tests measure different forces, they cannot be used interchangeably.17,26 Break-make ratios of 1.4 to 1.5 with break-force exceeding make-force by 10% to 70% have been reported.29 In this study, the position of the examiner prevented the participant from moving the HHD, and the test was terminated if the force applied by the examiner caused the participant to move. Thus, it is likely that in this application, the type of verbal instructions used does not influence the outcome.
Test of Postural Muscle Strength in Sitting: SCI Mean anteriorly and posteriorly directed forces generated in sitting without UE support by the participants in this study were less than forces reported for athletes with SCI.1 The athletes had comparatively lower levels of SCI (T10 –L2) and were participating in the Paralympic Games; therefore, they were likely more physically fit than the participants in this study. Compared with the participants in this study, individuals who had stroke generated greater forces in the anterior and lateral directions (both toward the involved and noninvolved sides).5 Matched control subjects generated forces that were approximately double and significantly greater than forces generated by the subjects who had stroke. In this study, there were no significant differences among the peak forces generated by the participants with SCI © 2010 Neurology Section, APTA
Assessment of Postural Muscle Strength in Sitting
for the four force-application locations. This finding was surprising because it is our observation that individuals with SCI most often fall forward or backward, indicating primary weakness of the posterior and anterior muscles, respectively. Significant differences in trunk strength have been reported; specifically, weaker lateral trunk flexion on the involved compared with the noninvolved side of the body in individuals who had stroke.5 We recommend that postural muscle strength in sitting be measured at the anterior, posterior, and right and left lateral locations to assess muscle strength symmetry and to guide intervention. All participants with SCI could perform the test of postural muscle strength in sitting. The participants were, on average, 4.5 years post-injury and were concurrently participating in an outpatient SCI rehabilitation program. It is possible that individuals in the earlier stages of the rehabilitation process may be unable to perform the test of postural muscle strength in sitting; however, participants in this study did have spinal injuries over a broad range of neurologic levels. The participants who performed the test with UE support were classified as having tetraplegia, and the participants tested without UE support were classified as having either tetraplegia or paraplegia.
Postural Muscle Strength in Sitting: Balance and Function The authors readily acknowledge that trunk strength may not directly correlate with sitting balance.2,32,33 A positive correlation between lateral trunk flexion strength and sitting balance has been reported for individuals who had stroke and head injury,3 whereas trunk strength did not correlate with sitting stability in individuals with paraplegia2 or elderly adults.32,33 Balance is a multifaceted skill requiring, but not limited to, appropriate muscle endurance, sensory and vestibular information processing, force control, multijoint coordination, and motor control. Static balance refers to the ability to maintain the body’s center of mass over the available BOS34 and is most frequently documented as the amount of time that an individual can maintain a given position.35,36 In this sense, static balance requires muscle endurance. Dynamic balance requires the ability to sense when the center of mass moves toward the limits of one’s BOS and to perform appropriate postural responses or equilibrium reactions.37,38 Protective reactions or change-in-support strategies are observed when individuals exceed their limits of stability and change their BOS by reaching out with an arm or stepping to prevent a fall.39 – 41 Thus, dynamic balance and protective reactions rely on appropriate sensory and vestibular processing, force control,42– 44 multijoint coordination, and motor control.45 Despite the fact that postural muscle strength is not a direct measure of sitting balance, it is likely that individuals with neuropathologies need to attain a minimum threshold postural muscle strength in sitting to successfully accomplish the wide variety of functional activities typically performed in the sitting position. Based on the results of this study, we cannot specify the minimum postural muscle strength required to achieve functional milestones or how much change in postural muscle strength is clinically meaningful. It can be speculated that
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incremental, functional milestones, such as achieving the ability to maintain static upright sitting (1) without UE support (hands slightly lifted from the support surface), (2) with one UE, or (3) both UEs reaching to a target within arm’s length, would require corresponding increases in postural muscle strength in sitting. When reaching with one arm and pointing to or grasping a target or object within 60% to 100% of arm’s length, the trunk acts as a postural stabilizer; whereas when reaching beyond arm’s length (100%–140%), the trunk and arm transport the hand to the target or object location.46,47 Although a more systematic study would be needed to identify the minimum postural muscle strength that is required to achieve identified functional milestones in sitting, this study can suggest that an estimated, minimum force-generating capacity range of 3.5 to 5.3 kg (7.8 –11.7 lb) is required to maintain upright sitting for five to 15 seconds without UE support. Regarding the issue of how much change in postural muscle strength is clinically meaningful, for participants sitting without UE support, changes in peak force of ⬃3 to 4 kg (7–9 lb) were associated with changes in participants’ sitting balance (poor to fair to good) abilities. In a study that examined elbow flexion and extension strength using an HHD, maximum force variability was 3.5 kg for individuals with tetraplegia.29 Others reported that strength changes of ⬍1% are within measurement error, whereas strength changes ⬎3.5% represent true changes in muscle strength.17
Limitations Although the authors attempted to control for sources of error, some limitations have been recognized. A relatively small number of individuals with SCI participated in this study. We assessed reliability only because it relates to repeatability within and between raters because we did not assess test-retest reliability over time. Because the participants were concurrently engaged in an outpatient rehabilitation program, it was possible that the participants improved between test 1 and 2; however, examination of the data did not reveal a consistent, positive trend in strength over this period. Participants’ body weight was not recorded. Although testing reliability is not affected, it is more appropriate that peak force be normalized for body weight and height particularly when comparing postural muscle strength in sitting among individuals1,2,6 and when determining the strength threshold corresponding to functional milestone achievement. Finally, the study assessed only postural muscle strength used to maintain an upright seated posture, and the relationship of this measure to postural control and seated balance is not known. Accordingly, it can be argued that application of the HHD provided some stabilization and assisted the participant in maintaining the upright sitting position.
Future Research Future research should be conducted to further assess the reliability of testing postural muscle strength in sitting using a larger sample size. Reference or normative strength values should be determined for healthy adults and children without any disabilities. Most importantly, minimum criterion strength required to achieve functional milestones or
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clinically meaningful change in strength must be systematically explored. Initial findings concerning these interrelationships may be forthcoming as a result of ongoing research using a constellation of outcome measures designed to document change across the body structure and function, activity, and participation levels for individuals with SCI participating in an intense rehabilitation program.
CONCLUSIONS Muscle weakness frequently impairs the ability to maintain upright sitting posture in individuals who have sustained an SCI. Because intrarater and interrater reliability was good to excellent, HHD can be used among different raters to objectively quantify postural muscle strength in sitting for individuals with SCI. Future research is needed to identify the minimum strength required to achieve identified functional milestones and clinically meaningful change in postural muscle strength in sitting. Studies are also needed characterize the relationship between postural muscle strength and sitting balance.
ACKNOWLEDGMENTS The authors acknowledge the contributions of Susan Harrington, PT, for data collection and Michel (Shelly) Denes for photography. REFERENCES 1. Hardcastle P, Bedbrock G, Curtis K. Long-term results of conservative and operative management in complete paraplegics with spinal cord injuries between T10 and L2 with respect to function. Clin Orthop Relat Res. 1987;224:88 –96. 2. Chen CL, Yeung KT, Bih LI, et al. The relationship between sitting stability and functional performance in patients with paraplegia. Arch Phys Med Rehabil. 2003;84:1276 –1281. 3. Bohannon RW. Lateral trunk flexion strength: impairment, measurement reliability and implications following unilateral brain lesion. Int J Rehabil Res. 1992;15:249 –251. 4. Bohannon RW. Recovery and correlates of trunk strength after stroke. Int J Rehabil Res. 1995;18:162–167. 5. Bohannon RW, Cassidy D, Walsh B. Trunk muscle strength is impaired multidirectionally after stroke. Clin Rehabil. 1995;9:47–51. 6. Shirado O, Ito T, Kaneda K, et al. Concentric and eccentric strength of trunk muscles: influence of test postures on strength and characteristics of patients with chronic low-back pain. Arch Phys Med Rehabil. 1995; 76:604 – 611. 7. Seelen HAM, Potten YJM, Drukker J, et al. Development of new muscle synergies in postural control in spinal cord injured subjects. J Electromyogr Kinesiol. 1998;8:23–34. 8. Seelen HAM, Potten YJM, Adams JJ, et al. Postural motor programming in paraplegic patients during rehabilitation. Ergonomics. 1998;41:302– 316. 9. Potten YJM, Seelen HAM, Drukker J, et al. Postural muscle responses in the spinal cord injured persons during forward reaching. Ergonomics. 1999;42:1200 –1215. 10. Janssen-Potten YJM, Seelen HAM, Drukker J, et al. Chair configuration and balance control in persons with spinal cord injury. Arch Phys Med Rehabil. 2000;81:401– 408. 11. Seelen HAM, Janssen-Potten YJM, Adams JJ. Motor preparation in postural control in seated spinal cord injured people. Ergonomics. 2001;44:457– 472. 12. Smith SS, Mayer TG, Gatchel RJ, et al. Quantification of lumbar function. Part 1: isometric and multispeed isokinetic trunk strength measures in sagittal and axial planes in normal subjects. Spine. 1985; 10:757–764. 13. Dvir Z, Keating J. Reproducibility and validity of a new test protocol for measuring isokinetic trunk extension strength. Clin Biomech. 2001;16: 627– 630.
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14. Hulens M, Vansant G, Lysens R, et al. Assessment of isokinetic muscle strength in women who are obese. J Orthop Sports Phys Ther. 2002;32: 347–356. 15. Hislop HJ, Montgomery J. Daniels and Worthingham’s Muscle Testing: Techniques of Manual Examination. Philadelphia, PA: W.B. Saunders Co.; 2002. 16. Kendall FP, McCreary EK, Provance PG, et al. Muscle Testing and Function With Posture and Pain. Baltimore, MD: Lippincott Williams and Wilkins; 2005. 17. Sisto SA, Dyson-Hudson T. Dynamometry testing in spinal cord injury. J Rehabil Res Dev. 2007;44:123–136. 18. Wiatt E, Flanagan SP. Lateral trunk flexors and low back pain: endurance and bilateral asymmetry. 2009;14:10 –12. 19. Schwartz S, Cohen ME, Herbisonh GJ, et al. Relationship between two measures of upper extremity strength: manual muscle test compared to hand-held myometry. Arch Phys Med Rehabil. 1992;73:1063–1068. 20. Herbison GL, Isaac Z, Cohen ME, et al. Strength post-spinal cord injury: myometer vs manual muscle test. Spinal Cord. 1996;34:543–548. 21. Dvir Z. Grade 4 in manual muscle testing: the problem with submaximal strength assessment. Clin Rehabil. 1997;11:36 – 41. 22. Noreau L, Vachon J. Comparison of three methods to assess muscular strength in individuals with spinal cord injury. Spinal Cord. 1998;36: 716 –723. 23. Sandin KJ, Smith BS. The measure of balance in sitting in stroke rehabilitation prognosis. Stroke. 1990;21:82– 86. 24. Black K, Zafonte R, Millis S, et al. Sitting balance following brain injury: does it predict outcome? Brain Injury. 2000;14:141–152. 25. Bohannon RW, Andrews AW. Interrater reliability of hand-held dynamometry. Phys Ther. 1987;67:931–933. 26. Bohannon RW. Make versus break tests for measuring elbow flexor muscle force with a hand-held dynamometer in patients with stroke. Physiother Canada. 1990;42:247–251. 27. Andrews AW, Thomas MW, Bohannon RW. Normative values for isometric muscle force measurements obtained with hand-held dynamometers. Phys Ther. 1996;76:248 –259. 28. Ottenbacher KJ, Branch LG, Ray L, et al. The reliability of upper- and lower-extremity strength testing in a community survey of older adults. Arch Phys Med Rehabil. 2002;83:1423–1427. 29. Burns S, Breuninger A, Kaplan C, et al. Hand-held dynamometry in persons with tetraplegia: comparison of make- versus break-testing techniques. Am J Phys Rehabil. 2005;84:22–29. 30. Horvat M, Croce R, Roswal G. Intratester reliability of the Nicholas manual muscle tester on individuals with intellectual disabilities by a tester having minimal experience. Arch Phys Med Rehabil. 1994;75: 808 – 811.
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31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47.
American Spinal Injury Association/International Medical Society of Paraplegia. International standards for neurologic and functional classification of spinal cord injury. Chicago, Illinois. 2003. Judge JO, Lindsey C, Underwood M, et al. Balance improvements in older women: effects of exercise training. Phys Ther. 1993;73:254 –265. Topp R, Mikesky A, Thompson K. Determinants of four functional tasks among older adults: an exploratory regression analysis. J Orthop Sports Phys Ther. 1998;27:144 –153. Horak FB, Shupert CL, Mirka A. Components of postural dyscontrol in the elderly: a review. Neurobiol Aging. 1989;10:727–738. Emery CA, Cassidy JD, Klassen TP, et al. Development of a clinical static and dynamic standing balance measurement tool appropriate for use in adolescents. Phys Ther. 2005;85:502–514. Verheyden G, Nieuwboer A, Mertin J, et al. The trunk impairment scale: a new tool to measure motor impairment of the trunk after stroke. Clini Rehabil. 2004;18:326 –334. Geurts ACH, de Haart M, van Nes IJW, et al. A review of standing balance recovery from stroke. Gait Posture. 2005;22:267–281. Carpenter MG, Frank JS, Adkin AL, et al. Influence of postural anxiety on postural reactions to multi-directional surface rotations. J Neurophysiol. 2004;92:3255–3265. Maki BE, McIlroy WE. The role of limb movements in maintaining upright stance: the “Change-in-Support” strategy. Phys Ther. 1977;77: 488 –507. Liu W, Kim SH, Long JT, et al. Anticipatory postural adjustments and the latency of compensatory stepping reactions in humans. Neurosci Lett. 2003;336:1– 4. Maki BE, McIlroy WE. Control of rapid limb movements for balance recovery: age-related changes and implications for fall prevention. Age Aging. 2006;35(Suppl 2):ii12–ii18. Basa P, Binder MD, Ruenzel P, et al. Recruitment order of motoneurons in stretch reflexes is highly correlated with their axonal conduction velocity. J Neurophysiol. 1984;52:410 – 420. Henneman E. The size-principle: a deterministic output emerges from a set of probabilistic connections. J Exp Biol. 1985;115:105–112. Kandel ER, Schwartz JH, Jessell TM. Principles of Neural Science. New York, NY: Elsevier Science Publishing, Inc.; 1991. Shumway-Cook A, Woollacott M. Motor Control-Theory and Practical Application. Baltimore, MD: Williams & Wilkins; 2001. Kaminski TR, Bock C, Gentile AM. The coordination between trunk and arm motion during pointing movements. Exp Brain Res. 1995;106:457– 466. Dean C, Shepherd R, Adams R. Sitting balance I: trunk-arm coordination and the contribution of the lower limbs during self-paced reaching in sitting. Gait Posture. 1999;10:135–146.
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ARTICLE
Assessment of Fine Motor Control in Individuals with Parkinson’s Disease Using Force Tracking with a Secondary Cognitive Task Sujata D. Pradhan, PT, PhD, Bambi R. Brewer, PhD, George E. Carvell, PT, PhD, Patrick J. Sparto, PT, PhD, Anthony Delitto, PT, PhD, FAPTA, and Yoky Matsuoka, PhD
Background and Purpose: Motor symptoms of Parkinson’s disease (PD) are typically assessed using clinical scales such as the Unified Parkinson’s Disease Rating Scale, but clinical scales are insensitive to subtle changes early in the disease process. The goal of this project was to use current sensing technology to develop a quantitative assessment tool to document fine motor deficits in PD based on the ability to control grip force output. The assessment was designed to challenge deficits commonly encountered as a result of PD, including dual-task performance of a motor task and a cognitive task simultaneously. Methods: Two force sensors were used to measure the isometric pinch grip force between the thumb and index finger in 30 individuals with PD and 30 control participants of similar age without disability. Participants performed a target force tracking task with each of two different target waveforms (sinusoidal or pseudorandom) under each of three different cognitive load conditions (none, subtract 1, and subtract 3). Dependent variables calculated from the force sensor data included root mean square error, tremor integral, and lag. Results: In general, individuals with PD showed significantly less accuracy in generating the target forces as shown by larger root mean square error compared with controls (P ⬍ 0.001). They also showed greater amounts of tremor and lag compared with controls (P ⫽ 0.001 and ⬍0.001, respectively). Deficits were more pronounced during the cognitive multitasking component of the test. Discussion and Conclusions: These results will serve as a preliminary work for the development of a clinical biomarker for PD that may help to identify subtle deficits in fine motor control early in the disease process and facilitate tracking of disease progression with time. Key words: Parkinson’s disease, force tracking, clinical biomarkers (JNPT 2010;34: 32–40) Departments of Rehabilitation Medicine (S.D.P.) and Computer Science and Engineering (Y.M.), University of Washington, Seattle, Washington; and Departments of Physical Therapy (G.E.C., P.J.S., A.D.) and Rehabilitation Sciences and Technology (B.R.B.), University of Pittsburgh, Pittsburgh, Pennsylvania. Supported, in part, by the Foundation for Physical Therapy, Promotion of Doctoral Studies II Scholarship (to S.D.P.). Address correspondence to: Sujata Pradhan, E-mail:
[email protected] Copyright © 2010 Neurology Section, APTA ISSN: 1557-0576/10/3401-0032 DOI: 10.1097/NPT.0b013e3181d055a6
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INTRODUCTION
P
arkinson’s disease (PD) is a progressive neurodegenerative disorder caused by the degeneration of the nigrostriatal dopaminergic pathways within the basal ganglia. Clinically, the disease is characterized by bradykinesia, akinesia, resting tremor, and rigidity.1– 4 Pathology studies have shown that by the time the disease is clinically diagnosed, there has been a loss of ⬎40% of dopaminergic neurons. The disease has a preclinical duration of approximately six years, with the rate of progression being higher in the initial six years.5,6 Motor dysfunction of the hand has been documented in the literature,7–15 and early involvement of the hand has been subjectively reported by individuals with PD.16 A majority of the population with PD is high functioning in terms of their activities of daily living, especially when on medication. When the individual is on medication, impairments in hand function are difficult to demonstrate using common clinical measures, such as the Unified Parkinson’s Disease Rating Scale (UPDRS), because the UPDRS cannot detect the minute changes in motor function that are observed early in the disease process.17 An additional disadvantage of the UPDRS is that it relies on self-report for some sections, and early in the disease process, many individuals with PD tend to underestimate their disability.18 Other clinical tests, such as the Grooved Pegboard Test, provide greater precision but offer little information as to which motor or cognitive parameters contribute to poor test performance. The goal of this project was to develop a quantitative assessment tool to document fine motor deficits in individuals with PD using current sensing technology. This study describes the development and evaluation of a test, the Advanced Sensing for Assessment of Parkinson’s disease (ASAP), to quantify impairments in fine motor control by high-precision force or torque sensors. This preliminary work will provide a foundation for the future development of the test into a clinical biomarker for early diagnosis and to quantify motor symptoms to assess outcomes of rehabilitation or neuroprotective interventions. We hypothesized that individuals with PD would show significant deficits in performance of force tracking tasks, especially when performing a simultaneous cognitive task, compared with control participants of similar age. JNPT • Volume 34, March 2010
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Force Tracking in Parkinson Disease
METHODS
informed consent for participation in a protocol approved by the institutional review board of the University of Pittsburgh.
Participants Thirty individuals with PD (23 men and seven women) and 30 control participants without PD (12 men and 18 women) enrolled in the study. Demographic characteristics of all participants are reported in Table 1. The mean age of the control participants was within five years of the participants with PD. Individuals with PD were included if they were 18 years or older, were at a mild to moderate level of the disease based on the the Hoehn-Yahr scale,19 and were willing and able to stay off medications for 12 hours before the testing. Participants with PD were excluded if they had severe involuntary movements that would interfere with the test tasks, had sensory loss or motor weakness in their hand, scored ⬍27/30 on the Mini-Mental State Examination, or had a deep brain stimulator implanted. All participants gave written TABLE 1. Demographic Characteristics a
Age, mean (SD); (yr) Gender (M/F) Handedness R/L No. of years since diagnosis, mean (SD) Hoehn-Yahr stage
PD
Controls
65 (10) 23/7 24/6 6 (1) 1–3
70 (10) 12/18 22/8 NA NA
a P ⫽ 0.069. Abbreviations: PD, Parkinson’s disease; SD, standard deviation; M, male; F, female; R, right; L, left; NA, not applicable.
Instrumentation Two force sensors (Nano17; ATI Automation Industries, Apex, NC) were used to measure the isometric pinch grip force between the thumb and the index finger. Each sensor was mounted on an aluminum plate fixed to a custommade arm support (Fig. 1). Each sensor was capable of measuring force and torque along three axes with a resolution of 0.003 N for force and a resolution of 0.01 Nm for torque. Force and torque data from the sensors were recorded at 100 Hz, and each data point represented the mean of ⬃16 samples. For this study, only the force data were considered.
Computer Display for the Force Tracking Tasks Sinusoidal Force Tracking Display A 0.13-Hz sine wave was displayed on the computer screen by a black line surrounded by a white window, indicating 1 N on either side of the target force (Fig. 2A). The horizontal axis of the display corresponded to time, whereas the vertical axis corresponded to force. The target sinusoidal waveform scrolled continuously across the screen from right to left, so that at each time point during the experiment, the current target force was positioned at the horizontal center of the screen. The participants’ average resultant force was displayed by a purple point at the horizontal center of the computer screen. The participants were shown the 12.5 seconds of the target wave that had recently passed (along with
FIGURE 1. Experimental setup. A, Test position for the left arm, with the computer screen showing the sinusoidal tracking task. B, Position of the index finger and thumb grasping the force sensors during the force tracking task.
FIGURE 2. Display for the sinusoidal tracking task (A) and the pseudorandom waveform task (B). In both displays, the smooth line in the center of the white band represents the target that the participant was asked to track and the irregular line represents the response force created by the participant. © 2010 Neurology Section, APTA
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their tracking performance for that previous period) and the 12.5 seconds of the target wave that was to come.
Pseudorandom Force Tracking Display The force target in the second task was a pseudorandom waveform (generated using pseudorandom ternary sequence), which made the waveform unpredictable.20 As in the sinusoidal tracking task, the force target was represented on the computer screen as a black line surrounded by a white window, indicating 1 N on either side of the target force (Fig. 2B). This waveform was chosen because its derivative approximated a random noise distribution. The pseudorandom waveform had a frequency of 0 to 2.5 Hz and a period of 60.5 seconds. In this display, the participants were shown a12.5second history of the target and their response forces, but were given no information about the shape of the upcoming waveform.
Experimental Tasks and Conditions Before performing the force tracking tasks, participants were familiarized with the equipment and trained for two minutes by tracking target waveforms that included periods of constant and ramping forces. The training session did not have a simultaneous task component. Participants performed both the sinusoidal tracking task and the pseudorandom tracking task (described later) with each arm, for a total of four trials per participant. A rest break of five minutes was provided between each trial. Participants performed both force tracking tasks with one arm before proceeding with the other arm. The sinusoidal tracking task was always performed first, followed by the pseudorandom tracking task. For all the participants, the right arm was tested first, followed by the left arm regardless of dominant side or degree of involvement (in participants with PD). Participants performed the force tracking tasks under each of the following three cognitive load conditions: Y Y
Y
No cognitive load (none) condition: force tracking task performed with no additional cognitive task Subtract 1 condition: force tracking task performed while simultaneously counting aloud backward consecutively from 100 (ie, 100, 99, 98, 97, 96 . . .) Subtract 3 condition: force tracking task performed while simultaneously counting aloud backward from 100 subtracting 3 each time (ie, 100, 97, 94, 91, 88 . . .)
A simultaneous mental task paradigm was chosen because cognitive distractions or dual-tasking has been shown to increase the difference in motor performance between individuals with and without PD.21,22 For this reason, we thought that the dual-task paradigm would be likely to magnify motor impairment in individuals with PD and may be valuable in improving the ability to detect small changes in performance early in the disease process. In addition, the dual-task paradigm increased the functional relevance of the assessment because most daily activities require individuals to function efficiently as they multitask, such as talking on the phone while walking or opening a door with a key.
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Sinusoidal Tracking Task Participants were asked to track the sinusoidal waveform (display as described in the Instrumentation section); the display of the target waveform provided an opportunity for the participants to observe their recent and current tracking performance and to see a portion of the upcoming waveform. The range of force required to track the target wave was 2 to 6 N, which is within the range of force necessary for everyday activities involving precision grip.23 The sinusoidal tracking task required a total time of three minutes and 20 seconds to complete, with time allocated as follows. In preparation for tracking the sinusoidal waveform in the three cognitive load conditions, the participant tracked a flat line corresponding to a constant force of 4 N for 20 seconds. After this, the participant tracked the target sinusoidal waveform under the no cognitive load condition for one minute. The participant was then prompted to continue the tracking task while simultaneously counting aloud backward from 100 to one for the next one minute. Subsequently, the participant was prompted to continue the tracking task while simultaneously counting aloud backward from 100 to three for one minute. The timeline for the sinusoidal tracking task is shown in Table 2. To determine whether fatigue may contribute to deterioration over time in performance of the tracking task, five participants with PD engaged in an additional three minutes of sinusoidal force tracking under the no cognitive load condition.
Pseudorandom Tracking Task Participants were asked to track the pseudorandom waveform (display as described in the Instrumentation section). The target force and the participant’s force response were shown at the horizontal center of the screen, and a 12.5-second history of the target and response forces was also shown. However, the participant was unable to predict how much force should be used as the right side of the computer screen was blank (unlike the sinusoidal tracking task in which the upcoming 12.5 seconds of the ensuing waveform was displayed). During the pseudorandom tracking task, the participant experienced the same cognitive load conditions, in the same order and time duration, as in the sinusoidal tracking task.
Data Analysis For each of the force tracking tasks, the data were separated into three consecutive one-minute sections corresponding to the cognitive load condition: no cognitive load, subtract 1, and subtract 3. Comparisons were made between data acquired from participants with and without PD, with dominant and nondominant sides considered separately. Three main response variables, tremor integral (TR), root mean square error (RMSE), and lag, were used to characterize the data.
TABLE 2. Timeline of Test Task Minute 1 Force tracking without cognitive task
Minute 2
Minute 3
Force tracking ⫹ count backward by 1 (100, 99, 98, 97 . . .)
Force tracking ⫹ count backward by 3 (100, 97, 94, 91 . . .)
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Tremor Integral The force fluctuations associated with tremor in participants with PD were quantified. Quantification was based on the integral (area under the curve) of the power spectral density function (which describes how the force signal is distributed with frequency) between the force frequencies of 2 and 8 Hz. This value was defined as the TR. In subsequent analyses, it was assumed that the tremor was superimposed on the desired force output. Therefore, to mitigate the influence of the tremor on the other computed variables, after quantification of the TR, the force data were filtered with a Butterworth low-pass filter (second order, cutoff frequency 2 Hz, dual pass). All other dependent variables were calculated from the filtered data.
RMSE To quantify force tracking accuracy, the RMSE was computed between the target force FT and the observed force F:
冑
1
兺i⫽1共Fi ⫺ FTi兲2, where N represents the number N of data points measured during the time period considered. RMSE ⫽
N
Lag The peak covariance between the target force and the response force (a measure of how these two variables changed together) was used to determine the time lag of the participant’s response. A very small covariance value indicated that the subject followed the target so poorly that calculating the lag was not meaningful. For this reason, if the covariance was ⬍0.35, then the trial was assigned the maximum lag value of 2.5 seconds for the sinusoidal tracking task and 5 seconds for the pseudorandom tracking task. The covariance threshold of 0.35 was conservative and chosen empirically with the intent to minimize the number of cases being artificially assigned the maximum lag value. The maximum lag values were also chosen empirically based on the visual inspection of data. Finally, data from five individuals with PD who performed the sinusoidal force tracking task for three minutes
Force Tracking in Parkinson Disease
under the no cognitive load condition were evaluated. Repeated-measures analysis of variance was performed to examine the effect of minutes of tracking on TR, RMSE, and lag.
Statistical Analysis Repeated-measures analysis of variance was performed on the three response variables (TR, RMSE, and lag) with presence of PD as the between-group variable. The following three repeated measures were included in the analysis: dominant side, waveform type (sinusoidal or pseudorandom), and cognitive load condition (no cognitive load, subtract 1, and subtract 3). The significance level was set at ␣ ⬍ 0.05. The Mauchly test indicated that the assumption of sphericity was violated for the main and interaction effects. Therefore, the degrees of freedom were corrected using Greenhouse-Geisser estimates of sphericity. The primary analyses of interest were the main effect of group (presence or absence of PD), which would indicate a significant effect of disease on the variables of interest, and the interaction of group and cognitive load condition, which would indicate whether individuals with versus without PD performed differently when simultaneously executing a cognitive task. Post hoc tests were performed when appropriate across the levels of cognitive load using the Bonferroni correction.
RESULTS The average performance of 30 controls and 30 individuals with PD for the sinusoidal and pseudorandom tracking task are illustrated in Figures 3 and 4, respectively. The majority of participants with PD were men (23/30), whereas men composed the minority of control participants (12/30); thus, preliminary analyses were carried out using gender as a covariate. As there was no main effect of gender, and there was no interaction between gender and any of the other variables, the analyses reported below are without the covariate of gender. The findings related to the three response variables as a function of group, cognitive load, and waveform type are illustrated in Figures 5–7, respectively. Because there was no main effect of dominant side in any of the
FIGURE 3. Ensemble plot of force traces from 30 participants with Parkinson’s disease, 30 controls, and the target during the sinusoidal tracking task. © 2010 Neurology Section, APTA
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FIGURE 4. Ensemble plot of force traces from 30 participants with Parkinson’s disease, 30 controls, and the target during the pseudorandom wave trial.
FIGURE 5. Sum of power of the force signal in the characteristic frequency range for parkinsonian tremor during the sinusoidal tracking task for the dominant side. Sinusoidal tracking task (A) and pseudorandom tracking task (B) for 30 controls and 30 participants with Parkinson’s disease during each of the three cognitive load conditions. Error bars represent one standard deviation.
FIGURE 6. Root mean square error between the target force and the pinch force during the sinusoidal tracking task for the dominant side. Sinusoidal tracking task (A) and pseudorandom tracking task (B) for 30 controls and 30 participants with Parkinson’s disease during each of the three cognitive load conditions. Error bars represent one standard deviation.
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Force Tracking in Parkinson Disease
FIGURE 7. Lag between the target force and the pinch force during the sinusoidal tracking task for the dominant side. Sinusoidal tracking task (A) and pseudorandom tracking task (B) for 30 controls and 30 participants with Parkinson’s disease during each of the three cognitive load conditions. The error bars represent one standard deviation.
response variables, these figures show data for the dominant side only.
Tremor Integral As expected, the force fluctuations during the force tracking task (as quantified by the TR) were significantly greater for participants with PD than for controls (F1,58 ⫽ 4.22, P ⫽ 0.04; Fig. 5). There was no main effect of cognitive load, waveform type, or dominant side on TR. There were no significant interactions among these variables. After analysis of TR, the force data were filtered (as described in the Methods section) to reduce the influence of tremor on the other response variables of interest.
RMSE As indicated by larger RMSE values, even when the influence of tremor was removed with filtering of the force data, participants with PD were significantly less accurate than controls in matching force levels across all conditions (F1,58 ⫽ 16.48, P ⬍ 0.001; Fig. 6). There was a significant effect for cognitive load (F1.4,79.5 ⫽ 21.06, P ⬍ 0.001), indicating that as the cognitive load increased, there was greater error in performance of the force tracking task. Furthermore, a significant interaction was identified between group and cognitive load (F1.4,79.5 ⫽ 7.90, P ⫽ 0.003). Post hoc analysis revealed that the increase in error with greater cognitive load occurred only for the participants with PD; error was significantly greater during the subtract 3 condition compared with the no cognitive load condition (P ⫽ 0.001). Greater error in performance was found in the sinusoidal tracking task compared with the pseudorandom tracking task (F1,58 ⫽ 64.17, P ⬍ 0.001), and this effect was influenced by the interaction between cognitive and waveform type (F1.7,98.1 ⫽ 10.29, P ⬍ 0.001), indicating that the cognitive load had a greater effect on the forces generated during the sinusoidal tracking task than the pseudorandom tracking task. Post hoc analysis revealed that the difference was significant for the comparison between no cognitive load condition and subtract 3 condition (P ⫽ 0.001). None of the three-way or four-way interactions were significant. © 2010 Neurology Section, APTA
Lag The time lag between the display forces and the response forces was significantly greater for participants with PD compared with controls (F1,58 ⫽ 15.28, P ⬍ 0.001; Fig. 7). The lag increased significantly with cognitive load (F1.7,100.0 ⫽ 34.18, P ⬍ 0.001), and was greater during the pseudorandom tracking task compared with sinusoidal tracking task (F1,58 ⫽ 28.54, P ⬍ 0.001). The interaction between group and waveform type was significant (F1,58 ⫽ 7.84, P ⫽ 0.007), indicating that the relative increase in lag from the sinusoidal tracking task to the pseudorandom tracking task was greater in participants with PD compared with controls. The interaction between group and cognitive load (F1.7,94.3 ⫽ 4.76, P ⫽ 0.014) was also significant, showing that the effect of cognitive load on lag was greater in participants with PD compared with controls. Post hoc analysis revealed that this significant effect was between the no cognitive load condition and the subtract 3 condition (P ⫽ 0.001). No other interactions were significant.
TABLE 3. Descriptive Statistics for Response Variables for the Sinusoidal Tracking Task Without Cognitive Load for Five Individuals with PD Variable RMSE Mean (SD) Min–Max TR Mean (SD) Min–Max Lag Mean (SD) Min–Max
No Cognitive Load
Subtract 1
Subtract 3
0.66 (0.50) 0.00–1.39
0.72 (0.54) 0.00–1.50
0.83 (0.75) 0.00–2.02
0.01 (0.02) 0.00–0.04
0.01 (0.02) 0.00–0.04
0.01 (0.01) 0.00–0.02
1.06 (1.31) 0.00–2.50
1.62 (1.20) 0.25–2.50
2.06 (0.98) 0.31–2.50
Abbreviations: PD, Parkinson’s disease; RMSE, root mean square error; SD, standard deviation; TR, tremor integral.
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Assessment of the Possible Influence of Fatigue on Force Tracking Performance Data from five individuals with PD who performed the sinusoidal force tracking task for three minutes under the no cognitive load condition were evaluated (Table 3). There was no main effect of time on any of the variables (TR, RMSE, or lag; P ⫽ 0.22– 0.31).
DISCUSSION Key Findings Our results indicate that participants with PD performed poorly at tracking forces compared with adults of comparable age, with performance becoming progressively worse as the degree of cognitive load increased. This was true whether visual information was available to allow the participant to predict the amount of force required. A significant main effect of waveform type (sinusoidal vs pseudorandom) demonstrated that error was largely dependent on waveform. Although participants made greater errors on the pseudorandom tracking task because of the unpredictability of the waveform, the magnitude of the error was greater in the sinusoidal tracking task. This was possibly due to the more gradual change in force levels in the pseudorandom tracking task compared with the sinusoidal tracking task. In general, the force produced by both individuals with PD and controls during both the sinusoidal and the pseudorandom force tracking tasks was less than the target force. This resulted in the RMSE values in this experiment being dominated by underscaling of forces (Figs. 3 and 4). The significant interaction between group (PD or control) and cognitive load demonstrates that the influence of increasing cognitive load on the deterioration in performance was greater for individuals with PD. Deterioration in performance with cognitive load in the pseudorandom tracking task was also demonstrated by the increase in lag with increased cognitive load. This increased lag may represent slowed response in force production. Although the tremor did not seem to be significantly influenced by cognitive load, the large variability in tremor may have resulted in a lack of adequate power to see any differences in this response variable across different levels of cognitive load. Post hoc analyses showed that, for all dependent variables, most differences in performance across cognitive load conditions occurred between the no cognitive load versus subtract 1 conditions, or the no cognitive load versus subtract 3 conditions. No differences were observed in the subtract 1 versus the subtract 3 conditions. In the future, this information could be used to make the test shorter by using only one of the distraction components.
Implications for Functional Performance Incorporating cognitive load makes a task more challenging, which may unmask subtle deficits in performance. The basal ganglia are responsible for execution of feedforward movements24 and the control of generation of internally guided force pulses.25 Dysfunction of the basal ganglia results in a shift from feed-forward control to feedback mechanisms that rely heavily on external cues for error
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detection and correction. In individuals with a dysfunctional basal ganglia, when attention to an activity is withdrawn, the movement breaks down and deficits become obvious. This phenomenon can be documented using the ASAP test. Our results concur with those of other investigators who have found deterioration of tracking performance because of distraction in individuals with PD.21,26 Our finding that lag was greater for participants with PD compared with controls during the pseudorandom tracking task (ie, unpredictable target force) compared with the sinusoidal tracking task (ie, predictable target force) is consistent with a study by Bloxham et al.27 Using a movement position tracking task, they found that individuals with PD could use preprogrammed responses to the predictable movements to eliminate the lag between their movements and the target movement. Other studies have demonstrated, however, that this predictive ability is still deficient in people with PD as compared with controls especially in the absence of visual guidance.28 We believe that because of the complex nature of the disease, unpredictability and cognitive components should be an integral part of motor performance tests.
Previous Applications of Technology to Assessment in PD A number of technology applications have been proposed for assessment of motor performance in individuals with PD. Montgomery et al29,30 included a device for automated wrist flexion measurement as a part of a larger diagnostic test battery. Cleveland Medical Devices, Inc., developed the “Kinesia” system (http://www.clevemed.com/ Kinesia/overview.shtml), which uses a wearable device to measure kinematic data in individuals with PD. Other proposed assessment tools use target tracking, an established paradigm for measuring differences between individuals with and without PD.31–33 For example, Allen et al34 used a joystick and steering wheel designed for video games to measure the ability of individuals to track pseudorandom or sinusoidal waveforms; they identified a significant betweengroup difference for individuals with and without PD. Many of the studies used manual tracking approaches in individuals with PD to quantify motor function as a means to evaluate the effects of medication, adjust medication dose, and evaluate effects of deep brain stimulation or other surgeries.35,36 Others used tracking to evaluate cognitive or emotional profiles of individuals with PD37 and to investigate tremor.38 Investigators also used larger movements of the arm39 or the wrist40 to track targets, approaches that may not be effective in documenting subtle changes in motor control that appear early on; these more subtle changes may require the use of tracking tasks involving precision control. Our methodology was based on previous work by Kurillo et al,41,42 who found that many individuals with neurologic disorders make greater errors during performance of precision grip tasks compared with other grips and that some of these impairments are apparent before the appearance of other motor symptoms.43 Thus, a variety of technologies have been explored for PD assessment, but none has been effectively applied to preclinical analysis of individuals with PD. © 2010 Neurology Section, APTA
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Implications for Development of a Clinical Assessment Tool for Use in PD Although positron emission tomography and singlephoton emission computed tomography are the current gold standard in the area of biomarkers for PD,44 there are several advantages to having a clinical marker. Because nigrostriatal damage accounts for less than half the variability observed in motor impairment in individuals with PD,45 a clinical marker would be a useful, direct, and noninvasive measure of motor impairments. Current clinical scales such as the UPDRS cannot precisely quantify motor symptoms early in the disease process,17 and by combining precise technology and a simultaneous task paradigm, we hope to create a quantitative functional assessment for PD that can be used for diagnosis and measurement of disease progression. Although the longterm goal is to evaluate whether such an assessment is sufficiently sensitive to detect subtle deficits, as a first step, the focus of this study was to develop a force tracking task and to examine whether the data obtained from people with PD are different from those who do not have PD.
Limitations Deterioration in performance during the latter two thirds of the task could be attributed to fatigue with time rather than cognitive load. Although this is a possibility, the amount of force required for this task is small (2– 6 N) relative to the maximum voluntary contraction for similar precision grip tasks (50 – 60 N). In addition, each trial was only three minutes long, and periods of increasing force were interspersed with periods of decreasing force. We attempted to address this through data collected for five participants with PD performing the three-minute sinusoidal tracking task without cognitive load. No significant deterioration in performance was detected during the subtract 1 or subtract 3 condition compared with the no cognitive load condition. The authors acknowledge that this may be due to lack of power because this observation was made only based on five participants; therefore, future studies should include randomization of the cognitive load conditions to ensure that the results observed were indeed due to the simultaneous cognitive task. The statistical analyses presented here are based on the average of each variable over one minute of tracking. Because data for force and torque were collected at 100 Hz, this is a considerable data reduction. By using shorter time intervals when calculating variables such as RMSE and lag, further distinctions between case and control participants will emerge. At the same time, using short time intervals will increase the total number of variables. Machine learning or data mining techniques will be needed to combine this large number of variables into a single “score” for this assessment.
CONCLUSIONS This study describes the development of a novel test, ASAP, to quantify impairments in fine motor control in individuals with PD using high-precision force or torque sensors. The assessment was designed to challenge the deficits commonly encountered as a result of PD, including performance of sequential activities that require switching between motor programs.46 These results provide preliminary © 2010 Neurology Section, APTA
Force Tracking in Parkinson Disease
evidence that the data acquired for individuals with PD using the ASAP test differ from that acquired for individuals without disabilities. We hope to expand on these results to create a precise, quantitative assessment for measurement of changes in early and preclinical PD. We would also like to expand our assessment to be able to document progressive deterioration of fine motor control as the disease progresses or a decline in progression as a result of neuroprotective therapies.
ACKNOWLEDGMENTS The authors thank Dr. Robert Y. Moore, and Dana Ivanco and Rita Vareha of the Movement Disorders clinic at the University of Pittsburgh Medical Center for all their support and help with this study. REFERENCES 1. Berardelli A, Rothwell JC, Thompson PD, et al. Pathophysiology of bradykinesia in Parkinson’s disease. Brain. 2001;124:2131–2146. 2. Berardelli A, Sabra AF, Hallett M. Physiological mechanisms of rigidity in Parkinson’s disease. J Neurol Neurosurg Psychiatr. 1983;46:45–53. 3. Contreras-Vidal JL, Stelmach GE. A neural model of basal gangliathalamocortical relations in normal and parkinsonian movement. Biol Cybern. 1995;73:467– 476. 4. Contreras-Vidal JL, Stelmach GE. Effects of parkinsonism on motor control. Life Sci. 1996;58:165–176. 5. Fearnley JM, Lees AJ. Ageing and Parkinson’s disease: substantia nigra regional selectivity. Brain. 1991;114(Pt 5):2283–2301. 6. Hilker R, Schweitzer K, Coburger S, et al. Nonlinear progression of Parkinson disease as determined by serial positron emission tomographic imaging of striatal fluorodopa F 18 activity. Arch Neurol. 2005;62:378 –382. 7. Agostino R, Curra A, Giovannelli M, et al. Impairment of individual finger movements in Parkinson’s disease. Mov Disord. 2003;18:560 – 565. 8. Carroll D. Hand function in Parkinson’s disease. Md State Med J. 1967;16:171–173. 9. Castiello U, Bennett KM, Adler CH, et al. Perturbation of the grasp component of a prehension movement in a subject with hemiParkinson’s disease. Neuropsychologia. 1993;31:717–723. 10. Castiello U, Bennett KM, Bonfiglioli C, et al. The reach-to-grasp movement in Parkinson’s disease before and after dopaminergic medication. Neuropsychologia. 2000;38:46 –59. 11. Catalan MJ, Ishii K, Honda M, et al. A PET study of sequential finger movements of varying length in patients with Parkinson’s disease. Brain. 1999;122(Pt 3):483– 495. 12. Contreras-Vidal JL, Teulings HL, Stelmach GE. Micrographia in Parkinson’s disease. Neuroreport. 1995;6:2089 –2092. 13. Fellows SJ, Noth J, Schwarz M. Precision grip and Parkinson’s disease. Brain. 1998;121(Pt 9):1771–1784. 14. Forssberg H, Ingvarsson PE, Iwasaki N, et al. Action tremor during object manipulation in Parkinson’s disease. Mov Disord. 2000;15:244 – 254. 15. Berardelli A, Rothwell JC, Day BL, et al. Movements not involved in posture are abnormal in Parkinson’s disease. Neurosci Lett. 1984;47: 47–50. 16. Uitti RJ, Baba Y, Wszolek ZK, et al. Defining the Parkinson’s disease phenotype: initial symptoms and baseline characteristics in a clinical cohort. Parkinsonism Relat Disord. 2005;11:139 –145. 17. Visser M, Marinus J, Stiggelbout AM, et al. Responsiveness of impairments and disabilities in Parkinson’s disease. Parkinsonism Relat Disord. 2006;12:314 –318. 18. Shulman LM, Pretzer-Aboff I, Anderson KE, et al. Subjective report versus objective measurement of activities of daily living in Parkinson’s disease. Mov Disord. 2006;21:794 –799. 19. Hoehn MM, Yahr MD. Parkinsonism: onset, progression, and mortality. 1967. Neurology. 2001;57(Suppl 3):S11–S26.
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20. Peterka RJ. Sensorimotor integration in human postural control. J Neurophysiol. 2002;88:1097–1118. 21. Hocherman S, Moont R, Schwartz M. Recruitment of attentional resources during visuomotor tracking: effects of Parkinson’s disease and age. Brain Res Cogn Brain Res. 2004;21:77– 86. 22. Rochester L, Hetherington V, Jones D, et al. Attending to the task: interference effects of functional tasks on walking in Parkinson’s disease and the roles of cognition, depression, fatigue, and balance. Arch Phys Med Rehabil. 2004;85:1578 –1585. 23. Smaby N, Johanson ME, Baker B, et al. Identification of key pinch forces required to complete functional tasks. J Rehabil Res Dev. 2004; 41:215–224. 24. Seidler RD, Noll DC, Thiers G. Feedforward and feedback processes in motor control. Neuroimage. 2004;22:1775–1783. 25. Vaillancourt DE, Yu H, Mayka MA, et al. Role of the basal ganglia and frontal cortex in selecting and producing internally guided force pulses. Neuroimage. 2007;36:793– 803. 26. Dalrymple-Alford JC, Kalders AS, Jones RD, et al. A central executive deficit in patients with Parkinson’s disease. J Neurol Neurosurg Psychiatr. 1994;57:360 –367. 27. Bloxham CA, Mindel TA, Frith CD. Initiation and execution of predictable and unpredictable movements in Parkinson’s disease. Brain. 1984; 107(Pt 2):371–384. 28. Flowers K. Lack of prediction in the motor behaviour of Parkinsonism. Brain. 1978;101:35–52. 29. Montgomery EB Jr, Koller WC, LaMantia TJ, et al. Early detection of probable idiopathic Parkinson’s disease: I. Development of a diagnostic test battery. Mov Disord. 2000;15:467– 473. 30. Montgomery EB Jr, Lyons K, Koller WC. Early detection of probable idiopathic Parkinson’s disease: II. A prospective application of a diagnostic test battery. Mov Disord. 2000;15:474 – 478. 31. Flowers K. Some frequency response characteristics of Parkinsonism on pursuit tracking. Brain. 1978;101:19 –34. 32. Hacisalihzade SS, Kuster F, Albani C. Computer-aided measuring of motor functions using pursuit tracking. Comput Methods Programs Biomed. 1986;23: 19–28. 33. Jones RD, Donaldson IM. Measurement of sensory-motor integrated function in neurological disorders: three computerised tracking tasks. Med Biol Eng Comput. 1986;24:536 –540.
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34. Allen DP, Playfer JR, Aly NM, et al. On the use of low-cost computer peripherals for the assessment of motor dysfunction in Parkinson’s disease— quantification of bradykinesia using target tracking tasks. IEEE Trans Neural Syst Rehabil Eng. 2007;15:286 –294. 35. Duval C, Panisset M, Strafella AP, et al. The impact of ventrolateral thalamotomy on tremor and voluntary motor behavior in patients with Parkinson’s disease. Exp Brain Res. 2006;170:160 –171. 36. Lemieux S, Ghassemi M, Jog M, et al. The influence of levodopainduced dyskinesias on manual tracking in patients with Parkinson’s disease. Exp Brain Res. 2007;176:465– 475. 37. Ong JC, Seel RT, Carne WF, et al. A brief neuropsychological protocol for assessing patients with Parkinson’s disease. NeuroRehabilitation. 2005;20:191–203. 38. Schwartz M, Badarny S, Gofman S, et al. Visuomotor performance in patients with essential tremor. Mov Disord. 1999;14:988 –993. 39. Dounskaia N, Ketcham CJ, Leis BC, et al. Disruptions in joint control during drawing arm movements in Parkinson’s disease. Exp Brain Res. 2005;164:311–322. 40. Liu X, Tubbesing SA, Aziz TZ, et al. Effects of visual feedback on manual tracking and action tremor in Parkinson’s disease. Exp Brain Res. 1999;129:477– 481. 41. Kurillo G, Gregoric M, Goljar N, et al. Grip force tracking system for assessment and rehabilitation of hand function. Technol Health Care. 2005;13:137–149. 42. Kurillo G, Zupan A, Bajd T. Force tracking system for the assessment of grip force control in patients with neuromuscular diseases. Clin Biomech (Bristol, Avon). 2004;19:1014 –1021. 43. Hocherman S, Giladi N. Visuomotor control abnormalities in patients with unilateral parkinsonism. Neurology. 1998;50:1648 –1654. 44. Brooks DJ, Frey KA, Marek KL, et al. Assessment of neuroimaging techniques as biomarkers of the progression of Parkinson’s disease. Exp Neurol. 2003;184(Suppl 1):S68 –S79. 45. Pirker W, Djamshidian S, Asenbaum S, et al. Progression of dopaminergic degeneration in Parkinson’s disease and atypical parkinsonism: a longitudinal beta-CIT SPECT study. Mov Disord. 2002;17:45–53. 46. Plotnik M, Flash T, Inzelberg R, et al. Motor switching abilities in Parkinson’s disease and old age: temporal aspects. J Neurol Neurosurg Psychiatr. 1998;65:328 –337.
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CASE REPORT
Rehabilitation Postfacial Reanimation Surgery After Removal of Acoustic Neuroma: A Case Study Christopher M. Wilson, PT, DPT, GCS, and Susan L. Ronan, PT, DPT, PCS
Background and Purpose: Facial paralysis can have a significant negative impact on an individual’s social, physical, and emotional well-being; however, little information has been reported on the efficacy of physical therapy interventions for this condition. The purpose of this case study was to describe the details of a physical therapy evaluation and intervention for a patient who underwent facial muscle transfer after resection of acoustic neuroma. Case Description: A 29-year-old woman underwent left-sided facial reanimation surgery, which included transplantation of the temporalis muscle and platysma muscle to the corner of the mouth. Intervention: The patient received 30 sessions of physical therapy that included electrical stimulation, biofeedback, lymphatic drainage, home exercises and facial stretching, and scar management. Outcomes: The patient exhibited an improvement in the Composite score of the Sunnybrook Facial Grading System from 17 to 41. She was able to regain function of the left side of her face with gains in expressions of smiling, frowning, and puckering, but symmetry was not completely restored. The patient had chronic difficulty with left-sided lymphedema, requiring frequent manual lymphatic drainage. Discussion: Data from this case study suggest that physical therapy management improves functional outcomes for individuals with postoperative changes in facial motor function from facial reanimation surgery. Further research is required to explore factors that influence the rate and extent of recovery derived from physical therapy interventions. Key words: facial reanimation, acoustic neuroma, electrical stimulation, lymphedema, facial paralysis (JNPT 2010;34: 41–49)
INTRODUCTION
F
acial paralysis has been described as the loss of unilateral or bilateral motor function as a result of injury to the facial nerve. This leads to an inability to close the eye and paralysis
Department of Physical and Occupational Therapy (C.M.W.), William Beaumont Hospital, Troy, Michigan; Department of Physical Therapy (C.M.W.), School of Health Sciences, Oakland University in Rochester, Michigan; and Department of Physical Therapy (S.R.), New York Medical College, School of Public Health, Valhalla, New York. Address correspondence to: Christopher M. Wilson, E-mail: Christopher.
[email protected] Copyright © 2010 Neurology Section, APTA ISSN: 1557-0576/10/3401-0041 DOI: 10.1097/NPT.0b013e3181cfc324
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of the muscles of facial expression.1 Facial nerve damage may also occur after acoustic neuroma resections, trauma, brain hemorrhage, birth trauma, and congenital causes, such as congenital bilateral facial paralysis (ie, Mo¨bius syndrome).2,3 The incidence of acoustic neuroma (eg, vestibular schwannoma) is one to two per 100,000 persons, with the median age of diagnosis being 55 years.4,5 Tumor resections in the posterior fossa and at or near the distal branches of the facial nerve can result in the loss of facial nerve function secondary to surgical procedures to resect the tumor.6 Loss of facial motor function results in decreased facial muscle tone and paralysis.7 Other possible sequelae may also occur, such as temporomandibular joint (TMJ) dysfunction, decreased lacrimation, drooling, poor dentition (as a result of poor oral hygiene because of sensory loss), and lip or cheek trauma caused by malocclusion.8 Corneal damage may occur secondary to poor eyelid closure and impaired lubrication of the eye. The physical and functional complications associated with facial paralysis can also affect an individual’s social, psychological, emotional, and physical well-being. Facial paralysis can result in the reduction and inability to express emotions.1 The social and psychological sequelae reported after facial paralysis include guilt, anger, depression, rejection, and paranoia.1,9 Individuals often feel ostracized, and their facial asymmetry serves as a point of social discomfort.8 These emotions may be coupled with the stress of other diagnoses and the resulting treatments. The treatment options for these individuals include surgical interventions and facial muscle rehabilitation. Surgical interventions, termed facial reanimation, are procedures used to improve cosmesis, resting facial symmetry, and functional recovery. The initial therapeutic approach used includes modalities of electrical stimulation and biofeedback. Oral motor stimulation and exercise are also incorporated.10 The goals of facial reanimation surgery are twofold: (1) to restore resting symmetry to the face and (2) to improve voluntary motor control for speaking and expression.11 The ideal candidate is someone with less than one year of facial paralysis. Facial reanimation surgery often consists of two stages. The first stage reinnervates the paralyzed side of the face by means of nerve grafting.12–14 In the second stage of the procedure, muscular connections are made to the grafted nerve. If the denervated muscles are not viable, it is possible to use a muscle transfer to restore movement to the face. The temporalis muscle is harvested and transferred to the zygomatic arch and temporal fascia. The muscle is also sutured to
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the dermis along the nasolabial crease. In cases of congenital paralysis or Mo¨bius syndrome, split temporalis grafts have been used to restore movement to the upper lip and cheek area. The nerve supply to the temporalis muscle is from the fifth cranial nerve (trigeminal) and is usually not affected by trauma to the facial nerve. The temporalis transfer is performed without the nerve graft surgery.12,13 These patients will need to initiate some jaw clenching to accomplish any facial movement. Physical therapy for individuals with facial nerve injuries has included facial exercise, electrical stimulation, oral motor stimulation, and biofeedback.15–18 Treatment can begin six weeks after facial reanimation surgery, that is, the muscle transfer stage. Byrne et al10 described physical therapy beginning once a week, progressing to once a month when the patient was able to be independent with a home program and was able to dissociate certain facial motions. The initial presentation of the surgical site can be swollen, slightly discolored, and tender. Patients will report changes in their oral function secondary to the surgery and swelling. Their presurgical compensatory strategies for articulations, speech, and eating may not be as efficient with the improved nerve supply and muscular alignment. Patients may report biting on foods differently because there may be a new alignment of the teeth and facial structures.19 The new alignment of the musculature will change an individual’s proprioceptive feedback for facial movement. Patients require a sensorimotor retraining program to improve their ability to control the transplanted muscle. Patients frequently have difficulty with bilabial sounds such as the “m” in “mother” and particularly in generating force behind phonations for plosive sounds such as the “b” in “boy.” VanSwearingen and Brach20 described facial neuromuscular reeducation exercise programs that target facial movement patterns used to improve facial movement and decrease synkinesis. Synkinesis is defined as the presence of inadvertent motion in one area of the face produced during intentional movement in another region of the face.21 Two commonly used grading systems for facial paralysis are the House-Brackmann Facial Nerve Grading Scale and Sunnybrook Facial Grading System. The House-Brackmann Scale was introduced in 1983 and is endorsed by the Facial Nerve Disorders Committee of the American Academy of Otolaryngology.22 Based on the degree of facial function, the patient is placed into one of the six categories (Table 1).23 Although accepted as a standard for clinical practice, the House-Brackmann Scale has not been shown to have strong interobserver reliability.23,24 It has been noted by Croxson et al25 that this is a gross scale not useful for determining small, incremental changes in facial function. The Sunnybrook Facial Grading System has demonstrated sensitivity to changes in facial function with rehabilitation.26 –28 This system grades facial Resting Symmetry on a zero to one- or two-point scale, with 0 representing normal symmetry. A five-point scale, where 1 is unable to initiate movement and 5 is a complete movement, is used to grade facial Voluntary Movements, such as forehead wrinkle, gentle eye closure, open mouth smile, snarl, and lip pucker. Synkinesis is graded on a scale of zero to three points, where
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TABLE 1. House-Brackmann Facial Nerve Grading System23
0 represents no synkinesis and 3 represents severe synkinesis. Once these category scores are determined, the Composite score is calculated by subtracting the weighted Resting Symmetry score and the Synkinesis score from the more heavily weighted Voluntary Movement score.29,30 The Sunnybrook System is frequently cited in the literature and has been considered to be reliable for this patient population, except for the grading of synkinesis, for which the reliability was rated as low by Coulson et al.30 Although the Sunnybrook System has been reported to be valid,29,31 no studies could be identified that have assessed the validity of the House-Brackmann Scale. The Sunnybrook System has been shown to have good to excellent repeatability, and the House-Brackmann Scale has fair to good repeatability.30,32 Balliet et al33 reported on patients after facial nerve anastomoses and noted functional progress made by the patients with feedback training, behavioral modification, and specific motor retraining, despite varying latencies of time to onset of rehabilitation after the surgical procedure. The authors attributed the progress to the improvement in sensory and motor awareness of the involved side. Mirror training was also used to improve motor control, increase facial awareness, and decrease synkinesis. Although the use of electrical stimulation for patients after facial reanimation has not been studied, electrical stimulation has been used as an intervention for facial paralysis with the intent to improve motor recovery. Daily use of subsensory stimulation for patients with chronic facial nerve paralysis has been reported to improve motor nerve action potential distal latencies and to be associated with the gain of one grade in the House-Brackmann Scale.34 The application of subsensory electrical stimulation to the hand of individuals with an intact nervous system has been shown to change cerebral blood supply to the associated representational area of the motor and somatosensory cortex, suggesting increased cortex activity.35 Daily use of subsensory stimulation and progression to functional electrical stimulation of the hand may improve muscle tone and increase motor control in individuals who have had a stroke.36 Electrical stimulation, © 2010 Neurology Section, APTA
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therefore, may aid in the retraining of muscles by facilitating activity in the cortical region representing the face. This may facilitate an alternative mechanism of recovery with electrical stimulation beyond the traditional use of local nerve and muscular stimulation, but further study is necessary. A Cochrane review of the literature related to Bell’s palsy showed no significant improvement with the use of electrical stimulation over control or no treatment groups.37 Biofeedback has been used for facial retraining to encourage muscle activity and decrease synkinesis.12 It is particularly helpful to retrain facial movements like lip closure, puckering, and smiling in facial reanimation recovery secondary to the grafted neural supply and muscle transfers. The patient requires training to use these newly grafted muscles and nerves for facial function. Biofeedback has been used to encourage movement and relaxation in muscles. Mirror training has also been used to reinforce muscular control and encourage symmetry of movement in patients after facial reanimation surgery.38 The purpose of this case study was to describe the physical therapy examination, evaluation, and intervention of a patient who received facial reanimation surgery that included muscle transfers to compensate for denervated muscles after acoustic neuroma removal. At the time of writing of this manuscript, no other articles could be located to describe detailed physical therapy interventions and outcomes after facial muscle transplantation for facial reanimation. The patient completed an informed consent before submission of this article. Approval for a retrospective medical record review was sought from the Beaumont Hospitals Human Investigation Committee (Royal Oak, MI). The Human Investigation Committee determined that the study was exempt from full review, and a written Waiver of Review was provided.
METHODS Examination Initial Observation The patient was a 29-year-old woman referred to physical therapy by her facial reconstruction surgeon five weeks after muscle transfer for facial paralysis. The patient presented with significant swelling and bruising around the left mandibular area and extensive loss of motor function of the muscles on the left side of her face.
Rehabilitation After Facial Reanimation Surgery
patient received limited speech and physical therapy and had minimal to no recovery of left facial function. The patient described that five weeks before the current physical therapy initial evaluation, she underwent facial muscle grafting and tissue transplantation. Before facial reanimation surgery, the patient underwent electromyography testing and physical examination, which demonstrated “severe paralysis” of the facial nerve. The surgical report noted that surgery included lifting the left temporalis and platysma muscle origins and transposing the origins to the upper and lower left corners of the mouth, respectively, while attempting to preserve the muscles’ innervation. The patient also had a portion of her left tensor fascia lata transplanted to provide an extension from the platysma to the inferior corner of the mouth. A segment of tensor fascia lata was grafted at her left nasolabial fold to improve symmetry of the nasolabial folds. A left hemilip elevation procedure and a left frontalis advancement procedure were performed to assist with restoring facial symmetry. Finally, a small gold weight was placed in the left eyelid to assist with eye closure. Her recovery from facial surgery was unremarkable; however, she was not instructed in any exercises or range of motion until starting formal physical therapy to allow for proper connective tissue healing. The patient stated that she was a bank manager for seven years, and her job involved a high degree of public interaction.
Tests and Measures Pain Assessment The patient reported postoperative pain in her left lateral thigh donor site and left facial region. Pain was assessed with a zero to 10 numerical pain rating scale for ease of administration. Pain was reported to be 3/10 and 5/10 for the left thigh and the left facial region, respectively. Numbness was detected in the left mandibular area as assessed subjectively by light moving touch.
Initial Observation On initial observation, the patient displayed healing incisions of ⬃2.0 cm along the left nasolabial fold, one crescent-shaped incision along the scalp at the origin of the temporalis muscle, a 2.5-cm incision along the underside of the left chin, and a circumferential incision along the outside border of the left upper and lower lip.
Active Range of Motion History and Interview The patient’s chief complaint was limited left-sided facial movement and edema, bruising, and pain after facial reanimation surgery. She stated that 11 years before the initial evaluation, she had a diagnosis of hydrocephalus and a large left-sided acoustic neuroma. There is an established relationship between hydrocephalus and acoustic neuroma, with the incidence of hydrocephalus being between 3.7% and 42% in those with acoustic neuroma.39 Excision of the tumor resulted in complete left-sided facial paralysis because the facial nerve was transected near the brainstem. She also experienced complete left-sided hearing loss, slurring of speech, and inability to close the left eye completely. After surgery, the © 2010 Neurology Section, APTA
The patient displayed 20 mm of jaw opening; left jaw lateral deviation was 10 mm and right jaw lateral deviation was limited to 4 mm (normal ranges have been cited as 35–55 mm and 10 –15 mm, respectively).40 Jaw active range of motion measurements were taken using a retractable cloth tape measure. Cervical range of motion into forward bending and right rotation was within 80% of normal limits, and right side bending was more limited at 60% of normal limits. Pain was not increased with any of the limited motions in the neck or the jaw; however, stiffness was reported for all of the limited movements. The patient was able to incompletely close the left eye gently, with a 3.0 to 4.0 mm opening remaining.
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Muscle Strength Testing Muscle strength testing was performed using a 0 to 5 grading scale as described by Hislop and Montgomery.41 Typically, when describing facial muscle strength, specific muscle names would be cited, but because of the extensive denervation and facial muscle grafting, it was determined that a description of the direction of motion would be more meaningful. Grades for the tested facial movement were as follows: Y Y Y Y Y Y
Closing and protruding the left inferior lip: 2/5 Closing and protruding the left superior lip: 3/5 Elevating the left upper lip: 2⫺/5 Elevating and drawing the left commissure (corner of the mouth) laterally (smiling): 1⫹ to 2⫺/5 Depressing the left commissure (frowning): 0 to 1/5 Left forehead or eyebrow elevation: 0/5
Anthropometric Measurements To monitor edema, the left side of the face was measured and compared with the right side using the same standard retractable cloth measuring tape and consistent landmarks. No standardized anthropometric facial measurements could be found in the literature; therefore, the therapist devised a method using stable facial landmarks not determined to be affected by this patient’s swelling, such as the superior and inferior seams of the earlobe, the nasolabial fold, and the cleft of the chin. The distance from the anterior earlobe to the cleft of the chin was 13.5 cm on the right and 14.5 cm on the left. The distance from the anterior earlobe to the corresponding nasolabial fold was 11.0 cm on the right and 12.0 cm on the left. The distance from the superior ear seam to the cleft of the chin was 16.5 cm on the right and 17.0 cm on the left.
Palpation Assessment The patient’s left-side perioral skin and subcutaneous tissue were stiff and hypomobile when compared with the right side and initially did not have sufficient flexibility to allow full excursion for a balanced smile as determined by subjective examiner assessment.
Functional Assessment The patient reported that her main functional limitations were difficulty with smiling, eye closure, and lack of overall facial symmetry, all of which affected her interpersonal interactions with the public and her co-workers. She stated that she was just beginning to eat solid foods but was having difficulty because of biting the inside of her mouth and pocketing food on the inside of the left cheek. She also noted increased periods of wakefulness when attempting to sleep on her left side because of increased pain in her face and left thigh. Two functional grading scales were used to assess function: the House-Brackmann Facial Nerve Grading Scale23 and the Sunnybrook Facial Grading System.29 According to the House-Brackmann Scale, the patient displayed a Grade V (severe) dysfunction, which is defined as only barely perceptible gross motion, asymmetry at rest, no fore-
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head motion, incomplete eye closure, and slight mouth movement. The patient was also graded with the Sunnybrook Facial Grading System and was determined to have a Voluntary Movement score of 40 (normal ⫽ 100; range, 20 – 100), a Resting Symmetry score of 15 (normal ⫽ 0; range, 0 –20), and a Synkinesis score of 8 (normal ⫽ 0; range, 0 –15) for a Composite score of 17 (unimpaired facial movement ⫽ 100).
Evaluation Examination identified commonly expected postsurgical changes such as pain, edema, difficulty eliciting muscular contraction of the grafted muscles, and TMJ active motion limitations. The patient arrived in physical therapy with a prescribed home exercise program and recommendation for use of neuromuscular electrical stimulation (NMES) from the surgeon. To target the appropriate muscle groups and avoid synkinesis during exercise, facial exercise retraining augmented by biofeedback, including exercising in front of a mirror and surface electromyography (sEMG), was deemed to be an optimal approach. The patient had significant softtissue restriction to the left facial skin and subcutaneous tissue, which required restoration. Unless perioral tissue flexibility was restored, the patient’s facial motion would be restricted despite underlying facial muscle strength. In addition, it was anticipated that the patient would have difficulty with chronic lymphedema because there are several lymphatic tracts around the mandible and anterior neck. It is likely that these tracts were disturbed during surgery, and the patient would possibly require manual lymphatic drainage (MLD) massage as described by Zuther.42
Diagnosis Based on the American Physical Therapy Association’s Guide to Physical Therapist Practice, the patient was assigned to the Practice Pattern 5F: impaired peripheral nerve integrity and muscle performance associated with peripheral nerve injury.43
Prognosis It was anticipated that because of the short duration of TMJ immobilization postoperatively, joint mobility was likely to return during normal use without the need for joint manipulation. Because no facial nerve reconstruction was noted in the operative report, it was anticipated that there would be no further muscular recovery in the facial nerve innervation pattern (including the forehead and eyebrow region) beyond the patient’s baseline status. Restoration of some left perioral motion and function was expected from the newly transplanted muscles around the left corner of the mouth.
INTERVENTION The patient received physical therapy for a total of 30 sessions spanning 14 weeks (labeled here as phase 1). Frequency was three times per week for sessions 1 to 18, decreased to two times per week for sessions 19 to 26, and finally decreased to once per week during the final four sessions, with increased emphasis on home treatment during © 2010 Neurology Section, APTA
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FIGURE 1. Intervention sequence for phase 1.
these last sessions. Home treatment included self-MLD and home exercises previously introduced in the clinic. Re-evaluation was performed by the same physical therapist every six sessions to assess progress, including administration of the Sunnybrook Grading System. Each session lasted approximately one hour. A synopsis of the series of interventions is illustrated in Figure 1. During the first phase of physical therapy, the patient was instructed extensively in the home exercise program developed by her surgeon and one of the study authors (S.R.). The exercise protocol included word pronunciation and active range of motion exercises, including puckering lips, smiling, smirking, grimacing, eye closure, brow lifting, nostril flaring, wrinkling forehead, whistling, eyebrow elevation and lowering, wrinkling chin, mandibular protraction, winking, opening eyes wide, and platysma contraction for 10 to 20 repetitions performed three times daily. In addition to this home exercise instruction, the patient received MLD massage to the left facial region. Lymphatic fluid was guided in the direction of the thoracic duct to empty into the subclavian vein (Fig. 2). The patient performed active-assistive range of motion with the therapist’s manual assistance in the direction of puckering, frowning, and smiling, which was continued for five sessions until the patient was independent in performing these movements. At the second session, the patient was provided an Empi 300 PV NMES unit (Empi, St. Paul, MN) and instructed on how to use the machine to electrically elicit muscle contraction with simultaneous volitional effort. Pa© 2010 Neurology Section, APTA
rameters for the NMES included a symmetric biphasic pulsatile current. Two 1.25-in self-adhering circular electrodes were used; one was placed under the left chin and the other over the left zygomatic arch. The placement of the electrodes was in accordance to the surgeon’s specifications to stimulate the muscle that was both innervated and transferred for optimizing facial function (Fig. 2). The “on time” (time at peak current amplitude) was seven seconds and the “off time” was 45 seconds, with additional ramp-up and ramp-down times of three seconds each. The frequency was 50 pps and the pulse duration was 200 microseconds. The intensity of the stimulation was increased to the level at which a minimal muscle twitch was observed in the transposed temporalis
FIGURE 2. Manual lymphatic drainage direction and electrode placement for neuromuscular electrical stimulation and surface electromyography.
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muscle, which was able to contract because its original innervation was preserved. The patient was instructed to achieve an observable active contraction (1/5 on muscle strength testing) using electrical stimulation and volitionally attempt to smile during the “on” period of the stimulation. In this and subsequent NMES sessions, the stimulation intensity was adjusted to achieve motor activation. The patient was instructed to perform NMES for 20 minutes three times per day. The patient continued home NMES until she was able to elicit consistent volitional contractions of smiling without the assistance of NMES; this was achieved at session 17. At the third session, the patient’s home program was modified to omit any eyebrow or forehead exercises because there was no further anticipation of forehead recovery. By the sixth session, the patient displayed full, painfree cervical range of motion without need for specific intervention. The patient was able to move the left commissure 1.2 to 1.5 cm into the direction of smiling. Commissure excursion measurements were performed as described by Manktelow et al.44 Also, all previously assessed edema measurements for the left face were within 0.5 cm of the right; therefore, MLD in the clinic was transitioned to the home program. At this time, sEMG biofeedback (Chattanooga Vectra Genisys unit; Chattanooga Group, Hixson, TN) was initiated to better allow the patient to relearn the smiling motion more effectively and efficiently. Three self-adhering circular sensor electrodes (3.17 cm) were placed superior and anterior to the left mandible (Fig. 2). Maximum voluntary contraction level was set according to the manufacturer’s instructions. The device was set to elicit an audio tone when the patient was able to achieve a contraction of ⬎80% of a maximum voluntary isometric contraction of the transplanted temporalis muscle. The patient was instructed to hold this contraction for 10 seconds, attempting to elicit the audio tone for the entire time. Initially, a rest time of 30 to 40 seconds was provided between sEMG contractions, but as the treatment progressed, the patient was able to hold a full contraction with only a 20-second rest. The patient completed three sets of 20 repetitions of sEMG isometric contractions each session. The patient performed sEMG in front of a mirror to emphasize symmetry of the smile to avoid synkinesis. The patient’s maximum voluntary contraction strength gradually increased over time, and, accordingly, the 80% threshold was readjusted at each treatment to the patient’s new maximum. Once the patient was able to elicit a voluntary smile contraction, focus was placed on reducing the effort required to smile. Blocked practice “rapid fire” smiling was initiated with visual feedback from a mirror for a high number of repetitions (50⫹) to help facilitate decreasing the conscious thought related to learning the new skill of smiling. This blocked practice was performed for three sessions and was phased into random practice interspersed throughout treatment once the skill was acquired, as indicated by Schmidt.45 By session 12, the patient was able to elicit an excursion of the left commissure in a smiling motion to 1.5 cm with maximal effort (according to patient’s subjective report) and a trace frowning motion. As a measurement of progress, isometric contraction duration was assessed, and the patient was able to hold her smile for 30 to 45 seconds before fatigue.
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She continued to have difficulty coordinating a natural bilateral smile; consequently, blocked practice of “rapid fire” smiling was resumed and incorporated in conjunction with random practice of smiling for six more sessions. The patient’s edema measurements continued to be stabilized; however, the patient indicated that home treatments were taking considerable time and effort. Thus, MLD massage was reintegrated into the clinic treatment plan at session 14. At this time, increased flexibility was noted in the left facial musculature and subcutaneous tissue, and no pain was noted in the left facial region. At the session 18, treatment was decreased to twice per week. The patient reported stiffness and discomfort in the left shoulder with a loss of the last 20 degrees of flexion and abduction range of motion; therefore, gentle manual stretching was performed between sessions 20 and 24, at which point full, pain-free range of motion was restored. Glenohumeral stretching used both physiologic and accessory motions. Beginning at sessions 23 and 24, the patient began to report left-sided cervical discomfort and stiffness and occasional cervicogenic headaches for which soft-tissue massage and postural exercises (scapular retraction and cervical retraction) were performed during sessions 25 to 30. These exercises were also added to the home program. At the session 26, the patient’s treatment was changed to once per week, with continued refinement and advancement of her home program. During sessions 29 and 30, the patient’s facial mobility, function, and Sunnybrook score stabilized; the patient demonstrated independence in her home program, and it was, therefore, determined that she should be discharged from physical therapy. Throughout treatment, the patient cited strong adherence to the home exercises, NMES, selfstretching, and self-MLD; however, no formal tracking log or diary was kept.
RESULTS Patient Outcomes: Phase 1 On completion of 30 sessions of physical therapy, the patient reported no pain in any areas and no difficulty with speech, eating, sleeping, or drinking. She also displayed continued equalization of facial edema measurements concurrent with the MLD treatments and with soft-tissue healing and recovery after surgery. It was noted that if the patient missed an MLD home session, there was an associated increase in left facial edema, which reinforced the plan for continued daily MLD techniques. She was able to display a smiling motion of 1.5 to 1.7 cm excursion of the left corner of the mouth (normal range cited between 0.7 and 2.2 cm, average ⫽ 1.4 cm)46 and was able to do this motion easily without hesitation, but reported that it was not reflexive and spontaneous. In addition, she was able to display movements of puckering, which was a 1.0-cm medial excursion of the left commissure from its resting position, and a limited frowning motion of 0.3 to 0.5 cm on the left (no normative data available in the literature for these measurements). She reported continued difficulty with grimacing or showing her teeth, but she indicated that this did not frequently affect her daily life. She displayed full TMJ mobility, but continued to © 2010 Neurology Section, APTA
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FIGURE 3. Sunnybrook Facial Grading System Component scores.
lack appreciable recovery of mobility in her left eyebrow or forehead region, which was anticipated, because there were no nerve or muscle transplants to this denervated area. Eyelid closure was described as “movement almost complete” on the Sunnybrook Grading System after this series of visits; however, the patient required eyedrops to prevent corneal dryness. Grades for the tested facial movement were as follows: Y Y Y
Smiling, closing, and protruding the left side of the mouth: 3⫹/5 Frowning: 1⫹/5 Elevating the left upper lip: 2/5
On discharge evaluation for phase 1, the patient had a Sunnybrook Composite score of 41 compared with a score of 17 on initial evaluation, an improvement of 24 points. The Sunnybrook Voluntary Movement score improved from 40 to 52, Resting Symmetry score from 15 to 5, and Synkinesis score from 8 to 6. It should be noted that decreased scores in Resting Symmetry and Synkinesis indicate an improvement according to the Sunnybrook System (Fig. 3 and Table 2). Finally, the patient’s initial Grade V (severe) disability on the House-Brackmann Scale improved on discharge to Grade IV (moderately severe) dysfunction. The patient met all of the criteria for achieving Grade III (moderate function) except for “moderate to good forehead function.” One of the criticisms of the House-Brackmann Scale is that low scores in one criterion can unduly restrict the score.30
to enhance symmetry. The surgical procedure included tightening of a muscular sling at the left temple and zygomatic arch, liposuction to the left mandibular area, removal of some deep stitches near the left nasolabial fold, and microdermabrasion to the scars surrounding the left hemilip. The patient participated in physical therapy for nine sessions during one month, which included left perioral facial stretching, scar tissue mobilization, MLD, cervical stretching, and sEMG biofeedback. On phase 2 initial evaluation, the patient had a
TABLE 2.
Sunnybrook Facial Grading System Resultsa
Follow-Up and Continued Care Four months after discharge, the patient returned to physical therapy (phase 2), which was initiated five weeks after undergoing a refinement surgery to her left facial region © 2010 Neurology Section, APTA
Sunnybrook Facial Grading System Web site: http://sunnybrook.ca/content/?page⫽ Dept_ENT_FGS. a Composite Score ⫽ Voluntary Movement ⫺ Resting Symmetry ⫺ Synkinesis.
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Sunnybrook Composite score of 27; on discharge, the score was 33, with most limitations in the Resting Symmetry category. Voluntary Movement scores improved from 36 to 52. It should be noted that the patient discharged herself early during this phase of intervention and did not fully return to values achieved at the end of phase 1 on the Sunnybrook scale because she was going on vacation and then having her next surgical revision. Two weeks after discharge from phase 2 of physical therapy, the patient underwent another revision surgery to remove more scar tissue at the left perioral region and to again tighten the temporal sling to enhance smile symmetry. She returned to physical therapy (phase 3) five weeks after this most recent surgery, which was 10 months after the initial physical therapy visit. During this latest phase of physical therapy, the patient reported setbacks, including edema, dysarthria, cervical spine stiffness, and drooling after her most recent surgery. This phase of physical therapy consisted of 12 sessions during two months. The focus was on cervical spine myofascial mobilization, including suboccipital release, resumption of MLD massage, NMES three times daily at home, scar mobilization, and sEMG biofeedback. On completion of phase 3, the patient returned to the status that was achieved at the end of phase 1, but with minimal further gains in function.
DISCUSSION A major focus of physical therapy for this patient was to address the adaptive shortening of the left perioral tissues caused by the long duration of facial paralysis before facial reanimation surgery. This adaptive shortening prevented the patient’s newly transplanted postsurgical muscles from generating sufficient force to perform facial excursions against the resistance of tightened soft tissues. Another challenge for this patient was that the temporalis muscle that had been transplanted could only create its newly intended motion by having the patient contract in the motion of its original purpose. The patient had to “clench her jaw” to create a smiling motion on the left side, while coordinating the original facial muscles on the right to create a symmetrical smile. The patient noted that this smile was never quite reflexive and required concentration and volitional effort using the learned technique when the social situation called for a bilateral smile. The precision of motor control was aided by the use of sEMG biofeedback, mirror exercises, and functional exercise to reinforce the muscular control of smiling performance. The cervical branch of the facial nerve innervates the platysma muscle, and there was no evidence during initial evaluation to show that the platysma had retained innervation, which raised the question why the surgeon transplanted the muscle. An article authored by this surgeon clarified the rationale for platysma transfer: “In the [surgeon’s] experience, however, even in cases of denervation of the cervical branch of the facial nerve, the “static” pull of the platysma/ autogenous fascia lata extension will effectively evaginate the lower lip and improve lip symmetry and function in repose.”19 Because it was unclear at the time of initial evaluation whether the platysma was innervated, it was determined that the patient’s progress would not be hindered by working
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on the motion of frowning, which the newly transplanted platysma would perform, if only partially innervated. To some extent, the positive outcomes for this patient were likely related to her adherence to her home program. Achievement of adequate functional outcomes is impeded when a patient is not able to adhere to a home program that requires performance of complex tasks. Subjectively, the patient reported that she was pleased by the ability to elicit a bilateral smile and to achieve increased left-sided expressions, but she continued to pursue operations to improve with cosmesis. These further surgeries did not modify the functioning or esthetics of the face as much as had the initial facial reanimation surgery; each surgical procedure was also associated with some regression in outcomes, prompting the need for further physical therapy. However, with physical therapy, the gains were re-established and no long-term negative effects of the repeated surgical procedures were noted. After phase 3, the therapist discussed with the patient some of the potential adverse effects of multiple surgeries, including keloid scar formation, risk of infection, and regression of cosmesis. Limitations of this case study include its single-subject retrospective design, which lacks the rigors of a prospective study with a large sample and statistical significance to support treatment effectiveness. Other limitations could include incomplete recording of the details of relevant examination and treatment information and the inability to plan for reporting all information that might later be determined to be important. Another limitation is the lack of digital photographic documentation of progression of facial symmetry. Digital photography was used initially for clinical documentation, but these records were destroyed by a flood at the treating clinic. The use of digital photography for quantifying symmetry and facial excursions is recommended for future studies to provide a graphic record of progress.
CONCLUSIONS Facial reanimation surgery, after acoustic neuroma excision and facial nerve transaction, carries with it a number of opportunities and challenges for a patient with facial hemiparalysis. The patient in this case study was able to achieve limited facial motion on the left side in the direction of smiling, puckering, and frowning, where there was no such motion for 11 years. The patient struggled with chronic edema of left cheek and mandible region, which was managed with frequent MLD massage. Although functional recovery was incomplete (according to measurement instruments used) and there remained a marked difference in motion between sides, this residual difference did not have an impact on the patient’s speech, eating, or drinking; the patient did, however, report continued perceived limitations in public interactions. The two subsequent surgeries temporarily reversed her functional gains, but additional sessions of physical therapy, concentrating on cervical spine myofascial mobilization, MLD, and daily home NMES, allowed her to recover to the functional levels achieved after the first intervention period. Implications of this case study include the need for further study of the detailed effects of physical therapy © 2010 Neurology Section, APTA
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interventions on facial muscle paralysis in surgical and nonsurgical cases. In addition, outcomes of various surgical techniques and use of electrical stimulation for facial reanimation should be compared to determine which procedures are most effective and offer the shortest recovery time.
ACKNOWLEDGMENTS The authors thank Elliot Rose, MD, Lisa Galazka, PT, MPT, and Janet Seidell, PT, MPT, for clinical advice during physical therapy management of the patient. They also thank Jackie Drouin, PT, PhD, Ralph Garcia, PT, PhD, and Chris Stiller, PT, PhD, for their critical review of this manuscript. REFERENCES 1. Stuart RM, Byrne PJ. The importance of facial expression and the management of facial nerve injury. Neurosurg Quart. 2004;14:239 –248. 2. Mitchell H. To smile again. Reanimation for unilateral facial palsy. Br J Perioper Nurs. 2000;10:16 –21. 3. Stedman, TL. Stedman’s Medical Dictionary. 27th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2000. 4. Tos M, Stangerup S, Caye-Thomasen P, et al. What is the real incidence of vestibular schwannoma? Arch Otolaryngol Head Neck Surg. 2004; 130:216 –220. 5. Stangerup S, Tos M, Caye-Thomasen P, et al. Increasing annual incidence of vestibular schwannoma and age at diagnosis. J Laryngol Otol. 2004;118:622– 627. 6. Magliulo G, D’Amico R, Forino M. Results and complications of facial reanimation following cerebellopontine angle surgery. Eur Arch Otorhinolaryngol. 2001;258:45– 48. 7. Gossman MR, Sahrmann SA, Rose SJ. Review of length-associated changes in muscle: experimental evidence and clinical implications. Phys Ther. 1982;62:1799 –1808. 8. Diels HJ. Facial paralysis: is there a role for a therapist? Facial Plast Surg. 2001;16:361–364. 9. Twerski A, Twerski B. The emotional impact of facial paralysis. In: May M, ed. The Facial Nerve. New York, NY: Thieme; 1986:788 –794. 10. Byrne PJ, Kim M, Boahene K, et al. Temporalis tendon transfer as part of a comprehensive approach to facial reanimation. Arch Facial Plast Surg. 2007;9:234 –241. 11. Tomat LR, Manktelow RT. Evaluation of a new measurement tool for facial paralysis reconstruction. Plast Reconstr Surg. 2005;115:696 –704. 12. Doud Galli SK, Valauri F, Komisar A. Facial reanimation by cross-facial nerve grafting: report of five cases. Ear Nose Throat J. 2002;81:25–29. 13. Rose EH. Aesthetic Facial Restoration. Philadelphia, PA: LippincottRaven; 1998. 14. VanSwearingen JM, Brach JS. The facial disability index: reliability and validity of a disability assessment instrument for disorders of the facial neuromuscular system. Phys Ther. 1996;76:1288 –1300. 15. Ross B, Nedzelski JM, McLean JA. Efficacy of feedback training in long-standing facial nerve paresis. Laryngoscope. 1991;101:744 –750. 16. Dalla Toffola E, Bossi D, Buonocore M, et al. Usefulness of BFB/EMG in facial palsy rehabilitation. Disabil Rehabil. 2005;27:809 – 815. 17. Targan RS, Alon G, Kay SL. Effect of long-term electrical stimulation on motor recovery and improvement of clinical residuals in patients with unresolved facial nerve palsy. Otolaryngol Head Neck Surg. 2000;122: 246 –252. 18. Coulson S, Croxon G. Facial nerve rehabilitation—the role of physiotherapy. Aus J Otolaryngol. 1994;1:418 – 421. 19. Rose EH. Autogenous fascia lata grafts: clinical applications in reanimation of the totally or partially paralyzed face. Plast Reconstr Surg. 2005;116:20 –32. 20. VanSwearingen JM, Brach JS. Validation of a treatment-based classification system for individuals with facial neuromotor disorders. Phys Ther. 1998;78:678 – 689.
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Rehabilitation After Facial Reanimation Surgery
21. Crumley RL. Mechanisms of synkinesis. Laryngoscope. 1979;89:1847–1854. 22. Kang TS, Vrabec JT, Giddings N, et al. Facial nerve grading systems (1985–2002): beyond the House-Brackmann Scale. Otol Neurotol. 2002; 23:767–771. 23. House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg. 1985;93:146 –147. 24. Smith IM, Murray JA, et al. A comparison of facial grading systems. Clin Otolaryngol Allied Sci. 1992;17:303–307. 25. Croxson G, May M, Mester SJ. Grading facial nerve function: HouseBrackmann vs Burres-Fisch methods. Am J Otol. 1990;11:240 –246. 26. Berg T, Jonsson L, Engstrom M. Agreement between the Sunnybrook, House-Brackmann, and Yanagihara facial nerve grading systems in Bell’s palsy. Otol Neurotol. 2004;25:1020 –1026. 27. Coulson SE, O’Dwyer NJ, Adams RD, et al. Expression of emotion and quality of life after facial nerve paralysis. Otol Neurotol. 2004;25:1014 –1019. 28. Hu W, Ross B, Nedzelski J. Reliability of the Sunnybrook Facial Grading System by novice users. J Otolaryngol. 2001;30:208 –211. 29. Ross BG, Fradet G, Nedzelski JM. Development of a sensitive clinical facial grading system. Otolaryngol Head Neck Surg. 1996;114:380 –386. 30. Coulson SE, Croxson GR, Adams RD, et al. Reliability of the “Sydney,” “Sunnybrook,” and “House-Brackmann” facial grading systems to assess voluntary movement and synkinesis after facial nerve paralysis. Otolaryngol Head Neck Surg. 2005;132:543–549. 31. Yanagihara N, Muakami S. New Horizons in Facial Nerve Research and Facial Expression. The Hague, Netherlands: Kugler Publications; 1998. 32. Kanerva M, Poussa T, Pitka¨ranta A. Sunnybrook and House-Brackmann facial grading systems: intrarater repeatability and interrater agreement. Otolaryngol Head Neck Surg. 2006;135:865– 871. 33. Balliet R, Shinn JB, Bacy-Y-Rita P. Facial paralysis rehabilitation: retraining selective muscle control. Int Rehabil Med. 1982;4:67–74. 34. Hyva¨rinen A, Tarkka I, Mervaala E, et al. Cutaneous electrical stimulation treatment in unresolved facial nerve paralysis: an exploratory study. Am J Phys Med Rehabil. 2008;87:992–997. 35. Golaszewski S, Kremser C, Wagner M, et al. Functional magnetic resonance imaging of the human motor cortex before and after wholehand afferent electrical stimulation. Scand J Rehabil Med. 1999;31:165– 173. 36. Dimitrijevic´ MM, Stokic´ DS, Wawro AW, et al. Modification of motor control of wrist extension by mesh-glove electrical afferent stimulation in stroke patients. Arch Phys Med Rehabil. 1996;77:252–258. 37. Teixeira LJ, Soares BGdO, Vieira VP, et al. Physical therapy for Bell’s palsy (idiopathic facial paralysis). Cochrane Database Syst Rev. 2008; 3:CD006283. 38. Johnson PJ, Bajaj-Luthra A, Llull R, et al. Quantitative facial motion analysis after functional free muscle reanimation procedures. Plast Reconstr Surg. 1997;100:1710 –1722. 39. Fukuda M, Oishi M, Kawaguchi T, et al. Etiopathological factors related to hydrocephalus associated with vestibular schwannoma. Neurosurgery. 2007;61:1186 –1193. 40. Magee DJ. Orthopedic Physical Assessment. 3rd ed. Philadelphia, PA: W.B. Saunders; 1997. 41. Hislop HJ, Montgomery J. Daniels and Worthington’s Muscle Testing. 7th ed. Philadelphia, PA: W.B. Saunders; 2002. 42. Zuther JE. Lymphedema Management: The Comprehensive Guide for Practitioners. New York, NY: Thieme; 2005. 43. American Physical Therapy Association. Guide to physical therapist practice. 2nd ed. Phys Ther. 2001;81:s269 –s286. 44. Manktelow RT, Zuker RM, Tomat LR. Facial paralysis measurement with a handheld ruler. Plast Reconstr Surg. 2008;121:435– 442. 45. Schmidt, RA. Motor learning principles in physical therapy. In: Lister MJ, ed. Contemporary Management of Motor Control Problems: Proceedings of the II-STEP Conference. Alexandria, VA: Foundation for Physical Therapy; 1991:49 – 63. 46. Paletz JL, Manktelow RT, Chanban R. The shape of a normal smile: implications for facial paralysis reconstruction. Plast Reconstr Surg. 1994;93:784 –791.
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DEPARTMENTS
Book Reviews Sisto SueAnn, Druin Erica, and Sliwinski Martha Macht. Spinal Cord Injuries: Management and Rehabilitation. St. Louis: Mosby Elsevier, 2008; 552 pp, ISBN: 978-0-323-00699-6. $79.95 This recently published textbook is aimed at a broad interdisciplinary audience, including physical and occupational therapists, nurses, physicians, rehabilitation professionals, psychologists, and case managers. The authors state that it is also meant to provide a useful resource for patients and families. The 55 contributors include experienced authors, researchers, and expert clinicians. The content is organized to follow a progression of the individual through the various stages of rehabilitation to community reentry. Content is organized in a fashion that progresses through specific steps in the care of individuals with spinal cord injury (SCI), beginning with perspectives from medicine, nursing, and respiratory care. Related to physical therapy, the use of standardized outcome measurements in everyday clinical practice is emphasized in the Evaluation chapter, something that should be useful to clinicians. A useful feature of this book is that as functional skills are presented and discussed, the authors address how they would be executed by someone with either a complete or incomplete SCI. Illustrations and pictures augment the detailed text descriptions of techniques that are unique to this population. Topics that would be expected in a comprehensive reference of SCI rehabilitation are included (eg, evidence related to SCI rehabilitation, medical management, complications, respiratory treatment, psychological adjustment, transfers and activities of daily living, and mobility training including wheelchair skills and ambulation). Additional topics included are challenges related to community reintegration such as assistive technology, fitness and exercise, transportation, aging with an SCI, and quality of life. “People first language” is used throughout the book. Excerpts of thoughts and feelings from those living with an SCI are included in each chapter. Each chapter includes tables that highlight key points. “Clinical notes” included throughout the book emphasize important points and are easy to find. The case study examples included with each chapter are presented using the format outlined in the Guide to Physical Therapist Practice and, in combination with the review questions, emphasize critical thinking and reflection. Each chapter includes an extensive list of current references, and more than 500 illustrations are used to enhance the material presented in the book. A companion DVD is included, which provides visual examples of functional skill training typically performed during rehabilitation. The viewer is able to see both the performance of the patient and the techniques used by the therapist for 38 different functional skills (each 1–2 minutes in length) as they are performed by different patients of varying skill levels. The DVD is easy to navigate, and the narration provides step by step trainer tips as each skill is demonstrated. Overall, the DVD is an excellent adjunct to the textbook. This book provides a comprehensive, up-to-date resource for readers interested in reviewing the broad spectrum of SCI rehabilitation and community reintegration. Some information overlaps between the Nursing and Medical Management chapters. Future editions of this text could include updated versions of SCI-specific outcome measures and address psychometrics of outcome measures. This textbook will be useful for anyone entering the SCI rehabili-
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tation field and for the experienced clinician wishing to review specific aspects of care. Mary Schmidt Read, PT, DPT, MS Magee Rehabilitation Philadelphia, Pennsylvania
Lisa Harvey. Management of Spinal Cord Injuries: A Guide for Physiotherapists. Philadelphia: Churchill Livingstone, 2008; 297 pp, ISBN: 978-0-443-06858-4. $72.95 This new textbook is intended for students of physical therapy (PT) or physical therapists who have not worked extensively with people with spinal cord injury (SCI). The book is divided into three major and two smaller sections. The first section (two chapters) includes a review of spinal cord anatomy and a comprehensive description of the American Spinal Injury Association (ASIA) classification system. A short summary of several common complications that interfere with rehabilitation after SCI is included. Although the author’s stated intent is to give a brief overview of these complications, this section lacks adequate explanations of their pathophysiology and their implications for rehabilitation. Also included in this portion of the book is a discussion of patient management within the framework of the International Classification of Function and Disability (ICF). Goal setting and predicting independence according to level of injury are both addressed within the context of the ICF model. In subsequent parts of the book, Harvey acknowledges the variability among patients with the same ASIA classification; however, this early chapter is somewhat simplistic in its descriptions of potential functional outcomes. This chapter contains a very useful summary of several standardized tools for assessing activity and participation in the SCI population. The second section of the book (four chapters) is devoted to the descriptions of basic mobility skills for the person with SCI, including transfers, bed mobility, wheelchair mobility, ambulation, and upper extremity function. The skills are well described and accompanied by valuable drawings. Each skill is further divided into subtasks, and each subtask is supplemented by suggested strategies for practice. This is an excellent section for new therapists because it also supports the development of realistic short-term goals. The third section (six chapters) of this book addresses impairments seen in people with SCI and includes chapters on training of motor tasks, strength training, contracture management, pain management, respiratory management, and cardiovascular fitness training. The impairments are presented in terms of their impact on mobility and their influence on general well-being throughout life. This section also describes general strategies for training that can be applied to all mobility skills, making it extremely useful in clinical problem solving. Harvey’s fourth section, a single chapter on wheelchair prescription, is basic but contains sufficient information related to prescribing a manual wheelchair. The information presented on power wheelchairs is very brief, thus the therapist will need to turn to additional sources on power mobility. The final section of this book JNPT • Volume 34, March 2010
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consists of a very short (3 page) chapter on evidence-based PT; this information could have been integrated into the other chapters. This textbook is appropriate for the entry-level therapist; however, the advanced clinician who is looking for more detail will need to refer to additional sources. This book focuses almost exclusively on direct PT interventions and management, largely omitting other relevant topics such as psychosocial issues facing people with SCI, or bowel and bladder management. It does not include a CD, though it is associated with a Web site containing videos that demonstrate mobility skills for people with SCI. Finally, this textbook would benefit from inclusion of case studies to promote clinical decision making. Sondra G. Siegel, PT, PhD Program in Physical Therapy Husson University Bangor, Maine
Edelle Field-Fote. Spinal Cord Injury Rehabilitation. Philadelphia: F.A. Davis Co; 2009; 592 pages, ISBN-13: 978-0-80361717-9. $88.95 This new textbook is the latest addition to the Contemporary Perspectives in Rehabilitation series and is written for both practicing clinicians and physical therapy students. The textbook is organized into three sections and 24 chapters. Section one (chapters 1–5) addresses both the basic and applied sciences of spinal cord injury (SCI). Specific topics covered in this section include a review of current animal models of SCI, musculoskeletal plasticity, current clinical trials, and neuroprosthetics. Section 2 (chapters 6 –18) addresses the restoration of function after SCI. Specific topics covered in this section include approaches to improve mobility, upper extremity function, lower extremity func-
Departments
tion, psychological wellness, respiratory and cardiovascular health, bowel and bladder function, pain, and spasticity. Section 3 (chapters 19 –24) addresses special topics that are of great importance to individuals living with SCI, yet usually receive little attention from clinicians. Specific topics covered in this section include adaptive sports, adaptive driving, assistive technology, sexuality, and fertility. In addition to bringing her considerable clinical and scientific knowledge to the table, the author assembled a top notch group of contributors (a “who’s who in SCI management” according to Steven Wolf, PhD, PT, FAPTA, FAHA, who wrote the foreword). Each chapter is written by experts in their respective fields and lays out a comprehensive, state of the art, evidence-based approach to SCI rehabilitation. All of the chapters have well-defined objectives, an outline, a summary, and review questions to help with reader comprehension and retention of the information. In addition, many chapters effectively use case studies to emphasize clinical relevance and promote evidence-based clinical decision making. Shortcomings of this text include (1) some issues with flow and overlap/repetition between chapters, commonly seen in textbooks with multiple contributors; (2) some out of focus and/or inadequately labeled figures (especially for entry level student readers); and (3) the lack of additional DVD or web-based resources to augment the written text. However, this book is clearly a necessary addition to the library of all physical therapists who treat or plan to treat individuals with spinal cord injuries. It is also a valuable resource to be incorporated into entry level DPT neurorehabilitation coursework. James V. Lynskey, PT, PhD Department of Physical Therapy A.T. Still University Mesa, Arizona
Note from the Reviews and Abstracts Editor and the Editor-in-Chief: As we went to press with this issue of JNPT, we learned that a fourth SCI rehabilitation text has just been published: Somers, Martha Freeman. Spinal Cord Injury Functional Rehabilitation, 3rd edition. Upper Saddle River, NJ: Pearson Education, Inc; 2010. 464 pages. ISBN-13: 978-0-13-159866-9. $73.33 We regret that we did not know of this publication in time to include a review of this text in the current issue of JNPT. However, we will review this text in a future issue of JNPT.
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PRESIDENT’S PERSPECTIVE
Evidence for Physical Therapist Practice: How Can We Reconcile Clinical Guidelines and Patient-Centered Care? Katherine J. Sullivan, PT, PhD
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he use of clinical guidelines has become the prevailing method for guiding healthcare professional practice throughout the world.1 Clinical practice guidelines (CPGs) are developed to improve the process and outcomes of healthcare, whereas systematic reviews (SRs) use extensive literature search with selection and critical appraisal of primary research to provide quantitative summaries from high-quality clinical trials.2 The SRs are considered to be the highest level of research evidence in the evidence-based practice (EBP) model. The use of an EBP model is a widely adopted tenet of physical therapist practice and education today; however, despite the apparent wide-spread acceptance, the actual adoption of EBP within clinical physical therapy practice is limited.3 Most physical therapists are familiar with the definition of EBP as the interplay between application of the best available research evidence, clinical expertise, and the patient’s perspective.4 However, a recent question on the neuromuscular listserve (
[email protected]) revealed several issues that may reflect the potential conflict between patient-centered care along with CPGs, and SRs, which are critical resources for the therapist who is attempting to practice with an evidence-based approach. A recent editorial by Kwakkel5 reinforces several important principles of evidence-based practice in neurorehabilitation. He states that healthcare professionals should address patient-identified problems and set realistic goals based on controlled clinical trials with high methodological quality. Although many clinicians are willing to meet this expectation, the challenge for the physical therapist in the clinic is to efficiently access the best available research evidence based on patient diagnoses, disease severity, and stage of disease progress. One solution is to access CPG and SR summaries of research evidence. This is the most pragmatic solution for clinicians to efficiently access research evidence for their daily practice.6 CPGs and SRs are most helpful to the clinician if intervention effects are reported with patient-related factors such as severity and disease/injury progression (ie, acute, subacute, or chronic) so that clinicians can establish a functional prognosis that is most relevant to their individual patient. CPGs have both benefits and limitations. The benefits of CPGs to clinicians and healthcare providers are that President, Neurology Section. Address correspondence to: Katherine J. Sullivan, E-mail:
[email protected] Copyright © 2010 Neurology Section, APTA ISSN: 1557-0576/10/3401-0052 DOI: 10.1097/NPT.0b013e3181d055c2
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clinical guidelines can improve quality of care by updating outdated practices, decreasing unwarranted variation in clinical settings, and providing some level of standardization between clinicians, institutions, and regions of the country. On the other hand, CPGs can have substantial limitations. Recommendations in guidelines can be incorrect or out of date. Timely and in-depth updates of SRs (an essential element of CPGs) can be delayed or incomplete if the development group lacks resources. Guidelines, by design, incorporate clinical expertise; thus, the expert panel is inherently biased by their own opinions, clinical experiences, and potential conflicts of interest.7 Finally, CPG recommendations include SRs that summarize evidence from randomized controlled trials (RCTs) that are designed to answer specific questions on intervention effectiveness, under standardized conditions, with rigid exclusion and inclusion criteria to decrease variability in the defined population that is studied. Thus, recommendations from a CPG may accurately reflect the characteristics of a group of patients but may not reflect the priorities of an individual patient. In addition to the importance of basing rehabilitation goals on evidence from controlled clinical trials, Kwakkel5 emphasizes the importance of appropriate selection of outcome measures for neurorehabilitation research. The World Health Organization’s International Classification of Functioning, Disability, and Health (ICF)8 framework is an example of a framework developed to improve communication between care providers. This framework has been embraced by the international rehabilitation community and is gaining rapid adoption in the United States. The ICF is an effective model for demonstrating how multiple factors impact patient perspective such as the impact of a health condition on body function and structures, activities, and participation. In addition, the ICF includes modifying influences (ie, barrier or a facilitator to goal achievement) on individual outcomes such as one’s personal contextual factors (eg, sex, age, coping style, and comorbidities) or environmental contextual factors (eg, family support, socioeconomic status, and access to healthcare). However, rehabilitation RCTs usually do not report the influence of contextual factors on patient outcomes but typically use outcome variables selected to detect treatment effects. For example, common measures used in neurorehabilitation RCTs include measures such as the Barthel Index, modified Rankin Scale, instrumental activities of daily living, walking velocity, or six-minute walk distance, which are considered “activity” measures in the ICF framework. JNPT • Volume 34, March 2010
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Activity measures may be effective for RCTs that compare effectiveness of rehabilitation interventions. However, an activity measure may not reflect what is most important to an individual patient or their family members. Hence, for the clinician attempting to use an evidencebased approach, two potential conflicts arise from the recommendations by Kwakkel. First, research evidence for the therapist is often derived from high-quality, controlled trials in which the selection of outcome measures is based on the research question and not a clinical question. Thus, SRs or CPGs often are not sufficiently patient-specific to be useful for physical therapist care that is provided to an individual patient.7 The second conflict for the clinician practicing using an evidence-based approach arises from the mismatch between the research evidence and the patient’s perspective. Typically, the outcomes of interest to the patient relates to daily functions such as returning to work or school, being able to resume caring for the family, or being less of a burden on family members. How does the physical therapist resolve the conflict between research evidence from clinical recommendations in CPGs or SRs and patient-centered care where the patient’s perspective and multiple interrelated factors are addressed between the patient, their family, and the therapist? How can the rehabilitation scientists conduct clinical trials in rehabilitation that are relevant to the clinician and their patient? As rehabilitation professionals, physical therapist, and other members of the rehabilitation team provide a very complex intervention that extends beyond that which can be extracted from a CPG or SR. According to Whyte et al,9 the complexity of the rehabilitation process needs a more systematic and phased approach to increase the likelihood that clinical rehabilitation research is well designed and implemented. Furthermore, the relevance of rehabilitation research needs to occur at the level of the person not the therapy. Thus, the ICF model is not only the most appropriate framework for outcome selection but also is the only framework that addresses the patient’s perspective (ie, the person with disability and the treatment recipient) compared with the researcher’s perspective.10 Physical therapists assess the interaction between individuals and their healthcare needs related to movement dysfunction. The most meaningful outcomes for our patients with physical disability are to maximize their participation and health.Based on the current state of evidence in rehabil-
© 2010 Neurology Section, APTA
President’s Perspective
itation research, the best research evidence to be gleaned from rehabilitation RCTs is to derive principles of therapeutic delivery that can guide therapists as they interact with their patient to make an informed, shared decision about the best plan of care to meet individual patient needs. The clinician who uses an evidence-based approach applies the current principles that seem to be supported by current understanding of neuroplasticity and learning. Thus, interventions that involve the acquisition or reacquisition of motor skills that are applied with specificity and intensity and dosed to meet the therapeutic outcome determined by the physical therapist (ie, strength, endurance, and functional training) are more effective than the interventions typically done in the past. The responsibility of physical therapists is to read CPGs, SRs, and well-designed RCTs to derive therapeutic principles to guide practice; it is the responsibility of all healthcare professionals to be informed. Thus, the wellinformed, clinician takes the evidence from the best available research, the perspectives and realities of the real world in which their patients live in, and applies their clinical expertise to take care of a person with movement dysfunction; one individual at a time. REFERENCES 1. Woolf SH, Grol R, Hutchinson A, et al. Clinical guidelines: potential benefits, limitations, and harms of clinical guidelines. BMJ. 1999;318: 527–530. 2. Cook DJ, Greengold NL, Ellrodt AG, et al. The relation between systematic reviews and practice guidelines. Ann Intern Med. 1997;127: 210 –216. 3. Salbach NM, Jaglal SB, Korner-Bitensky N, et al. Practitioner and organizational barriers to evidence-based practice of physical therapists for people with stroke. Phys Ther. 2007;87:1284 –1303. 4. Straus SE. Evidence-Based Medicine: How to Practice and Teach EBM. Edinburgh/New York: Elsevier/Churchill Livingstone; 2005. 5. Kwakkel G. Towards integrative neurorehabilitation science. Physiother Res Int. 2009;14:137–146. 6. Tilson JK, Settle SM, Sullivan KJ. Application of evidence-based practice strategies: current trends in walking recovery interventions poststroke. Topics Stroke Rehabil. 2008;15:227–246. 7. Shaneyfelt TM, Centor RM. Reassessment of clinical practice guidelines: go gently into that good night. JAMA. 2009;301:868 – 869. 8. World Health Organization. International Classification of Functioning, Disability and Health: ICF. Geneva, Switzerland: WHO; 2001. 9. Whyte J, Gordon W, Gonzalez Rothi LJ. A phased developmental approach to neurorehabilitation research: the science of knowledge building. Arch Phys Med Rehabil. 2009;90:S3–S10. 10. Brown M. Perspectives on outcome: what disability insiders and outsiders each bring to the assessment table. Arch Phys Med Rehabil. 2009; 90:S36 –S40.
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SECTION NEWS & NOTES
Neurology Section Awards
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he following individuals were recognized by the Neurology Section at the Combined Sections Meeting in San Diego, CA, February 2010.
Service to the Section Award Dorian Rose, PT, PhD Any Neurology Section member who has attended the Combined Sections Meeting in the past 15 years has benefited from the efforts of Dorian Rose. Perhaps you saw her as she scooted from room to room making sure everything was running smoothly, or she may have helped you with the onsite preparations for your talk, or perhaps you simply attended and were amazed by the great speakers and awesome programming. Serving as a member of the Program Committee since 1994 and then as Chair of the committee since 2005, Dorian has left her mark on all of us. During this time, she also assisted section members in less visible ways, including as a reviewer for JNPT, a member of the III-Step Dissemination Task Force, and a member of the nominating committee from 1997 to 2000. With her charming sense of humor and inimitable style, Dorian Rose has given outstanding service to the Section, and this award is but a small gesture of our great appreciation.
Clinical Excellence Award Kathleen “Kathie” Klerk, PT Kathie is an internationally recognized expert in the physical therapy for individuals with spinal cord injury. As the Chief of the Spinal Cord Injury Unit at Miami’s Jackson Memorial Hospital for more than 30 years (since 1977), countless individuals with spinal cord injury and their family members have benefitted from Kathie’s experience. Throughout these years, Kathie has also mentored innumerable others to disseminate her clinical expertise. As one of the nominators noted, “in clinical practice, one sometimes encounters questions for which there are no answers in a textbook or article, questions that can only be Copyright © 2010 Neurology Section, APTA ISSN: 1557-0576/10/3401-0054 DOI: 10.1097/NPT.0b013e3181d48abc
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answered by someone with the broad knowledge base that comes from a long history of dedicated clinical experience, someone like Kathie Klerk.” Her clear thinking, insightfulness, and creativity in addressing clinical issues are an inspiration to physical therapists and others who work with individuals with spinal cord injury.
Excellence in Clinical Education Award Beth Fisher, PT, PhD Beth has been instrumental in guiding many future physical therapists and neurologic clinical specialists in developing their skills in neurologic physical therapy. With more than 20 years of experience in treating individuals with neurologic disorders at Rancho Los Amigos National Rehabilitation Center and teaching clinical management of these disorders at University of Southern California, Beth’s influence has been long and far reaching. She has lectured and taught many courses nationwide on the treatment of the neuromotor disorders and has presented numerous times at scientific meetings on the local, national, and international level. She was instrumental in starting the Neurologic Physical Therapy Residency program at the University of Southern California and in getting the program credentialed by the APTA, only the second such program to earn that status and the first within a university setting.
Student Research Awards Post-Professional Student: Shilpa Patil, PT, NCS, University of Florida For the study entitled: Unilateral Paretic Limb Power Training Produces Bilateral Locomotor Effects Post-Stroke, conducted by Shilpa Patil, Ilse Jonkers, and Carolynn Patten. Professional Students: Marissa Schaeuble, MS, ATC, and Joy Resetar, BA, University of Indianapolis For the study entitled: Gait Characteristics in Persons with Chronic Stroke Classified as Limited and Full Community Ambulators, conducted by Marissa Schaeuble, Joy Resatar, Michelle Dumit, Jeannie Hartley, Kendall Schultz, Peter Rundquist, and Margaret Finley.
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DEPARTMENT
Thank You to JNPT 2009 Reviewers The work of reviewing is essential to the advancement of neurologic physical therapy practice and science. We are grateful to the following individuals who shared their knowledge and expertise by serving as reviewers in 2009.
Nicole Elizabeth Acerra, PT, PhD Lucinda Baker, PT, PhD Theresa Bernsen, PT, MA Mary Tischio Blackinton, PT, EdD Susy Braun, PT, PhD Laura Busick, PT, MS, DPT, NCS Phil Chilibeck, PhD Jennifer Braswell Christy, PT, PhD Carmen Cirstea, MD, PhD Helen Cohen, OTR, EdD Evan Cohen, PT, MA, NCS Tracey Collins, PT, PhD Rachel Cowan, PhD Beth Crowner, DPT, NCS Kathleen Cullen, PhD Vanina Dal Bello Haas, PT, PhD Shannon de l’Etoile, PhD Judy Deutsch, PT, PhD Ruthy Dickstein, PT, DSc Kari Dunning, PT, PhD Gammon Earhart, PT, PhD Terry Ellis, PT, PhD, NCS Lisa Farrell, PT, PhD Nancy Fell, PT, PhD Dennis Fell, PT, MD Daniel Ferris, PhD Beth Fisher, PT, PhD Julaine Florence, PT, DPT Cheryl Ford Smith, PT, MS, NCS Bo Foreman, PT, PhD George Fulk, PT, PhD Kenda Fuller, PT, NCS Meryl Roth Gersh, PT, PhD Laura Gilchrist, PT, PhD Diana Glendinning, PT, PhD Joyce Rios-Gomes, PT Phyllis Guarrera-Bowlby, PT, Med, PCS Kimberly Harbst, PT, PhD Cathy Harro, PT, MS, NCS Lisa Harvey, PT, PhD
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Jennifer Hastings, PT, PhD Lois Hedman, PT, MS Susan Herdman, PT, PhD Larisa Hoffman, PT, PhD T. George Hornby, PT, PhD Arun Jayaraman, PT, PhD Therese Johnston, PT, PhD Herb Karpatkin, PT, NCS Valerie Kelly, PT, PhD Teresa Jacobson Kimberley, PT, PhD Patricia Kluding, PT, PhD Tania Lam, PT, PhD David Lehman, PT, PhD Stephanie Lew, SPT Mike Lewek, PT, PhD Michele Lewis, MPT Yang Hua Lin, PhD Wen Ling, PT, PhD Michael Majsak, PT, EdD Francine Malouin, PT, PhD Avril Mansfield, PhD Karen McCulloch, PT, PhD, NCS Vicki Mercer, PT, PhD Alma Merians, PT, PhD Anat Mirelman, PT, PhD James Moore, PT, PhD, PCS Laura Morris, PT, NCS Sarah Morrison, PT Susanne Morton, PT, PhD Kurt Mossberg, PT, PhD Katharina Mueller, PhD Roberta Newton, PT, PhD Susan Perry, PT, DPT, NCS Samuel Pierce, PT, PhD, NCS Patricia Pohl, PT, PhD Barbara Quaney, PT, PhD Lori Quinn, PT, EdD Darcy Reisman, PT, PhD Rose Marie Rine, PT, PhD Mark Rogers, PT, PhD
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Margaret Roller, PT, MS, DPT Dorian Rose, PT, PhD Sandy Ross, DPT, MHS, PCS Matthew Scherer, PT, PhD Brian Schilling, PhD Michael Schubert, PT, PhD Neil Shepard, PhD Catherine Siengsukon, PT, PhD Martha Sliwinski, PT, PhD Britta Smith, PT, MMSc Stephen Sprigle, PhD James Stephens, PT, PhD
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Jane Sullivan, PT, DHS Matthew Taylor, PT, PhD Gregory Thielman, PT, EdD Julie Tilson, PT, DPT, NCS Suzanne Tinsley, PT, PhD Eugene Tunik, PT, PhD Eric Vidoni, PT, PhD Joanne Wagner, PT, PhD Susan Whitney, PT, PhD Patricia Winkler, PT, DSc Jonathan Wolpaw, PhD Diane Wrisley, PT, PhD
JNPT • Volume 34, March 2010
DEPARTMENTS
JNPT Thanks Retiring Electronic Media Editor Jim Cavanaugh, PT, PhD In recent years, there has been an explosion of new electronic media options available for augmenting the print version of journals. Dr. Jim Cavanaugh has been instrumental in shepherding JNPT into this new era of information technology. Since his appointment in 2006, Dr. Cavanaugh has served the Editorial Board and the JNPT readers with his innovative and resourceful perspectives on the use of electronic media, and his capable talents in the technical aspects of his role. Dr. Cavanaugh now prepares to undertake some new and exciting challenges in his professional life, and JNPT bids him a fond farewell. We look forward to his continued involvement with the Section on Neurology.
New Features Available on Your JNPT Website Enjoy all the benefits of your online journal at www.JNPT.org
My Favorites: Save important items to your My Favorites folder. Mobile View: Read your journal on the go with the Mobile View. Export Images to Microsoft® PowerPoint™: Create one-click presentations with Export Images to Microsoft威 PowerPoint™. E-mail a Colleague: Share key articles with E-mail a Colleague.
Copyright © 2010 Neurology Section, APTA ISSN: 1557-0576/10/3401-0057 DOI: 10.1097/NPT.0b013e3181d0ba25
JNPT • Volume 34, March 2010
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