gene arrays in pharmacogenomics

The Institute for MS Neuroscience

Outcome Measures for Gait

Susan E. Bennett, PT, EdD, NCS, MSCSClinical Associate Professor

University at Buffalo Director, MS Comprehensive Care Center

Jacobs Neurological Institute


Key Points of Discussion

Complexities of measuring gait in MS Existing measuresLimitations and strengths of existing measuresMeasurement differences based on setting (clinical vs. research)Validation studies


Gait Outcome Measures

Gait is an important outcome measure because it is a frequent functional limitation displayed by individuals with MSGait deviations often suggest a variety of underlying impairments

Weakness and spasticityBalanceAtaxia


Qualities of Gait Measures Desired

Validity and reliabilityEase of administration [does not require excessive training or materials to implement] Sensitivity and specificity Applicable in a variety of clinical environments [neurologists office, rehab clinic]


Complexities of Measuring Gait in MS

Gait may vary throughout the course of the day due to fatigue, spasticity and weakness Environments may trigger changes in gait performance [uneven surface, visual stimuli]

This may suggest the need for multiple measures of gait that would include speed, distance, fatigue, gait deviations, and falls risk


Gait Measures in MS

In a reviewing the literature the most common gait measures used in clinical assessment in MS are:EDSS (Expanded Disability Status Scale)Dynamic Gait Index25-Foot Walk TestSix-minute Walk TestTinetti Gait AssessmentRancho Los Amigos Gait Scale12-item MS Gait Scale


Gold Standard in MS

The EDSS which has been a gold standard in measurement in MS has a a major component of gait.

It is the most common gait scale used though the gait measure is limited to distance walked and utilization of an assistive device


EDSSConsidered a disability scale which includes ambulation criteria to assess global disability caused by MS. Ordinal scale from zero to ten with increasing increments of 0.5 as deficits increase.

Scores of 0 - 4.5 indicate that patients are “fully ambulatory.” Scores of 5.0 and above are indicative of ambulation deficits and other functional impairments.

Limitations Ambulation criteria are poorly defined—only in terms of distance walked and unilateral or bilateral assistive device. Falls risk, speed, indoor/outdoor setting, are not clarified. Qualitative changes in gait are not assessed Depending upon the practitioner, reliability can vary.


The EDSS quantifies disability in eight Functional Systems (FS) and allows neurologists to assign a Functional System Score (FSS) in each of these. The Functional Systems are:

• pyramidal • cerebellar • brainstem • sensory • bowel and bladder • visual • cerebral • other


EDSS

http://www.mult-sclerosis.org/expandeddisabilitystatusscale.html





Dynamic Gait Index

An 8-item ordinal scale that is reasonably quick and easy to administer, and inexpensive. Score is 0-24 range with scores below 19 correlating to higher falls risk. Assessment includes

Observation of gait and changes in gait withChange in gait speedAmbulation with head turns left/right and up/downambulation and 180° degree turnAmbulation while stepping over 2 objects and around 2 objects [figure 8 pattern]Ascending and descending 4 steps


DGI Limitations

The 8 items of gait overlap, and therefore are not mutually exclusive.

The effects of fatigue are not measured in the DGI due to the short walking distances.

Variation in assistive devices is not reflected in the scores obtained.


25’ Timed Walk

Most often initiated by neurologists, rather than by physical therapists, as part of the MS Functional Composite. Patient starts walking at command to begin, walks 25’, time recorded in secondsVariation may exist in command for gait speed [walk as fast as you can, or at your comfortable speed]Significant gait deviations or fatigue may not be observed25 feet may simply not be intense enough to see how gait is affected, nor does it assess the ability to modify gait.


Six Minute Walk Test

Originally developed for the cardiac rehab population, high inter- and intra-rater reliabilityPatient walks back and forth in a specified area for 6 minutes, the distance walked is recorded

Some clinicians perform a two-minute version of this test.Covers fatigue missed in shorter evaluations, although it may not be appropriate for those patients with severe fatigue. It will not account for:

changes over six minutes—for example, whether the first few minutes are faster than the last few. presence or absence of any gait defects, especially those that might appear later in the test.

A fairly long test can provide solid information if administered properly.


Tinetti Gait Scale

Originally developed to assess fall risk in the elderly, it has been used in many MS studies and is similar to the Dynamic Gait Index, It was combined with the Tinetti Balance Scale for composite scores of gait and balance. A 16-item test with binary scoring that examines specific aspects and phases of gait. Valid and reliable for elderly fallers. Several studies have shown Tinetti as a whole —combining balance and gait — reliable for the MS population, but reliability of the gait portion alone for MS patients has not yet been examined.


Tinetti Gait Assessment

http://www.ohsu.edu/sgimhartford/toolbox/TinettiBalanceAndGaitEvaluation.pdf





Rancho Los Amigos Gait Scale

Observational Analysis is performed by the majority of clinicians. It is something most physical therapists learn to conduct early in their training. A sample scale from Ranchos Los Amigos provides simple binary recordings [mild, moderate, severe] of deviations from normal gait. Observational analysis requires a good basic understanding of the gait cycle, so it may not be appropriate for those who have not received specific training in this area. There are also issues with poor inter-rater reliability, depending upon the training of the grader.


Rancho Los Amigos Gait Scale

http://moon.ouhsc.edu/dthompso/gait/knmatics/oga.htm




Self Assessment of Gait

Determining the patient’s perspective through a self-report scale can provide clinicians with valuable insight into a patient’s perception of his or her gaitThe 12 Item MS Walking ScaleScoring 1 = not at all, 5 = extremely


1In the past two weeks, how much has your MS ...

1. Limited your ability to walk? 1 2 3 4 5

2. Limited your ability to run? 1 2 3 4 5

3. Limited your ability to climb up and down stairs? 1 2 3 4 5

4. Made standing when doing things more difficult? 1 2 3 4 5

5. Limited your balance when standing or walking? 1 2 3 4 5

6. Limited how far you are able to walk? 1 2 3 4 5

7. Increased the effort needed for you to walk? 1 2 3 4 5

8. Made it necessary for you to use support when walking indoors (e.g., holding on to furniture, using a stick, etc.)?

1 2 3 4 5

9. Made it necessary for you to use support when walking outdoors (e.g., using a stick, a frame, etc.)? 2 3 4 5

10. Slowed down your walking? 1 2 3 4 5

11. Affected how smoothly you walk? 1 2 3 4 5

12. Made you concentrate on your walking? 1 2 3 4 5

Please check that you have circled ONE number for EACH question

© 2000 Neurological Outcome Measures Unit.


Consensus

Attendees agreed there is a need to know how these measures and variables behave in different settings, such as in-home versus clinical. Measures should also be continuous over a period of time and have strong psychometric properties. Space and safety have to be considered.


Consensus

We also debated other issues, such asSensitivity of measures for gait deviations in higher-functioning patientspros and cons of various additional measureshow many of these measures, in what combinations, should be utilized.


Consensus

We also agreed that for the present, we would focus on outcome measures versus assessments. Objective gait measures are very valuable, as they can show the impact of interventions.

The measures identified must be validated for the MS population. There will be a need for clinics to participate in validation studies.


Consensus

The 25-Foot Walk is now considered the standard, We next considered whether to add the Timed Up and Go (TUG) which was favored for its ease of administration and measure of ability to rise from a chair, walk, turn around and return to the chair. Though not a gait measure it was agreed that it had value in our population of patients The 12-item Walking Scale could easily be completed in a waiting room, so this scale could be added to the list of appropriate tools as well. Reporting falls also had to be incorporated. In the rehab setting, goals for reporting falls would be medical management, interdisciplinary communications, and documentation.


Consensus

Attendees tentatively agreed that in arehab setting

25-Foot WalkTimed Up and GO (TUG)Dynamic Gait Index (DGI) 2-Minute Walk A subjective report of the 12-Item MS Walking Scale

should be the tools initially included in a gaitoutcomes chart.


Video Demonstration

25’ walkTUGDGI2 minute walk


References

Eastlack, M.E., Arvidson, J., & Snyder-Mackler, L., et. al. (1991). Interrater reliability of videotaped observational gait analysis assessments. Physical Therapy, 71, 465-472. Krebs, D.E., Edelstein, J.E., & Fishman, S. (1985). Reliability of observational kinematic gait analysis. Physical Therapy, 65, 1027-1033. Professional Staff Association of Rancho Los Amigos Medical Center. (1989). Observational gait analysis handbook. Downey, CA: AuthorPerformance-oriented assessment of mobility problems in elderly patients. By Tinetti, M.E. Copyright* 1986 by Williams and Wilkins. Adapted with permission of Williams and Wilkins via the Copyright Clearance Center.


References

McConvey JL, Bennett SE, “Validity and Reliability of the Dynamic Gait Index in Multiple Sclerosis" Archives of Physical Medicine and Rehabilitation ” 2005, Jan;86 (1), 130-133Kurtzke, Neurology (1983) Hobart, JC Riazi, A. et al Measuring the impact of MS on walking ability: The 12 Item MS Walking Scale (MSWS-12) Neurology 2003;60:31-36 Finch E, Brooks D, Stratford P, Mayo N. Physical Rehabilitation Outcome Measures. 2nd ed: Canadian Physical Therapy Association; 2002.Goldman M, Ann Marrie R, Cohen J. Evaluation of the Six-minute Salk in Multiple Sclerosis Subjects and Healthy Controls. Multiple Sclerosis. October 17 2007.


References

Whitney SL. Marchetti GF. Schade A Wrisley The sensitivity and specificity of the Timed "Up & Go" and the Dynamic Gait Index for self-reported falls in persons with vestibular disorders.Journal of Vestibular Research. 14(5):397-409, 2004.Steffen TM. Hacker TA. Mollinger L. Age- and gender-related test performance in community-dwelling elderly people: Six-Minute Walk Test, Berg Balance Scale, Timed Up & Go Test, and gait speeds.[see comment].Comments Comment in: Phys Ther. 2002 Aug;82(8):826-7; author reply 827-8; PMID: 12147012 Physical Therapy. 82(2):128-37, 2002 Feb.

gene arrays in pharmacogenomics

Documents