Evaluation of the six-minute walk in multiple sclerosis subjects and healthy controls

• Published in: Multiple sclerosis Vol. 14; no. 3; pp. 383 - 390
• Main Authors: Goldman, Myla D, Marrie, Ruth Ann, Cohen, Jeffrey A
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.04.2008; Arnold; Sage Publications Ltd
• Subjects: Adult; Biological and medical sciences; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Disability Evaluation; Exercise Test - methods; Exercise Test - standards; Female; Gait; Health Status; Humans; Male; Medical sciences; Middle Aged; Multiple sclerosis and variants. Guillain barré syndrome and other inflammatory polyneuropathies. Leukoencephalitis; Multiple Sclerosis, Chronic Progressive - physiopathology; Multiple Sclerosis, Relapsing-Remitting - physiopathology; Muscle Fatigue; Neurology; Reproducibility of Results; Surveys and Questionnaires; Walking; motor fatigue; outcome measures; multiple sclerosis; six-minute walk; Evaluation; Nervous system diseases; Multiple sclerosis; Prognosis; Healthy subject; Central nervous system disease; Fatigue; Degenerative disease; Inflammatory disease
• ISSN: 1352-4585; 1477-0970
• DOI: 10.1177/1352458507082607

Objective To assess the characteristics of the 6-min walk (6MW) in multiple sclerosis (MS) subjects of varied disability, and controls. To assess the correlation of 6MW to subjective measures of fatigue, health status and ambulation using the modified fatigue impact scale (MFIS), short form-36 Health Questionnaire physical component score and MS walking scale (MSWS). Methods Forty MS expanded disability status scale [(EDSS) 0—6.5] and 20 control subjects were recruited from a MS outpatient clinic. Subjects completed survey material and three 6MWs with 1-h interval rest in a single study visit. Results There was no practice effect or fatigability with repeat 6MW tests with a one-h rest period between test sessions. The 6MW had excellent intra-[intraclass correlation coefficient (ICC) = 0.95] and inter-rater (ICC = 0.91) reliability. MS subjects demonstrated reduced 6MW distance and speed compared with controls (P < 0.0001). Within the MS population 6MW distance was significantly reduced with increasing disability (P = 0.05). Compared with the EDSS, the 6MW had a stronger correlation to subjective measures of ambulation and physical fatigue: MSWS (r = -0.81 versus 0.69) and MFISphy (0.66 versus 0.63). Conclusions The 6MW is a feasible, reproducible, and reliable measure in MS. MS subjects demonstrate motor fatigue in both 6MW distance and speed compared with controls. In MS subjects there is an inverse relationship between motor fatigue and disability. 6MW has a strong correlation to subjective measures of ambulation and physical fatigue. Multiple Sclerosis 2008; 14: 383—390. http://msj.sagepub.com