Prevalence of Walking-Related Motor Fatigue in Persons With Multiple Sclerosis: Decline in Walking Distance Induced by the 6-Minute Walk Test.

OBJECTIVE: To investigate the individual occurrence of walking-related motor fatigue in persons with multiple sclerosis (PwMS), according to disability level and disease phenotype.Study design This was a cross-sectional, multinational study.Participants They were 208 PwMS from 11 centers with Expanded Disability Status Scale (EDSS) scores up to 6.5. METHODS: The percentage change in distance walked (distance walked index, DWI) was calculated between minute 6 and 1 (DWI(6-1)) of the 6-Minute Walk Test (6MWT). Its magnitude was used to classify participants into 4 subgroups: (1) DWI(6-1)[≥5%], (2) DWI(6-1)[5%; -5%], (3) DWI(6-1)[-5%; > -15%], and (4) DWI(6-1)[≤-15%]. The latter group was labeled as having walking-related motor fatigue. PwMS were stratified into 5 subgroups based on the EDSS (0-2.5, 3-4, 4.5-5.5, 6, 6.5) and 3 subgroups based on MS phenotype (relapsing remitting [RR], primary progressive [PP], and secondary progressive [SP]). RESULTS: The DWI6-1was ≥5% in 16 PwMS (7.7%), between 5% and -5% in 70 PwMS (33.6%), between -5% and -15% in 58 PwMS (24%), and ≤-15% in 64 PwMS (30.8%). The prevalence of walking-related motor fatigue (DWI(6-1)[≤-15%]) was significantly higher among the progressive phenotype (PP = 50% and SP = 39%; RR = 15.6%) and PwMS with higher disability level (EDSS 4.5-5.5 = 48.3%, 6 = 46.3% and 6.5 = 51.5%, compared with EDSS 0-2.5 = 7.8% and 3-4 = 16.7%;P< .05). Stepwise multiple regression analysis indicated that EDSS, but not MS phenotype, explained a significant part of the variance in DWI(6-1)(R(2)= 0.086;P< .001). CONCLUSION: More than one-third of PwMS showed walking-related motor fatigue during the 6MWT, with its prevalence greatest in more disabled persons (up to 51%) and in those with progressive MS phenotype (up to 50%). Identification of walking-related motor fatigue may lead to better-tailored interventions.

Which walking capacity tests to use in multiple sclerosis? A multicentre study providing the basis for a core set.

BACKGROUND: Many different walking capacity test formats are being used. It is unclear whether walking speed, obtained from short tests, and walking distance, obtained from long tests, provide different clinical information. OBJECTIVES: To determine the differential effect of various short and long walk test formats on gait velocity, and the actual relationship between walking speed and walking distance in multiple sclerosis (MS) patients with diverse ambulation status. METHODS: A cross-sectional multicentre study design was applied. Ambulatory MS patients (Expanded Disability Status Scale (EDSS) 0-6.5; n = 189) were tested at 11 sites. Short tests consisted of the Timed 25-Foot Walk (static start, fastest speed) and 10-Metre Walk Test (dynamic start, usual and fastest speed). Long tests consisted of the 2- and 6-Minute Walk Tests (fastest speed). Subjects were divided into mild (EDSS 0-4; n = 99) or moderate (EDSS 4.5-6.5; n = 79) disability subgroups. RESULTS: In both subgroups, the start protocol, instructed pace and length of test led to significantly different gait velocities. Fastest walking speed and 6-Minute walking distance showed the strongest correlation (R (2) = 0.78 in mild and R (2) = 0.81 in moderate MS; p < 0.01). Short tests' relative estimation errors for 6-Minute walking distance were 8-12% in mildly and 15-16% in moderately affected subjects. Based on the 2-Minute Walk Test, estimation errors significantly reduced to approximately 5% in both subgroups. CONCLUSIONS: A single short test format at fastest speed accurately describes an MS patient's general walking capacity. For intervention studies, a long test is to be considered. We propose the Timed 25-Foot Walk and 2-Minute Walk Test as standards. Further research on responsiveness is needed.

Functional assessment of lower extremities in hereditary spastic paraplegia.

OBJECTIVES: To characterize the spasticity and range of motion (ROM) in patients with hereditary spastic paraplegia (HSP) and to correlate these parameters with walking speed. DESIGN: An observational population-based cohort study. SETTING: Patient data were acquired from a population-based epidemiologic study performed earlier in Estonia. PARTICIPANTS: Persons (N=46) (mean age, 50.1y) with clinically confirmed HSP diagnosis (mean duration, 20.9y) participated in the study. INTERVENTIONS: Active and passive ROMs were measured with a plastic 360 degrees goniometer. Spasticity was evaluated by using the modified Ashworth scale (MAS). The time it took a patient to walk 10m was recorded. MAIN OUTCOME MEASURES: Measurements included testing of active and passive ROM as a marker for mobility, the MAS for spasticity, and time to complete a 10-m walk. RESULTS: A higher degree of spasticity in hip muscles was associated with lower values of active ROM and slower walking. Walking speed was negatively correlated to disease duration and participant age. CONCLUSIONS: The present study provides analysis of the contributions of spasticity and ROM to walking speed in HSP, both factors negatively influence gait in persons with HSP.