Clinical profiling, manifestation and assessment of walking-related performance fatigability in persons with Multiple Sclerosis: a cross-sectional study

Abstract

Fatigue and walking difficulties are the most common symptoms in persons with Multiple Sclerosis (PwMS). Previous research recommended the six-minute walking test (6MWT) as an objective assessment for walking fatigability (WF) by calculating differences in walking distance between the first and last minute. For this study, 49 PwMS (EDSS 0-6) and 28 healthy controls (HC) performed a 6MWT twice. Short objective screening for spasticity, balance and strength was performed before, immediately after, and after 10, 20 and 30 minutes of the 6MWT. The severity of 11 common MS symptoms was rated on a 0-10 scale at the same time slots. By including a control group, it was shown that a DWI6-1'-10% was sufficient to state WF. The DWI during the 6MWT of PwMS showed a good test-retest reliability in the total MS group (ICC=0.76). Only the last minutes of the 6MWT showed significant differences between the groups in walking distance decline compared to minute 1, suggesting long walking tests are recommended to differentiate between WF and non-walking fatigability (NWF). Half of the MS patients showed WF, where it significantly manifested in gait impairments and muscle weakness. Most symptoms returned to baseline 10 minutes after the 6MWT. Further research is recommended to further investigate the clinical profile and underlying factors of WF with a larger sample size and better objective testing.