Clinical manifestation and perceived symptoms of walking-related performance fatigability in persons with multiple sclerosis

Fatigue and walking difficulties are common impairments and activity limitations in persons with multiple sclerosis (PwMS). Walking fatigability (WF) can be measured by a Distance Walked Index and is defined as a decline in walking distance of 10% or more during the six-minute walking test (6MWT). However, the clinical manifestation and perceived symptoms related to fatigability are still not well documented. Forty-nine PwMS [Expanded Disability Status Scale (EDSS) <= 6] and 28 healthy controls (HC) performed a 6MWT. The perceived severity of 11 common symptoms was rated on a visual analogue scale of 0-10 before, immediately after, and 10, 20 and 30 minutes after the 6MWT by means of the symptom inventory. Short motor impairment screening tests at baseline together with other descriptive measures were performed. Twenty pwMS were categorized in the WF group and were more disabled (EDSS: 4.16 +/- 1.41) than the non-walking fatigability group (n = 29, EDSS: 2.62 +/- 1.94). PwMS showed exacerbations of several perceived symptoms in MS, where most symptoms returned to baseline within 10 minutes after the walking test. The WF group showed significantly more muscle weakness and gait impairment, together with balance problems, and experienced an increase in spasticity, pain and dizziness after 6MWT. Our findings showed that perceived severity of symptoms are higher in pwMS presenting WF, and increase temporally after the 6MWT. Future research with quantitative measurement during and after walking is recommended.