Gait and cognitive disorders are frequently reported in patients with multiple sclerosis, leading to decreased quality of live. The objective of this prospective study was to examine the impact of four specific cognitive tasks on gait in patients with relapsing-remitting multiple sclerosis (RRMS) with low disability.
The mean±standard deviation (SD) of walking speed, stride time and stride length were measured in 25 patients with RRMS (age: 39.46±8.32years; Expanded Disability Status Scale [EDSS] score: 1.90±1.01; disease duration: 5.62±5.12years) and in 25 age-matched controls. Gait was assessed during single task and while doing four different cognitive tasks (forward counting, backward counting, semantic verbal fluency, phonemic verbal fluency). Spatiotemporal gait parameters were recorded by a 12-camera optoelectronic system.
Patients walked slower and with a decrease stride length during the single task and the four dual tasks than controls, except for the condition of backward counting. RRMS patients and controls presented the same cognitive performances for the four conditions during walking. EDSS score was correlated with gait speed and stride length in single task, and in the dual tasks of the backward counting and phonemic fluency.
Quantitative gait assessment reveals subtle gait disorders in patients with low disability of relapsing-remitting multiple sclerosis. The impact of different cognitive domains on gait induces specific gait disturbances that highlight the strong interaction between gait and cognition.