Gait pattern in patients with different multiple sclerosis phenotypes

Abstract

Background: Gait pattern is frequently impaired in multiple sclerosis (MS), however gait characteristics in patients with different MS phenotypes have not been fully elucidated. Methods: We analyzed spatio-temporal gait pattern characteristics in patients with relapsing-remitting (RR, n=52) and primary-progressive (PP, n=18) MS in comparison with age-matched healthy controls (HC, n=40). All subjects performed a standardized simple walking task, a dual motor-motor task, a dual motor-mental task, and a triple combined motor-mental task at a GAITRite electronic walkway of 5.5 m active area. We measured: cycle time (CT), stride length (SL), swing time (ST), double support time (DST), gait velocity (GV) and calculated symmetry index (SI) for CT, SL and ST. Results: With each task performed, CT and DST in the total MS group were significantly longer while SL was significantly shorter and GV significantly lower than in HC. ST was similar in the total MS patient group and HC. In both MS patients and HC, CT and DST increased and SL and GV decreased over repeated assessments. Dual and triple tasks while walking influenced walking performance in both MS patients and HC. Although patients with PPMS differed significantly from those with RRMS in the majority of gait parameters, the subgroup analysis in patients matched for age and disability (Expanded Disability Status Scale Score -EDSS, 3.0-5.0) showed similar gait performance in RRMS and PPMS patients having the same level of disability, except for CT and ST-symmetry parameters that were more impaired in the PPMS group. The EDSS score correlated significantly with CT, DST, SL and GV, but no significant correlation was found with ST except at the triple combined motor-mental task. Conclusion: A disturbed gait pattern in MS patients with different MS phenotypes depends on disability and reflects a cognitive-motor interference.