Muscular and gait abnormalities in persons with early onset multiple sclerosis

Muscular and gait abnormalities are common complaints among persons with multiple sclerosis, even in the early stages of the disease. Our aim was to evaluate peak isometric strength, major lower limb muscle fatigue, and spatiotemporal gait parameters in persons with a first neurological event suggestive of multiple sclerosis, defined as a clinically isolated syndrome (CIS).

Fifty-two individuals (36 women, 16 men) with CIS, aged 35.2 (SD = 7.2) with an Expanded Disability Status Scale score of 1.7 (SD = 1.3), participated in the study. Peak isometric torque and fatigue index were measured at the knee and ankle bilaterally as well spatiotemporal parameters of gait. Twenty-eight age- and gender-matched healthy subjects served as controls.

The CIS group demonstrated increased muscle fatigue, and greater ankle muscle torque asymmetries compared with the control group. The overall fatigue index scores intensified on an average of 40% in the CIS group (27% vs 19% in controls). Participants in the CIS group walked with a larger step length difference, longer step time difference, wider base of support, and prolonged double support period compared with the control group. Positive correlations were identified between double support period and some muscle parameters.

At this early stage of clinically isolated syndrome, evidence of a reduction in lower limb motor performance can already be identified. The possibility of early identification and potential for developing an intervention program that may alter treatment outcome warrants further exploration.