The relationship between relapse, impairment and disability in multiple sclerosis

Abstract

Our data suggest that motor pathways are relatively resistant to chronic impairment from acute relapse, whereas afferent pathways are more susceptible. This, in combination with prominent usage of the Expanded Disability Status Scale, which is dependent on mobility and motor function at higher scores, may explain the paradox between natural history studies that suggest relapses are irrelevant to long-term disability and shorter studies at lower disability levels suggesting relapses are responsible for disability accumulation.