Disease mechanisms in MS: Phases of disease improvement unrelated to relapses

摘要

In natural history studies of multiple sclerosis (MS), the evolution of disease is composed of two types of deterioration: subacute relapses (over days or weeks) and chronic insidious progression (over months and years). Subacute relapses are mainly caused by focal inflammation with myelin dysfunction, whereas additional neuro-degeneration is involved in the progressive course. Disease improvement—complete or incomplete—is traditionally dependent on the remission phase after relapses. Tremlett et al.1 now report quantitative data on frequent spontaneous improvements in disability of patients with MS in the absence of a relapse phase, suggesting that these events are part of the natural course of the disease.