Natural history of multiple sclerosis

The natural history of multiple sclerosis (MS) has been reviewed extensively. Since the introduction of disease-modifying treatments, such as interferon-beta, glatiramer acetate, and mitoxantrone, study of the natural history has become more than an academic issue as it influences the decision as to whether or not and when to initiate long-term treatments. Current understanding of MS pathogenesis suggests that axonal damage starts early in MS and that early intervention promises the benefit of preventing longterm disability. Clinical trials of MS are limited in duration given the time over which disability develops. Long-term benefit from these treatments remains to be established. Long-term benefit with minimal toxicity is optimized by treating patients who are at highest risk for an adverse outcome and are most likely to respond.