Natural history of multiple sclerosis

The natural history of prototypical MS at the population level is well established. Conversion to definite MS in patients who have clinically isolated demyelinating events is the subject of great interest in the context of several large clinical trials, and reasonable stratification of individual risk is possible in this context. The natural history of some of the more rare forms of IIDDs only recently are being elucidated. Most of the predictors of outcome are individually weak but a combination of initial demographic and clinical findings with measures of early disease activity and course evaluated clinically and with imaging can be used to predict outcome. Inasmuch as practicing clinicians need to be aware of the existence of benign cases and isolated IIDDs that never convert to definite MS, they also need to realize that for patients who have early deterioration, the long-term course likely is unfavorable and an aggressive approach to application of proven therapies is appropriate.This review emphasizes the importance of evaluating patient-specific factors to predict outcome and tailor therapy for the individual. But considering the imperfection of any of the current predictors of disease outcome, it is necessary to monitor patients with standard clinical measurements and, in research contexts, with increasingly sophisticated imaging and other tools. Hopefully, some of these newer modalities may prove more sensitive and predictive of clinically important consequences. There have been some promising developments in terms of predicting treatment response; they are limited, however, to short-term responses; predictors of long-term response have not yet been established. The MS community still is in need of better surrogate markers and predictors of treatment response and long-term outcome that can be instituted cost effectively into clinical management pathways. Research in the areas of genetics, immunology, and pathology of IIDDs promises to provide us with such markers in the future.