Progress in determining the causes and treatment of multiple sclerosis

The cause of multiple sclerosis remains unknown after more than a century o f study. Unconfirmed work has once more indicated that a viral infection ma y be important In the aetiology of the disease, and there is considerable e vidence for an important genetic influence on disease susceptibility. The c linical course is as variable as that of any disease in medicine. Studies u sing serial magnetic resonance imaging have helped to define the disease co urse and response to experimental therapies. Although the predominant patho logical characteristic is myelin loss with preservation of axons, some stud ies recall classic descriptions that irreversible axonal destruction may oc cur, perhaps even in the early stages of the illness. There are now several , partially effective therapies for relapsing forms of multiple sclerosis a nd here I review progress in determining the timing and course of the Illne ss and the steps that need to be taken to identify more effective treatment s for this disease.