MULTIPLE SCLEROSIS

Multiple Sclerosis (M.S.) is one of the most common chronic neurologic disorders of young adults in North America and Europe affecting as many as 500,000 individuals in the United States alone. The disease was first described in detail by Jean M. Charcot, the father of French neurology. Despite intense investigation, its etiology and pathogenesis still remain obscure.^ Extensive epidemiologic data have clearly established that the prevalence of M.S. increases with latitude (a notable exception is Japan). Studies of immigrants to Israel have demonstrated a protective effect of moving to an area of lower prevalence if the move is made before the age of 15.̂ Whether this is due to a change in temperature or sanitation, or due to avoidance of early exposure to a prevalent virus remains the subject of widespread debate. A putative virus must be able to produce a disease with a long incubation period, with demyelination, and with exacerbations and remissions. No known virus has fulfilled all of these criteria. There have been several sporadic reports of virus isolation from M.S. brain. A modest rise in titer of IgG against measles has been reported in both blood and CSF, but despite the excitement this has produced in the neurologic