Multiple sclerosis. A hypothesis on the aetiology

Based on personal experience with multiple sclerosis a hypothesis is set out concerning a possible viral origin for M.S, a protective immunological defense mechanism for sequestration of the virus, the processes involved in the occasional failure of this defense mechanism, thus permitting the onset of exacerbations, the avoidance of such exacerbations by blood-brain barrier protection with a phenothiazine during the prodromal pressor phase, and the probable site of action of the drug. The processes described may be general rather than specific to M.S. and may also occur in other encephalitides of viral or other slow agent origin.