THE LATENT PERIOD OF MULTIPLE-SCLEROSIS - A CRITICAL-REVIEW

It is a widely held belief that multiple sclerosis is a disease with a long latent period that is preceded by heightened susceptibility befo re adolescence. There has, however, been little research focused on ei ther the estimation of the latent period or determination of the susce ptibility period. In this article, we present a critical assessment of the relevant literature on migrant studies, cluster studies, the Faro e Islands ''epidemic,'' a sibling study, and novel statistical approac hes as they pertain to the pre-onset natural history of multiple scler osis. We also discuss the roles of the latent and susceptibility perio ds in the design, analysis, and interpretation of epidemiologic studie s.