Region with persistent high frequency of multiple sclerosis in Croatia and Slovenia.

Objective: The aim of this study was to evaluate the prevalence of multiple sclerosis (MS), and to determine the clinical characteristics and the occurrence of familial MS in the Gorski kotar-Kocevje region, which was previously considered to be a region of high prevalence of MS.

Methods: All clinically and laboratory supported definite cases of MS according to Poser's criteria, living residents of the chosen area on June 1, 1999 were included in the study. The patients were ascertained through national case registers for MS at the University Medical Centers (Rijeka and Ljubljana), registries of the national associations of MS patients, as well as from the medical records of regional outpatient clinics.