RESUMEN
Despite edidemiologic similarity of multiple sclerosis worldwide, prevalence shows considerable variability. According to Kurtzke, Iran is considered to have a low prevalence. In this study, we wanted to estimate the prevalence period and Indicate Epidemiologic aspect of MS in Mazandaran Province, North of Iran. A cross- sectional registered case Study Conducted in 2007 on all definite MS Patients that live and reside within Mazandaran, as well az being a member of the Mazandaran MS Society. 582 difinite patients [161 men and 421 women] were identified. The patients were Viu interview and questionaire to record demographic and Case related information. According to the national Sensius Reports, the population of Mazandaran was 2,893,087. The mean [SD] age of the participants was 34.3 [9.4] years. The MS period pervalence was 20.1 per 100,000 [95% confidence interval[CI] 18.7-22.1]. The Female/male ration was 2.6 and MS rates were highest among 3[rd] decade. Visual and sensory distorbancec were the most common initial persontations with prevalence of 40.1% [95% CI: 38.5-42.9] and 34.2% [95% CI: 32.8 - 36.1], respictively. Mazandaran is in medium MS prevalence area. This is in clear contrast with background hypothesis, but other epidemiologic indices were almost pursuant with pervious information