Temporal changes and geographical differences in multiple sclerosis phenotypes in Japanese: nationwide survey results over 30 years

摘要: BackgroundThere are two distinct phenotypes of multiple sclerosis (MS) in Asians, manifesting as optic-spinal (OSMS) and conventional (CMS) forms. In Japan, four nationwide surveys MS have been conducted. The first three were 1972, 1982, 1989, we performed the fourth 2004.ResultsThe recent survey showed six main findings follows: (1) a four-fold increase estimated number clinically definite patients with 2003 (9900; crude prevalence, 7.7/100,000) compared 1972; (2) shift peak age at onset from early 30s 1989 to 20s 2003; (3) successive proportional decrease involvement MS; (4) significant north–south gradient for CMS/OSMS ratio; (5) after subdivision mainland (30–45° North) into northern southern parts 37°N, northern-born residents (northern patients) significantly higher ratio frequency brain lesions fulfilling Barkhof cri...