Temporal changes and geographical differences in multiple sclerosis phenotypes in Japanese: nationwide survey results over 30 years
- 9 October 2008
- journal article
- research article
- Published by SAGE Publications in Multiple Sclerosis Journal
- Vol. 15 (2), 159-173
- https://doi.org/10.1177/1352458508098372
Abstract
Background There are two distinct phenotypes of multiple sclerosis (MS) in Asians, manifesting as optic-spinal (OSMS) and conventional (CMS) forms. In Japan, four nationwide surveys of MS have been conducted. The first three were in 1972, 1982, and 1989, and we performed the fourth in 2004. Results The recent survey showed six main findings as follows: (1) a four-fold increase in the estimated number of clinically definite patients with MS in 2003 (9900; crude MS prevalence, 7.7/100,000) compared with 1972; (2) a shift in the peak age at onset from early 30s in 1989 to early 20s in 2003; (3) a successive proportional decrease in optic-spinal involvement in clinically definite patients with MS; (4) a significant north–south gradient for the CMS/OSMS ratio; (5) after subdivision of the mainland (30–45° North) into northern and southern parts at 37°N, northern-born northern residents (northern patients) showed a significantly higher CMS/OSMS ratio and higher frequency of brain lesions fulfilling the Barkhof criteria (Barkhof brain lesions) than southern-born southern residents (southern patients); (6) among northern patients, the absolute numbers of patients with CMS and those with Barkhof brain lesions rapidly increased with advancing birth year. Conclusions These findings suggest that MS phenotypes are drastically altered by environmental factors, such as latitude and “Westernization.”Keywords
This publication has 49 references indexed in Scilit:
- Heterogeneity of aquaporin-4 autoimmunity and spinal cord lesions in multiple sclerosis in JapaneseBrain, 2007
- Complexity and heterogeneity in demyelinating diseaseBrain, 2007
- Clinical and MRI features of Japanese patients with multiple sclerosis positive for NMO-IgGJournal of Neurology, Neurosurgery & Psychiatry, 2006
- OSMS is NMO, but not MS: proven clinically and pathologicallyThe Lancet Neurology, 2006
- “OSMS is NMO, but not MS”: confirmed by NMO-IgG?The Lancet Neurology, 2005
- A serum autoantibody marker of neuromyelitis optica: distinction from multiple sclerosisThe Lancet, 2004
- Multiple sclerosisThe Lancet, 2002
- Western versus asian types of multiple sclerosis: Immunogenetically and clinically distinct disordersAnnals of Neurology, 1996
- Clinical studies of multiple sclerosis in JapanNeurology, 1973
- Multiple sclerosis and allied diseases in JapanNeurology, 1958