Optic Nerve and Spinal Cord Are the Major Lesions in Each Relapse of Japanese Multiple Sclerosis

For the purpose of predicting multiple sclerosis (MS) and neuromyelitis optica (NMO) relapses in Japanese population, we evaluated the localization and age of each demyelinating attack. We retrospectively analyzed the 78 medical records of Japanese MS and NMO patients. Then we identified 49 cases of relapsing-remitting-type patients and defined each of 116 demyelinating attacks. NMO had an older age at onset than MS, although the initial symptoms cannot predict the clinical phenotypes. Only 21.3% of demyelinating attacks were localized in the cerebrum and 78.7% were optic-spinal lesions, although MS comprised 70% and NMO comprised 30% of these 78 cases. Brainstem lesion had a relative male predominancy and a young age at attack. Our findings showed that optic nerve and spinal cord lesions are the major and critical lesions in each attack of Japanese CNS demyelinating diseases. There might be distinctive Japanese pathogenic features even in Western type MS.