%0 Journal Article %T Optic Nerve and Spinal Cord Are the Major Lesions in Each Relapse of Japanese Multiple Sclerosis %A Yoko Warabi %J ISRN Neurology %D 2011 %R 10.5402/2011/904706 %X 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. 1. Introduction Multiple sclerosis (MS) and neuromyelitis optica (NMO) are inflammatory demyelinating diseases of the central nervous system (CNS). Although MS and NMO are characterized by dissemination of lesions in space and dissemination in time, it has not been able to predict when and where the next relapse will appear. One of the possibilities that suggests where the next relapse occurs is due to the clinical phenotype of the CNS inflammatory demyelinating diseases in the Japanese population. Japanese CNS demyelinating disease has two major clinical phenotypes. One is NMO [1, 2] which is characterized by lesions confined to the optic nerve and spinal cord, especially, longitudinally extensive spinal cord lesions [3], positive aquaporin-4 (AQP4) autoantibody seropositivity [4], and the astrocytic impairment associated with the loss of AQP4 in the NMO lesions [5]. The other is conventional Western type MS which is known to be the same pathophysiology as MS in western countries and frequently involves cerebral lesions [6]. Human leukocyte antigen (HLA)-DR2 antigen is reported to associate with MS both in Japan and western countries [7], whereas DPB1 £¿ 0501 is associated with NMO in Asian population [8, 9]. There is a consensus that NMO comprises about one-third or one-fourth of the Japanese CNS inflammatory demyelinating diseases [10]. In this paper, for the purpose of predicting the lesions of the demyelinating relapses, we evaluated the localization, sex ratio, and age of each demyelinating attack, retrospectively. As the results, we found that the attacks in optic nerve and spinal cord accounted %U http://www.hindawi.com/journals/isrn.neurology/2011/904706/