[P1-139] Clinical features of pediatric acquired demyelinating syndromes in Japan
[Introduction] Acquired demyelinating syndromes (ADSs) are clinical CNS events with presumably immune-mediated inflammatory demyelination. They are classified into several clinical entities based on lesion location and disease progression as follows: multiple sclerosis (MS), acute disseminated encephalomyelitis (ADEM), and neuromyelitis optica (NMO). We conducted a nationwide survey of pediatric ADSs to elucidate their clinical features in Japanese children. [Methods] We used the questionnaires to collect clinical data from children with ADS who were at or under 15 years of age and visited hospitals in Japan from 2005 to 2007. [Results] We analyzed data from 204 children, including those with ADEM (66), MS (58), and NMO (10). We found that Japanese children with ADEM exhibited more frequent gait and urinary disturbances and less visual loss than did Japanese children with MS at the first demyelinating event. Laboratory and MRI findings of Japanese children with ADEM were similar to those with MS at the first demyelinating event, but the presence of oligoclonal bands and optic nerve involvement on MRI are less frequently seen in those with ADEM. Japanese children with MS had more frequent seizures and visual disturbances, fewer elevated IgG indices and oligoclonal bands in the CSF, and fewer typical MS features on MRI compared to children in other countries. Lastly, Japanese children with NMO had more inflammatory CSF findings than did children in other countries. [Conclusions] This study elucidated the characteristic clinical features of pediatric ADS in the Japanese population.