title: Epidemiology of acute encephalopathy in Japan, with emphasis on the association of viruses and syndromes.
abstract: A research committee supported by the Japanese government conducted a nationwide survey on the epidemiology of acute encephalopathy in Japan using a questionnaire. A total of 983 cases reportedly had acute encephalopathy during the past 3 years, 2007-2010. Among the pathogens of the preceding infection, influenza virus was the most common, followed by human herpesvirus-6 (HHV-6) and rotavirus. Among syndromes of acute encephalopathy, acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) was the most frequent, followed by clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS), acute necrotizing encephalopathy (ANE) and hemorrhagic shock and encephalopathy syndrome (HSES). Influenza virus was strongly associated with ANE and MERS, HHV-6 with AESD, and rotavirus with MERS. Mortality was high in ANE and HSES, but was low in AESD, MERS and HHV-6-associated encephalopathy. Neurologic sequelae were common in AESD and ANE, but were absent in MERS.
authors.affiliation: Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Hoshino
authors.forename: Makiko
authors.initials: M
authors.lastname: Saitoh
authors.forename: Akira
authors.initials: A
authors.lastname: Oka
authors.forename: Akihisa
authors.initials: A
authors.lastname: Okumura
authors.forename: Masaya
authors.initials: M
authors.lastname: Kubota
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Saito
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Takanashi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Hirose
authors.forename: Takanori
authors.initials: T
authors.lastname: Yamagata
authors.forename: Hideo
authors.initials: H
authors.lastname: Yamanouchi
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizuguchi
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004660:Encephalitis / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D007223:Infant; D007251:Influenza, Human / Q000150:complications*; D007564:Japan / Q000453:epidemiology; D008297:Male; D019349:Roseolovirus Infections / Q000150:complications*; D012400:Rotavirus Infections / Q000150:complications*