title: Influenza-associated acute encephalopathy in Japanese children in 1994-2002.
abstract: We addressed the incidence of influenza-associated acute encephalopathy, which is distinct from Reye syndrome, in children in Japan. Eighty-nine children with a mean age of 3.8 years were reported to have developed this disease during eight influenza seasons (December 1994-April 2002) in Hokkaido, Japan. None of them had received aspirin. Most of the patients rapidly became comatose with or without convulsions with a mean interval of 1.7 days from the onset of fever to the onset of central nervous system symptoms. Thirty-three (37.1%) patients died and 17 (19.1%) patients had neurological sequelae. A total of 53 (59.6%) cases were proved to have an influenza virus infection. Interleukin-6 and tumor necrosis factor-alpha were markedly elevated in serum and cerebrospinal fluid samples from two patients who died after a rapid, fulminant course. A post-mortem examination of one fatal case revealed vasogenic brain edema with generalized vasculopathy, suggesting that the generalized impairment of vascular endothelial cells caused by highly activated cytokines plays a central role in the pathophysiology of this disease. We conclude that influenza-associated acute encephalopathy may be an underestimated syndrome and is another reason to promote vaccination against influenza in infants and younger children.
authors.affiliation: Department of Pediatrics, Sapporo City General Hospital, N 11 W 13, Chuo-ku, Sapporo 060-8604, Japan. takehiro.togashi@doc.city.sapporo.jp
authors.forename: Takehiro
authors.initials: T
authors.lastname: Togashi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsuzono
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Narita
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Morishima
mesh_terms: D000208:Acute Disease; D001927:Brain Diseases / Q000453:epidemiology / Q000401:mortality / Q000503:physiopathology / Q000821:virology; D002648:Child; D002675:Child, Preschool; D018792:Encephalitis, Viral / Q000453:epidemiology / Q000401:mortality / Q000503:physiopathology / Q000821:virology; D006801:Humans; D007223:Infant; D007251:Influenza, Human / Q000150:complications* / Q000453:epidemiology; D015850:Interleukin-6 / Q000097:blood / Q000134:cerebrospinal fluid; D007564:Japan / Q000453:epidemiology; D008297:Male; D014409:Tumor Necrosis Factor-alpha / Q000134:cerebrospinal fluid / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha