title: Brain magnetic resonance imaging in acute phase of pandemic influenza A (H1N1) 2009--associated encephalopathy in children.
abstract: Pandemic influenza A (H1N1) 2009 has been shown to be associated more with neurological complications than the seasonal influenza virus. In this study, we focused on the clinical usefulness of magnetic resonance imaging (MRI) in the acute phase of influenza A (H1N1) 2009-associated encephalopathy. A questionnaire was distributed to pediatric and general hospitals in Japan that treat children with encephalopathy. We conducted a questionnaire-based study involving the collection of information regarding 207 patients with encephalopathy. Brain MRI was performed in 97 of these 207 patients in the age group of 9 months to 15 years (mean, 7.5 years) within 48 hours after the development of encephalopathy symptoms. Sixty-six patients (68%) showed normal imaging. Diffuse brain edema was visible in five patients and an abnormal signal in the deep gray matter in two patients which is consistent with acute necrotizing encephalopathy. Abnormal signals of the splenial lesion, subcortical white matter (bright tree appearance), and cortical area were observed in 15, 1, and 8 patients, respectively. From our findings based on the questionnaire results, we suggest that MRI is useful for determining fatal cases of pandemic influenza A (H1N1) 2009 infection when performed in the acute phase. However, MRI is not useful in predicting the development of sequelae.
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Kawashima
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Morichi
authors.affiliation: Department of Pediatrics, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan.
authors.forename: Gaku
authors.initials: G
authors.lastname: Yamanaka
authors.affiliation: Department of Pediatrics, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, Japan.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Okumura
authors.affiliation: Department of Intensive Care, National Center for Child Health and Development, Setagaya-ku, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakagawa
authors.affiliation: Department of Pediatrics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama City, Okayama, Japan.
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Morishima
mesh_terms: D000293:Adolescent; D001921:Brain / Q000473:pathology*; D001927:Brain Diseases / Q000150:complications* / Q000473:pathology* / Q000821:virology; D002648:Child; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000472:pathogenicity*; D007251:Influenza, Human / Q000150:complications*; D007564:Japan; D008297:Male