title: Human brain structural change related to acute single exposure to sarin.
abstract: OBJECTIVE
  This study aimed to identify persistent morphological changes subsequent to an acute single-time exposure to sarin, a highly poisonous organophosphate, and the neurobiological basis of long-lasting somatic and cognitive symptoms in victims exposed to sarin.
  
  
  METHODS
  Thirty-eight victims of the 1995 Tokyo subway sarin attack, all of whom had been treated in an emergency department for sarin intoxication, and 76 matched healthy control subjects underwent T1-weighted and diffusion tensor magnetic resonance imaging (DTI) in 2000 to 2001. Serum cholinesterase (ChE) levels measured immediately and longitudinally after the exposure and the current severity of chronic reports in the victims were also evaluated.
  
  
  RESULTS
  The voxel-based morphometry exhibited smaller than normal regional brain volumes in the insular cortex and neighboring white matter, as well as in the hippocampus in the victims. The reduced regional white matter volume correlated with decreased serum cholinesterase levels and with the severity of chronic somatic complaints related to interoceptive awareness. Voxel-based analysis of diffusion tensor magnetic resonance imaging further demonstrated an extensively lower than normal fractional anisotropy in the victims. All these findings were statistically significant (corrected p < 0.05).
  
  
  CONCLUSIONS
  Sarin intoxication might be associated with structural changes in specific regions of the human brain, including those surrounding the insular cortex, which might be related to elevated subjective awareness of internal bodily status in exposed individuals.
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Tokyo, Japan. yamasue-tky@umin.ac.jp
authors.forename: Hidenori
authors.initials: H
authors.lastname: Yamasue
authors.forename: Osamu
authors.initials: O
authors.lastname: Abe
authors.forename: Kiyoto
authors.initials: K
authors.lastname: Kasai
authors.forename: Motomu
authors.initials: M
authors.lastname: Suga
authors.forename: Akira
authors.initials: A
authors.lastname: Iwanami
authors.forename: Haruyasu
authors.initials: H
authors.lastname: Yamada
authors.forename: Mamoru
authors.initials: M
authors.lastname: Tochigi
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ohtani
authors.forename: Mark A
authors.initials: MA
authors.lastname: Rogers
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Sasaki
authors.forename: Shigeki
authors.initials: S
authors.lastname: Aoki
authors.forename: Tadafumi
authors.initials: T
authors.lastname: Kato
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Kato
mesh_terms: D000328:Adult; D001921:Brain / Q000187:drug effects* / Q000473:pathology; D001931:Brain Mapping; D002800:Cholinesterase Inhibitors / Q000097:blood / Q000506:poisoning*; D003710:Demography; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012524:Sarin / Q000097:blood / Q000506:poisoning*; D013223:Statistics as Topic
chemical_list: D002800:Cholinesterase Inhibitors; D012524:Sarin