title: Atypical developmental patterns of brain chemistry in children with autism spectrum disorder.
abstract: OBJECTIVE
  Autism spectrum disorder (ASD) is a neurodevelopmental disorder with symptoms emerging during early childhood. The pathophysiology underlying the disorder remains incompletely understood.
  
  
  OBJECTIVE
  To examine cross-sectional and longitudinal patterns of brain chemical concentrations in children with ASD or idiopathic developmental delay (DD) from 3 different age points, beginning early in the clinical course.
  
  
  METHODS
  Proton magnetic resonance spectroscopic imaging data were acquired longitudinally for children with ASD or DD, and primarily cross-sectionally for children with typical development (TD), at 3 to 4, 6 to 7, and 9 to 10 years of age.
  
  
  METHODS
  Recruitment, diagnostic assessments, and magnetic resonance imaging were performed at the University of Washington in Seattle.
  
  
  METHODS
  Seventy-three children (45 with ASD, 14 with DD, and 14 with TD) at 3 to 4 years of age; 69 children (35 with ASD, 14 with DD, and 20 with TD) at 6 to 7 years of age; and 77 children (29 with ASD, 15 with DD, and 33 with TD) at 9 to 10 years of age.
  
  
  METHODS
  Concentrations of N-acetylaspartate (NAA), choline (Cho), creatine (Cr), myo-inositol (mI), and glutamine plus glutamate (Glx) in cerebral gray matter (GM) and white matter (WM) at 3 to 4, 6 to 7, and 9 to 10 years of age, and calculation of rates of change of these chemicals between 3 and 10 years of age.
  
  
  RESULTS
  At 3 to 4 years of age, the ASD group exhibited lower NAA, Cho, and Cr concentrations than did the TD group in both GM and WM, alterations that largely were not observed at 9 to 10 years of age. The DD group exhibited reduced GM and WM NAA concentrations at 3 to 4 years of age; GM NAA concentrations remained reduced at 9 to 10 years of age compared with the TD group. There were distinct differences between the ASD and DD groups in the rates of GM NAA, Cho, and Cr changes between 3 and 10 years of age.
  
  
  CONCLUSIONS
  The GM chemical changes between 3 and 10 years of age differentiated the children with ASD from those with DD. Most notably, a dynamic reversal of GM NAA reductions was observed in the children with ASD. By contrast, persistent GM NAA reductions in the children with DD suggest a different, more static, underlying developmental process.
authors.forename: Neva M
authors.initials: NM
authors.lastname: Corrigan
authors.forename: Dennis W W
authors.initials: DW
authors.lastname: Shaw
authors.forename: Annette M
authors.initials: AM
authors.lastname: Estes
authors.forename: Todd L
authors.initials: TL
authors.lastname: Richards
authors.forename: Jeff
authors.initials: J
authors.lastname: Munson
authors.forename: Seth D
authors.initials: SD
authors.lastname: Friedman
authors.forename: Geraldine
authors.initials: G
authors.lastname: Dawson
authors.forename: Alan A
authors.initials: AA
authors.lastname: Artru
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Dager
mesh_terms: D000367:Age Factors; D001923:Brain Chemistry / Q000502:physiology*; D002540:Cerebral Cortex / Q000737:chemistry / Q000503:physiopathology; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D002658:Developmental Disabilities / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods; D008297:Male