title: Late proton MR spectroscopy in children after traumatic brain injury: correlation with cognitive outcomes.
abstract: OBJECTIVE
  Proton MR spectroscopy has demonstrated reduced levels of N-acetylaspartate (NAA) in normal-appearing occipital and frontal regions of patients with acute nonpenetrating traumatic brain injury (TBI). We studied the relationship of frontoparietal NAA, choline (Cho), and creatine (Cr) to test the hypothesis that reduction in NAA is predictive of cognitive outcome.
  
  
  METHODS
  Proton spectra were collected by using conventional 2D chemical shift imaging in five healthy children and seven children (6 weeks to 3 years) with severe (n=4), moderate (n=2), or mild (n=1) TBI. Spectra in the anterior and posterior regions of the left and right frontoparietal areas were averaged for analysis by using LCModel, with a phantom-established basis function, for quantification of NAA, Cho, and Cr concentrations. Intellectual function, expressive language, and arithmetic capability were measured within 4 months of imaging.
  
  
  RESULTS
  NAA/Cho concentration was lower in TBI patients than in control subjects, but no group differences were present for Cho or Cr. Hemispheric levels for NAA, Cho, and Cr were higher on the left than on the right, but we found no effect of region and no interactions. Cognition was lower in the TBI group than the control group and correlated with NAA levels. Left frontal Cho was also correlated with arithmetic scores, whereas Cr was not significantly correlated.
  
  
  CONCLUSIONS
  NAA levels remain low after TBI and are related to cognitive function. Neurometabolite values are greater in the left frontoparietal region than in the right, and the left frontal Cho level is related to arithmetic ability.
authors.affiliation: Department of O.I., Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Jill V
authors.initials: JV
authors.lastname: Hunter
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Thornton
authors.forename: Zhiyue J
authors.initials: ZJ
authors.lastname: Wang
authors.forename: Harvey S
authors.initials: HS
authors.lastname: Levin
authors.forename: Garland
authors.initials: G
authors.lastname: Roberson
authors.forename: William M
authors.initials: WM
authors.lastname: Brooks
authors.forename: Paul R
authors.initials: PR
authors.lastname: Swank
mesh_terms: D000293:Adolescent; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D001930:Brain Injuries / Q000378:metabolism* / Q000523:psychology; D016022:Case-Control Studies; D002648:Child; D002794:Choline / Q000378:metabolism; D003071:Cognition; D003401:Creatine / Q000378:metabolism; D004292:Dominance, Cerebral; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008433:Mathematics; D008606:Mental Processes; D009994:Osmolar Concentration; D014949:Wounds, Nonpenetrating / Q000378:metabolism* / Q000523:psychology
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline