title: Lower orbital frontal white matter integrity in adolescents with bipolar I disorder.
abstract: OBJECTIVE
  To examine white matter microstructure, as assessed via diffusion tensor imaging (DTI), in adolescents with bipolar I disorder compared with control volunteers.
  
  
  METHODS
  Twenty-six (12 male and 14 female subjects) adolescents (mean age, 16.0 years) with bipolar I disorder and 26 (14 male and 12 female subjects) control volunteers (mean age, 15.3 years) completed structural and DTI examinations. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) maps were compared between groups in the brain white matter using a voxelwise analysis after intersubject registration to Talairach space. Exploratory analyses were performed to assess structure-function correlations in a subgroup of 11 patients with available neuropsychological measures.
  
  
  RESULTS
  Compared with the control volunteers, the patients demonstrated abnormalities in white matter regions predicted to differ a priori between groups, including lower FA in the right orbital frontal lobe and higher ADC in the right and left subgenual region (p <.005, uncorrected; cluster size >or= 100). There were no areas of higher FA or lower ADC in patients compared with control volunteers. Lower FA across regions that differed significantly between groups correlated significantly with slower visuomotor speed among patients with bipolar disorder.
  
  
  CONCLUSIONS
  Abnormalities involving the orbital frontal and subgenual white matter in adolescents with bipolar disorder are consistent with neurobiological models that implicate dysregulation of affective systems and impulsivity in the pathophysiology of the disorder. Preliminary findings suggest that white matter abnormalities in pediatric bipolar disorder have functional correlates and may be useful in constructing neurobiological models of the disorder.
authors.affiliation: Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System. vkafanta@lij.edu
authors.forename: Vivian
authors.initials: V
authors.lastname: Kafantaris
authors.forename: Peter
authors.initials: P
authors.lastname: Kingsley
authors.forename: Babak
authors.initials: B
authors.lastname: Ardekani
authors.forename: Ema
authors.initials: E
authors.lastname: Saito
authors.forename: Todd
authors.initials: T
authors.lastname: Lencz
authors.forename: Kelvin
authors.initials: K
authors.lastname: Lim
authors.forename: Philip
authors.initials: P
authors.lastname: Szeszko
mesh_terms: D000293:Adolescent; D000339:Affect / Q000502:physiology; D016880:Anisotropy; D001369:Axons / Q000473:pathology / Q000502:physiology; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000503:physiopathology; D001925:Brain Damage, Chronic / Q000473:pathology* / Q000503:physiopathology; D015331:Cohort Studies; D038524:Diffusion Magnetic Resonance Imaging; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007175:Impulsive Behavior / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology* / Q000502:physiology; D009483:Neuropsychological Tests; D012016:Reference Values