title: Cortical and subcortical white matter abnormalities in adults with remitted first-episode mania revealed by Tract-Based Spatial Statistics.
abstract: OBJECTIVE
  Abnormalities of brain white matter have been noted in structural magnetic resonance imaging and diffusion tensor imaging (DTI) studies of bipolar disorder, but there are fewer investigations specifically examining white matter integrity early in the course of illness. In this study, we employed DTI to elucidate white matter changes in adult patients with remitted first-episode mania and hypothesized that first-episode mania was associated with decreased fractional anisotropy in cortical (frontal) and subcortical (thalamus, striatum) white matter as well as white matter tracts (cingulum, corpus callosum).
  
  
  METHODS
  Diffusion tensor images were acquired from 16 patients with remitted first-episode mania and 16 healthy controls matched for age, gender, handedness, and years of education. Fractional anisotropy and radial and axial diffusivities were analyzed using Tract-Based Spatial Statistics.
  
  
  RESULTS
  Patients had lower fractional anisotropy and higher radial diffusivity in the left anterior frontal white matter, right posterior thalamic radiation, left cingulum, and bilateral sagittal striatum. In addition, increased radial diffusivity was found in the left corpus callosum.
  
  
  CONCLUSIONS
  Our findings highlighted that white matter abnormalities were present by the time of remission of first-episode mania. The widespread occurrence of these white matter abnormalities both in first-episode mania and chronic bipolar disorder suggested that disruption of white matter cortical-subcortical networks as well as projection, associative, and commissural tracts is a hallmark of the illness.
authors.affiliation: Research Division, Institute of Mental Health, Singapore.
authors.forename: Wai-Yen
authors.initials: WY
authors.lastname: Chan
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Yang
authors.forename: Ming-Ying
authors.initials: MY
authors.lastname: Chia
authors.forename: Puay-San
authors.initials: PS
authors.lastname: Woon
authors.forename: Jimmy
authors.initials: J
authors.lastname: Lee
authors.forename: Richard
authors.initials: R
authors.lastname: Keefe
authors.forename: Yih-Yian
authors.initials: YY
authors.lastname: Sitoh
authors.forename: Wieslaw Lucjan
authors.initials: WL
authors.lastname: Nowinski
authors.forename: Kang
authors.initials: K
authors.lastname: Sim
mesh_terms: D000328:Adult; D016880:Anisotropy; D001714:Bipolar Disorder / Q000175:diagnosis / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged