title: White matter tract abnormalities between rostral middle frontal gyrus, inferior frontal gyrus and striatum in first-episode schizophrenia.
abstract: BACKGROUND
  Previous studies have shown that frontostriatal networks, especially those involving dorsolateral prefrontal cortex (DLPFC) and ventrolateral prefrontal cortex (VLPFC) mediate cognitive functions some of which are abnormal in schizophrenia. This study examines white matter integrity of the tracts connecting DLPFC/VLPFC and striatum in patients with first-episode schizophrenia (FESZ), and their associations with cognitive and clinical correlates.
  
  
  METHODS
  Diffusion tensor and structural magnetic resonance images were acquired on a 3T GE Echospeed system from 16 FESZ and 18 demographically comparable healthy controls. FreeSurfer software was used to parcellate regions of interest. Two-tensor tractography was applied to extract fibers connecting striatum with rostral middle frontal gyrus (rMFG) and inferior frontal gyrus (IFG), representing DLPFC and VLPFC respectively. DTI indices, including fractional anisotropy (FA), trace, axial diffusivity (AD) and radial diffusivity (RD), were used for group comparisons. Additionally, correlations were evaluated between these diffusion indices and the Wisconsin Card Sorting Task (WCST) and the Brief Psychiatric Rating Scale (BPRS).
  
  
  RESULTS
  FA was significantly reduced in the left IFG-striatum tract, whereas trace and RD were significantly increased in rMFG-striatum and IFG-striatum tracts, bilaterally. The number of WCST categories completed correlated positively with FA of the right rMFG-striatum tract, and negatively with trace and RD of right rMFG-striatum and right IFG-striatum tracts in FESZ. The BPRS scores did not correlate with these indices.
  
  
  CONCLUSIONS
  These data suggest that white matter tract abnormalities between rMFG/IFG and striatum are present in FESZ and appear to be significantly associated with executive dysfunction but not with symptom severity.
authors: Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02301, USA.
authors: Meina
authors: M
authors: Quan
authors: Sang-Hyuk
authors: SH
authors: Lee
authors: Marek
authors: M
authors: Kubicki
authors: Zora
authors: Z
authors: Kikinis
authors: Yogesh
authors: Y
authors: Rathi
authors: Larry J
authors: LJ
authors: Seidman
authors: Raquelle I
authors: RI
authors: Mesholam-Gately
authors: Jill M
authors: JM
authors: Goldstein
authors: Robert W
authors: RW
authors: McCarley
authors: Martha E
authors: ME
authors: Shenton
authors: James J
authors: JJ
authors: Levitt
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016880:Anisotropy; D001931:Brain Mapping; D010054:Brief Psychiatric Rating Scale; D003342:Corpus Striatum / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000473:pathology*; D055815:Young Adult