title: Diffusion tensor imaging of anterior commissural fibers in patients with schizophrenia.
abstract: BACKGROUND
  Alterations in white matter connections in schizophrenia have been investigated using diffusion tensor imaging (DTI). There is also evidence from post-mortem studies as well as from magnetic resonance imaging morphometry studies that the anterior commissure (AC) might be implicated in schizophrenia, but no studies, to date, have investigated the AC using DTI or tractography.
  
  
  METHODS
  DTI scans were analyzed from 25 patients and 23 controls. Mean fractional anisotropy (FA) and trace were measured from the AC tracts. SANS and SAPS were used to evaluate clinical symptoms, and the Iowa Gambling Task, related to decision making, was also examined.
  
  
  RESULTS
  Results revealed a significant decrease in mean FA and a significant increase in mean trace of AC tracts in patients compared with controls. In addition, patients, but not controls, showed a negative correlation between age and AC integrity. Statistically significant positive correlations were also found between AC FA and total positive symptom score. Decision making was negatively correlated with FA in patients on the Iowa Gambling Task, but not in controls.
  
  
  CONCLUSIONS
  This study provides quantitative evidence for a reduction of interhemispheric connectivity in schizophrenia within the AC. Negative correlation between age and AC FA in the patients is consistent with the idea that schizophrenia may be a disorder of white matter maturation. Positive correlation between FA and positive symptom is discussed in the context of white matter's established role in modulating neural conduction velocity.
authors.affiliation: Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: Hongyoon
authors.initials: H
authors.lastname: Choi
authors.forename: Marek
authors.initials: M
authors.lastname: Kubicki
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Whitford
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Alvarado
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Terry
authors.forename: Margaret
authors.initials: M
authors.lastname: Niznikiewicz
authors.forename: Robert W
authors.initials: RW
authors.lastname: McCarley
authors.forename: Jun Soo
authors.initials: JS
authors.lastname: Kwon
authors.forename: Martha E
authors.initials: ME
authors.lastname: Shenton
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002908:Chronic Disease; D003337:Corpus Callosum / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D012559:Schizophrenia / Q000473:pathology*; D013223:Statistics as Topic; D055815:Young Adult