title: A longitudinal study of the corpus callosum in chronic schizophrenia.
abstract: BACKGROUND
  Decreased callosal size and anisotropy have been described in schizophrenia patients but their longitudinal progression remains poorly understood.
  
  
  METHODS
  We performed diffusion-tensor and structural magnetic resonance imaging at baseline and at follow-up four years later in 49 chronic schizophrenia patients and 16 healthy comparison subjects. Schizophrenia patients were subdivided into good-outcome (n=23) and poor-outcome (n=26) groups. Baseline-to-follow-up changes in size, shape, position and fractional anisotropy of the corpus callosum, divided into five sagittal sections and five rostro-caudal segments, were assessed.
  
  
  RESULTS
  At baseline scan and in comparison to healthy subjects, schizophrenia patients displayed 1) smaller callosal size, 2) lower average anisotropy in all sagittal sections except the midline, and 3) more dorsal average coordinate position. During the four years after the baseline scan, patients with schizophrenia exhibited a more pronounced decline in absolute size of the corpus callosum than healthy comparison subjects. As compared with the good-outcome group, the corpus callosum in poor-outcome patients at baseline was of smaller size and lower average anisotropy, more elongated and posteriorly positioned. During the follow-up interval, poor-outcome patients displayed a more pronounced decline in size but less pronounced decline in anisotropy of the corpus callosum than patients with good outcomes.
  
  
  CONCLUSIONS
  Differences in callosal size between schizophrenia patients and healthy subjects seen at baseline continue to widen in the chronic phase of the illness, especially in patients with poor functional outcome. Baseline differences in callosal anisotropy among patients with different outcomes, however, diminish over time.
authors.affiliation: Department of Psychiatry, Mount Sinai School of Medicine, New York, New York 10029, USA. serge.mitelman@mssm.edu
authors.forename: Serge A
authors.initials: SA
authors.lastname: Mitelman
authors.forename: Yekaterina K
authors.initials: YK
authors.lastname: Nikiforova
authors.forename: Emily L
authors.initials: EL
authors.lastname: Canfield
authors.forename: Erin A
authors.initials: EA
authors.lastname: Hazlett
authors.forename: Adam M
authors.initials: AM
authors.lastname: Brickman
authors.forename: Lina
authors.initials: L
authors.lastname: Shihabuddin
authors.forename: Monte S
authors.initials: MS
authors.lastname: Buchsbaum
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016880:Anisotropy; D001931:Brain Mapping; D002908:Chronic Disease; D003337:Corpus Callosum / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D018450:Disease Progression; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000473:pathology*