title: Magnetic resonance imaging measurement of posterior fossa structures in schizophrenia.
abstract: OBJECTIVE
  Previous research has yielded conflicting results regarding the hypothesis that structural abnormalities of the cerebellar vermis and other posterior fossa structures are associated with schizophrenia. The purpose of this study was to apply techniques of measuring posterior fossa structures from magnetic resonance imaging scans that have proven reliable in identifying structural abnormalities in other patient populations.
  
  
  METHODS
  Midsagittal areas of cerebellar vermis and its subsections (anterior vermis, lobules VI-VII, and lobules VIII-X), brainstem (pons, medulla, and midbrain), and fourth ventricle, as well as intracranial area and cortical area, were measured. Subjects included 36 schizophrenic patients and 51 normal comparison subjects. Groups were matched on age, sex, race, and family socioeconomic status.
  
  
  RESULTS
  No significant group differences were detected for any posterior fossa structure. When corrected for intracranial area, fourth ventricle area was significantly larger in patients than in the comparison group. Fourth ventricle area was not, however, correlated with any measures of symptom severity.
  
  
  CONCLUSIONS
  The size of posterior fossa structures is not abnormal in schizophrenia.
authors.affiliation: Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21287-7362.
authors.forename: E H
authors.initials: EH
authors.lastname: Aylward
authors.forename: A
authors.initials: A
authors.lastname: Reiss
authors.forename: P E
authors.initials: PE
authors.lastname: Barta
authors.forename: A
authors.initials: A
authors.lastname: Tien
authors.forename: W
authors.initials: W
authors.lastname: Han
authors.forename: J
authors.initials: J
authors.lastname: Lee
authors.forename: G D
authors.initials: GD
authors.lastname: Pearlson
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000033:anatomy & histology*; D001933:Brain Stem / Q000033:anatomy & histology; D002531:Cerebellum / Q000033:anatomy & histology; D002552:Cerebral Ventricles / Q000033:anatomy & histology; D003388:Cranial Fossa, Posterior; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000175:diagnosis*; D012720:Severity of Illness Index