Magnetic resonance imaging study of corpus callosum abnormalities in patients with different subtypes of schizophrenia

Background. Reductions in the size of the corpus callosum (CC) have been described for schizophrenia patients, but little is known about the possible regional differences in schizophrenia subtypes (paranoid, disorganised, undifferentiated, residual). Methods. We recruited 58 chronically schizophrenic patients with different subtypes, and 31 age-and-gender matched healthy controls. The callosum was extracted from a midsagittal slice from T1 weighted magnetic resonance images, and areas of the total CC, its five subregions, CC length and total brain volume were compared between schizophrenia subtypes and controls. Five subregions were approximately matched to fibre pathways from cortical regions. Results. Schizophrenia patients had reduced CC total area and length when compared with controls. Disorganised and undifferentiated schizophrenics had a smaller prefrontal area, while there was no significant difference for the paranoid and residual groups. The premotor/supplementary motor area was smaller in all schizophrenia subtypes. The motor area was smaller only in the disorganised group. A smaller sensory area was found in all subtypes except the residual group. Parietal, temporal and occipital areas were smaller in the paranoid and undifferentiated groups. Total brain volume was smaller in all schizophrenia subtypes compared with controls, but did not reach statistical significance. Conclusion. These findings suggest that the heterogeneity of symptoms may lead to the different CC morphological characteristics in schizophrenia subtypes.