Mid-sagittal anatomy in late-onset schizophrenia

Abstract

Background. Of the midline brain structures, abnormalities have been demonstrated in the corpus callosum and cerebellum in young schizophrenic patients. Whether similar abnormalities are also present in late-onset schizophrenia (LOS) is not known.

Methods. The mid-sagittal cross-sectional areas of brain regions, in particular the corpus callosum and cerebellum, on magnetic resonance imaging were examined in a group of patients with late-onset schizophrenia (N=25) and contrasted with two comparison groups – early-onset schizophrenia (EOS) (N=2524) and healthy volunteers (NC) (N=2530) matched for age and gender.

Results. While the mean corpus callosum area in the LOS group was smaller than in the EOS (by 10·2%) and NC (by 6·2%) groups, the three groups did not differ statistically in the corpus callosum area or the corpus callosum to cerebrum ratios. The cross-sectional cerebellar areas or the cerebellum: cerebrum ratios also did not differ across the groups. The brainstem was smaller in the schizophrenic groups because of smaller cross-sectional areas of the pons, a statistically significant difference which could not be accounted for by any gross lesions on visual inspection.

Conclusion. We found no abnormality in the mid-sagittal area of the corpus callosum and cerebellum in our early- or late-onset schizophrenia subjects. The significance of the finding of a smaller pontine cross-sectional area is unclear and speculation on it awaits independent replication using a volumetric measure.