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.