Mid-sagittal anatomy in late-onset schizophrenia.

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 = 24) and healthy volunteers (NC) (N = 30) 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.