Developmental abnormalities of the corpus callosum in schizophrenia.

Magnetic resonance imaging was used to evaluate neuroanatomical and neuropathologic abnormalities in a consecutive series of 140 patients with schizophrenia for comparison with normal controls. Partial agenesis of the corpus callosum, a rare neurodevelopmental abnormality, was found in two patients, one of whom also had a callosal lipoma. Evidence is presented suggesting that this finding represents an increased prevalence of partial agenesis in schizophrenia. The corpus callosum develops embryologically in intimate relationship to the hippocampal formation, fornix, septum pellucidum, and cingulate gyrus. In individuals with callosal agenesis, abnormalities also occur in the development of these limbic structures. Recent neuropathologic studies have suggested the occurrence of abnormal neurogenesis in the hippocampal formation and in the cingulate gyrus in schizophrenic patients. An increased prevalence of callosal agenesis and its related limbic abnormalities would further support investigation into neurodevelopmental abnormalities of these anatomical regions in schizophrenia.