Abnormalities of the septum pellucidum on MR scans in first-episode schizophrenic patients.

PURPOSE AND METHODS: Cavities in the septum pellucidum have been widely regarded in clinical neurology or in autopsy series as incidental findings of little clinical importance; however, an association between this developmental anomaly and a diagnosis of psychosis has been reported. We compared MR brain scans of schizophrenic patients with normal control subjects to determine the prevalence of this finding in the two groups: RESULTS: A cavum septum pellucidum was found in 14 of 62 (23%) schizophrenic patients and only one of 46 control subjects (2%). Pronounced enlargement of the cavum septum and a cavum vergae were seen only in two schizophrenic subjects. A partial agenesis of the corpus callosum was also seen in one of the schizophrenic cases with the largest cavum septum pellucidum. CONCLUSIONS: The increased prevalence of a cavum septum pellucidum, the cavum vergae, and partial callosal agenesis in schizophrenics support the hypothesis that anomalous development of the brain is an important aspect of this disorder. The disturbed structures are closely linked developmentally to the limbic system which has been implicated etiologically in studies of schizophrenia.