Frequency and Severity of Enlarged Cavum Septi Pellucidi in Childhood-Onset Schizophrenia

OBJECTIVE: Patients with schizophrenia have been reported to have a higher frequency of enlarged cavum septi pellucidi (CSP) in comparison with normal subjects. Neurodevelopmental models of schizophrenia suggest that the more severe the brain dysgenesis, the earlier the onset of psychotic symptoms. Study of patients with childhood-onset schizophrenia allows the opportunity to test this hypothesis. METHOD: Two groups of subjects were evaluated: healthy volunteers (N=95, mean age=11.7 years) and patients with childhood-onset schizophrenia (N=24, mean age=14.6 years). Magnetic resonance images of 1-mm resampled contiguous brain slices were rated blind to diagnosis. The size of the CSP was recorded as the number of consecutive slices in which the CSP was present. Abnormal enlargement was defined as a CSP greater than 6 mm in length. RESULTS: The frequency of an enlarged CSP was significantly higher in the patient group: 12.5% (three of 24 subjects) versus 1.1% (one of 95 subjects). Also, two of the three patients with an enlarged CSP had complete nonfusion of the septal leaflets, a more severe anomaly than was found in the one comparison subject with an enlarged CSP and typically more severe than anomalies seen in groups with adult-onset schizophrenia. CONCLUSIONS: These findings suggest that patients with extremely early-onset (childhood) forms of schizophrenia may have more severe developmental brain anomalies than those with adult onset. (Am J Psychiatry 1998; 155:1074–1079)