Objective-A cavum between the septi pellucidi may reflect neurodevelopmental anomalies in midline structures of the brain. The authors examined cavum septi pellucidi in subjects with schizophrenia, affective disorder, and schizotypal personality disorder and in normal subjects.Method-Thirty schizophrenic patients (15 chronic, 15 first-episode), 16 patients with affective disorder (first-episode), 21 patients with schizotypal personality disorder, and 46 normal subjects were evaluated with magnetic resonance imaging. Cavum septi pellucidi was assessed by counting the number of 1.5-mm slices containing cavum septi pellucidi.
Results-The presence or absence of cavum septi pellucidi did not differentiate among groups. However, the prevalence of abnormal cavum septi pellucidi (i.e., cavum septi pellucidi contained on four or more slices) was 30.4% for schizophrenic patients (36.4% for chronic, 25.0% for firstepisode), 20.0% for patients with affective disorder, 18.8% for patients with schizotypal personality disorder, and 10.3% for normal subjects. When the authors used the Nopoulos et al. criteria for rating cavum septi pellucidi, which omitted borderline cases with cavum septi pellucidi on three slices, the prevalence of abnormal cavum septi pellucidi increased to 35.0% for schizophrenia (40.0% for chronic, 30.0% for first-episode), 25.0% for affective disorder, 27.3% for schizotypal personality disorder, and 13.0% for normal subjects. There was a statistically significant difference in ratings between schizophrenic and normal subjects.
Conclusions-The results suggest that alterations in midline structures during the course of neurodevelopment may play a role in the pathogenesis of schizophrenia.The cavum septi pellucidi is the space between the two leaflets of the septum pellucidum (1). Examples of "fused" and cavum septi pellucidi can be seen in figure 1 (fused in right panel, cavum in left panel [see black arrow]). In normal development it closes in 15% of humans within 1 month of birth, with 85% closure within 6 months of life (1,2). This fusion likely results from rapid growth of the hippocampus and corpus callosum. Incomplete fusion results in the persistence of a cavum, which, in turn, reflects possible neurodevelopmental anomalies of these midline structures (1-3). Two cavum septi pellucidi anomalies have been described:
NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript "noncommunicating," in which the walls of the cavum are intact and do not "communicate" with the lateral ventricular system, and "communicating," in which the cavum opens to the lateral ventricular system. The latter is the result of later-developing internal hydrocephalus, or acquired/secondary cavum septi pellucidi due to blows to the head, as in, for example, professional and semiprofessional boxers (2,4). Here, we focus on noncommunicating cavum septi pellucidi, since this is thought to be neurodevelopmental in origin.Because abnormalities in temporal lobe structures, including the hippocampus, have been ...