Cavum septi pellucidi, cavum vergae, and cavum veli interpositi in schizophrenia: A case-control MRI study of prevalence, size, and clinical significance.

BACKGROUND: Persistent midline brain cavities -cavum septi pellucidi (CSP), cavum vergae (CV), and cavum veli interpositi (CVI)- arise from incomplete embryonic obliteration and are proposed markers of disrupted perinatal neurodevelopment of limbic and commissural structures.This study investigated their prevalence, two-dimensional morphometry, and clinical correlates in schizophrenia spectrum disorders. METHODS: MRI scans from 252 patients and 260 matched healthy controls were analyzed. CSP was classified using three established systems; CVI was evaluated against an empirically derived height threshold. Multivariate logistic regression, adjusted for age, sex, MR field strength, and septum pellucidum length, assessed the independent association of anomalies with group membership. RESULTS: Large CSP and large CVI were significantly more prevalent in patients. CSP transverse width was significantly greater in patients, remaining independently associated with group membership after adjustment for anteroposterior length and covariates. ROC analyses showed significant, modest discriminative performance. A significant sex interaction was observed, with large CSP and large CVI being associated with group membership in female participants. CONCLUSIONS: Midline anomalies exhibit size-dependent associations with schizophrenia spectrum disorders, with CSP transverse width and CVI height providing dimensional information beyond conventional length-based classification. These findings are consistent with the neurodevelopmental hypothesis of schizophrenia, while individual-level diagnostic utility remains limited.