Cavum septum pellucidum (CSP) and cavum vergae (CV) have separately and together been associated with an increased risk of neurodevelopmental disorders and psychosis; however, there is little literature on the psychopathological significance of isolated CV, and no previous report of isolated CV in late-onset psychosis. We describe an 80-year-old woman who presented with a 1-month history of psychotic symptoms qualifying for a diagnosis of schizophreniform disorder. Physical (including neurological) examination, bedside cognitive testing, and laboratory investigations were all within normal limits. A magnetic resonance imaging scan of the brain revealed an insignificant CSP with prominent CV. The patient showed almost complete recovery from psychosis after 4-6 weeks of treatment with quetiapine (200 mg/day). She maintained improvement with this medication at an 18-month follow-up; medication taper was associated with re-emergence of hallucinations. We briefly discuss CSP and CV in the context of vulnerability to psychosis. We examine whether isolated CV is a benign and incidental finding versus a biological risk factor for neuropsychiatric illness. We suggest specific studies to resolve the uncertainty.
Keywords: Cavum septum pellucidum; cavum vergae; late-onset psychosis; magnetic resonance imaging scan; schizophrenia.