Delayed-onset psychosis in carotid cavernous fistula: A case report of dual neuropsychiatric manifestations following traumatic brain injury

Carotid cavernous fistula (CCF) is a rare vascular complication of traumatic brain injury (TBI) that typically presents with ophthalmological manifestations. Neuropsychiatric symptoms, particularly psychosis, associated with CCF are exceptionally rare. We report a 21-year-old male who developed delayed-onset psychosis 6 months following severe TBI complicated by CCF. The patient presented with paranoid delusions, auditory hallucinations, and violent behavior. Initial evaluation suggested organic delusional disorder secondary to TBI. However, concurrent ophthalmological symptoms, including bilateral proptosis and chemosis, prompted neuroimaging, which revealed bilateral cavernous sinus enlargement with nonvisualization of the right cavernous internal carotid artery, consistent with direct CCF. Treatment involved multidisciplinary management, including low-dose antipsychotic medication and endovascular embolization of the fistula. The patient showed gradual improvement in psychiatric symptoms following fistula repair. This case highlights the importance of considering vascular complications in patients presenting with delayed-onset psychiatric symptoms following TBI and the need for comprehensive neuroimaging when ophthalmological signs are present.