Psychosis and brainstem malformations: A case series

Background: First episode psychosis can be secondary to many psychiatric and medical conditions including congenital neurological abnormalities. This case series explores the association between first-episode psychosis and structural brainstem malformations—Dandy-Walker variant, Arnold-Chiari malformation, and aqueductal stenosis. Cases: Case 1: A 16-year-old male presented with disorganized behavior and affective symptoms; Magnetic resonance imaging (MRI) revealed a Dandy-Walker variant. Significant improvement was achieved only with clozapine. Case 2: An 18-year-old male with irritability, disinhibition, and poor medication response was found to have Arnold–Chiari Type I malformation; clinical recovery occurred following electroconvulsive therapy. Case 3: A 17-year-old male with psychosis, seizures, and borderline intellect demonstrated aqueductal stenosis; symptom recurrence followed medication discontinuation but improved post-seizure. Conclusion: Brainstem malformations may underlie certain psychoses via cerebellar dysfunction and predictive processing deficits. Early recognition and multidisciplinary management are vital, and further research into cerebellar contributions to psychosis is warranted.