Whispers from the Cerebellum: Psychosis Unveiled in Chiari I Malformation

Abstract Chiari I malformation, characterized by cerebellar tonsillar herniation through the foramen magnum, is typically associated with neurological symptoms. Psychiatric manifestations, though increasingly recognized, rarely include psychosis. Diagnosis and subsequent management of such a rare syndrome with uncommon presentations can be challenging. We present a case of an 18-year-old male who presented with posterior headaches and a first episode of schizophrenia-like psychosis, who was subsequently diagnosed with type I Chiari malformation. This case underscores the cerebellum’s potential role in affective and cognitive regulation and highlights the importance of neuroimaging in atypical psychiatric presentations. The overlap between structural brain anomalies and psychiatric symptoms necessitates a high index of suspicion and an integrative diagnostic approach. This report contributes to the limited literature on psychosis in Chiari I malformation and advocates for neuropsychiatric vigilance in similar clinical scenarios.