ABSTRACT
Colpocephaly, a congenital anomaly in the ventricles, is usually discovered early in infancy and rarely during adulthood. Partial or complete agenesis of the corpus callosum or Chiari malformations (developmental arrest of white matter formation in early fetal development) can lead to abnormal asymmetrical ventricular enlargement. Minimal literature about colpocephaly is available for clinicians, making diagnosis and treatment very challenging. Colpocephaly in adults is an infrequent condition, mostly found as an incidental finding with no neurological or cognitive impairment. Symptoms usually represent the affected lobe in the brain as our patient's visual hallucination may be attributed to the lesioned occipital horn. Differentiating from normal pressure hydrocephalus, representing new-onset dementia, can help avoid unnecessary procedures. Neurological and psychiatric consultation should be practiced to exclude other causes of neurological and cognitive impairment. While there is no definitive treatment for this condition, seizure prophylaxis has been helpful. Cognitive behavioral therapy, psychotherapy, and social skills training are recommended in some literature. Typical and atypical antipsychotics can control symptoms with uncertain efficacy.