Fahr's Disease Presenting with Aneurysmal Subarachnoid Hemorrhage.

Fahr's disease is a rare disorder of slowly progressive cognitive, psychiatric, and motor decline associated with idiopathic basal ganglia calcification (IBGC) and widespread calcification in the brain and cerebellum. Acute presentation of IBGC is most often as a seizure disorder; however, we present a case of an acute IBCG presentation in which the cause of the deterioration was an aneurysmal subarachnoid hemorrhage.