[Giant brain-base aneurysm--manifested by psychotic symptoms].

An extensive aneurysm in two lobes simulated schizophrenic behavior for six months in a 55-year old man. Headaches, neurological symptoms, unconsciousness and computed tomography led to the diagnosis of a frontobasal tumor. The patient died several days later on hematocephalus internus and constriction of the cerebellum in the foramen occipitale magnum, followed by aneurysm wall dissection. This case shows the necessity of complementing computed tomography with angiography and all other possible tests for exogenous causes of psychotic symptoms.