Subarachnoid hemorrhage in a 46-year-old woman

A CT of the head showed a diffuse homogeneous hyperdensity in the basal cisterns, the left Sylvian fissure, the posterior horns of the lateral ventricles, and the anterior and medial aspect of the left temporal lobe (Figures A, B). There was also mild hydrocephalus. Ancillary testing showed EKG signs of left ventricular hypertrophy, a normal platelet count, and normal international normalized ratio (INR). A urine drug screen was positive for cocaine. After a bedside external ventricular drainage was placed in the emergency room, a CT angiogram showed a large irregular saccular aneurysm at left posterior communicating artery segment of the left internal carotid artery (Figure C, arrow). A digital subtraction angiogram confirmed the 8 mm multilobulated left posterior communicating artery aneurysm, and identified a smaller 2.5 mm superior hypophyseal aneurysm as well (Figure D, arrows). Using intra-arterial balloon-assisted technique, detachable coils were placed in both aneurysms to occlude the aneurysms (Figure E). Following the procedure, she was treated in the neurocritical care unit, and on hospital day 18, she was discharged to rehabilitation with mild right hemiparesis. (Contributed by Dr. James R Brorson.)