[Distal anterior cerebral artery aneurysm causing acute subdural hematoma: report of two cases].

We report two cases of distal anterior cerebral artery aneurysms (distal ACA-aneurysm) causing acute subdural hematomas, which were diagnosed preoperatively. Case 1: 56 y.o. female who presented with stupor and right hemiparesis, was operated on 8 hrs. post-ictus. Case 2: 51 y.o. female who presented with semi-coma, anisocoria and decerebrate posture was operated on 5 hrs. post-ictus. She is alive in fair condition at present. Incidence of acute subdural hematomas in association with ruptured cerebral aneurysms has been reported as variously as 0.5 to 7.9% (clinical cases), with their source of bleeding being either IC or MCA aneurysms. Acute subdural hematomas as complication of ruptured distal ACA aneurysms are rare, and to the authors' knowledge, only 6 cases have been reported so far. Review of the literature regarding mechanism of formation of subdural hematoma, clinical course and treatment of choice are also reported.