False traumatic aneurysm of the dorsal wall of the supraclinoid internal carotid artery--case report.

A 32-year-old male presented with subarachnoid hemorrhage following head trauma. Initial carotid angiography revealed an aneurysm protruding from the dorsal wall of the supraclinoid internal carotid artery. Two weeks later, following two additional hemorrhagic episodes, repeat carotid angiography showed severe vasospasm and dramatic expansion of the aneurysm. He died 17 days after the accident. Autopsy and histological examination confirmed the diagnosis of a traumatic, false aneurysm of the internal carotid artery. Improved prognosis requires early recognition and surgical obliteration of such aneurysms.