Interhemispheric subdural hematoma caused by a ruptured internal carotid artery aneurysm: Case report

BACKGROUND Interhemispheric subdural hematoma (ISH) usually occurs after head trauma; nontraumatic ISH is extremely rare. CASE DESCRIPTION The authors describe a 62-year-old male presenting with severe headache and ptosis on the left side. Computed tomography (CT) and magnetic resonance imaging disclosed a hematoma in the interhemispheric subdural space without subarachnoid hemorrhage. Cerebral angiography revealed an aneurysm arising from the left internal carotid-posterior communicating artery (IC-PC) junction. The patient underwent emergency clipping of the aneurysm and was discharged without neurological deficit. CONCLUSION Ruptured aneurysms resulting in ISH without subarachnoid hemorrhage have been reported in only a few cases; this is the second case to describe the association of a ruptured IC-PC aneurysm with an ISH. The etiology of ISH formation due to ruptured aneurysms and the diagnosis are discussed. (C) 2000 by Elsevier Science Inc.