くも膜下出血を伴わず被殻出血のみで発症した破裂中大脳動脈分岐部動脈瘤の1例

A Case of Ruptured Middle Cerebral Artery Bifurcation Aneurysm Presenting as Putaminal Hemorrhage without Subarachnoid Hemorrhage

はじめに

　破裂脳動脈瘤に脳内血腫を伴うことは血腫型くも膜下出血ではしばしば経験されるが，くも膜下出血を伴わず脳内血腫のみで発症した破裂脳動脈瘤の報告は少ない^1－18）。

　今回われわれは，くも膜下出血を伴わず被殻出血のみで発症した破裂中大脳動脈分岐部動脈瘤の1例を経験したので，文献的考察を加え報告する。

Abstract

　Ruptured aneurysms typically present as subarachnoid hemorrhage (SAH); however, they can also cause intracerebral hemorrhage (ICH) that can be mistaken for hypertensive hemorrhage.

　We report a rare case of a ruptured middle cerebral artery bifurcation aneurysm presenting as putaminal hemorrhage without subarachnoid hemorrhage (SAH).　A 47-year-old man, with a past history of hypertension, presented with a decreased level of consciousness.　Neurological examination revealed hemiparesis of the right side.　A CT scan on admission demonstrated left putaminal hemorrhage without SAH.　Three-dimensional CT and conventional angiograms demonstrated a superiorly directing aneurysm of the M1/M2 portion of the left middle cerebral artery (MCA).　We performed aneurysmal clipping and hematoma evacuation.　The postoperative course was uneventful.

　This case suggested that ruptured aneurysms situated on the middle cerebral artery can present as putaminal hemorrhage without SAH.

（Received: March 17,2009,Accepted: May 29,2009)