孤立性第4脳室内出血で発症した椎骨動脈巨大動脈瘤の1例

Isolated Intraventricular Hemorrhage due to a Ruptured Vertebral Artery Aneurysm

I．はじめに

　頭蓋内脳動脈瘤は破裂時，ほとんどが蜘蛛膜下出血で発症するが比較的高率に脳実質内出血や脳室内出血を伴う．しかし脳動脈瘤からの出血が直接脳室内に流入し「一次的な脳室内出血」を起こすことは稀である．さらにこの中で脳動脈瘤破裂により明らかな脳実質内出血や蜘蛛膜下出血を認めない「孤立性の脳室内出血］をきたすことはきわめてまれで現在まで数例の報告があるにすぎない．またこのような孤立性の脳室内出血をしめした椎骨動脈瘤症例の報告は現在までのところ無い．われわれは孤立性の第4脳室内出血発症しその原因が椎骨動脈巨大動脈瘤であった1例を経験したので文献的考察を加えて報告する．

Abstract

A rare case of ruptured aneurysm originating from the vertebral artery, and presenting an isolated clot in the fourth ventricle is reported. The patient underwent surgery via a right lateral suboccipital craniectomy on the third day. As the aneurysm was huge and partially thrombosed, trapping was performed and completed successfully. If isolated intraventricular hematoma was found without obvious parenchymal hemorrhage or subarachnoicl clot, the diagnosis of vertebral artery aneurysm should be considered as a possibility in addi-tion to posterior inferior cerebellar artery aneurysm. Complete vertebral angiography is indispensable for the recognition of this condition.