右後下小脳動脈瘤の破裂により椎骨脳底動脈血栓閉塞をきたした1例

A Case of Posterior Inferior Cerebellar Artery Aneurysm Which Caused Occlusion of Vertebrobasilar Artery after Subarachnoid Hemorrhage

I．はじめに

　近年，CTスキャンの普及に伴い，くも膜下出血の診断率の向上がみられる，しかし，くも膜下出血の診断を得ているにもかかわらず，脳動脈瘤の発見されない場合もある．その原因としては血管撮影上の条件の不的確なものも多いが，脳動脈瘤のneckが細い場合，脳血管攣縮で造影されない場合，また他の脳血管と重なって見逃されることもある．今回，20歳女性でくも膜下出血で発症し，four vessel studyで脳底動脈閉塞のみの所見を呈しており，剖検にて右椎骨動脈後下小脳動脈分岐部動脈瘤と，その主幹動脈である椎骨脳底動脈の血栓閉塞を認めた症例を経験したので，そのメカニズムを考察し報告する．

An autopsied case of ruptured saccular aneurysm at the junction of posterior inferior cerebellar artery and vertebral artery with which the aneurysm and basilar artery were occluded was reported.

A 20-year-old female was admitted to our hospital because of consciousness disturbance and convulsion.

CT scan revealed subarachnoid hemorrhage. Four vessel angiography did not show any aneurysms nor arteriovenous malformations but revealed occulusion of vertebrobasilar artery.

Continuous ventricle drainage was performed but she died 5 days after the onset.