後下小脳動脈末梢部動脈瘤の3例

Distal Aneurysm of Posterior Inferior Cerebellar Artery:Report of 3 cases

I．はじめに

　後頭蓋窩における脳動脈瘤の発生頻度は，全頭蓋内脳動脈瘤の4-15％と少ないが，なかでも後下小脳動脈末梢部の脳動脈瘤は稀である．今回われわれは，3例の後下小脳動脈末梢部動脈瘤を経験したので，文献的考察を加え報告する．

The incidence of posterior fossa aneurysm is re-ported to be 4-15% of all intracranial aneurysms in large series. Most aneurysms of the posterior inferior cerebellar artery (PICA) arise at the origin of the PICA. However, aneurysms of the distal part of the PICA have only rarely been described.

This report presents three cases of distal PICA aneurysm with subarachnoid hemorrhage. Two aneurysms were located in the superior retrotonsillar segment of the PICA in two cases, and another was located in the tonsillohemispheric branch in one case.