Internal acoustic meatus aneurysmの1治験例

A Case of Aneurysm of the Left Internal Acoustic Meatus

Ⅰ．はじめに

　後頭蓋窩の脳動脈瘤発生頻度は，全脳動脈瘤中約10％前後であり，発生部位は大部分が椎骨動脈又は脳底動脈上やこれらの分岐部に生じる．前下小脳動脈—内耳動脈分岐部附近に発生する動脈瘤はきわめて稀で，現在まで5例の報告がみられるに過ぎない^2,3,5,6,7）．

　我々は最近耳鳴を主訴としたきわめて稀な前下小脳動脈—内耳動脈分岐部動脈瘤（internal acoustic meatus aneurysm）を経験したので，若干の文献的考察を加えて報告する．

A case of aneurysm of the left internal acoustic meatus has been reported. The patient was 53-year-old man who was admitted with the history of sudden onset of a severe occipital headache 18 days previously. He also noted nausea, vomiting and became drowsy at that time. He was seen at a local clinic and a lumbar puncture showed bloody fluid.

The next day his level of consciousness improved but he noted left tinnitus and neck stiffness. On admission, he only complained of a left tinnitus. The rest of the neurological examination was normal.