前下小脳動脈・内耳動脈分岐部動脈瘤の2治験例

Aneurysm of the Anterior Inferior Cerebeller Artery at the Internal Auditory Meatus: Report of two cases

I．はじめに

　椎骨・脳底動脈瘤は全脳動脈瘤の5-10％を占め，決して稀なものではない．しかしその多くは，basilar bi—furcation近傍あるいは後下小脳動脈分岐部に発生し，前下小脳動脈末梢部動脈瘤は現在まで20例の報告を見るにすぎない．われわれは，極めて興味ある発症経過を示した前下小脳動脈・内耳動脈分岐部動脈瘤の2例を経験したので報告する．

Aneurysm of the vertebrobasilar system is not a rare lesion but constituting 5-10% of all intracranial aneurysms. Aneurysm at the peripheral part of the anterior inferior cerebellar artery (AICA), however, is rare and only 20 cases have been reported pre-viously. In this report, two cases of aneurysm arising at the junction between the AICA and internal audi-tory artery and extending into the internal auditory meatus are reported.

The first patient was a 51-year-old male who was admitted because of sudden onset of dizziness, rt. tinnitus and deafness. Left vertebral angiograms dem-onstrated an AVM in the rt.