後下小脳動脈に発生した解離性動脈瘤の1例

Dissecting Aneurysm of the Posterior Inferkor Ceroebellar Artery;A case repirt

I．はじめに

　頭蓋内の解離性動脈瘤は，近年，画像診断技術の進歩により，報告例が増しており，外科的治療の対象となるものが多く含まれていると考えられ，その重要性が強調されている^1,2,12）．今回，われわれは，巨細胞性動脈炎に起因する後下小脳動脈（以下PICA）末梢部に隈局して発生した解離性動脈瘤の1例を経験したので文献的考察を加えて報告する．

A case of a dissecting aneurysm of the left posterior inferior cerebellar artery caused by giant cell angiitis is presented. A 22-year-old woman was admitted on Au-gust 30, 1990, with sudden onset of severe occipital headache and vomiting. Neurological examination on admission only showed severe meningismus. CT scan demonstrated subarachnoid hemorrhage and a small hematoma in the 4th ventricle. A left vertebral angio-gram demonstrated that the left posterior inferior cere-bellar artery was occluded at the lateral medullary seg-ment. We diagnosed subarachnoid hemorrhage from a dissecting aneurysm. On the day following admission, the patient underwent a left suboccipital craniectomy.The posterior inferior cerebellar artery was enlarged for a distance of about 8 mm and there was typical pur-plish-red appearance in the dissecting aneurysm. This aneurysm was excised after trapping. The histological diagnosis was primary localized giant cell angiitis with-out systemic involvement. The etiology of the intracra-nial dissecting aneurysm is obscure, but this report sug-gests that cerebral angiitis can be considered as an im-portant factor.