解離性椎骨動脈瘤により急性増悪した片側顔面痙攣の1例

Hemifacial Spasm Caused by a Dissecting Aneurysm of the Vertebral Artery, and Resulting in Acute Exacerbation

Ⅰ．はじめに

　片側顔面痙攣は発作的に不随意に顔面の表情筋が攣縮するもので，器質的病変が存在し顔面神経のroot exit zone（REZ）への圧迫により生じると考えられている．血管圧迫が最も多い原因であるが，そのほかに腫瘍，脳動静脈奇形，動脈瘤によるものが報告されている^7,10,14,16)．今回われわれは，解離性椎骨動脈瘤により増悪した片側顔面痙攣の1症例を経験したので，文献的考察を含めて報告する．

　The authors report a rare case of a symptomatic hemifacial spasm caused by a dissecting vertebral artery aneurysm and by an anterior inferior cerebellar artery（AICA). A 54-year-old man presented with left hemifacial spasm persisting for 5 years, and the spasm had undergone acute aggravation. Brain magnetic resonance imaging and digital subtraction angiography showed a vertebral artery dissecting aneurysm and an AICA compressing the root exit zone of the left facial nerve. Microvascular decompression of the facial nerve with proximal clipping of the vertebral artery dissecting aneurysm was successfully performed. The hemifacial spasm disappeared immediately after the surgery.