ガンマナイフ治療が奏功した顔面神経鞘腫の2例

Two Cases of Facial Neurinoma Successfully Treated with Gamma Knife Radiosurgery

I．はじめに

　神経鞘腫は全脳腫瘍のうち約8％を占めるが，大多数が聴神経に発生し，顔面神経に発生することは稀である^{3,5,9,13,14）}．従来は顔面神経鞘腫に対し外科的治療が行われてきたが，術後重度の顔面神経麻痺を来すことが多かった．

　今回われわれは顔面神経鞘腫2例に対しガンマナイフ治療を行い良好な結果を得たので報告する．

Two cases of facial neurinoma successfully treated with gamma knife radiosurgery are reported.

Case 1, a 33-year-old female, developed a right-sided hemifacial spasm about five years ago. Then shesuffered gradual progression of right-sided facial palsy, dysgeusia and reduction of lacrimation, but she hadno hearing disturbance. Tl-weighted MRI with gadolinium DTPA showed a well-circumscribed tumor atthe geniculate ganglion extending to the middle cranial fossa. The tumor was treated with gamma kniferadiosurgery which reduced its size, but didn't reduce the patient's facial palsy. Case 2, a 36-year-old fe-male, presented with fluctuating facial palsy and sensorineural hearing loss lasting for fourteen years. T1-weighted enhanced MRI showed a well-enhanced tumor at the CP angle extending to the middle cranialfossa. The tumor was treated with gamma knife radiosurgery, which caused central tumor necrosis, butdidn't reduce the tumor size. Meanwhile the patient's facial palsy improved.

Gamma knife radiosurgery is apparently effective against facial neurinomas without producing seriouscomplications such as complete facial palsy and hearing loss. Our study indicates that gamma kniferadiosurgery is a useful therapeutic alternative for facial neurinomas.