定型的症候を示さない聴神経腫瘍例

Abstract

Acoustic neurinoma can be easily diagnosed by the following symptoms such as progressive unilateral hearing loss, tinnitus, and a feeling of dizziness. It also can be diagnosed by abnormal results of tests such as pure-tone audiometry, auditory brain stem response (ABR), and caloric nystagmus. Recently, with the development of imaging diagnostics, cases of acoustic nerve tumor without these typical symptoms or findings have been reported.This paper reports the following six cases of acoustic neurinoma with atypical symptomology experienced in Tokushima Municipal Hospital: 1) two patients first developed sudden hearing loss,2) one patient had an abnormal tongue sense as the chief complaint,3)two patients had normal hearing, and 4) one patient showed a normal ABR.The nerves of the internal acoustic meatus are the pars superior vesti bularis, pars inferior vestibularis, pars cochlearis, and nervus facialis. Examination methods for all of these nerves except the pars inferior vestibularis have been developed. Acoustic neurinoma often originates in the pars inferior vestibularis. The establishment of an examination method for tumors of this nerve is desirable.