特発性両側性感音難聴の難聴進行，とくに急速進行症例について

Rapid Progression of Hearing Impairment in Idiopathic Bilateral Sensorineural Hearing Loss (IBSH)

I．はじめに

　特発性両側性感音難聴（以下特難と略す）はこの数年来厚生省調査研究班の調査，研究によってその臨床像が解明されてきたが，原因は依然不明の感音難聴である。

　特難の特徴の一つはこの難聴が両側性であり，しかも進行するということであり，このことが臨床上重要な意義をもつことはいうまでもない。

　IBSH is one of the sensorineural hearing losses of unknown etiology, and characterized by bilateral progressive hearing impairment. There are two types. slow or rapid progression of hearing loss. Recently we encountered 15 cases of rapid progress type of this disease in our clinic. The purpose of this study is to describe the clinical and audiological findings of IBSH.

　The results are summarized as follows :

　1. In rapid progress, the hearing loss developed within a half day, a day or several days.

　2. The hearing loss occurred at any frequencies and the hearing impairment was about 20-30 dB threshold level comparing before the onset.

　3. In 9 cases, there were tinnitus, fullness and vertigo several days before the onset, and these symptoms seemed like aura.