急性低音障害型感音難聴を呈した外リンパ瘻の1例

Acute Low-tone Sensorineural Hearing Loss caused by Round Window Rupture

I．緒言

　1968年のSimmons^1）の論文以来，特発性の外リンパ瘻が急性，反復性の蝸牛・前庭障害を引き起こす新しい疾患概念として注目されてきた。当初は突発性難聴の成因として重要視されていた外リンパ瘻ではあるが，聴力障害を欠く症例の報告^2,3）もみられるようになり，その内耳障害の実態はいまだ明らかではない。

　一方急性低音障害型感音難聴については最近の報告^4,5）によりその概念がまとまりつつある。しかし病因についてはまだ明らかではなく，種々の病因が考えられている。

A 53-year-old woman developed an acute low-tone sensorineural hearing loss caused by perilymph fistula. She complained of left tinnitus and sense of fullness after blowing her nose. Audiogram showed a mild low-tone deafness, and vestibular function was normal except for head shaking nystagmus test. No fistula symptom was found but she felt dizzy when the auditory tube was inflated. Exploratory tympanotomy revealed left round window rupture, and the fistula was covered by perichondrium. Hearing was recovered and head shaking nystagmus was also disappeared. Since the causes of acute low-tone sensorineural hearing loss was various, a bibliographic review was briefly performed.