急激に骨導閾値上昇を示した外リンパ瘻の症例

A case of post-traumatic perilymph fistula with delayed deterioration of bone conduction hearing level

Ⅰ　はじめに

　外リンパ瘻は，外リンパが内耳窓などを介して鼓室腔へ漏出し，聴覚や平衡の障害を生じる疾患である。発症原因は，外傷（圧外傷を含む）の頻度が高いが，ほかにアブミ骨手術，奇形，梅毒や，原因不明の特発性のものもある。発症の誘因があった場合，その後突発的あるいは数日をかけて感音難聴が生じ，まためまいや平衡障害を伴う場合もある。今回われわれは，側頭骨骨折後数か月後に急激に骨導閾値が上昇した外リンパ瘻症例を経験したので報告する。

　Perilymph fistula is a disease caused by the leakage of perilymph fluid to the middle ear mostly through the inner ear windows. It results in hearing loss and disequilibrium. We report the case of a 20-year-old woman who complained of hearing impairment after temporal bone fracture caused by a traffic accident. Her hearing improved following medical treatment. However,seven months after the accident,a sudden deterioration of hearing and nystagmus were observed. She underwent exploratory tympanotomy,which revealed dislocation of the stapes. The operative findings suggested that the traumatic perilymph fistula had healed spontaneously,but later relapsed.