直達外力によるアブミ骨陥入症例の検討

Luxation of the Stapes into the Vestible due to Direct Trauma

　はじめに

　外傷性鼓膜損傷は日常診療においてしばしば経験するが，耳かきなどの直達外力により内耳に損傷をきたし，とくに前庭へのアブミ骨陥入をきたすものは比較的稀である。過去約13年間にわれわれが経験した，直達外力によりアブミ骨陥入をきたした症例は，過去の数例の報告^1,2）を含め6症例のみである。今回，これらの臨床症状，とくに前庭および蝸牛症状の経過について検討した。

We reported six cases of luxation of the stapes. In five cases, the ear drum was perforated at the posterior-superior part. Pure tone audiometry showed moderate mixed hearing loss in all cases. Almost all cases presented with horizontal rotatory nystagmus, and especially rotatory torsional compo-nent was strong. This nystagmus suggested that there was damage to the otolith organs. In almost all cases, surgical closure of the round window was effective for improvement of the vestibular symp-toms.

We suggest that immediate operation should be carried out to prevent exacerbation of symptoms caused by direct trauma.