初診後も聴力が悪化した突発性難聴

Sudden Deafness with Hearing Loss Progression after Initial Examination

I．はじめに

　突発性難聴（以下突難と略）における難聴の発来については，我が国では厚生省班研究の診断基準^1）に定められているように，突然高度の難聴，すなわち，即時的な難聴，または朝目が覚めて気付くような難聴で，それ以後聴力の悪化は起こらないものとされている。

　一方，欧米の報告をみると，Byl^11），Mattoxら^12）は，12時間以内のものを突難としているが，Byl^11）は実際には2時間以内，あるいは朝目が覚めた時気付くものであると述べ，我が国の基準とほとんど同様である。

　It is said that severe hearing loss appears suddenly in sudden deafness, i.e. instantaneous hearing loss or hearing loss noted on awakening in the morning, with no progression of hearing loss thereafter. However, while treating sudden deafness, 40 cases have been observed in recent 10 years with the hearing loss in the early stage after onset, aggravating also after the initial examination and reaching the maximum in several days.

　Studying these cases from the aspects of clinical findings and prognosis, the progression of hearing loss does not seem to be caused by steroid treatment, but it seems the spontaneous course in most cases. Namely, it suggests the possibility of hearing loss progression for several days in a very few cases of sudden deafness, especialy in lower frequencies.