緩徐形成型突発性難聴の1症例

Sudden Deafness with a Gradual Progress:Report of a Case

　はじめに

　原因不明で突然に発症した高度感音難聴を突発性難聴（以下，突難と略）というが，その中で聴力障害が緩徐に形成される，つまり治療経過中に聴力の悪化を示すタイプの難聴が知られている。このタイプの難聴は，すでにslow typeの突難^1），緩徐形成型の突難^2）として報告されているが，その頻度は低い。今回われわれはこのような経過を示した1症例を経験したので報告し，また文献的考察を行った。

A 13-year-old woman noticed a hearing loss in her left ear on awaking, then she developed dizziness with nausea and vomiting and tinnitus in her left ear several hours after the onset of hearing loss. Her hearing loss gradually progressed for seven days after the onset, whereas dizziness disappeared four days after the onset. Her past history did not indicate the presence of a perilymph leak. On hospitalization she was treated withsteroid for nine days from the third day after the onset. The audiometric examination revealed a cochear lesion. Her hearing loss began to improve on the eighth day after the onset, and recoveredto normal hearing threshold levels at 2 kHz or lower frequencies with a moderate hearing loss at 4 and 8 kHz two months later.