聾型聴力を示す耳硬化症に対するアブミ骨手術

Stapes surgery for otosclerosis with deaf-type hearing loss

はじめに

　純音聴力検査にて気導聴力が100dB以上の聾型聴力を示す症例のなかには，骨導聴力がある程度保たれている混合性難聴症例が少なからず存在する。それらのなかで聴器CTにて蝸牛型耳硬化症を認める例も少なくない。今回，われわれは純音聴力検査にて聾型を示す混合性難聴症例のなかで，骨導閾値が残存していることを確認し，側頭骨CTにより耳硬化症と考えられた症例に対し，両側のアブミ骨手術を施行し，聴力の著明な改善をみた症例を3例経験したので報告する。

　Stapedotomy was performed in three cases who suffered from bilateral otosclerosis and had profound hearing loss of over 100 dB. They were examined twice puretone audiometry which showed conductive deafness and a c4dip every time. They were also examined with accuitomography（0.35 mm slice）which showed an osteolytic lesion and osteoplastic lesion around the cochlea. Their hearing has remarkably improved and they can now hear moderately with hearing aids.