人工内耳により良好な聴覚補償を得たType Ⅲ Usher症候群の1例

A Case of Type Ⅲ Usher Syndrome with Satisfactory Compensation of Hearing Loss by Cochlear Implant

　はじめに

　Usher症候群（USH）^1〜4）は感音性難聴と網膜色素変性を合併する遺伝疾患として知られ，視力障害も進行して盲に至るため，聴覚補償が極めて重要となる^4）。

　今回われわれは，同胞，いとこ，はとこに発症したUSHの1家系を経験し，進行性両側高度難聴に至った重症例に人工内耳埋め込み術を施行し，良好な経過を得たので報告する。

Cochlear implantation was performed in a 47-year-old male with type III Usher syndrome. Despiteof a 30-year-history of total deafness in the operat-ed left ear, good speech communication without any visual cue was achieved. A free and excellent speech as telephone communication became possible in one year.

The speech and hearing were still improving in six years in contrast to the impaired visual acuity. It was emphasized that one should never miss the appropriate period for cochlear implants in patients with Usher syndrome because of the progressive and rapid visual impairment.