術前術後に自発眼振を認めた真珠腫性中耳炎による迷路瘻孔症例

Cholesteatoma with Labyrinthine Fistula and Spontaneous Nystagmus

　はじめに

　迷路瘻孔は，真珠腫性中耳炎の重大な合併症の1つである。迷路瘻孔存在例では末梢前庭機能は高度に低下しやすく，ENGで自発眼振が記録されることも多いが，一般的には手術を契機にめまいおよび自発眼振は消退すると考えられている^1,2）。今回われわれは，迷路瘻孔に対する瘻孔閉鎖手術によりめまいが完全に消失したにもかかわらず，3年以上にわたりENG検査で自発眼振のみが記録された症例を報告する。

A 51-year-old male suddenly experienced rota-tory vertigo soon after he removed cerumen from the right ear canal. Otoscopic examination showed a giant ear polyp due to cholesteatoma. The patient had spontaneous nystagmus with a fine amplitude and low frequency. On CT, labyrinthine fistula due to cholesteatoma was suspected. At surgery, a fis-tula 1×2mm in length was found. The removal of cholesteatoma matrix was performed by one-stage operation. After 3 years, ENG test showed spontane-ous nystagmus similar to that was observed before the surgery. The interpretation of this residual nystagmus was discussed.