1側内耳単独奇形（X線的）の2症例

Unilateral Congenital Anomalies of the Inner Ear

　I．はじめに

　組織学的，またX線的内耳奇形の報告はすでに100編を越えるが^16），ふつうそれは，他奇形との合併，また両側性にみられ，1側性の，しかもほぼ内耳にのみ限局した耳奇形の報告は数少ない。しかし幾つかの報告^{4,7,17〜18）}より，それが，先天性1側聾，またはその可能性を含む，幼小児期に発見される，いわゆる原因，発症時期不詳の若年性片側聾^6,9）（または若年性1側高度難聴^8,18））の，隠れた原因として看過し得ないと感じられている。今回筆者らは，最近経験されたかかる1側内耳単独奇形（X線的）の2症例につき報告し，その奇形型，またこの難聴との関係等につき考察を加えてみることにした。

　The authors presented two cases of unilateral congenital anomalies of the inner ear, revealed by multidirectional tomography of the temporal bones. The patientssuffered from a complete loss of hearing in one ear since early infancy, and also showed absence of vestibular function and x-ray abnormalities of the labyrinth on the deaf ear. The radiological findings were the total absence of any vestige of the inner ear structure in one case, and the presence of a rudimentary cyst-like cavity resembling no part of the normal inner ear along with narrowing of the internal auditory meatus in another case. The anomalies were classified as Michel type. Unilateral anomalies of the inner ear without associated anomalies in other part of the body are uncommon, and a survey of the literature was made.