听神经病106例听力学分析

目的 分析106例听神经病患者的临床特点和听力学测试结果.探讨听神经病纯音听力图和听性脑干反应(ABR)的特点.方法 回顾性分析2001年12月至2007年5月就诊的106例(212耳)听神经病患者的症状及纯音听阈、声导抗图及镫骨肌反射、ABR、畸变产物耳声发射(DPOAE)和颅脑影像学检查的结果.结果 患者中男54例,女52例;年龄11～37岁,以青少年居多(75例,70.8%).伴有其他外周神经病者8例,伴视神经病者4例,未查出明确病因者94例.患者均为双耳发病.在212耳中,有173耳(81.6%)听力下降最多的频率为0.25 kHz和0.5 kHz.轻至中度听力损失共209耳(98.6%),均为感音神经性听力损失.按WHO(1997)听阈的均值计算法统计,本组有49耳(23.1%)的听阈≤25 dB,按WHO推荐的听力减退分级标准,使这些有听力障碍的病耳列入了正常范围.212耳听性脑干反应的测试中,各波形皆未引出者124耳(58.5%),余88耳有1或2个波未引出,而可引出的波的波幅很小,但有重复性.在1或2个可引出小波病例中,有23例其另1侧耳各波皆缺失.另有2例伴其他周围神经病和1例伴视神经病的患者,其双耳均有1或2个小波可引出.畸变产物耳声发射除1例左侧3～6 kHz,右侧5～6 kHz未引出外,余均可引出.结论 听神经病在青少年中并不罕见.因听神经病大多以低频听力下降为主,对听神经病患者平均听阈的计算方法值得讨论.

Electrophysiological findings for 106 cases with auditory neuropathy

OBJECTIVE: To analyses the clinical characteristics and electrophysiological finding of 106 patients with auditory neuropathy (AN). Investigate the differential curve type of pure tone audiogram and the abnormal ABR. METHODS: Review the history of patients, pure tone audiometry, middle ear acoustic reflexes, auditory brainstem response, distortion product otoacoustic emission and radiologic imaging studies of the brain of 106 patients with AN during December 2001 to May 2007 in retrospect. RESULTS: The 106 patients with AN were of both genders. The age were between 11-37 years old, and the average age was 17.5 years old. The most patients were adolescences (70.8%). Twelve cases of the 106 patients had evidence of other peripheral neuropathy in addition to hearing loss. Another 94 patients were idiopathic origins. The pure tone audiogram showed a minimal to moderate sensorineural hearing loss at low frequencies 0.5 kHz and 0.25 kHz in 209 ears (98.6%). The average hearing threshold (WHO 1997) in 23.2% of disordered ears at less than 25 dB in the "normal" range. Auditory brainstem response could not be recorded in 124 ears (58.5%) at maximum stimulus. The other 88 ears showed 1 or 2 wave, but the wave were small. There were 23 patients which one side ear ABR was 1 or 2 small waves presented, but the contralateral side were all waves absent. In 3 cases of AN with other peripheral neuropathy which ABR were both ears 1 or 2 small wave ear recorded. However, 1 patient in our sample could not be detected distortion product otoacoustic emission at 3-6 kHz (left ear) and 5-6 kHz (right ear). CONCLUSIONS: AN was not rare in adolescences. The average hearing threshold for AN should be discussed.