听神经病患者纯音听力和耳声发射表现特征分析

目的 探讨听神经病的病损部位及发病机制。方法 常规检测听神经病患者（10例，20耳）和正常听力者（10例，20耳）的纯音听力及DPOAE，并对结果进行比较和统计学分析。结果 听神经病组20耳中18耳纯音测听呈低频下降型听力损失，另2耳呈鞍型听力曲线，低频（250．500、1000Hz）听力损失一般大于40dB。畸变产物耳声发射均可引出，各频率耳声发射幅值与正常对照组差异无统计学意义，纯音听力与相应频率耳声发射出现矛盾。结论 听神经病的病损部位可能位于耳蜗传人通路，神经冲动非同步化或同步化受损是听神经病的发病机制之一。

The Contradiction between Pure Tone Threshold and Distortion Product Otoacoustic Emission of Auditory Neuropathy Patients

Objective To investigate and analyze the site of lesion and the machanism of auditory neuropathy.Methods 10 patients(20 ears)with auditory neuropathy(AN) and 10 normal hearing youth(20 ears)were of audiological battery assessed with routine pure tone audiometry and distortion product otoacoustic emission. Data of the two groups were compared and analyzed statistically.Results Pure tone audiograms in 18 ears of AN group showed low-frequency hearing loss, while the other 2 showed a saddle-like threshold curve. The hearing loss at low frequency(250,500,1 000 Hz) was more than 40 dB in most ears. Distortion product otoacoustic emission responses were present in all cases. The average amplitude at each frequency exhibited no significant difference compared with control group. Conclusion The site of lesion of auditory neuropathy may be in the cochlear afferent pathway. The asynchronization of the cochlear afferent nerve fibers may be responsible for auditory neuropathy,thus causing the contradiction.