听神经病的听功能状态分析

The status of auditory function in auditory neuropathy

目的 :探讨听神经病的听功能状态及病损部位。方法 :分析 6 5例听神经病患者的临床资料、纯音测听、声导抗测试、听性脑干反应 (ABR)、4 0Hz听觉相关电位及OAE检查结果。结果 :听神经病的低频听力损失源于蜗后的传入、传出神经及听性脑干受损 ,表现为声反射、传出抑制、ABR异常及诱发性OAE与纯音听阈不呈平行关系 ,与之相对应 ,低频区的外毛细胞处于失抑制的超常活动状态 ,表现为低频区SOAE增强、TEOAE反应幅值及DPOAE幅值升高 ;听神经病的高频听力损失源于耳蜗的外毛细胞损害 ,表现为高频区DPOAE幅值与纯音听阈呈一致性下降 ;听神经病的中频听力损失最轻或接近正常 ,表现为 2kHz附近的纯音听阈和DPOAE幅值均接近于正常。结论 :听神经病的传入、传出系统及耳蜗水平均有不同程度的功能障碍 ,其病损部位主要在耳蜗传入、传出神经 ,向上可侵及脑干 。

Objective:To study the status of auditory function and the site of lesion in auditory neuropathy.Method:The data of 65 patients were analyzed including the clinic signs, pure tone audiometry,auditory brainstem response(ABR),40 Hz auditory event related potential(40 Hz AERP) and otoacoustic emissions (OAEs).Result:The low frequency hearing loss in auditory neuropathy arose from the lesion of retrocochlear auditory afferent and efferent nerve and auditory brainstem, presented at the abnormality of acoustic reflex,efferent suppresion,ABR and the unparallel relationship between evoked OAE amplitude and pure tone threshold.To corresponding,the outer hair cells in low frequency region were out of suppression,presented at the strong response of SOAE,TEOAE and DPOAE in low frequency region.The high frequency hearing loss in auditory neuropathy arose from the lesion of cochlear outer hair cells, presented at the parallel relationship between DPOAE amplitude and pure tone threshold in high frequency region. The intermediate frequency hearing loss in auditory neuropathy was damaged gently or close to normal, presented at both pure tone threshold and DPOAE amplitude nearby 2 kHz were close to normal.Conclusion:The dysfunction in differ degree lied in the afferent and efferent nervous systems and cochlear level in auditory neuropathy, the main site of lesion was in the cochlear afferent and efferent nerve, up to the brainstem and down to the cochlea.