噪声性听损伤者听性脑干诱发电位的变化特点

Changes of auditory brainstem response in the patients with noise-induced hearing loss

目的:观察噪声性听损伤者听性脑干诱发电位(auditory brainstem response,ABR)的变化特点。方法:对接触噪声作业的47例工人进行纯音测听(pure tone audiometry,PTA)和ABR测试;依PTA正常者和4、3、2kHz处的听力受损者分为4组;对各组的ABR结果进行比较分析。结果:(1)随听力损失频率和程度的增加,逐渐出现低声强Ⅴ波潜伏期延长、高声强Ⅰ波的异常,继之伴Ⅲ波、Ⅴ波的异常,同时伴Ⅴ波反应阈的逐渐上升。(2)仅有4kHz受累的轻度噪声性听力损失者,主要表现为低声强的Ⅴ波潜伏期延长和半数耳高声强的Ⅰ波异常。结论:(1)噪声性听损伤的ABR变化反映了声损伤始于外毛细胞,逐渐累及内毛细胞、听神经和脑干听觉通路的病变过程。(2)低声强的Ⅴ波潜伏期延长和高声强的Ⅰ波异常系轻度噪声性听损伤ABR的主要异常表现;对于可疑噪声性听损伤者在ABRⅤ波阈值正常时,还应观察其阈值处潜伏期,并结合其他听力学检查结果才能作出合理判断。

Objective To observe the changes of auditory brainstem response in the patients with noise-induced hearing loss. Methods Forty-seven workers exposed to occupational noises were tested by pure tone audiometry （PTA） and auditory brainstem response （ABR）. All of the subjects were divided into 4 groups based on the patterns of PTA. The ABR results in each group were analysed and compared to their behavioral thresholds of PTA. Results （1）With the increase in the frequency and extent of hearing loss, the prolongation of wave Ⅴ latency at the lower stimulating level first occurred, followed by the prolongation or absence of wave Ⅰ , and then the abnormalities of wave Ⅲ to Vat the higher level; In this process, wave Ⅴ thresholds gradually increased, which became more obvious in the latter stage of noise-induced hearing loss. （2）For the mild hearing loss at 4 kHz alone, the ABR abnormality mainly presented as prolonged wave Ⅴ latency at lower level and in half cases was the change of wave Ⅰ at higher level. Conclusions （ 1 ）The ABR results of noise-induced hearing loss are correlated with a gradual pathological process from outer to inner hair cells, then to auditory nerve and brainstem auditory pathway. （2）For the suspected cases of noiseinduced hearing loss, wave Ⅴ latency at lower level should be observed and combined with other auditory tests to make a logical diagnosis.