电诱发听性脑干反应的电生理特征及其在人工耳蜗植入中的评估价值

Electrophysiological characteristics of EABR and its value assessment of cochlear implant

目的:探讨电诱发听性脑干反应(EABR)的电生理特征及对残余听神经数量的评估作用。方法:用Bio-logic Navigator Pro诱发电位仪记录,通过Cochlear Nucleus 24CA植入体给予刺激,对23例人工耳蜗使用者进行术后EABR测试,并与行为学测试及神经反应遥测技术(NRT)结果相比较。结果:23例患儿均记录到EABR的Ⅲ～Ⅴ波,其波形特点及起源与ABR相似。EABR的阈值为(172.61±14.61)CL,阈上20CL时Ⅲ、Ⅴ波的潜伏期分别为(2.93±0.18)ms、(4.80±0.28)ms,较ABR相应缩短1～2ms,而Ⅲ-Ⅴ波间期不变,为(1.86±0.18)ms。EABR阈值与行为学结果、NRT阈值均有相关性,EABR的输入-输出函数曲线斜率与术后电刺激行为学动态范围有相关性(P<0.05)。结论:EABR能够客观反映听觉传导通路的功能状态,为预测残余的听神经数量提供了一定的参考价值。

Objective：To evaluate the electrophysiologicat characteristics of electrically evoked auditory brain- stem responses（EABR） and its application in cochlear implantation, especially in evaluating acoustic nerve surviw al. Method： An auditory evoked potential instrument was used to record responses and Cochlear Nucleus 24CA im- plants were used to generate electrical stimulation. We measured EABR in 23 patients with cochlear implants and compared EABR with behavioral measures and neural response telemetry（NRT）. Result： EABRⅢ-Ⅴ waveforms were recognized in all of the 23 patients. The characteristics and origins of EABR waveforms were similar to those of ABR. The average EABR threshold was（172.61±14.61）CL. At 20 CL above threshold, the average latencies of WaveⅢ ,Ⅴ were（2.93＋0.18）ms,（4.80±0.28）ms which were 1--2 ms shorter than ABR latencies. But Ⅲ-Ⅴ intervals remained at（1.86±0.18）ms. EABR thresholds were strongly correlated with behavioral performance and NRT thresholds, while EABR input-output function is correlated with behavioral dynamic range（DR）. Conclu- sion：EABR is such an effective method to objectively evaluate the function of auditory pathway which can estimate residual spiral ganglion cell count. This is consistent with the foreign study leading to the conclusion that DR re- flects spiral ganglion cell survival.