耳蜗外电刺激诱发听力正常幼猫听性脑干反应

The Application of the EABR to Normal Hearing Kittens with Promontory Stimulation

目的探讨幼猫蜗外电诱发听性脑干反应(electrically audiotory brainstemresponses,EABR)检测的可行性,总结猫蜗外EABR的波形特点。方法选取健康幼猫13只,氯胺酮(50mg/kg)肌注麻醉后,首先行ABR测试,选取听力正常耳行蜗外EABR检测。结果13只健康幼猫中,23耳听力正常,对其中21耳行EABR检测,皆可记录到EABR波形,可以记录到Ⅱ、Ⅲ、Ⅳ、Ⅴ波,其中波Ⅲ和波Ⅳ最清晰,波Ⅰ因被刺激伪迹所掩盖一般记录不到。其EABR波形与ABR相似,振幅随刺激强度的减小而减小,潜伏期随刺激强度的减小而延长。刺激电流强度为1mA时,EABR波Ⅱ、Ⅲ、Ⅳ的潜伏期分别为1.60±0.09、2.38±0.10、2.93±0.13ms,较ABR相应的波潜伏期明显缩短。与ABR相比,EABR的Ⅱ-Ⅲ、Ⅲ-Ⅳ、Ⅱ-Ⅳ波间期分别平均缩短约0.24、0.19、0.41ms,差异均有统计学意义(P<0.05)。结论通过一系列减少伪迹干扰的方法,可稳定地记录到听力正常幼猫蜗外EABR波形,其波形与ABR相似,但各波潜伏期及波间期均较ABR缩短。

Objective To investigate the feasibility of recording the EABR with promontory stimulation in normal cats , and to analyze the features of the EABR. Methods Thirteen healthy kittens were selected for the study. The sedated animals received click-evoked auditory brainstem response testing. The ears with normal hearing were used to record EABR. Results Among 23 normal hearing ears in 13 healthy kittens, 21 ears were tested with promontory EABR stimulation. Wave Ⅱ , Ⅲ , Ⅳ and Ⅴ were recorded in EABR test; however, Wave Ⅰ was not recorded because of excessive artifacts. Wave Ⅲ and IV had the best morphology and were similar to ABR. As stimulating intensity was decreasing , the amplitude of EABR decreased and the latency was prolonged. As compared with the results of ABR, the interpeak latencies of all the major waves were statistically reduced. Conclusion Promontory EABR was tested in normal hearing kittens and EABR was recorded steadily using methods of reducing artifacts.