术中经蜗窗龛电刺激记录听性脑干反应方法的建立及初步应用

目的 建立人工耳蜗手术中经蜗窗龛电刺激记录听性脑干反应的方法.方法 应用自制铂铱合金球形电极作为刺激电极,改装的人工耳蜗植入体连接体外言语处理器作为电刺激仪及Bio-logic Navigator Pro诱发电位仪,对17例不同病因(包括听神经病2例、耳蜗骨化1例、内耳畸形5例、脑白质异常1例,原因不明8例),不同年龄的人工耳蜗植入患者在手术中进行测试.植入人工耳蜗装置前,将刺激电极放置在蜗窗龛内,用电荷平衡双相脉冲电流经蜗窗龛进行电刺激,记录电诱发听性脑干反应.结果 17例患者均记录到明确的电诱发听性脑干反应波形,Ⅲ波和Ⅴ波的潜伏期分别为(2.12±0.18)ms 和(4.18±0.19)ms,阈值为(220.00±16.04)CL.其中2例听神经病、5例内耳畸形、1例耳蜗骨化、1例脑白质异常患者均记录到分化良好的波形.结论 电诱发听性脑干反应是一项能够较准确地反映听觉传导通路功能完整性的客观神经电生理测试方法,对于判断人工耳蜗植入后患者能否获得听性反应,具有重要的应用价值.本研究方法的安全性符合要求,听性反应的引出率高,值得推广应用.

Establishment and rudimentary application of the method of recording auditory brainstem responses electrically stimulated via round-window niche in cochlear implants

Objective To establish the method of recording auditory bralnstem responseselectrically stimulated via round·window niche in cochlear implants.Methods Self-made phfinum iridiumauoy as a spherical electrode stimulation electrode,modified cochlear implants connected to in vitro speech processor 88 a electro·stimulator and evoke potential instrument for Bio-logic Navigator Pro,17 cechlear implant patients with various ages and of d～erent CaUlS,including auditory neuropathy(2 CS84gS),08si6ed cochlea(1 case),inner ear malformation(5 cases),leukodystrophy(1 case),unknown and reason(8 cases)were investigated during cochlear implant surgery.Before cochlear implantation,stimulation electrode was placod in the round.wiMow niche while charge balanced biphasic constant current Was used as electrical stimulation via round window niche,and then electrically evoked auditory brainstem responge was recorded.Results Electrically evoked auditory brainstem response waveforms were clearlv recorded in all 17 cases.The Iatencies of Ⅲ and Ⅴ waves were(2.12±0.18)ms and(4.18±0.19)ms respectively,with threshold as (220.0±16.04)CL.Thewaveforms of the 2 patientswith auditory neuropathy,5 pailentswithinner ear malformation.1 patient with ossifiod cochlea and 1 patient with leukodystrophy were well differentiated.Conclusions Monitoting electrically evoked auditory brainstem response was an obiective nerve electmphysiological testing method that accurately reflects function complexness of auditory pathway.It had important value for helping making the judgment whether patients could acquire auditory response after cochlear implantation.This method Was safe and gave high emission of auditory response,therefore should be spread widely.