声诱发的镫骨肌反射阈确定人工耳蜗植入者最大舒适阈

Application of acoustically evoked stapedius reflex threshold via cochlear implant for maximum comfortable level determination

目的研究经人工耳蜗引出的声诱发的镫骨肌反射阈确定人工耳蜗植入者开机状态下的最大舒适阈值。方法选择11例Nucleus C124型人工耳蜗植入者,其中4例为双侧大前庭水管综合征,1例共同腔内耳畸形,这5例内耳畸形的患者神经反应遥测值(neural response telemetry,NRT)阈值很高或几乎测不出。分别测试其激活状态下C值的平均值(real-MCL)水平和声诱发(白噪声,110dB)的镫骨肌反射阈(acoustically evoked stapedius reflex threshold,ASRT)(单位：电流级CL)。结果real-MCL与ASRT值(CL)有很好的一致性,经统计学分析两者比较无显著性差异(P＞0.05),并且在开机的初期ASRT值随real-MCL值的升高而升高。结论人工耳蜗植人者的声诱发的镫骨肌反射阈能较好的反映激活状态下患者的最大舒适阈值,该方法操作较其他方法简单,结果可靠,可尝试用于确定小儿人工耳蜗植入者的最大舒适阈。

OBJECTIVE To investigate the feasibility of determining the maximum comfortable level by using the acoustically evoked stapedius reflex threshold via cochlear implant. METHODS Eleven cases of Nucleus CI24 cochlear implant recipients operated in our hospital were selected（8-39 years old ,who can decide T/C value by themselves with the postoperative time ranging from device initiation to 1 year after operation）,of those four cases were diagnosed as bilateral large vestibular aqueduct syndrome,1 case as common cavity dysplasia ,.neural response telemetry of these five patients with inner ear dysplasia were very high or barely measurable.Real- MCL level and acoustically evoked stapedius reflex threshold under activated condition were measured respectively. The stimulating sound was 110dB of white noise.RESULTS The two group values of ASRT and reaI-MCL were found to be consistant .There is no significant difference statistically （P〉 0.05）. The thresholds of ASR increase with the increasing of real-MCL at the beginning of device initiation. CONCLUSION The acoustically evoked stapedius reflex threshold may reflect （ASRT） the maximum comfortable stimulation level under activated conditions in patients with cochlear implants.It is simple, reliable and may be used to determine the MCL of child cochlear implanted patients.