电脑干诱发电位记录在聋幼儿人工耳蜗植入术中的应用

Application of Intraoperative EABR in the Young Deaf With Cochlear Implants

目的 观察术中应用电脑干诱发电位 (EABR)技术判断聋幼儿人工耳蜗植入后的效果及采用EABR数据调试言语处理器的敏感性和优越性。方法 二例聋幼儿 ,一例 2岁 ,另一例 3岁半 ,均被植入法国DIGISONIC人工耳蜗 ,术中采用MXMDIGISTIM电刺激器刺激 ,刺激电极编号为 15、13、10、7和 4 ,由法国专用计算机记录到电脑干诱发电位波形图。结果 从术中EABR波形图可很清楚分辨出III和V波 ,术后测得行为听阈值和术中预测的效果基本相一致。 2岁患儿各电极的EABR阈值分别是 :15 μs× 6 0 μV ,2 0 μs× 6 0 μV ,2 5 μs× 6 0 μV ,30 μs× 6 0 μV和 30μs× 6 0 μV ,3岁半患儿各电极的EABR阈值为 :15 μs× 5 0 μV ,2 0 μs× 5 0 μV ,2 5 μs× 5 0 μV ,2 0 μs× 5 0 μV和 2 0 μs× 5 0μV。言语处理器振幅阈值应设置在小于 15～ 2 0 μV的EABR振幅阈值。在电极 15阈值的设置与电诱发刺激时间宽度 (pulswidths)一致 ,每降低一个电极号码 ,增加阈值 2～ 3dB ,而设置舒适阈与阈值相差 3～ 5dB。结论 术中电脑干诱发电位应用不但可以预示人工耳蜗植入后的效果 ,而且为术后快速精确调试言语处理器提供客观依据。

Objective The aim of the study was to investigate the intraoperative EABR as a reference of beginning of fitting the cochlear implant(CI)and predicting the result.Methods Intraoperative EABR were recorded in two young children(two years,and three and half years)receiving the Digisonic DX 10 Cochlear Implant.Electrodes 15,13,10,7 and 4 were investigated using Digistim Stimulation Mode.Results During the surgery,wave Ⅲ and Ⅴ were clearly seen in the EABR.It was to demonstrate that the function of the auditory pathway of cochlear nerve and brainstem would be good.Measuring behavioral thresholds after implanted chochlea in patient was similar to predict the result.In young child the EABR thresholds were 15 μs×60 μV,20 μs×60 μV,25 μs×60 μV,30 μs×60 μV and 30 μs×60 μV at electrodes 15,13,10,7 and 4,whereas in another child the EABR thresholds had 15 μs×50 μV,20 μs×50 μV,25 μs×50 μV,20 μs×50 μV,and 20 μs×50 μV.Based upon the EABR thresholds,the amplitude for beginning of fitting was set at the 15～20 μV differences between the Digisonic PDX10 and the EAB stimulation.Minima threshold level was set at 15 dB for starting of the number of electrode 15, and then the number of electrodes were decreased with increasing minima threshold levels(2～3 step).This was also achieved by increasing the maximum electrical thresholds.Conclusion It is confirmed that the intraoperative EABR could predict the result,and could be more precise and sensitive for beginning of fitting the cochlear implant as a reference.