多导人工耳蜗植入后电极阻抗和ECAP的变化及意义

Change and Application of Electrode Impedances and Electrically-evoked Compound Action Potentials after Cochlear Implantation

目的观察人工耳蜗植入后不同时间段的电极阻抗和电诱发复合动作电位(ECAP)阈值的变化,探讨其对调试间隔的指导意义。方法对17例植入人工耳蜗的患儿术中及术后30d开机时、开机使用10、20、30、40、50、60、90、150d的电极阻抗值和ECAP阈值进行观测和分析。结果术中和术后30d开机两个时间点与其它各时间点的阻抗值的差异有极显著意义;第22号电极的阻抗值与第2、4、6、8、10、12号等电极的差异有显著性意义,余电极间差异无显著性;电极2、4、6、8、10、12等的术中ECAP阈值与术后30d开机时的ECAP阈值的差异有显著意义。结论人工耳蜗植入电极的阻抗在开机使用后10d有急速的下降,开机使用30d时达最低值,但ECAP阈值的变化不明显;如果电极的阻抗和ECAP阈值在开机使用后2个月均变化不大,可以根据患者的表现适当推迟下次调试的时间。

[Objective] To observe the change of the electrode impedances and the thresholds of the electricallyevoked compound action potentials in different time points after cochlear implantation and to help for deciding the interval of the mapping. [Methods] To test the electrode impedances and electrically-evoked compound action potentials of 17 cases who had accepted the cochlear implantation in different time points： intra-operatian, initial stimulation in 30 days after operation, and I0, 20, 30, 40, 50, 60, 90, 150 days after initial stimulation. [Results] Compared with the other time points, the electrode impedances were the lowest at intra-operation and the highest at initial stimulation, with statistical significance; There were significant differences in the electrode impedances between the 22nd electrode and the 2nd, 4th, 6th, 8th, 10th, 12th electrodes in different time points. There were significant differences in the ECAP thresholds of the 2nd, 4th, 6th, 8th, 10th, 12th electrodes between intra-operation and initial stimulation.[Conclusion] The impedance had a rapid decrease after initial stimulation, and got the lowest level I0 days later after initial stimulation; but the distinct change of ECAP threshold could not be found; If the electrode impedance and ECAP threshold had tended to maintain stable in two months after initial stimulation, mapping could be postponed according the performance of the patients.