人工耳蜗植入术后神经反应遥测阈值与行为阈值及舒适阈的比较

目的 通过对人工耳蜗植入术后不同患者神经反应遥测（neural response telemetr,NRT)阈值与行为反应阈值（T-level,T级）及舒适阈（C-level,C级）的比较，试图为小年龄或不能给予准确反应的患者客观估算人工耳蜗植入术后行为反应T、C级提供依据。方法 受试对象为使用Nucleus CI24M型多导人工耳蜗系统的70例患者。共测试329个电极。测试软件为NRT2.04版本。NRT阈值的测试采用单极刺激方式（monopolar stimulation mode)，分别测试每一位患者的第3、5、10、15、20号电极。T级和C级的测试均于NRT测试同日进行。结果 70例患者的329个电极的NRT波形检出率为92.7%。同一患者不同编号电极的NRT反应幅值和阈值及不同患者同一编号电极的NRT反应幅值和阈值均存在差异。NRT阈值的均值介于行为反应T级和C级的均值之间。NRT阈值及T、C级的数值自蜗底至蜗顶呈下降趋势。结论 NRT阈值、T级和C级的个体差异较大，尚不能根据NRT阈值对T级和C级进行准确的判断。但NRT技术可为不能配合术后调试的儿童患者的行为反应T、C级的估算提供客观的方法。NRT这一新技术仍有待于改进。

Comparison of neural response telemetry thresholds with behavioral T/C levels]

OBJECTIVE: To provide an objective method to estimate T-levels and C-levels using neural response telemetry (NRT) thresholds for children, from whom we can not get accurate responses because they are very young or have other disabilities, by comparing NRT thresholds and T/C levels. METHODS: Seventy patients implanted with the nucleus CI24M multiple cochlear implant system participated in this study. 329 electrodes were tested. The software used in this study was NRT 2.04. Monopolar stimulation mode was used during NRT threshold measurement. No. 3, 5, 10, 15, 20 electrodes were tested for each patient. The T-levels and C-levels were obtained at the same visit. RESULTS: 92.7% of all the tested electrodes recorded NRT responses. There were variations in the amplitudes and thresholds of NRT responses across subjects and electrodes. NRT thresholds fell within the different points of the MAP dynamic range. The mean of NRT thresholds was shown to fall between the mean of T-levels and C-levels. The NRT thresholds and T/C levels reduced from basal to apical ends of the cochlear. CONCLUSIONS: Considerable variability across subjects was noted. So it is difficult to estimate T-levels and C-levels accurately by testing only NRT thresholds only. NRT technology provides a new objective method for estimating T-levels and C-levels for children who are unable to cooperate with audiologists during mapping after operation. The new NRT technology should be improved in the future.