Responsiveness of the Electrically Stimulated Cochlear Nerve in Children With Cochlear Nerve Deficiency.
Responsiveness of the Electrically Stimulated Cochlear Nerve in Children With Cochlear Nerve Deficiency.
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DOI：
10.1097/aud.0000000000000467
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发表时间：
2018
期刊：
影响因子：
3.7
通讯作者：
He N
中科院分区：
文献类型：
--
作者：
He S;Shahsavarani BS;McFayden TC;Wang H;Gill KE;Xu L;Chao X;Luo J;Wang R;He N
本研究旨在 1) 调查患有耳蜗神经缺陷 (CND) 的植入儿童的耳蜗神经 (CN) 对单个双相电脉冲的反应性； 2) 将他们的结果与植入正常大小 CN 的儿童的测量结果进行比较。参与者包括 23 名 CND 儿童 (CND1 – CND23) 和 18 名 CND 正常大小的儿童 (S1 – S18)。除 CND1 之外的所有受试者均使用 Cochlear® Nucleus 人工耳蜗 (CI)，并在其测试耳中配备轮廓电极阵列。 CND1 被植入 Cochlear® Nucleus Freedom CI，并在测试耳中植入直电极阵列。对于每个受试者，使用电极阵列上多个电极位点的电诱发复合动作电位 (eCAP) 的电生理测量来测量 CN 输入/输出 (I/O) 功能和不应恢复功能。因变量包括 eCAP 阈值、最大 eCAP 幅度、I/O 函数的斜率以及耐火恢复函数的时间常数。 I/O 函数的斜率是使用 S 形函数的统计模型来估计的。使用具有指数衰减函数的统计模型来估计恢复时间常数，包括绝对不应期和相对不应期的测量。广义线性混合效应模型用于评估电极部位对 CND 儿童中测量的因变量的影响，并比较受试者组之间这些因变量的结果。记录具有正常大小 CN 的儿童的所有测试电极的 eCAP。相比之下，四名 CND 儿童的任何电极部位均无法记录 eCAP。对于所有其他患有 CND 的儿童，随着刺激部位从基底到心尖方向移动，具有可测量 eCAP 的电极百分比有所下降。对于CND患儿，刺激部位对I/O函数斜率和相对不应期有显着影响，但对eCAP阈值和最大eCAP幅度无显着影响。与 CN 正常大小的儿童相比，CND 儿童的 eCAP 阈值显着更高，最大 eCAP 幅度更小，I/O 函数斜率更平坦，绝对不应期更长。这两个受试者组中测量的相对不应期没有显着差异。在患有 CND 的儿童中，CN 的功能状态沿着耳蜗的长度变化。与 CN 正常大小的儿童相比，CND 儿童的 CN 对电刺激的反应性降低。 CND 儿童的 CN 绝对不应期延长可能至少部分解释了在这些患者中使用相对较慢的脉搏频率所观察到的益处。
This study aimed to 1) investigate the responsiveness of the cochlear nerve (CN) to a single biphasic-electrical pulse in implanted children with cochlear nerve deficiency (CND); and 2) compare their results with those measured in implanted children with normal-size CNs. Participants included 23 children with CND (CND1 – CND23) and 18 children with normal-size CNs (S1 – S18). All subjects except for CND1 used Cochlear® Nucleus cochlear implants (CIs) with contour electrode arrays in their test ears. CND1 was implanted with a Cochlear® Nucleus Freedom CI with a straight electrode array in the test ear. For each subject, the CN input/output (I/O) function and the refractory recovery function were measured using electrophysiological measures of the electrically evoked compound action potential (eCAP) at multiple electrode sites across the electrode array. Dependent variables included eCAP threshold, the maximum eCAP amplitude, slope of the I/O function, and time constants of the refractory recovery function. Slopes of I/O functions were estimated using statistical modeling with a sigmoidal function. Recovery time constants, including measures of the absolute refractory period and the relative refractory period, were estimated using statistical modeling with an exponential decay function. Generalized Linear Mixed effect Models were used to evaluate the effects of electrode site on the dependent variables measured in children with CND, and to compare results of these dependent variables between subject groups. The eCAP was recorded at all test electrodes in children with normal-size CNs. In contrast, the eCAP could not be recorded at any electrode site in four children with CND. For all other children with CND, the percentage of electrodes with measurable eCAPs decreased as the stimulating site moved in a basal-to-apical direction. For children with CND, the stimulating site had a significant effect on the slope of the I/O functions and the relative refractory period, but showed no significant effect on eCAP threshold and the maximum eCAP amplitude. Children with CND had significantly higher eCAP thresholds, smaller maximum eCAP amplitudes, flatter slopes of I/O functions, and longer absolute refractory periods than children with normal-size CNs. There was no significant difference in the relative refractory period measured in these two subject groups. In children with CND, the functional status of the CN varied along the length of the cochlea. Compared to children with normal-size CNs, children with CND showed reduced CN responsiveness to electrical stimuli. The prolonged CN absolute refractory period in children with CND might account for, at least partially, the observed benefit of using relatively slow pulse rate in these patients.