耳蜗电极位置间eCAP测量的年龄依赖性变异：耳蜗植入使用者中相间间隙的影响

文献信息

中文摘要

目的： 从耳蜗植入物获得的电生理测量可提供关于电极-神经元界面（ENI）的客观信息。尽管常规的电诱发复合动作电位（eCAP）测量被广泛用于表征神经反应性，但其对年龄和电极依赖性差异的敏感性仍不清楚。本研究探讨了电极位置和相间间隙（IPG）对儿童和成人耳蜗植入使用者eCAP测量的影响。
方法： 12名儿童（平均年龄：6.1岁）和11名成人（平均年龄：32.8岁）使用带有蜗轴周围电极阵列的Cochlear™装置参与研究。在基底、中部和顶部电极测量阻抗、峰值幅度75%处的兴奋扩散（SOE）宽度，以及eCAP阈值、幅度和幅度增长函数（AGF）斜率。使用7和30 µs的IPG记录eCAP。采用互补的统一和归一化分析方法评估IPG效应。
结果： 阻抗在基底电极最高，而SOE宽度在年龄组或电极位置间无显著差异。常规eCAP阈值、幅度和AGF斜率沿耳蜗阵列变化，eCAP幅度和AGF斜率存在区域差异，但年龄相关差异很少。增加IPG在两种分析方法中均显著影响eCAP阈值、幅度和AGF斜率。然而，对于IPG对AGF斜率的相关效应，统一分析显示IPG、组别和电极之间无显著交互作用，而归一化分析显示儿童的斜率效应大于成人，且无显著高阶交互作用。阻抗还与IPG相关的AGF斜率变化相关。
结论： 常规eCAP测量揭示了沿耳蜗阵列的明显区域模式，而IPG操作一致影响阈值、幅度和AGF斜率，在部分测量中观察到组别和电极差异。这些发现提示，IPG敏感的eCAP测量可能提供超越单独常规eCAP测量的关于ENI的补充信息，而观察到的年龄和区域依赖性模式及其对分析方法的依赖性值得进一步研究。

英文摘要

PURPOSE: Electrophysiological measures obtained from cochlear implants provide objective information about the electrode-neuron interface (ENI). Although conventional electrically evoked compound action potential (eCAP) measures are widely used to characterize neural responsiveness, their sensitivity to age- and electrode-dependent differences remains unclear. This study investigated the effects of electrode location and interphase gap (IPG) on eCAP measures in pediatric and adult cochlear implant users.
METHODS: Twelve children (mean age: 6.1 years) and 11 adults (mean age: 32.8 years) using Cochlear™ devices with perimodiolar electrode arrays participated. Impedance, spread of excitation (SOE) width at 75% of peak amplitude, and eCAP threshold, amplitude, and amplitude growth function (AGF) slope were measured at basal, middle, and apical electrodes. eCAPs were recorded using IPGs of 7 and 30 µs. IPG effects were evaluated using complementary unified and normalized analytical approaches.
RESULTS: Impedance was highest at basal electrodes, whereas SOE width did not differ significantly by age group or electrode location. Conventional eCAP thresholds, amplitudes, and AGF slopes varied across the cochlear array, with regional differences in eCAP amplitude and AGF slope but few age-related differences. Increasing IPG significantly affected eCAP threshold, amplitude, and AGF slope across both analytical approaches. However, for the IPG-related effect on AGF slope, the unified analysis showed no significant interaction among IPG, group, and electrode, whereas the normalized analysis showed a larger slope effect in children than adults, without a significant higher-order interaction. Impedance was additionally associated with the IPG-related change in AGF slope.
CONCLUSIONS: Conventional eCAP measures revealed distinct regional patterns across the cochlear array, whereas IPG manipulation consistently affected threshold, amplitude, and AGF slope, with group and electrode differences observed for selected measures. These findings suggest that IPG-sensitive eCAP measures may provide complementary information about the ENI beyond conventional eCAP measures alone, while the observed age- and region-dependent patterns and their dependence on analytical approach warrant further investigation.