Manchester Centre for Audiology and Deafness, University of Manchester, Manchester Academic Health Science Centre, UK.
Manchester Centre for Audiology and Deafness, University of Manchester, Manchester Academic Health Science Centre, UK; Manchester University NHS Foundation Trust, UK.
Hear Res. 2019 Apr;375:34-43. doi: 10.1016/j.heares.2019.01.018. Epub 2019 Jan 23.
Investigations of cochlear synaptopathy in living humans rely on proxy measures of auditory nerve function. Numerous procedures have been developed, typically based on the auditory brainstem response (ABR), envelope-following response (EFR), or middle-ear-muscle reflex (MEMR). Validation is challenging, due to the absence of a gold-standard measure in humans. Some metrics correlate with synaptic survival in animal models, but translation between species is not straightforward; measurements in humans are likely to reflect greater error and greater variability from non-synaptopathic sources. The present study assessed the reliability of seven measures, as well as testing for correlations between them. Thirty-one young women with normal audiograms underwent repeated measurements of ABR wave I amplitude, ABR wave I growth, ABR wave V latency shift in noise, EFR amplitude, EFR growth with stimulus modulation depth, MEMR threshold, and an MEMR across-frequency difference measure. Intraclass correlation coefficients for ABR wave I amplitude, EFR amplitude, and MEMR threshold ranged from 0.85 to 0.93, suggesting that such tests can yield highly reliable results, given careful measurement techniques. The ABR and EFR difference measures exhibited only poor-to-moderate reliability. No significant correlations, nor any consistent trends, were observed between the various measures, providing no indication that these metrics reflect the same underlying physiological processes. Findings suggest that many proxy measures of cochlear synaptopathy should be regarded with caution, at least when employed in young adults with normal audiograms.
在活体人类中进行耳蜗突触病的研究依赖于听神经功能的替代测量。已经开发了许多程序，通常基于听觉脑干反应（ABR）、包络跟随反应（EFR）或中耳肌反射（MEMR）。由于在人类中缺乏金标准测量，因此验证具有挑战性。一些指标与动物模型中的突触存活相关，但物种间的翻译并不简单；人类的测量结果可能反映出更大的误差和更大的非突触源变异性。本研究评估了七种测量方法的可靠性，并测试了它们之间的相关性。31 名听力正常的年轻女性接受了 ABR 波 I 幅度、ABR 波 I 生长、噪声中 ABR 波 V 潜伏期偏移、EFR 幅度、刺激调制深度的 EFR 生长、MEMR 阈值和 MEMR 跨频差测量的重复测量。ABR 波 I 幅度、EFR 幅度和 MEMR 阈值的组内相关系数范围为 0.85 至 0.93，表明在使用仔细的测量技术时，此类测试可以产生高度可靠的结果。ABR 和 EFR 差值测量仅表现出较差至中等的可靠性。各种测量值之间没有观察到显著的相关性或任何一致的趋势，这表明这些指标没有反映出相同的潜在生理过程。研究结果表明，许多耳蜗突触病的替代测量值应谨慎使用，至少在听力正常的年轻成年人中应如此。
