Bramhall Naomi, Beach Elizabeth Francis, Epp Bastian, Le Prell Colleen G, Lopez-Poveda Enrique A, Plack Christopher J, Schaette Roland, Verhulst Sarah, Canlon Barbara
VA RR&D National Center for Rehabilitative Auditory Research (NCRAR), VA Portland Health Care System, Portland, OR, USA; Department of Otolaryngology/Head and Neck Surgery, Oregon Health & Science University, Portland, OR, USA.
National Acoustic Laboratories, Macquarie University, Australia; The HEARing CRC, Melbourne, Australia.
Hear Res. 2019 Jun;377:88-103. doi: 10.1016/j.heares.2019.02.016. Epub 2019 Mar 9.
Animal studies demonstrate that noise exposure can permanently damage the synapses between inner hair cells and auditory nerve fibers, even when outer hair cells are intact and there is no clinically relevant permanent threshold shift. Synaptopathy disrupts the afferent connection between the cochlea and the central auditory system and is predicted to impair speech understanding in noisy environments and potentially result in tinnitus and/or hyperacusis. While cochlear synaptopathy has been demonstrated in numerous experimental animal models, synaptopathy can only be confirmed through post-mortem temporal bone analysis, making it difficult to study in living humans. A variety of non-invasive measures have been used to determine whether noise-induced synaptopathy occurs in humans, but the results are conflicting. The overall objective of this article is to synthesize the existing data on the functional impact of noise-induced synaptopathy in the human auditory system. The first section of the article summarizes the studies that provide evidence for and against noise-induced synaptopathy in humans. The second section offers potential explanations for the differing results between studies. The final section outlines suggested methodologies for diagnosing synaptopathy in humans with the aim of improving consistency across studies.
动物研究表明，即使外毛细胞完好无损且没有临床上相关的永久性听阈位移，噪声暴露也会永久性地损害内毛细胞与听神经纤维之间的突触。突触病变会破坏耳蜗与中枢听觉系统之间的传入连接，并预计会损害在嘈杂环境中的言语理解能力，并可能导致耳鸣和/或听觉过敏。虽然在众多实验动物模型中已证实存在耳蜗突触病变，但突触病变只能通过死后颞骨分析来确认，这使得在活体人类中进行研究变得困难。人们已使用多种非侵入性方法来确定噪声诱发的突触病变是否发生在人类身上，但结果相互矛盾。本文的总体目标是综合关于噪声诱发的突触病变对人类听觉系统功能影响的现有数据。文章的第一部分总结了支持和反对人类噪声诱发突触病变的研究。第二部分对各研究结果存在差异提供了可能的解释。最后一部分概述了诊断人类突触病变的建议方法，目的是提高各研究之间的一致性。
