Ferraro J A, Tibbils R P
University of Kansas Medical Center, Kansas City, USA.
Am J Audiol. 1999 Jun;8(1):21-8. doi: 10.1044/1059-0889(1999/001).
Conventional analysis of the click-evoked electrocochleogram includes measurement of the amplitudes of the cochlear summating potential (SP) and auditory nerve action potential (AP) to derive the SP/AP amplitude ratio. It is now well documented that an amplitude ratio where SP is elevated relative to AP may be a positive finding for endolymphatic hydrops in patients suspected of having Ménière's disease (MD). However, the incidence of an elevated SP/AP amplitude ratio in the general MD population is only approximately 60%. This relatively low value necessitates efforts to improve the diagnostic sensitivity of electrocochleography (ECochG) for MD. A review of early and more recent literature in this area indicates that consideration of both the amplitude and duration of ECochG components may help to achieve this goal. The present study combined these features to measure the "area" of the SP-AP complex in normal and MD populations. A software routine was used to measure the amplitude x duration area of the SP-AP complex in (a) normally hearing adults with normal SP/AP amplitude ratios (Group 1), (b) confirmed MD patients with elevated SP/AP amplitude ratios (Group 2), and (c) probable MD patients with normal SP/AP amplitude ratios (Group 3). Ninety percent of the confirmed MD patients in Group 2 displayed elevated SP/AP area ratios relative to the normative value established from Group 1. In addition, almost half of the probable MD patients from Group 3 displayed elevated area ratios. These findings indicate that measurement of the SP/AP area ratio holds promise for improving the sensitivity of ECochG in the diagnosis of MD.
传统的点击诱发耳蜗电图分析包括测量耳蜗总和电位（SP）和听神经动作电位（AP）的幅度，以得出SP/AP幅度比。现在有充分的文献记载，对于疑似梅尼埃病（MD）的患者，SP相对于AP升高的幅度比可能是内淋巴积水的阳性发现。然而，在一般MD人群中，SP/AP幅度比升高的发生率仅约为60%。这个相对较低的值使得有必要努力提高耳蜗电图（ECochG）对MD的诊断敏感性。对该领域早期和近期文献的回顾表明，考虑ECochG成分的幅度和持续时间可能有助于实现这一目标。本研究结合这些特征，测量了正常人群和MD人群中SP-AP复合体的“面积”。使用一个软件程序测量了（a）SP/AP幅度比正常的听力正常成年人（第1组）、（b）SP/AP幅度比升高的确诊MD患者（第2组）和（c）SP/AP幅度比正常的疑似MD患者（第3组）中SP-AP复合体的幅度×持续时间面积。第2组中90%的确诊MD患者相对于第1组确定的标准值显示出升高的SP/AP面积比。此外，第3组中几乎一半的疑似MD患者显示出升高的面积比。这些发现表明，测量SP/AP面积比对提高ECochG在MD诊断中的敏感性有希望。
