A Review of Electrocochleography: Instrumentation Settings and Meta-analysis of Criteria for Diagnosis of Endolymphatic Hydrops

Abstract

This paper reviews the literature on instrumentation settings used for transtympanic (TT-ECOG) and extratympanic electrocochleography ( ET-ECOG). There is wide variation with regard to the applied stimulus, the settings and interpretation of ECOG results. For most physicians, the presence of endolymphatic hydrops is indicated either by the summating/action potential (SP/AP) ratio for click stimuli or the SP amplitude after tone bursts. Different upper limits have been proposed to discriminate hydropic from non-hydropic ears. Based upon a meta-analysis and classification criteria obtained from multivariate statistics, the authors propose that an SP/AP ratio with click stimulation > 0.35 using TT-ECOG, or >0.42 using ET-ECOG, is indicative of hydrops. With tone burst stimulation set at a repetition rate of 30-40 stimuli per second, a SP of < -2 y V using TT-ECOG for at least one frequency within the range 0.5-8.0 kHz is considered pathologic.

Diagnostic Value of Combining Bilateral Electrocochleography Results for Unilateral Ménière’s Disease

“…In this study, ECoG results were not well correlated with audiometric data and the side of disease for patients with definite and probable Ménière’s disease with unilateral low-frequency loss. This finding was consistent with previous reports [4, 8, 9]. In addition, we also showed that the SP/AP ratio was not affected significantly by sex or age (by multivariate linear regression analysis).…”

Does ‘Cochlear Ménière’s Disease’ Exist? An Electrocochleographic and Audiometric Study

“…This diagnostic criterion was obtained from a meta-analysis performed by Wuyts et al [1997]. This analysis showed that, based on the results of 9 TT-ECoG studies, an SP/AP ratio of 0.35 was able to discriminate normal individuals from MD patients.…”

“…The test was performed and interpreted following the test protocol that was published by Wuyts et al [1997Wuyts et al [ , 2001. After the ipsilateral mastoid and the forehead were cleansed with alcohol-soaked wipes, electrode gel was applied to reduce impedance.…”

“…Using tone burst stimuli, the SP amplitudes at 0.5, 0.75, 1, 1.5, 2, 3, 4 and 8 kHz were collected. TT-ECoG was performed and interpreted following the test protocol that was published by Wuyts et al [1997Wuyts et al [ , 2001. A binary logistic regression calculation was carried out to determine a combination of variables allowing the discrimination between definite MD and non-MD.…”

Diagnostik des endolymphatischen Hydrops mit tieftonmodulierten DPOAE

“…Die se Er wei te rung des End olym ph rau mes, die auf eine Re gu la ti onsstö rung der In ne nohr flüs sig kei ten zu rück-zu füh ren ist [14], hat eine Be we gungs einschrän kung der Ba si lar mem bran zur Folge. Bis her wird v. a. die Elek tro koch leo graphie [3,20] ein ge setzt, um auf eine Funkti ons stö rung des Cor ti-Or gans beim EH zu schlie ßen.…”