Copyright © 2016 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited. Letters to the Editor Electrocochleography for the Diagnosis of Me´nie`re’s Disease: The Wrong Stimulus To the Editor: We wish to comment on the recent article entitled ‘‘Click stimulus electrocochleography versus MRI with intratympanic contrast in Menie`re’s disease: A systematic review’’ by Ziylan et al. (1). The authors discussed four relevant articles (2 – 5). The three employ- ing click stimulus electrocochleography (EcochG) (2 – 4) were used for their conclusion which was that ‘‘there is relative low sensitivity and negative predictive value for, click stimulus electrocochleography compared with MRI with intratympanic gadolinium administration for detect- ing endolymphatic hydrops in patients with Me´nie`re’s disease.’’ It highlights the reasons for widespread scep- ticism of electrocochleography as a reliable test for Me´nie`re’s disease (6). Three authors (2–4) have used a click SP/AP ratio of >0.33 which is not diagnostic for endolymphatic hydrops and which will have enhanced its apparent sensitivity. The sensitivity and specificity figures for tone-burst ECochG were not available from our data as we com- pared the two tests with a clinical diagnosis of Me´nie`re’s disease, rather than using magnetic resonance imaging (MRI) as the ‘‘gold standard’’ of this condition. We have subsequently revised our data in this manner to compare tone-burst ECochG in our patients with an MRI scan demonstrating endolymphatic hydrops. Table 3 in (1) has been reproduced in Table 1 here to include our own results for click and tone burst stimuli with a diagnostic sensitivity for clicks of 28.6 and 92.9% for tone bursts. As is mentioned in our article, we think that tone burst ECochG may detect electrophysiologic changes from pathologic basilar membranes with more sensitivity than the degree of hydrops that can be detected currently with MRI scanning. That cochlear endolymphatic hydrops could be ascertained by electrophysiological testing arose from a publication by Gibson et al. (7) in 1977. Using trans- tympanic electrocochleography they claimed that an enlarged direct current component of the click stimulus action potential (AP) called the summating potential (SP) could be an indication of cochlear hydrops. This was confirmed by Coats et al. (8) which lead to numerous publications using an SP/AP ratio of 0.33 to 0.35, and to an eventual disenchantment as to the reliability of the test (6). It was further compounded by audiologists using remote eardrum or canal electrodes that give responses approximately one-tenth of the magnitude of those achieved by direct contact with the cochlea. Sub- sequently, Gibson (9) by comparing click response SP/AP ratios of Me´nie`re’s ears with ears with compar- able hearing instead of Me´nie`re’s patient opposite ears, retracted this claim, unless the SP/AP ratio reaches a severe criterion of 0.5. Meanwhile, Gibson (9) had employed tone bursts as a stimulus , giving the test a significantly higher sensitivity and specificity, confirmed by others (5,10). It cannot yet be achieved using a remote eardrum or canal electrode. Nonetheless, click stimulus EcochG continues to be employed as a diagnostic test for Me´nie`re’s disease despite the evidence that it should abandoned. The recent advent of MRI inner ear imaging to detect hydrops in Me´nie`re’s disease (11) has predictably inspired studies comparing its sensitivity with that of electrocochleography (1). Images and conclusions from MRI inner ear imaging seem to be confounded by variables such as brand of scanner, head coil specifi- cations, and the possibility that gadolinium entry may be uneven and favor the vestibule. Meanwhile, trans- tympanic tone burst electrocochleography remains the most simple, cheap, and sensitive test for detecting TABLE 1. Diagnostic values of electrocochleography compared with MRI with intratympanic gadolinium administration Click Stimulus Sensitivity Specificity PPV NPV Yamamoto et al. (2) a 85.7 100% 100% 50.0% Fukuoka et al. (3) a 66.7% 100% 100% 25.0% Seo et al. (4) a 71.4% 80% 93.8% 40.0% Hornibrook et al. (5) b 28.6% 66.7% 44.4% 50.0% Tone burst stimulus Hornibrook et al. (5) 92.9% 26.7% 54.2% 80.0% a SP/AP diagnostic ratio >0.33. b SP/AP diagnostic ratio >0.5. MRI indicates magnetic resonance imaging; NPV, negative predictive value; PPV, positive predictive value. 1677 Otology & Neurotology 37:1677–1681 ß 2016, Otology & Neurotology, Inc.