Electrocochleography in the diagnosis of Meniere's disease

Click SP/AP Area Ratio Vesrus Tone Burst SP Amplitude to Diagnose Ménière's Disease Using Electrocochleography

OBJECTIVES

To evaluate the sensitivity and the specificity of summating potential (SP)/action potential (AP) area under the curve (AUC) ratio by a transtympanic electrode and a click stimulus (TT-CS), SP/AP AUC ratio by an extratympanic electrode and a click stimulus (ET-CS) and SP amplitude value by a transtympanic electrode and tone burst stimulus (TT-TBS) in regard of Ménière's disease (MD) diagnosis. This is the first study that compares SP amplitude value performed by a TT-TBS and the SP/AP AUC ratio performed by a TT-CS.

STUDY DESIGN

Retrospective comparative study.

SETTINGS

Ninety-five patients met the inclusion criteria for electrocochleography (ECochG) testing in a tertiary care center.

METHODS

The sensitivity and specificity of our different ECochG protocols were calculated in regard of the diagnosis of MD.

RESULTS

The patients' mean age was 54 years old (female predominance). The sensitivity and the specificity of SP/AP area ratio by a TT-CS were 88.5% and 70.0%, respectively. On the other hand, the sensitivity and specificity for the SP amplitude value by a TT-TBS were 60.0% and 55.6%, respectively. SP/AP area ratio by TT-CS was statistically better than SP amplitude value by TT-TBS to detect MD disease (P = .016). However, no difference was identified between SP/AP area ratio by ET-CS and SP amplitude value by a TT-TBS (P = .573).

CONCLUSION

SP/AP area ratio by click stimulation has higher sensitivity and specificity to detect MD compared to SP amplitude value by tone burst stimulation. ECochG would be extremely useful in the diagnosis of MD if we use the SP/AP area ratio (sensitivity: 88.5%); therefore, it changes the bad reputation of ECochG sensitivity using SP/AP amplitude ratio (sensitivity: 51.7%) for the diagnosis of MD.

Confrontation of endolymphatic hydrops diagnosis on 3-Tesla MRI to clinical and audiovestibular findings in Meniere's disease

Objective

The aim of this study was to compare different MRI diagnostic criteria for endolymphatic hydrops (EH) and to investigate the relation between audiovestibular and MRI findings in Meniere's disease (MD).

Materials and methods

Prospective cross-sectional cohort study in 2 referral centers included 76 patients with unilateral (n = 62) or bilateral (n = 14) MD. All patients underwent inner ear 3T-MRI 4 h (n = 52) or >24H (n = 24) following audiovestibular tests. T2-CISS and 3D-FLAIR images 4H after gadolinium were obtained. EH diagnosis was based on saccular morphology on coronal views (T2 and 3D-FLAIR), semi quantitative estimation of endolymphatic space enlargement, and saccule utricle ratio inversion (SURI) on 3D-FLAIR axial views.

Results

SURI was the best criterion related to the disease side (43 SURI+ on symptomatic ears, n = 77, vs. 6 SURI+ on asymptomatic ears, n = 53, p < 0.0001, Chi-2). Same-day MRI revealed relation between EH, hearing loss and caloric weakness which could not be detected on delayed MRI: SURI was associated with a higher pure-tone average (43 ± 4.1 dB in SURI+ ears, n = 42 vs. 23 ± 2.6 SURI-, n = 62, p < 0.0001, unpaired t-test,), and a higher proportion of vestibular caloric weakness (23/46 SURI+ ears vs. 4/62 SURI-, p < 0.001, Chi-2). Among all criteria, SURI combined to caloric weakness was the best predictor of the affected side in a logistic regression model.

Conclusion

SURI had the strongest relation to the side the disease and audio vestibular findings for unilateral, probable and definite meniere disease. A short delay between MRI and audio vestibular tests improved the coherence between the findings.

Lack of neural contributions to the summating potential in humans with Meniere's disease

Objective

To investigate the electrophysiology of the cochlear summating potential (SP) in patients with Meniere's disease (MD). Although long considered a purely hair cell potential, recent studies show a neural contribution to the SP. Patients with MD have an enhanced SP compared to those without the disease. Consequently, this study was to determine if the enhancement of the SP was in whole or part due to neural dysfunction.

Design

Study participants included 41 adults with MD and 53 subjects with auditory neuropathy spectrum disorder (ANSD), undergoing surgery where the round window was accessible. ANSD is a condition with known neural dysfunction, and thus represents a control group for the study. The ANSD subjects and 17 of the MD subjects were undergoing cochlear implantation (CI) surgery; the remaining MD subjects were undergoing either endolymphatic sac decompression or labyrinthectomy to alleviate the symptoms of MD. Electrocochleography was recorded from the round window using high intensity (90 dB nHL) tone bursts. The SP and compound action potential (CAP) were measured to high frequencies (> = 2 kHz) and the SP, cochlear microphonic (CM) and auditory nerve neurophonic (ANN) to low frequencies. Linear mixed models were used to assess differences between MD and ANSD subjects.

Results

Across frequencies, the MD subjects had smaller alternating current (AC) response than the ANSD subjects (F = 31.61,534, p < 0.001), but the SP magnitudes were larger (F = 94.31,534, p < 0.001). For frequencies less than 4 kHz the SP magnitude in the MD group was significantly correlated with the magnitude of the CM (p's < 0.001) but not in the ANSD group (p's > 0.05). Finally, the relative proportions of both ANN and CAP were greater in MD compared to ANSD subjects. The shapes of the waveforms in the MD subjects showed the presence of multiple components contributing to the SP, including outer and inner hair cells and neural activity.

Conclusion

The results support the view that the increased negative polarity SP in MD subjects is due to a change in the operating point of hair cells rather than a loss of neural contribution. The steady-state SP to tones in human subjects is a mixture of different sources with different polarities.

Comparison of Glycerol Test, ECochG and VEMP Findings in Patients with Meniere’s Disease

Present study aimed to find if multiple audio-vestibular tests can be used to improve in diagnosing Meniere's disease. The study compares the results of four test procedures of glycerol test, Electrocochleography (ECochG), cervical Vestibular Evoked Myogenic Potential (c-VEMP) and ocular Vestibular Evoked Myogenic Potential (o-VEMP) individually and also together to see whether the diagnosis of Meniere's disease can be improved. Experimental group consist of 16 participants (32 ears) diagnosed with Meniere's disease as per American Academy of Otolaryngology (AAO) -Head and Neck Foundation (2020) guidelines. Control group consist of 16 participants with compliant of only vertigo participated in the study. Participants in both group underwent glycerol test, Electrocochleography (ECochG), cervical Vestibular Evoked Myogenic Potential (c-VEMP) and ocular Vestibular Evoked Myogenic Potential (o-VEMP). Glycerol test showed a 38% positive rate for the presence of Meniere's disease. ECochG indicated the presence of endolymphatic hydrops in 62% of the participants. Abnormal finding in c-VEMP and o-VEMP was seen in 31% and 56% of the participants respectively. The combination of two tests such as ECochG and o-VEMP has increased the positive rate upto 87%. Adding one more test of c-VEMP or combining all four audiovestibular tests had a positive rate of 94% only. The present study indicated ECochG is a more sensitive tool in the diagnosis of Meniere disease followed by o-VEMP. Thus, the present study indicated that combination ECochG and o-VEMP could be used to find the presence of Meniere's disease successfully.

A Portrait of Menière's Disease Using Contemporary Hearing and Balance Tests

OBJECTIVE

Menière's disease (MD) is characterized by recurrent vertigo and fluctuating aural symptoms. Diagnosis is straightforward in typical presentations, but a proportion of patients present with atypical symptoms. Our aim is to profile the array of symptoms patients may initially present with and to analyze the vestibular and audiological test results of patients with a diagnosis of MD.

DESIGN

A retrospective study of patient files.

SETTING

A tertiary, neuro-otology clinic Royal Prince Alfred Hospital, Sydney, Australia.

METHOD

We identified 375 patients. Their history, examination, vestibular-evoked myogenic potentials (VEMP), video head-impulse test, canal-paresis on caloric testing, subjective visual horizontal (SVH), electrocochleography, ictal nystagmus, and audiometry were assessed.

RESULTS

Atypical presenting symptoms were disequilibrium (n = 49), imbalance (n = 13), drop-attacks (n = 12), rocking vertigo (n = 2), and unexplained vomiting (n = 3), nonspontaneous vestibular symptoms in 21.6%, fluctuation of aural symptoms only (46%), and headaches (31.2%). Low velocity, interictal spontaneous-nystagmus in 13.3% and persistent positional-nystagmus in 12.5%. Nystagmus recorded ictally in 90 patients was mostly horizontal (93%) and of high velocity (48 ± 34°/s). Testing yielded abnormal caloric responses in 69.6% and abnormal video head impulse test 12.7%. Air-conducted cervical VEMPs were abnormal in 32.2% (mean asymmetry ratio [AR] 30.2 ± 46.5%) and bone-conducted ocular VEMPs abnormal in 8.8% (AR 11.2 ± 26.8%). Abnormal interictal SVH was in 30.6%, (ipsiversive n = 46 and contraversive n = 19). Mean pure-tone averages 50 dB ± 23.5 and 20 dB ± 13 for affected and unaffected ears.

CONCLUSION

Menière's disease has a distinctive history, but atypical presentations with normal vestibular function and hearing are a diagnostic challenge delaying treatment initiation.

Clinical, oculographic and vestibular test characteristics of Ménière's disease

Seventy Ménière's disease (MD) patients with spontaneous vertigo (100%), unilateral aural fullness (57.1%), tinnitus (78.6%), and subjective hearing loss (75.7%) self-recorded nystagmus during their episodes of vertigo using portable video oculography goggles. All demonstrated ictal spontaneous nystagmus, horizontal in 94.3% (n = 66) and vertical in 5.7% (n = 4), with a mean slow-phase velocity (SPV) of 42.8 ± 31.1°/s (range 5.3-160.1). Direction reversal of spontaneous horizontal nystagmus was captured in 58.6%, within the same episode in 34.3%, and over different days in 24.3%. In 18.6%, we observed ipsiversive then contraversive nystagmus, and in 12.9% contraversive to ipsiversive direction reversal. Ictal nystagmus SPV (42.8 ± 31.1°/s) was significantly faster than interictal (1.4 ± 3.1°/s, p < 0.001, CI 34.277-48.776). Compared to age-matched healthy controls, interictal video head impulse test gains in MD ears were significantly lower, cumulative and first saccade (S1) amplitudes were significantly larger, and S1 peak velocities were significantly faster (p = 0.038/0.019/0.008/ < 0.001, CI 0.002-0.071/0.130-1.444/0.138-0.909/14.614-41.506). Audiometry showed asymmetrically increased thresholds in 100% of MD ears (n = 70). Significant caloric, air-conducted (AC) cervical vestibular-evoked myogenic potential (VEMP), and AC ocular VEMP asymmetries were found in 61.4, 37.9, and 44.4% of patients (MD ear reduced). Transtympanic electrocochleography tested in 36 ears (23 patients) showed 81.8% of MD ears had a positive result for hydrops (either a summating potential at 1/2 kHz < - 6 µV, or an SP/AP ratio > 40%). Using ictal nystagmus findings of SPV > 12°/s, and a caloric canal paresis > 25%, we correctly separated a diagnosis MD from Vestibular Migraine with a sensitivity and specificity of 95.7% and 85.1% (CI 0.89-0.97).

Clinical, oculographic, and vestibular test characteristics of vestibular migraine

BACKGROUND

We characterise the history, vestibular tests, ictal and interictal nystagmus in vestibular migraine.

METHOD

We present our observations on 101 adult-patients presenting to an outpatient facility with recurrent spontaneous and/or positional vertigo whose final diagnosis was vestibular migraine (n = 27) or probable vestibular migraine (n = 74). Ictal and interictal video-oculography, caloric and video head impulse tests, vestibular-evoked myogenic potentials and audiometry were performed.

RESULTS

Common presenting symptoms were headache (81.2%), spinning vertigo (72.3%), Mal de Débarquement (58.4%), and motion sensitivity (30.7%). With fixation denied, ictal and interictal spontaneous nystagmus was observed in 71.3 and 14.9%, and purely positional nystagmus in 25.8 and 55.4%. Spontaneous ictal nystagmus was horizontal in 49.5%, and vertical in 21.8%. Ictal spontaneous and positional nystagmus velocities were 5.3 ± 9.0°/s (range 0.0-57.4), and 10.4 ± 5.8°/s (0.0-99.9). Interictal spontaneous and positional nystagmus velocities were <3°/s in 91.8 and 23.3%. Nystagmus velocities were significantly higher when ictal (p < 0.001/confidence interval: 2.908‒6.733, p < 0.001/confidence interval: 5.308‒10.085). Normal lateral video head impulse test gains were found in 97.8% (mean gain 0.95 ± 0.12) and symmetric caloric results in 84.2% (mean canal paresis 7.0 ± 23.3%). Air- and bone-conducted cervical-vestibular-evoked myogenic potential amplitudes were symmetric in 88.4 and 93.4% (mean corrected amplitude 1.6 ± 0.7, 1.6 ± 0.8) with mean asymmetry ratios of 13.0 and 9.0%. Air- and bone-conducted ocular-vestibular-evoked myogenic potentials were symmetric in 67.7 and 97.2% (mean amplitude 9.2 ± 6.4 and 20.3 ± 12.8 µV) with mean asymmetry ratios of 15.7 and 9.9%. Audiometry was age consistent and symmetric in 85.5%.

CONCLUSION

Vestibular migraine is characterised by low velocity ictal spontaneous nystagmus, which can be horizontal, vertical, or torsional, and normal audiovestibular test results.

On the Relationship Between Menière's Disease and Endolymphatic Hydrops

: The relationship between Menière's disease and endolymphatic hydrops is ambiguous. On the one hand, the existence of cases of endolymphatic hydrops lacking the classic symptoms of Menière's disease has prompted the assertion that endolymphatic hydrops alone is insufficient to cause symptoms and drives the hypothesis that endolymphatic hydrops is a mere epiphenomenon. Yet, on the other hand, there is considerable evidence suggesting a relationship between the mechanical pressure effects of endolymphatic hydrops and resultant disordered auditory physiology and symptomatology. A critical appraisal of this topic is undertaken, including a review of key histopathologic data chiefly responsible for the epiphenomenon hypothesis. Overall, a case is made that A) the preponderance of available evidence suggests endolymphatic hydrops is likely responsible for some of the auditory symptoms of Menière's disease, particularly those that can be modulated by mechanical manipulation of the basilar membrane and cochlear microphonic; B) Menière's disease can be reasonably considered part of a larger spectrum of hydropic inner ear disease that also includes some cases that lack vertigo. C) The relationship with endolymphatic hydrops sufficiently robust to consider its presence a hallmark defining feature of Menière's disease and a sensible target for diagnostic detection.

Establishing Reproducibility and Correlation of Cochlear Microphonic Amplitude to Implant Electrode Position Using Intraoperative Electrocochleography and Postoperative Cone Beam Computed Tomography

Supplemental Digital Content is available in the text.

Objectives:

The primary objective of this study was to establish the reproducibility of cochlear microphonic (CM) recordings obtained from a cochlear implant (CI) electrode contact during and immediately after insertion. This was achieved by evaluating the insertion angle and calculating the position of the apical electrode contact during insertion, using postoperative cone beam computed tomography (CBCT). The secondary objective was to create individualized patient maps of electrode contacts located within acoustically sensitive regions by correlating the CM amplitude to the electrode position determined using CBCT.

Methods:

CMs were recorded from a CI electrode contact during and immediately after insertion in 12 patients (n = 14 ears). Intraoperative recordings were made for a 0.5 kHz tone burst stimulus and were recorded from the apical electrode contact. Postinsertion recordings were made from the odd-numbered electrode contacts (1–15) along the array, using a range of stimulus frequencies (from 0.125 to 2 kHz). The time point at which each electrode contact passed through the round window was noted throughout the insertion, and the CM amplitude at this point was correlated to postoperative CBCT. This correlation was then used to estimate the CM amplitude at particular points within the cochlea, which was in turn compared with the amplitudes recorded from each electrode postoperatively to assess the reproducibility of the recordings.

Results:

Significant correlation was shown between intraoperative insertion and postinsertion angles at two amplitude events (maximum amplitude: 29° mean absolute error, r = 0.77, p = 0.006; 10% of maximum amplitude: 52° mean absolute error, r = 0.85, p = 0.002).

Conclusion:

We have developed a novel method to demonstrate the reproducibility of the CM responses recorded from a CI electrode during insertion. By correlating the CM amplitude with the postoperative CBCT, we have also been able to create individualized maps of CM responses, categorizing the cochlea into acoustically responsive and unresponsive regions. If the electrode contacts within the acoustically sensitive regions are shown to be associated with improved loudness discrimination, it could have implications for optimal electrode mapping and placement.

Usefulness of Intravenous Gadolinium Inner Ear MR Imaging in Diagnosis of Ménière's Disease

This study aimed to investigate the usefulness of the intravenous gadolinium enhanced inner ear magnetic resonance imaging (IV-Gd inner ear MRI) in diagnosing Ménière's disease(MD) and find a correlation between the degree of endolymphatic hydrops(EH) and the audiovestibular tests. Total 29 patients diagnosed with unilateral definite MD were enrolled. All patients underwent IV-Gd inner ear MRI and auditory and vestibular function tests such as pure tone audiometry (PTA), electrocochleography (ECoG), cervical vestibular evoked myogenic potential (cVEMP) and caloric test. The hydrops ratio in the cochlea and vestibule were significantly higher in the affected side than the unaffected side (p < 0.001). Average pure-tone thresholds for 0.5, 1 k, 2 k, and 4 k Hz correlated significantly with cochlear and vestibular hydrops (p < 0.01) in the affected side. When comparing the SP/AP ratio of ECoG with hydrops ratio in the vestibule, the affected and unaffected ears showed a significant difference (p < 0.05). Similarly, the results of the caloric test also showed a significant correlation (p < 0.05) with relative vestibular hydrops. However, the cVEMP response was not related to the hydrops ratio in the cochlea or vestibule. This study presents pertinent data with appropriate correlations with auditory vestibular functional testing which demonstrates the usefulness of IV-Gd inner ear MRI as a diagnostic method for visualizing the endolymphatic hydrops in MD.

Assessment Tools for Use in Patients with Ménière Disease: An Update

A number of electrophysiological tests have been proposed for the initial diagnostic assessment or for the follow-up phase of patients affected by Ménière disease. The most common are: (i) vestibular evoked myogenic potentials (VEMPs); (ii) electrocochleography (ECochG); and (iii) otoacoustic emissions (OAEs). This paper presents the latest clinical developments with these 3 testing modalities. The PubMed, Embase, and Cinahl databases were searched from 2006 to December 2016. Full-text articles were obtained in cases where the title, abstract, or key words suggested that the study may be eligible for this review. The medical subject heading (MeSH) terms included the following: Ménière, hearing threshold, vestibule, otoacoustic emissions, inner ear, ECochG, VEMPs. There were 368 identified papers, out of which 87 were eligible for inclusion. Overall the data in the literature are still limited and the recommended procedures have not reached an international consensus. From the available data, one can conclude that none of the electrophysiological tests could be considered as pathognomonic, for the diagnosis of Ménière disease: presently, the tests could be mostly used in a supportive role to the clinical diagnosis. Hopefully, in the future, improved technology in electrophysiological testing could contribute to the development of better strategies for the diagnosis of Ménière disease.

Human Summating Potential Using Continuous Loop Averaging Deconvolution: Response Amplitudes Vary with Tone Burst Repetition Rate and Duration

Electrocochleography (ECochG) to high repetition rate tone bursts may have advantages over ECochG to clicks with standard slow rates. Tone burst stimuli presented at a high repetition rate may enhance summating potential (SP) measurements by reducing neural contributions resulting from neural adaptation to high stimulus repetition rates. To allow for the analysis of the complex ECochG responses to high rates, we deconvolved responses using the Continuous Loop Averaging Deconvolution (CLAD) technique. We examined the effect of high stimulus repetition rate and stimulus duration on SP amplitude measurements made with extratympanic ECochG to tone bursts in 20 adult females with normal hearing. We used 500 and 2,000 Hz tone bursts of various stimulus durations (12, 6, 3 ms) and repetition rates (five rates ranging from 7.1 to 234.38/s). A within-subject repeated measures (rate x duration) analysis of variance was conducted. We found that, for both 500 and 2,000 Hz stimuli, the mean deconvolved SP amplitudes were larger at faster repetition rates (58.59 and 97.66/s) compared to slower repetition rates (7.1 and 19.53/s), and larger at shorter stimulus duration compared longer stimulus duration. Our concluding hypothesis is that large SP amplitude to short duration stimuli may originate primarily from neural excitation, and large SP amplitudes to long duration, fast repetition rate stimuli may originate from hair cell responses. While the hair cell or neural origins of the SP to various stimulus parameters remains to be validated, our results nevertheless provide normative data as a step toward applying the CLAD technique to understanding diseased ears.

Is Electrocochleography Still Helpful in Early Diagnosis of Meniere Disease?

Background and Objectives

Despite the extensive research for the Meniere’s disease (MD), it’s pathophysiology still remains uncertain and questionable among scientists. Clinical symptoms and audiometric tests form the basis for the diagnosis. Nevertheless the differential diagnosis can be extremely challenging, due to subjective and not specific results. Incorrect diagnosis is most likely and for this reason there is a great demand for objective and reliable tests.

Subjects and Methods

The presence of endolymphatic hydrops is necessary condition but non enough for the diagnosis. In this study we analyze retrospectively the summating potentials (SP)/action protentials (AP) ratio from peritympanic electrocochleography in 34 patients,divided in two groups (13 patients classified as defined MD and 21 patients classified as probable MD). The purpose was to identify the utility of the exam so to be able to achieve an early defined diagnosis. Furthermore our intention was to obtain an objective test, besides the clinical criteria currently in use for the diagnosis and the classification of the MD.

Results

The analysis of the SP/AP results shows high predictability for the MD (positive in six out of seven cases with a sensitivity greater than 80%).

Conclusions

Our study demonstrates a satisfactory sensibility percentage in recurrent defined MD presentation (>80%). Early identification of MD can lead to an early treatment and control of the progression of the disease. Furthermore it could be a valuable instrument for the follow up and evaluation of the patients classified as probable MD in accordance with the criteria of the American Academy of Otolaryngology-Head and Neck Surgery (1995).

Tone Burst Electrocochleography for the Diagnosis of Clinically Certain Meniere's Disease

The technique of transtympanic electrocochleography was initially developed as an objective hearing threshold test by Eggermont. Gibson et al. (1977) claimed that an enlarged direct current component of the action potential (AP) called the summating potential (SP) is an indication of endolymphatic hydrops, later confirmed by Coates who proposed an SP/AP ratio measure. This led to numerous publications using diagnostic ratios of 0.33-0.35. The insensitivity led to an eventual disenchantment with the test as a reliable objective test for Meniere's disease. It was further confused by audiologists employing remote canal or ear drum electrodes which give a response about one-fourth of the magnitude obtained by an electrode in contact with the cochlea. Subsequently Gibson stated that an SP/AP ratio of <0.5 is not diagnostic for hydrops. He then showed that a tone burst stimulus gave the test a significantly higher sensitivity and specificity, which has been supported by others. On MRI inner ear imaging with gadolinium hydrops can be seen, but the quality of images and what is seen may vary according to brand of scanner, settings, mode of gadolinium administration, and the possibility that gadolinium entry may favor the vestibule. Transtympanic tone burst electrocochleography is to date the simplest, cheapest and most sensitive technique for detecting cochlear endolymphatic hydrops to confirm a diagnosis of Meniere's disease.

Evaluation of vestibular evoked myogenic potentials (VEMP) and electrocochleography for the diagnosis of Ménière's disease

Introduction

Ménière's disease (MD) is an inner ear disorder characterized by episodic vertigo, tinnitus, ear fullness, and fluctuating hearing. Its diagnosis can be especially difficult in cases where vestibular symptoms are present in isolation (vestibular MD). The definitive diagnosis is made histologically and can only be performed post-mortem, after analysis of the temporal bone. Endolymphatic hydrops is a histopathological finding of the disease and occurs more often in the cochlea and saccule, followed by the utricle and semicircular canals. Vestibular evoked myogenic potentials (VEMP) emerged as the method of assessment of vestibular function in 1994. Until then, there was no unique way of assessing saccular function and the inferior vestibular nerve. Given that the saccule is responsible for most cases of severe hydrops, VEMP appears as a new tool to assist in the diagnosis of MD.

Objective

To evaluate the sensitivity and specificity of VEMP and electrocochleography (EcochG) in the diagnosis of definite MD compared with clinical diagnosis.

Methods

The study includes 12 patients (24 ears) diagnosed with definite MD defined according to the clinical criteria proposed by the American Academy of Otolaryngology – Head and Neck Surgery (AAO-HNS) in 1995, as well as 12 healthy volunteers allocated to the control group (24 ears). A clinical diagnosis by the AAO-HNS criteria was considered as the gold standard. All patients underwent an otoneurological examination, including pure tone and speech audiometry, VEMP, and extratympanic EcochG. The sensitivity and specificity to detect the presence or absence of disease were calculated, as well as their 95% confidence intervals. The reliability of VEMP and EcochG in both ears was assessed using the kappa index.

Results

In both tests and in both ears, the ability to diagnose healthy cases was high, with specificity ranging from 84.6% to 100%. Moreover, the ability of the tests to diagnose the disease varied from low to moderate sensitivity, with values ranging from 37.5% to 63.6%. The agreement of both tests in the right ear, measured by the kappa coefficient, was equal to 0.54 (95% CI: 0.20–0.89), indicating a moderate agreement. In the left ear, that agreement was equal to 0.07 (95% CI: −0.33 to 0.46), indicating a weak correlation between the tests. The sensitivity of the VEMP for the right ear was 63.6% and for the left ear, 62.5%. The sensitivity of EcochG for the right ear was 63.6% and 37.5% for the left ear.

Conclusion

The specificity of both tests was high, and the sensitivity of VEMP was higher than that of EcochG.

Trends in the diagnosis and the management of Meniere's disease: Results of a survey

OBJECTIVE: To determine the practices of the American Neurotology Society (ANS) membership in the evaluation and treatment of the Meniere's patient.

STUDY DESIGN: Prospective.

INTERVENTION: Questionnaire.

MAIN OUTCOME MEASURE: Respondents’ response to questions pertaining to the diagnostic and therapeutic practices in the management of Meniere's disease.

RESULTS: Three hundred members of ANS were mailed a 15-item questionnaire. Two hundred three responded, for a 67.7% response rate. For the diagnosis of Meniere's disease, 1 in 3 practitioners relied solely on history, physical exam, and audiometry, whereas 2 in 3 relied in part on adjunctive tests, such as electrocochleography (ECOG) and electronystagmography (ENG). Two in 3 practitioners pursued retrocochlear studies on initial evaluation, with the overwhelming majority using MRI. In treating Meniere's disease, conservative medical management was preferred. For medically recalcitrant Meniere's disease, endolymphatic sac surgery (ESS) was the most commonly employed initial intervention (50%), followed by transtympanic gentamicin (38%). Currently, <10% routinely recommend the Meniett device. Eighty-three percent include ESS as a therapeutic option for medically recalcitrant Meniere's disease. The vast majority continue to perform surgical labyrinthectomies and vestibular nerve sections for Meniere's disease.

CONCLUSIONS: Meniere's disease continues to pose a difficult diagnostic and therapeutic problem, resulting in heterogeneous approaches to both evaluation and treatment. Despite the 1995 American Academy of Otolaryngology guidelines in the diagnosis of Meniere's disease, most clinicians rely in part on ENG or ECOG in diagnosing Meniere's disease. Furthermore, despite the passing of 20 years since the publications claiming a purely placebo effect, ESS is the most commonly employed initial surgical treatment for Meniere's disease. (Otolaryngol Head Neck Surg 2005;132: 722-6.)

Meniere's disease

Meniere's disease (MD) is a disorder of the inner ear that causes vertigo attacks, fluctuating hearing loss, tinnitus and aural fullness. The aetiology of MD is multifactorial. A characteristic sign of MD is endolymphatic hydrops (EH), a disorder in which excessive endolymph accumulates in the inner ear and causes damage to the ganglion cells. In most patients, the clinical symptoms of MD present after considerable accumulation of endolymph has occurred. However, some patients develop symptoms in the early stages of EH. The reason for the variability in the symptomatology is unknown and the relationship between EH and the clinical symptoms of MD requires further study. The diagnosis of MD is based on clinical symptoms but can be complemented with functional inner ear tests, including audiometry, vestibular-evoked myogenic potential testing, caloric testing, electrocochleography or head impulse tests. MRI has been optimized to directly visualize EH in the cochlea, vestibule and semicircular canals, and its use is shifting from the research setting to the clinic. The management of MD is mainly aimed at the relief of acute attacks of vertigo and the prevention of recurrent attacks. Therapeutic options are based on empirical evidence and include the management of risk factors and a conservative approach as the first line of treatment. When medical treatment is unable to suppress vertigo attacks, intratympanic gentamicin therapy or endolymphatic sac decompression surgery is usually considered. This Primer covers the pathophysiology, symptomatology, diagnosis, management, quality of life and prevention of MD.

Extra-tympanic electrocochleography in a normal population. A descriptive study

INTRODUCTION AND OBJECTIVES

Extra-tympanic electrocochleography is an electrophysiological register obtained after stimulating the cochlea with an audible stimulus. This stimulus is applied using an earphone over the external auditory canal, while the electrical activity is registered by surface electrodes. There are few studies that analyse normal electrocochleography in our environment. Thus, the main objective of our study was to regularize the values obtained with electrocochleography in ears without any otoneurological diseases. We explain in detail the process of obtaining the register.

METHODS

Sixty healthy ears were studied by extratympanic electrocochleography. Statistical results were analysed. While 30 ears were studied with a stimulus at 90dB, another 30 ears were studied with a stimulus at 80dB.

RESULTS

Summating potential and action potential latencies and amplitudes were measured. Summating potential/action potential ratios were calculated. Wave I and wave II latencies were also determined. These results were analysed in function of stimulus intensity, patient gender, patient age group and ear side studied.

CONCLUSIONS

This study collected extra-tympanic electrocochleography data in a normal population and the results were in the range of other international studies obtained in other countries. These data can be used as a reference to evaluate illnesses that affect cochlear structure or functions.

MRI Inner Ear Imaging and Tone Burst Electrocochleography in the Diagnosis of Ménière's Disease

Objective

To compare the sensitivity of gadolinium MRI inner imaging with tone burst electrocochleography (EcochG) for diagnosing endolymphatic hydrops.

Study Design

A prospective study on patients who were to have an MRI scan to exclude retrocochlear pathology.

Setting

Tertiary care center.

Patients

One hundred and two patients: 57 patients with Possible, Probable, or Definite Ménière’s Disease, 25 with asymmetrical hearing loss, 18 with sudden sensorineural hearing loss, and 2 with unilateral tinnitus had additional MRI inner ear imaging and click and tone burst stimulus EcochG testing.

Intervention

Diagnostic.

Main Outcome Measure

To compare the sensitivity of the two techniques.

Results

In 30 patients with symptom-based Definite Ménière’s Disease, tone burst EcochG was positive in 25 (83%) and the click EcochG was positive in 9/30 (30%), and gadolinium MRI imaging diagnosed hydrops in 14 (47%). A positive result for either MRI imaging or tone burst EcochG was seen in 26 patients (87%). In 14 subjects with symptom-based Probable Ménière’s Disease, 10 (71%) had either a positive EcochG or MRI. In 13 with Possible Ménière’s Disease, four (31%) had a positive EcochG or MRI.

Conclusion

This study confirms the greatly enhanced diagnostic sensitivity of tone burst EcochG over click response in diagnosing endolymphatic hydrops in Ménière’s disease. Even though adequate MRI imaging was achieved in 90%, tone burst EcochG was a more sensitive test.

Application of Vestibular Spontaneous Response as a Diagnostic Aid for Meniere's Disease

In this paper, we report on a new method for assisting in Meniere's disease diagnosis. An accurate diagnosis of Meniere's is challenging, and requires an expert opinion after observing several clinical assessments and tests over a period of time. Our proposed method is based on the analysis of the spontaneous and driven ear evoked responses recorded using Electrovestibulography (EVestG). We used the EVestG signals of 35 individuals suspected of Meniere's and 26 age-matched healthy controls, out of which data of 14 patients with Meniere's and 16 healthy controls were used for developing the diagnostic algorithm (training set) and the rest for testing. While recording and analyzing the test dataset, the researchers were only aware the patients suffered some dizziness, and were kept blind to the exact diagnoses till the end of study. EVestG field potentials (FPs) and their firing pattern, in response to several whole body tilt stimuli from both left and right ears were extracted. We investigated several features of the extracted FPs in response to each of side, back/forward, rotation, up/down, supine rotation, and supine up/down tilt stimulations, and selected the top five features showing the most significant differences between of the groups of the training set for every tilt. An ad-hoc average voting classifier was designed based on building five single-feature classifiers (using Linear Discriminant analysis) and taking the average of the single-feature classifiers' votes. The results showed the side tilt data were best for the purpose of Meniere's diagnosis; it resulted in 78% and 90% sensitivity and specificity for test dataset, respectively. The second best accuracy was achieved using back/forward tilt. The results and their implications are discussed. Overall, the EVestG side tilt results encourage the use of vestibular response as a non-invasive, robust and quick screening for Meniere's and separating it from other types of dizziness.

Electrocochleography for Ménière's disease: is it reliable?

Introduction

Endolymphatic hydrops, the histopathological substrate of Ménière's disease, is an almost universal finding in postmortem studies of patients with this disease. The cause of hydrops is still unknown, as is the mechanism by which it causes progressive dysfunction of the sensory organs of inner ear. The fluctuating course of the disease complicates the interpretation of certain tests, such as electrocochleography; thus, for some authors its diagnostic value is questionable.

Objective

The aim of this study was to analyze the clinical applicability of electrocochleography in the diagnosis of hydrops. It is a valuable tool, but still generates conflicting opinions among otolaryngologists.

Methods

Systematic review of the literature on electrocochleography in patients diagnosed with endolymphatic hydrops.

Results

A total of 34 articles regarding the use of electrocochleography in patients with hydrops, from the year 2000 onwards, were selected. Of these, 15 were excluded from the review as they were not observational studies. Only one cross-sectional study addressing the clinical use of electrocochleography by otolaryngologists was included.

Conclusion

Electrocochleography is a valuable tool in the diagnosis of hydrops, as it is a non-invasive, easy to handle procedure, which offers new techniques to increase the sensitivity of the test, and thereby assists otolaryngologists in the management of Ménière's disease.

Can we use electrocochleography as a clinical tool in the diagnosis of Meniere's disease during the early symptomatic period?

CONCLUSION

Our results indicate that electrocochleography (ECoG) has limited value in diagnosing Meniere's disease during the early symptomatic period.

OBJECTIVE

We hypothesized that if endolymphatic hydrops is a cause of Meniere's disease, ECoG results obtained in normal subjects would differ from those obtained during the early symptomatic period of Meniere's disease. We aimed to investigate the usefulness of ECoG in the diagnosis of Meniere's disease during the early symptomatic period.

METHODS

Extratympanic ECoG was used to evaluate 60 patients in a Meniere's group (17 men, 43 women; mean age 43.6 years, range 19-62 years) and 30 controls (11 men, 19 women; mean age 43.5 years, range 21-63 years). The summating potential/action potential (SP/AP) amplitude ratio and SP/AP area ratio were compared between the groups.

RESULTS

Statistically significant differences were not demonstrated in the SP/AP amplitude ratio between the definite Meniere's, probable Meniere's, overall Meniere's, or control groups (0.35 ± 0.02, 0.30 ± 0.03, 0.33 ± 0.02, and 0.30 ± 0.01, respectively). Additionally, statistically significant differences were not indicated in the mean SP/AP area ratio between the definite Meniere's, probable Meniere's, overall Meniere's, or control groups (5.18 ± 0.98, 4.78 ± 0.21, 4.01 ± 0.78, and 3.72 ± 0.66, respectively).

Transtympanic Electrocochleography for the Diagnosis of Ménière's Disease

This paper evaluated the diagnostic power of electrocochleography (ECochG) in detecting Ménière's disease (MD) as compared with two subjective assessment methods, including the clinical guidelines provided by the American Academy of Otolaryngology—Head and Neck Surgery Committee on Hearing Equilibrium and the Gibson score. A retrospective study of 250 suspected MD cases was conducted. The agreement between the three assessment methods was found to be relatively high, with a total reliability being higher than 70%. Participants who tested “positive” with ECochG exhibited a higher occurrence rate of asymmetric hearing threshold as well as the four MD symptoms, namely, vertigo, hearing loss, tinnitus, and aural fullness. The “positive” ECochG group also showed a high correlation between the ECochG measures in response to stimuli at adjacent frequency ranges, suggesting that the interfrequency ECochG correspondence may be sensitive to the presence of endolymphatic hydrops and thus may serve as a useful diagnostic marker for MD.

Audiovestibular testing in patients with Meniere's disease

In this article, the present state of the art with respect to audiovestibular testing for Meniere's disease (MD) is reviewed. There is no gold standard for MD diagnosis, and the classic dictum is that even the "best" tests yield positive results in only two-thirds of patients with MD. Still, we advocate the use and further investigation of advanced audiovestibular testing in patients with MD in an attempt to answer the questions that confront any clinician who cares for patients with audiovestibular symptoms.

Clinical utility of electrocochleography in the diagnosis and management of Ménière's disease: AOS and ANS membership survey data

OBJECTIVE

Evaluate the clinical use of electrocochleography (ECoG) for diagnosis/treatment of Ménière's disease among members of the American Otological Society (AOS) and American Neurotology Society (ANS).

SUBJECTS

Clinically active members of the AOS/ANS.

MAIN OUTCOME MEASURE

Survey responses.

RESULTS

A total of 143 responses were received from 344 possible respondents (41.6%). In suspected cases of Ménière's disease, 45.5% of respondents did not use ECoG at all, 17.5 % used ECoG routinely, and 37.1% used it only in questionable cases. Electrocochleography users differed widely in electrode approach and stimulus modality used, with extratympanic approach and click stimuli used most frequently. Most respondents (73.2%) thought that ECoG is a test of indeterminate value. Only 3.6% required an abnormal ECoG to diagnose endolymphatic hydrops. An abnormal test was a requirement to proceed with ablative therapy for just 8.6% of respondents. Still, 77.9% think that ECoG findings do fluctuate with activity of the disorder, but only 18.0% agree that when the ECoG reverts to normal, one can predict remission of symptoms. Almost half of respondents (46.7%) reported that they have now stopped ordering ECoG due to variability in results and lack of correlation with their patients' symptoms.

CONCLUSION

Among AOS/ANS members, there is low clinical use of ECoG in diagnosis/management of Ménière's disease. For approximately half of respondents, ECoG has no role in their clinical practice. Electrocochleography was used routinely by only 1 in 6 respondents. Those who used ECoG differed widely in electrode placement and type of stimuli paradigm used.

Changes in audiometric thresholds before, during and after attacks of vertigo associated with Meniere's syndrome

CONCLUSION

No significant changes in hearing thresholds were observed during vertigo attacks associated with Meniere's disease.

OBJECTIVES

To determine if the hearing alters during the period of the attacks of vertigo in Meniere's disease.

PATIENTS AND METHODS

The study group consisted of patients who had a clinical diagnosis of definite Meniere's syndrome according to the AAOOHNS criteria, a score on the Gibson scale of 7 or over and an enhanced negative summating potential on transtympanic electrocochleography. These patients were supplied with a programmable hearing aid and a portable programmer that allowed them to measure their own hearing in situ. They were asked to measure their audiometric thresholds daily and if possible during the attacks of vertigo.

RESULTS

Six of the patients were able to measure their hearing during attacks of vertigo and their hearing thresholds obtained before, during and after the vertigo attacks were compared. Five of six subjects showed <10 dBHL change in the hearing levels at all tested audiometric frequencies before, during and after the attacks of vertigo. One subject had a probable change in threshold before the attack but not during the attack of vertigo.

Clinical Significance of the Summating Potential—Action Potential Ratio and the Action Potential Latency Difference for Condensation and Rarefaction Clicks in Meniere's Disease

Objectives:

This study was aimed to elucidate the diagnostic significance of the summating potential (SP)–action potential (AP) ratio and the AP latency difference between condensation and rarefaction clicks (AP con-rar difference) in Meniere's disease.

Methods:

The AP and SP were recorded transtympanically in 67 patients with definite Meniere's disease. The SP/AP ratio and the AP con-rar difference were assessed in terms of 1) their interrelationship, 2) their relationship to hearing level, and 3) the rate of occurrence of abnormal values according to the stages of Meniere's disease.

Results:

No correlation was found between the SP/AP ratio and the AP con-rar difference. Neither the SP/AP ratio in general nor the AP con-rar difference was correlated with the hearing level. However, enhanced values of the SP/AP ratio (0.35 or higher) were moderately correlated with the hearing level (r = 0.51), and their occurrence rate was 55.2%. An increased AP con-rar difference (0.13 ms or longer) was not correlated with the hearing level, and its occurrence rate was 50.2%; it appeared most frequently at stage 3 (p < 0.05).

Conclusions:

An enhanced SP/AP ratio might not always indicate the presence of endolymphatic hydrops associated with an increase in endolymphatic pressure. An increased AP con-rar difference might reflect the presence of a biased basilar membrane resulting from an increased endolymphatic pressure, and hence it is diagnostically essential to simultaneously evaluate the SP/AP ratio and the AP con-rar difference.

Low-frequency distortion product otoacoustic emission test compared to ECoG in diagnosing endolymphatic hydrops

Previous studies assumed that specific audiometric measures like low-frequency biasing were noninvasive and inexpensive techniques for diagnosing endolymphatic hydrops (EH). The aim of this study was to compare the results of low-frequency DPOAE (LF-DPOAE) with those of transtympanic electrocochleography (ECoG) in patients with Menière's disease (MD). The prospective study included 50 patients, 22 to 72 years old, who were diagnosed with Menière's disease according to the criteria laid down by the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) in 1995. LF-DPOAE and ECoG were performed on the same day after standard audiometry. Enlarged amplitude of summation potential to action potential ratio was used as the diagnostic criterion for EH. The results were compared to those of LF-DPOAE. In this audiometric examination we used the modulation index (MI) to detect EH if MI < 0.5. ECoG yielded a result in 46 of the 50 patients examined. An enlarged SP/AP ratio was found in 23 patients (50%). The results of 33 patients could be compared, i.e. assessable results in both tests. The two tests yielded the same results in 13 patients and different ones in 20 patients. ROC analysis and Mann-Whitney statistics showed no significant correlation between the two tests. With ECoG as the gold standard for verifying EH, we found that LF-DPOAE is not yet a suitable method for diagnosing EH.

Ménière disease: diagnostic instrumental support

The current guidelines of the American Academy of Otolaryngology-Head and Neck Surgery entrust the diagnosis of Ménière disease (MD) only to the clinical presentation and the pure tone audiometry. However, most otolaryngologists request a widened instrumental evaluation of the patients suspected of MD. The effective reliability of the further instrumental support for the diagnosis of MD is still debated in the literature because of nonstandardized procedures and sometimes incoherence among authors. New and more sophisticated diagnostic tests have been developed both in audiovestibology and in imaging in the last few years. A review of the recent literature on this controversial subject is provided.

Clinical diagnosis of Ménière's disease: how useful are the American Academy of Otolaryngology Head and Neck Surgery Committee on Hearing and Equilibrium guidelines?

INTRODUCTION

Ménière's disease is a diagnosis requiring expert clinical judgment. There are several differences between the American Academy of Otolaryngology Head and Neck Surgery diagnostic guidelines and Prosper Ménière's original description of the disease.

METHODS

Six hundred and fifty patients attending a specialist balance clinic had their clinical profiles fully analysed according to each set of diagnostic criteria.

RESULTS

Application of the American Academy of Otolaryngology Head and Neck Surgery guidelines resulted in the diagnosis of three times more patients than did use of Ménière's diagnostic criteria. Treatment options for patients in both groups were similar. It is unlikely that the application of different diagnostic criteria would have an effect on the treatment of individual patients.

DISCUSSION

The American Academy of Otolaryngology Head and Neck Surgery guidelines are more sensitive and less specific in diagnosing Ménière's disease than Prosper Ménière's original description. Standardised criteria should be applied across published series, in order to make results accurate, comparable and useful in the long term. We would recommend the introduction of a stricter diagnostic category for definite Ménière's disease.

Analytic view to concordance between electrocochleography and caloric test in Meniere’s disease

We aimed to investigate if there is a concordance between summation potential (SP)/action potential (AP) ratio and unilateral weakness in patients with definite-Meniere's disease. There were two groups, a group of unilateral definite-Meniere patients who received no treatment and another group of control subjects. Twenty-six patients were identified as complying with the defined criteria. Fifteen healthy subjects with no hearing and balance disorders were assigned to the control group. Arithmetic mean of the four-tone average of thresholds at 0.5, 1, 2, and 3 or 4 kHz, SP/AP ratio and degree of unilateral weakness were calculated. The number of patients was tabulated based on the presence of abnormal SP/AP ratio and unilateral weakness. Co-occurrence of unilateral weakness and elevated-SP/AP ratio was investigated with reference to the stage of the disease. A correlation was sought among pure-tone average, SP/AP ratio and degree of unilateral weakness in a pair-wise manner. Unilateral weakness and abnormal SP/AP ratio were identified in 53.8% and 38.4% of the patients, respectively. Co-occurrence of unilateral weakness and abnormal SP/AP ratio was observed in 34.6% of the patients. However, it was noticed that this co-occurrence gradually increased when the disease progressed. Mean SP/AP ratio also gradually increased as the stage progressed. Of pair-wise correlations among pure-tone average, SP/AP ratio and degree of unilateral weakness, a weak correlation (r = 0.383) was found only between SP/AP ratio and degree of unilateral weakness with marginal significance (P = 0.053). We concluded that co-occurrence of unilateral weakness and elevated SP/AP ratio increases when the disease progresses. This co-occurrence is less encountered in earlier stages. This difference might be resulted from a difference in distension capability of the endolymphatic space of the cochlea and the vestibule. Albeit weak, there was a correlation between mean SP/AP ratio and degree of unilateral weakness, which suggests that the disease parallelly disturbs the lateral semicircular or cochlear functions especially in advanced stages.

Changes in distortion of two-tone cochlear microphonic and otoacoustic emission signals during an acute endolymphatic hydrops in the guinea pig

An acute endolymphatic hydrops was induced by the injection of 1.1 mul of artificial endolymph into the scala media of guinea pig cochleas. This volume corresponds with an acute endolymphatic hydrops of 23%. During and after the injection, cochlear function was assessed by measuring the 2f(1)-f(2 )and f(2)-f(1) distortion products in cochlear microphonics (CMDP) and the 2f(1)-f(2) distortion product otoacoustic emission (DPOAE). A reversible pressure increase of 23 Pa and a relatively stable endocochlear potential (EP) were accompanied by a mean decrease in 2f(1)-f(2) DPOAE of only 3.4 dB. Similarly, the 2f(1)-f(2) CMDP amplitude change was minimal during and after the injection. The only substantial change was measured in the f(2)-f(1) CMDP amplitude. The measured range of distortion amplitudes during an acute endolymphatic hydrops can be related to small changes in the cochlear transducer operating point.

Electrocochleography in patients with Meniere's disease

OBJECTIVE

The objective of this study was to evaluate the role of electrocochleography (ECoG) in the diagnosis of Meniere's disease.

STUDY DESIGN

This study is a retrospective case review.

METHODS

Patients undergoing ECoG for Meniere's disease between 1995 and 2003 were identified and segregated as having definite , probable , or possible Meniere's disease according to the 1995 American Academy of Otolaryngology-Head and Neck Surgery guidelines for Meniere's disease classification. Those determined to have probable and possible Meniere's disease were then combined to form a less-than-definite group for statistical analysis. Electrocochleography summating potential (SP)/action potential (AP) ratios were determined, and ratios greater than 0.4 were considered abnormal. The 2 groups were then compared to assess for any correlation between ECoG with the 1995 American Academy of Otolaryngology-Head and Neck Surgery Meniere's disease classification.

RESULTS

Sixty patients with definite Meniere's disease and 37 with less-than-definite Meniere's disease were identified. Overall, 59.8% had abnormally elevated SP/AP ratios. Of those with definite Meniere's disease, 66.7% had abnormally elevated SP/AP ratios, whereas of those with less-than-definite Meniere's disease, 52.7% had abnormal ECoGs ( P = .069).

CONCLUSIONS

A significant difference in ECoG results was not seen between the definite and less-than-definite Meniere's disease groups. Furthermore, approximately 30% of those with definite Meniere's disease would not be classified as having Meniere's disease based on ECoG results. Because of its lack of sensitivity, ECoG should not play a decisive role in determining the presence or absence of Meniere's disease.

Clinical Usefulness of Extratympanic Electrocochleography in the Diagnosis of Ménière’s Disease

OBJECTIVE

Electrocochleography has been introduced to aid the diagnosis of endolymphatic hydrops. The aim of this study was to evaluate the clinical effectiveness of extratympanic electrocochleography in the diagnosis of Ménière's disease.

STUDY DESIGN

The medical records of patients diagnosed as having Ménière's disease at the department of otolaryngology were reviewed retrospectively. Thirty-seven healthy ears were included to calculate the upper level of the 95th percentile range of the extratympanic electrocochleography variables.

SETTING

Tertiary referral university hospital.

PATIENTS

One hundred fifty-eight patients (97 women and 61 men) diagnosed as having Ménière's disease without previous treatments were included. A retrospective analysis of their medical records, electrocochleographic results, audiograms, and follow-up records was performed. The mean age was 48.6 years.

MAIN OUTCOME MEASURES

The upper level of the 95th percentile range of the extratympanic electrocochleography variables of normal subjects were calculated. Electrocochleography recording results were compared with the diagnostic scale and stage, presence of fluctuating hearing loss, and duration of symptoms.

RESULTS

The 95% upper limit for baseline summating potential and action potential ratio was 0.34. Sensitivity and specificity of electrocochleography in the diagnosis of Ménière's disease were 71% and 96%, respectively. The results statistically correlated with the Ménière's current diagnostic criteria and did not correlate with the stage of disease, presence of fluctuating hearing loss, or duration of symptoms.

CONCLUSION

Extratympanic electrocochleography may play an important role, especially in patients with less definite symptoms, but the diagnosis should also be anchored in the patient's clinical history, symptoms, and audiogram.

Da eletrococleografia transtimpânica em pacientes com e sem hydrops endolinfático e limiares auditivos iguais ou maiores que 50 decibéis

OBJETIVOS: Por meio da análise de eletrococleografias transtimpânicas realizadas em indivíduos controles, em pacientes com diagnóstico clínico definido de hydrops endolinfático e limiares auditivos iguais ou maiores que 50 decibéis e em pacientes com labirintopatias sem evidência clínica de hydrops endolinfático e limiares auditivos iguais ou maiores que 50 decibéis, este estudo tem como objetivos determinar diferenças estatísticas entre os três grupos em relação aos parâmetros estudados; avaliar qual o parâmetro mais sensível na identificação do grupo com hydrops endolinfático e analisar se a associação de parâmetros é útil para a caracterização laboratorial do grupo com hydrops endolinfático. FORMA DE ESTUDO: Clínico retrospectivo. MÉTODO: Estudo retrospectivo de 60 eletrococleografias. Foram analisadas a relação percentual entre o potencial de somação e o potencial de ação (SP/AP), a amplitude entre o primeiro pico positivo do segundo componente do potencial de ação e a linha de base (I/BSL) e a amplitude entre o segundo pico positivo do segundo componente do potencial de ação e a linha de base (II/BSL). RESULTADOS: A análise estatística revelou comportamento diferente entre os três grupos quanto à relação SP/AP, mas não quanto aos outros dois parâmetros. O valor da relação SP/AP equivalente a 46,0% apresentou índices de 75,0% de sensibilidade e 60,0% de especificidade para a identificação do grupo com hydrops endolinfático. CONCLUÕES: Os três grupos apresentaram comportamentos estatísticos diferentes entre si; a relação SP/AP foi o parâmetro mais sensível e específico para identificação dos pacientes com diagnóstico de hydrops endolinfático e a análise da associação dos parâmetros não foi possível.

The effects of high stimulus rate on the electrocochleogram in normal-hearing subjects

The use of high stimulus rates has the potential to improve the electrocochleogram's (ECochG) sensitivity and specificity in endolymphatic hydrops and Menière's disease, but is currently hindered by the absence of an acceptable normative database. In response, this study recorded click-evoked ECochG tracings from 51 normal-hearing subjects (102 ears), between 18 and 60 years of age, at 7.1, 51.1, 101.1 and 151.1 clicks/s using a tympanic membrane electrode. As stimulus rate increased, various statistically significant (p < 0.05) changes were observed. In general, summating potential (SP) latency and amplitude and action potential (AP) latency increased, SP/AP amplitude ratio and waveform width increased but then plateaued, and AP amplitude fluctuated. While providing the largest contribution to a high-stimulus-rate ECochG normative database published to date, potential clinical limitations were identified and a possible solution proposed.