Classification of patients with Ménière's disease using otoacoustic emissions

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.

Vestibular Evoked Myogenic Potentials and Distortion-Product Otoacoustic Emissions Combined with Glycerol Testing in Endolymphatic Hydrops: Their Value in Early Diagnosis

The present investigation was specifically designed to evaluate the ability of the glycerol test combined with pure tone audiometry, distortion-product otoacoustic emissions (DPOAEs), and vestibular evoked myogenic potentials (VEMPs) to diagnose endolymphatic hydrops early and to identify cases that may evolve toward Meniere's disease. This investigation consisted of 29 consecutive patients with mild dizziness or vertigo who received no treatment. Each patient underwent glycerol testing measured with conventional pure tone audiometry and with both DPOAEs and VEMPs. It is interesting to note that in 7 and 8 of the 29 cases, the VEMPs and DPOAEs, respectively, showed an improvement after glycerol administration that had not been shown on traditional audiometry. A further element worthy of consideration emerges from an analysis of the VEMP results compared to the DPOAE results that divided the patients into 4 groups. The first group had a postglycerol improvement with both methods, which would seem to suggest hydrops in both the anterior and posterior parts of the labyrinth. In the second and third groups, there was an improvement only either with VEMPs or DPOAEs, and this finding seems to indicate that only one endolymphatic compartment might be involved. In the last group, all patients had a positive glycerol test with positive DPOAEs on one side and with positive VEMPs on the other. Although endolymphatic hydrops can only be proven after death, a combination of VEMPs and DPOAEs with the glycerol test may permit early diagnosis of endolymphatic hydrops. These results clearly imply that these methods should be permanently included in the diagnostic protocol of patients with vestibular and audiological symptoms.

Role of transient evoked otoacoustic emission beyond screening of hearing impairment: a study of 400 cases

The primary purpose of this study was to investigate the potential role of transient-evoked Otoacoustic emissions (TEOAEs) beyond screening for hearing impairment in different middle/inner ear disorders in 3-65 years age group. Because TEOAEs are present in ears with normal cochlear and middle ear function and typically are absent or reduced in ears with cochlear and/or middle ear disorders of even mild degree. This was a prospective study of four hundred cases. Out of these 364 cases were having problems related to otology and 36 were healthy volunteers who attended the department of otorhinolaryngology of our institute. All the cases were kept in different eight groups and then subjected to Otoacoustic emission testing with the 'GSI AUDIO screener' equipment installed in our ENT department. The data obtained in all groups were analyzed and conclusion was made. TEOAEs is a reliable, simple and cost effective screening technique for hearing disorders with sensitivity varying from 72 to 96.42 % among the study groups and 88 % in composite group comprising all study groups.

Effects of glycerol intake and body tilt on otoacoustic emissions reflect labyrinthine pressure changes in Menière's disease

It is known that by influencing stapes stiffness thus the ear's impedance, changes in intracranial and intralabyrinthine pressure induce a characteristic phase shift in otoacoustic emissions (OAE) around 1 kHz in human ears. Thus, if the regulation of pressure in intralabyrinthine compartments were abnormal in Menière patients, OAEs might help detect it. Body tilt, which acts on intracranial pressure, and administration of an osmotically active substance provide two simple ways of manipulating intralabyrinthine pressure. Here, 14 patients with typical signs of an attack of unilateral endolymphatic hydrops were submitted to postural changes and a glycerol test. Their OAEs initially collected in upright position served as references, then OAEs were measured in supine position, and back to the upright posture one and 3h after glycerol intake. Twenty control subjects were also tested for body tilt. The main effect of body tilt and glycerol was a phase rotation of OAEs peaking around 1 kHz. Its frequency dependence matched the one due to a pressure-related change in stapes or basilar membrane stiffness predicted by the ear model of Zwislocki (1962). The average glycerol-induced phase shifts were similar in size in Menière vs. asymptomatic ear and audiometric thresholds were stable after glycerol intake in line with the model predicting little change in the magnitude of the transfer function. These data support a simple conductive pressure-related mechanism explaining the action of glycerol on inner ear responses. The fact that the mean postural shift was three times larger in Menière than asymptomatic and control ears suggests an additional effect in allegedly hydropic ears.

Multifrequency admittancemetry in Ménière's Disease: a preliminary study for a new diagnostic test

OBJECTIVE

To assess the qualitative and quantitative aspects of multifrequency tympanograms in patients with Ménière's disease.

STUDY DESIGN

Prospective study of adults.

SETTING

University medical center.

PATIENTS

Forty patients with Ménière's disease outside of episodes and 24 normal-hearing subjects with no otologic history.

INTERVENTIONS

Resonance frequency sweep and tympanograms of admittance, conductance, and susceptance at 2 kHz and at resonance frequency were performed in each ear.

MAIN OUTCOME MEASURES

A qualitative assessment was performed to find reproducible and comparable tympanograms (Student's t test) as a prerequisite for quantitative assessment. Four measurement criteria were compared between the groups to establish a diagnostic test (chi Pearson test). A p value less than 0.05 was considered statistically significant.

RESULTS

Resonance frequency was decreased in Ménière's disease. Only conductance tympanograms at 2 kHz had a constant pattern. Width of conductance tympanograms at 2 kHz was increased in symptomatic Ménière's disease compared with normal ears. Using conductance width at 2 kHz as a diagnostic test with a threshold of 235 daPa, we found a statistically significant difference between symptomatic ears of patients with Ménière's disease and ears of normal subjects (p < 10). More than 95% of normal subjects' ears had a negative test; 56.5% of affected ears of patients with Ménière's disease and 45.8% of nonaffected ears of patients with Ménière's disease had a positive test.

CONCLUSION

Width of conductance at 2 kHz seems to be a sensitive, simple diagnostic test in Ménière's disease. It would also be of great interest in studying Ménière's disease bilaterality.

Quantification of audiogram fine-structure as a function of hearing threshold

We investigated the amount of fine-structure in the audiograms of patients with Menière's disease. Both ears (often an affected and an unaffected ear) were investigated. Data are presented from 39 ears of 21 patients with hearing thresholds varying from about 0 to 70 dB HL. The fine-structure was measured in the frequency range from 500 to 3500 Hz; this agrees with a part of the basilar membrane from 10 to 22.5 mm from the apex. The fine-structure was characterized by means of the number of peaks N(p) and the sum S(p) of the heights of all the peaks in an audiogram. From these quantities, we also determined average peak height H(p). We found a negative correlation between hearing loss and strength of fine-structure, i.e. the higher the thresholds the smaller N(p) and S(p) as well as H(p). Also N(p) and H(p) were correlated, i.e. the more peaks the higher the average peak height. The summated peak height S(p)=N(p)H(p) showed a strong dependence on the hearing loss. In cases of strong fine-structure, S(p) reached values around 200 dB.

Evoked otoacoustic emissions in patients with Ménière's disease

HYPOTHESIS

This study investigated whether otoacoustic emissions (OAEs) in patients with Ménière's disease show abnormal properties.

BACKGROUND

Patients with Ménière's disease experience vertigo, tinnitus, and hearing loss. OAEs are sounds generated in the inner ear, and their presence is associated with normal hearing.

METHODS

Click-evoked OAEs and distortion product OAEs were measured in 100 patients with Ménière's disease.

RESULTS

The incidence of the emissions in affected ears (56%) was lower than in unaffected (i.e., contralateral) ears (85%). The mean emission amplitude in affected ears was also significantly lower (2.6 dB), and the mean amplitude in unaffected ears was lower than in normal-hearing ears (5.3 dB). These differences were likely caused by the hearing loss involved. Further, ears with OAEs clearly showed smaller hearing losses than ears without OAEs (24-dB difference). The average hearing loss showed correlations with the emission amplitudes, although this correlation was not very strong; when plotted against the smallest hearing loss, a certain upper boundary for the emission amplitude was present. Also, the amplitude of click-evoked OAEs showed a considerable correlation with the largest of the three distortion product OAEs.

CONCLUSION

OAEs in patients with Ménière's disease differed from those in normal-hearing ears but did not differ from those in non-Ménière's ears with equivalent hearing loss. This was best observed by comparing emission amplitude with smallest hearing loss instead of mean hearing loss.

History of Meniere's disease and its clinical presentation

The term Meniere's disease is used to define either the classic triad of vestibular and cochlear symptoms and aural pressure from known or unknown causes or its clinical variants, vestibular and cochlear Meniere's disease. Some variants evolve after years into typical forms, whereas others do not. Some symptoms (positional vertigo) have been long underestimated in previous reports. The more we study our patients and correlate clinical findings and the natural history with pathologic studies on temporal bones and laboratory research, the more we will understand Meniere's disease and its causes. Some causes have already been identified as most probable. Extrinsic factors (inflammation, trauma, otosclerosis, autoimmunity, endocrine disorders, and such) interact with congenital (genetic) and developmental intrinsic factors (primary or secondary, acquired) into a multifactorial inheritance that is, to date, the best explanation for the basis of Meniere's disease. Endolymphatic hydrops is widely accepted as the pathologic substrate, but not all hydrops seems to be progressive or becomes clinically manifest. Endolymphatic hydrops is the result of a dysfunction in the mechanism of production/absorption of endolymph, which is mainly due to defective absorptive activity of the endolymphatic duct and sac. Hyperproduction of endolymph cannot be excluded in some cases. Ruptures of the labyrinthine membranes do not satisfactorily substantiate the multiform duration, recurrence, and repetitiveness of attacks of Meniere's disease, nor do they explain the entire complex of symptoms. It seems reasonable to explain symptoms of Meniere's disease on the basis of mechanical factors (as observed in temporal bone studies) associated with biologic and biochemical factors.

Pure-tone and speech audiometry in patients with Menière's disease

The aim of this study was to reinvestigate many of the claims in the literature about hearing loss in patients with Menière's disease. We carried this out on a well-defined group of patients under well-controlled circumstances. Thus, we were able to find support for some claims and none for many others. As part of a diagnostic protocol, pure-tone and speech audiometry was performed on 111 patients with Menière's disease according to the 'Definition Menière Groningen'. This was a prospective clinical cohort study. Affected ears of patients suffering from Menière's disease show reduced hearing, both in pure-tone and in speech audiometry. A classification method was devised to determine audiogram shape in an objective manner. The results of this method indicate that affected ears more frequently show 'low' or 'low + high' hearing losses (P = 0.006). The shape of the hearing loss does not depend on the duration of the affection of the disease. In combination with the fact that the average hearing loss does not correlate with the duration of the disease, this leads to the conclusion that, if a classification of the hearing loss in Menière's disease is possible, such a classification cannot be connected to the duration. This conclusion is further supported by the fact that no relationship is found between the duration of the disease and the classification of the hearing loss over the 3 months before hospital admission, as given by the patients in a questionnaire. A relationship between the (objective) audiometric data and the (subjective) classification of the hearing loss by the patient seems to be present, but is not very strong. Correlations between pure-tone and speech audiometry are present as in non-Menière ears (r = 0.899, P < 0.001), and no indications are found of reduced speech discrimination relative to the expectation based on pure-tone loss. The audiogram shape does not appear to play any additional role in speech discrimination (in addition to the influence of the average pure-tone loss).

Distortion-product otoacoustic emissions and cochlear microphonics: relationships in patients with and without endolymphatic hydrops

OBJECTIVES

Because endolymphatic hydrops causes cochlear malfunction, and both otoacoustic emissions and cochlear microphonics measure specific cochlear activities, some insight into the pathology of Meniere's disease might be gained by using these two test modalities. Specifically, the involvement of cochlear outer hair cells in patients with endolymphatic hydrops may be detected. Furthermore, it is hoped that these two tests might help determine which regions of the cochlea are affected by endolymphatic hydrops, as well as where along the auditory pathway abnormalities are present.

STUDY DESIGN

Data were gathered prospectively on patients presenting to a private, tertiary referral otology/neurotology practice.

METHODS

From February 1999 to April 2000, clinical information was collected on patients presenting with vertigo, hearing loss (HL), sudden HL, fluctuant HL, aural fullness, and/or tinnitus. Data included demographics, diagnosis, pure-tone and speech audiometry, tympanometry, summating potential, action potential, cochlear microphonic, and distortion-product otoacoustic emissions. Descriptive statistics were calculated, and relationships between distortion-product otoacoustic emissions and cochlear microphonics in patients with hydrops (defined as summating potential to action potential ratio > or =0.40) and without hydrops were analyzed.

RESULTS

Distortion-product otoacoustic emissions were present more often and had larger amplitudes at the lower frequencies. No differences were found in the presence of distortion-product otoacoustic emissions across the frequencies for the two groups, but larger mean amplitudes were found for hydropic ears at 7966 Hz. As hearing levels worsened, both hydropic and nonhydropic ears were less likely to have emissions present; however, 18% of hydropic ears had emissions unexpectedly present when the pure-tone thresholds were > or =50 dB. The cochlear microphonic from the hydrops group tended to be smaller, but this was not statistically significant. Analysis of variance showed a small negative correlation between summating potential to action potential ratio and level of emission at 1968 Hz in hydropic ears; otherwise, there was no relationship between the ratio and emissions. The only statistically significant finding when analyzing the relationship between cochlear microphonic and otoacoustic emission was a small positive correlation between level of microphonic and level of emission at 1406 Hz in hydropic ears. No significant relationships were found between hearing thresholds and emissions or microphonics.

CONCLUSIONS

Even though both distortion-product otoacoustic emissions (DPOAEs) and cochlear microphonics (CMs) measure specific cochlear activities, they were not found to be useful for differentiating patients with hydrops from those without. In some patients, however, unexpected distortion-product otoacoustic emissions were present. This may represent localizing information about which regions of the cochlea are being affected by hydrops in these patients. Also, a small positive correlation between the CM and the DPOAE at 1406 Hz was detected in the hydrops group, which may represent the effects of endolymphatic hydrops on the outer hair cell. Future investigations involving hydropic patients with unexpected DPOAEs and studies looking for more DPOAE and CM correlations at frequencies surrounding 1406 Hz are being planned.