Novel techniques for the diagnosis of Ménièreʼs disease:

Can switching stimulus polarity identify Meniere's disease? A preliminary investigation on ABR

BACKGROUND

Meniere's disease (MD) affects 0.2% to 0.5% of the global population, with regional variations. Standard diagnostic methods, including the glycerol test and EcochG, show variable sensitivity and specificity, highlighting the need for more reliable diagnostic approaches.

OBJECTIVE

This study aims to investigate latency differences in wave V of the Auditory Brainstem Response (ABR) by comparing waveforms for rarefaction and condensation clicks to identify MD.

MATERIALS AND METHODS

The study analyzed latency differences in wave V of the ABR using condensation and rarefaction clicks in 15 ears diagnosed with MD. The control groups included 10 ears with sensorineural hearing loss (SNHL) [non-MD ears] and 20 ears with normal hearing sensitivity.

RESULTS

MD patients exhibited a significant wave V latency shift between rarefaction and condensation stimuli, suggesting altered cochlear dynamics due to endolymphatic hydrops. No such shift was observed in normal hearing or SNHL ears. Patients with definite MD showed a greater latency difference than those with probable MD, possibly reflecting varying endolymphatic pressure.

DISCUSSION

These findings suggest that ABR testing with opposite polarity stimuli could serve as an adjunctive diagnostic tool for MD, particularly in differentiating the severity of the condition but further research is needed to validate these preliminary.

Wideband tympanometry as a diagnostic tool for Meniere's disease: a retrospective case-control study

PURPOSE

The main purpose of this study was to investigate the usefulness of wide band tympanometry (WBT) as a diagnostic tool for Ménière's disease (MD) by comparing differences in absorbance measures between normal hearing ears and patient diagnosed with MD.

METHODS

We conducted a retrospective case-control study. From a cohort of 116 patients diagnosed with Ménière disease, 52 MD patients and 99 normal hearing adults with no history of otological disease served as subjects. Wideband tympanometry was conducted using at Titan Impedance module and audiometry was performed with a MADSEN Astera². Mean energy absorbance curves with 95% confidence intervals were computed across cases with MD and controls in the frequency range 226-8000 Hz. An overall test for difference between curves of cases and controls was calculated by multivariate analysis of variance.

RESULTS

The MD group and the subpopulations of MD patients who fulfilled the International criteria for MD showed a statistically significant lower absorbance at tympanic peak pressure compared to the control group (p < 0.001). No overlap of confidence intervals between mean curves was found within the frequency range of 2000-4000 Hz.

CONCLUSION

Absorbance measures obtained by WBT were able to distinguish between MD ears and normal ears within the frequency range of 2000-4000 Hz. The results indicate that WBT potentially could be a useful and simple non-invasive diagnostic tool for MD. However, more research on the association between absorbance measures and inner ear pathologies is needed.

[Labyrinth hydrops and its diagnosis]

The article deals with the basic theories of maze and labyrinth hydrops, which are often used in clinical practice for its diagnosis according to the world literature. Tonal threshold, suprathreshold audiometry, broadband thympanometry, ultrasound tests, test for determination of lateralization of loud sounds, dehydration test, extra-timbanical electrocochleography, method of registration of evoked vestibular myogenic potentials, study of vestibular function (video pulse test, caloric sample), CT of temporal bones with gadolinium, MRI, and other methods are considered. None of these study methods gives an accurate confirmation of the presence of maze hydrops. Only taking into account the history, complaints of the patient, clinical manifestations of the disease and a comprehensive evaluation of the results of all the above methods of study can we speak with confidence about hydropse.

Change of VOR gain and pure-tone threshold after single low-dose intratympanic gentamicin injection in Meniere's disease

Background: Intratympanic gentamicin injection (ITG) is a well-accepted means to treat intractable Meniere's disease (MD).Aims/Objectives: To investigate change of vestibule-ocular reflex (VOR) gain and pure-tone threshold after low-dose ITG for MD.Methods: Sixteen patients with definite MD who were treated by low-dose ITG were retrospectively reviewed. We defined VOR gain difference as an amount of decreased gain in video head impulse test one month after ITG. Patients were classified into two groups: single injection vs. multiple injections. Multiple injections group was composed of patients with poor vertigo control after initial ITG who required second or third ITG later in follow up period.Results: VOR gain differences of both horizontal and posterior canal plane were higher than those of anterior canal plane. Between two groups, mean VOR gain difference of horizontal canal plane in multiple injections group was lower than that in single injection group. Only two patients showed increased pure-tone threshold more than 10 dB.Conclusion and significance: Our results suggest that ITG appears to cause a differential loss of function across three semicircular canals. Furthermore, if VOR gain difference of horizontal canal is relatively low after initial ITG, patient might have poor vertigo control and be required another ITG.

Biomarkers in Vestibular Schwannoma-Associated Hearing Loss

Vestibular schwannomas (VSs) are benign tumors composed of differentiated neoplastic Schwann cells. They can be classified into two groups: sporadic VS and those associated with neurofibromatosis type 2 (NF2). VSs usually grow slowly, initially causing unilateral sensorineural hearing loss (HL) and tinnitus. These tumors cause HL both due to compression of the auditory nerve or the labyrinthine artery and due to the secretion of different substances potentially toxic to the inner ear or the cochlear nerve. As more and more patients are diagnosed and need to be managed, we are more than ever in need of searching for biomarkers associated with these tumors. Owing to an unknown toxic substance generated by the tumor, HL in VS may be linked to a high protein amount of perilymph. Previous studies have identified perilymph proteins correlated with tumor-associated HL, including μ-Crystallin (CRYM), low density lipoprotein receptor-related protein 2 (LRP2), immunoglobulin (Ig) γ-4 chain C region, Ig κ-chain C region, complement C3, and immunoglobulin heavy constant γ 3. Besides, the presence of specific subtypes of heat shock protein 70 has been suggested to be associated with preservation of residual hearing. It has been recently demonstrated that chemokine receptor-4 (CXCR4) is overexpressed in sporadic VS as well as in NF2 tumors and that hearing disability and CXCR4 expression may be correlated. Further, the genetic profile of VS and its relationship with poor hearing has also been studied, including DNA methylation, deregulated genes, growth factors, and NF2 gene mutations. The knowledge of biomarkers associated with VS would be of significant value to maximize outcomes of hearing preservation in these patients.

A network-based method using a random walk with restart algorithm and screening tests to identify novel genes associated with Menière's disease

As a chronic illness derived from hair cells of the inner ear, Menière’s disease (MD) negatively influences the quality of life of individuals and leads to a number of symptoms, such as dizziness, temporary hearing loss, and tinnitus. The complete identification of novel genes related to MD would help elucidate its underlying pathological mechanisms and improve its diagnosis and treatment. In this study, a network-based method was developed to identify novel MD-related genes based on known MD-related genes. A human protein-protein interaction (PPI) network was constructed using the PPI information reported in the STRING database. A classic ranking algorithm, the random walk with restart (RWR) algorithm, was employed to search for novel genes using known genes as seed nodes. To make the identified genes more reliable, a series of screening tests, including a permutation test, an interaction test and an enrichment test, were designed to select essential genes from those obtained by the RWR algorithm. As a result, several inferred genes, such as CD4, NOTCH2 and IL6, were discovered. Finally, a detailed biological analysis was performed on fifteen of the important inferred genes, which indicated their strong associations with MD.

Validity and Reliability of the Diagnostic Tests for Ménière's Disease

Ménière's disease is defined as an idiopathic syndrome characterized by endolymphatic hydrops. Various tests and measurement methods have been employed for the diagnosis of Ménière's disease. These include audiological, vestibular, radiological, clinical, and biochemical tests. However, the lack of a definitive or gold standard diagnostic test sometimes complicates the process of diagnosis. Hence, the clinician should be well-experienced in deciding when to perform a test and how to interpret the results of the test. Furthermore, having the knowledge of the validity and reliability of these tests plays a critical role. This review particularly emphasizes on remarking the validity and reliability of each test performed for the diagnosis of Ménière's disease and discussing the results according to the up-to-date literature.

Meniett device in meniere disease: Randomized, double-blind, placebo-controlled multicenter trial

OBJECTIVE

To evaluate the efficacy of portable Meniett low-pressure pulse generator (Medtronic Xomed, Jacksonville, FL) in Meniere disease.

STUDY DESIGN

Randomized, double-blind, placebo-controlled, multicenter trial carried out in 17 academic medical centers.

METHODS

One hundred twenty-nine adults presenting Meniere disease (American Academy of Otolaryngology-Head and Neck Surgery criteria) not controlled by conventional medical treatment were included. The protocol included three phases: 1) placement of a transtympanic tube and evaluation of its effect (if resolution of symptoms, the patient was excluded); 2) randomization: 6-weeks treatment with Meniett (Medtronic Xomed) or placebo device; 3) removal of the device and 6-week follow-up period. The evaluation criteria were the number of vertigo episodes (at least 20 minutes with a 12-hour free interval) and the impact on daily life as assessed by self-questionnaires.

RESULTS

Ninety-seven patients passed to the second phase of the study: 49 and 48 patients received the Meniett (Medtronic Xomed) or the placebo device, respectively. In the placebo group, the number of vertigo episodes decreased from 4.3 ± 0.6 (mean ± standard error of the mean) during the first phase to 2.6 ± 0.5 after 6 weeks of treatment, and to 1.8 ± 0.8 after the removal of the device. Similar results were observed in the Meniett device (Medtronic Xomed) group: 3.2 ± 0.4 episodes during the first phase, 2.5 ± after 6 weeks of Meniett device (Medtronic Xomed) treatment, and 1.5 ± 0.2 after the third phase.

CONCLUSION

An improvement of symptoms was evidenced in all patients, with no difference between the Meniett (Medtronic Xomed) and the placebo device groups. The decrease in the number of vertigo episodes could be explained by an effect of the medical care.

LEVEL OF EVIDENCE

1b. Laryngoscope, 2016 127:470-475, 2017.

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.

Differences in perilymphatic space enhancement and adverse inflammatory reaction after intratympanic injection of two different gadolinium agents: A 9.4-T magnetic resonance imaging study

PURPOSE

To compare the inner ear enhancement after intratympanic injection of two widely used gadolinium (Gd) agents by 9.4 T micro-magnetic resonance imaging (MRI) and to investigate the effects of Gd on the inner ear.

METHODS

Twelve ears of six rats received intratympanic administration of 1/5 diluted Gd agents: gadoterate meglumine (Gd-DTPA) for the left ear and gadodiamide (Gd-DTPA-BMA) for the right ear. MRI was performed every 30 min from 1 to 4 h after administration. The normalized signal intensity was evaluated by quantitative analysis at each cochlear fluid compartment. Eight, six, and seven ears treated with Gd-DTPA, Gd-DPTA-BMA, and nothing as controls, respectively, were processed for histological evaluation after MRI. After hematoxylin & eosin staining, adverse inflammatory reactions were evaluated for turbid aggregation and lymphocytes.

RESULTS

The perilymphatic enhancement of Gd-DTPA was superior to that of Gd-DTPA-BMA regardless of cochlear turn, compartment, and time point. Inflammatory reactions were found in 4/8 (50.0%) and 4/6 (66.6%) ears administered Gd-DTPA and Gd-DTPA-BMA, respectively. Regardless of the contrast agent used, inflammatory reactions were most definite in the scala tympani of the basal turn, i.e., near the round window. Slightly greater inflammatory reactions were observed in ears injected with Gd-DTPA-BMA compared to Gd-DTPA although the difference was not statistically significant. No inflammatory reaction was observed in any of the seven controls. The auditory brainstem response threshold was 11.8 ± 2.5 dB SPL before IT Gd injection and it did not change for up to 5 days (15.4 ± 6.6 dB SPL) post-injection.

CONCLUSIONS

Gd-DTPA was superior to Gd-DTPA-BMA for visualization of the inner ear. Administration of diluted Gd agents intratympanically may induce considerable inflammatory reactions in the inner ear.

The dissociation of video head impulse test (vHIT) and bithermal caloric test results provide topological localization of vestibular system impairment in patients with "definite" Ménière's disease

PURPOSE

We report 3 patients with Ménière's disease and describe how the combination of audiometry, video head impulse testing, and caloric results may prove helpful in the diagnosis of Ménière's disease.

METHOD

Three patients with "definite" Ménière's disease were evaluated in a tertiary care medical center. Each patient underwent videonystagmography, horizontal canal video head impulse testing, and audiometry.

RESULTS

All 3 patients demonstrated moderate, flat, sensorineural hearing losses; significant caloric asymmetries; and bilaterally normal video head impulse testing. This pattern of findings suggests differential preservation of high-frequency function (video head impulse testing) with impairment of low-frequency function (unilaterally abnormal caloric test results) in these patients.

CONCLUSION

Ipsilesional abnormal caloric testing in the presence of normal video head impulse testing is a pattern of findings observed in a cohort of patients who have "definite" Ménière's disease.