Histopathology of Meniere's disease

The ANTI-LAMBDA: A Non-statical Tonal Indicator Low-Frequency Air-Bone Gap of Ménière's Bouts and Disease Activity

INTRODUCTION

 There have been reports of patients with Ménière´s disease (MD) showing unexplained audiometric air-bone gaps at low frequencies. Little is known about the clinical significance of this finding. The objective of this study was to describe this phenomenon while relating it with clinical features, namely the incidence of attacks.

METHODS

Unilateral MD patients were selected and cerebral magnetic resonance imaging (cMRI) was assessed to exclude structural pathology. A retrospective longitudinal analysis regarding disease activity and audiometric details was performed. A coincidence index and regression predictive models were considered to assess the relationship between the air-bone gap and MD activity.

RESULTS

 A total of 70 MD patients were enrolled and 252 audiograms were assessed. Low-frequency air-bone gaps (LFABGs) were significantly associated with unstable MD (p < 0.001), demonstrating a sensitivity and specificity of 93.8% and 82.7%, respectively. The incidence of unstable disease with the presence of LFABG was 89.1 %. A higher LFABG magnitude correlated with increased disease activity (p < 0.001) and was particularly pronounced at 250 Hz and 500 Hz.

CONCLUSION

The typical LFABG encountered was here called ANTI-LAMBDA (A Non-statical Tonal Indicator Low-Frequency Air-Bone Gap of Ménière's Bouts and Disease Activity). It relates to MD activity and is a potential new tool to assess MD stability/need for additional therapeutics.

Diagnostic Role of Combined Electrocochleography and Pure-Tone Audiometry Monitoring During Dehydrating Test in Ménière's Disease: A Case Series

OBJECTIVES

To evaluate the diagnostic role of combined electrocochleography and pure-tone audiometry monitoring during dehydrating test in Ménière's disease and consider its suitability as a diagnostic tool to differentiate those patients with unclear differential diagnosis and therefore identify those with clear endolymphatic hydrops responsive to dehydrating test. To study the efficacy of dehydrating therapy on vertiginous symptoms and hearing loss in patients with Ménière's disease.

STUDY DESIGN

Prospective case series.

SETTINGS

University hospital, secondary referral center.

PATIENTS

Thirty patients, 20 women and 10 men, age range of 25 to 75 years, matching the criteria for definite Ménière's disease according to the Barany Society classification.

INTERVENTION

Diagnostic. During an active phase of the disease, electrocochleography and pure-tone audiometry were performed, and repeated at 30th, 45th, and 60th minutes after intramuscular injection of 40 mg furosemide and 40 mg methylprednisolone.

MAIN OUTCOME MEASURE

Data related to symptoms, electrocochleography, and pure-tone audiometry during the dehydrating test were collected at different times and statistically analyzed.

RESULTS

After the administration of dehydrating therapy, we observed that both summating potential and action potential ratio and summating potential and action potential area ratio were normalized in 21 of 30 subjects. Furthermore, pure-tone audiometry thresholds improved significantly. An improvement of ear fullness was also observed, whereas tinnitus unchangeably persisted.

CONCLUSIONS

The monitoring of the electrocochleography and pure-tone audiometry thresholds during dehydrating tests with furosemide and methylprednisolone could allow to detect an improvement of instrumental features and clinical symptoms related to endolymphatic hydrops, and therefore, it could be used as a diagnostic tool in the identification of those patients affected by Ménière's disease with unclear differential diagnosis.

Thyroid Axis and Vestibular Physiopathology: From Animal Model to Pathology

A recent work of our group has shown the significant effects of thyroxine treatment on the restoration of postural balance function in a rodent model of acute peripheral vestibulopathy. Based on these findings, we attempt to shed light in this review on the interaction between the hypothalamic-pituitary-thyroid axis and the vestibular system in normal and pathological situations. Pubmed database and relevant websites were searched from inception through to 4 February 2023. All studies relevant to each subsection of this review have been included. After describing the role of thyroid hormones in the development of the inner ear, we investigated the possible link between the thyroid axis and the vestibular system in normal and pathological conditions. The mechanisms and cellular sites of action of thyroid hormones on animal models of vestibulopathy are postulated and therapeutic options are proposed. In view of their pleiotropic action, thyroid hormones represent a target of choice to promote vestibular compensation at different levels. However, very few studies have investigated the relationship between thyroid hormones and the vestibular system. It seems then important to more extensively investigate the link between the endocrine system and the vestibule in order to better understand the vestibular physiopathology and to find new therapeutic leads.

A Drosophila model for Meniere's disease: Dystrobrevin is required for support cell function in hearing and proprioception

Meniere's disease (MD) is an inner ear disorder characterised by recurrent vertigo attacks associated with sensorineural hearing loss and tinnitus. Evidence from epidemiology and Whole Exome Sequencing (WES) suggests a genetic susceptibility involving multiple genes, including α-Dystrobrevin (DTNA). Here we investigate a Drosophila model. We show that mutation, or knockdown, of the DTNA orthologue in Drosophila, Dystrobrevin (Dyb), results in defective proprioception and impaired function of Johnston's Organ (JO), the fly's equivalent of the inner ear. Dyb and another component of the dystrophin-glycoprotein complex (DGC), Dystrophin (Dys), are expressed in support cells within JO. Their specific locations suggest that they form part of support cell contacts, thereby helping to maintain the integrity of the hemolymph-neuron diffusion barrier, which is equivalent to a blood-brain barrier. These results have important implications for the human condition, and notably, we note that DTNA is expressed in equivalent cells of the mammalian inner ear.

Speech Recognition During Follow-Up of Patients with Ménière's Disease: What Are We Missing?

BACKGROUND

Hearing loss causes a significant reduction in the quality of life of patients with Ménière's disease. Although speech recognition is also affected, it has not been extensively studied. The objective of the study was to describe speech recognition behavior during a prolonged period in patients with unilateral Ménière's disease.

METHODS

A prospective case-control study was performed. The case group included patients with defined unilateral Ménière's disease and the control group included patients with progressive non-fluctuating hearing loss. Patients underwent an auditory evaluation periodically. Pure-tone audiometry and speech recognition tests-speech recognition threshold and speech discrimination score-were administered. The dissociation between pure-tone audiometry and speech recognition was assessed through a linear regression analysis. During follow-up, Ménière's disease patients were subdivided into a stable and fluctuating subgroup (a change of >20% in the speech discrimination score with a change no greater than 15 dB in pure-tone audiometry).

RESULTS

The average follow-up time was 79.9 months. Fifty-seven patients were included (30 cases, 27 controls). Dissociation between puretone audiometry and speech recognition threshold began to appear in the case group after 21 months, and it was statistically significant at 108 months. Duration of the disease was the only variable studied that influenced the dissociation. The fluctuation subgroup in cluded 56.6% of the cases.

CONCLUSION

We described 2 audiological peculiarities in Ménière's disease patients: dissociation between pure-tone audiometry and speech recognition during the evolution of the disease and the fluctuation of speech recognition regardless of the change in pure-tone audiometry. Our results highlight the importance of performing speech recognition tests during follow-up in patients with Ménière's disease.

[Clinical significance of radiological methods for diagnosing endolymphatic hydrops in Ménière's disease]

Ménière's disease is a chronic disorder of the inner ear, a permanent sing of which is endolymphatic hydrops. For the diagnosis of Ménière's disease in clinical practice, criteria that are primarily based on the clinical picture. However, instrumental methods for diagnosing Ménière's disease, aimed at identifying endolymphatic hydrops, continue to be developed and improved. Radiation diagnostics contribute significant contribution and aimed at identifying the characteristic signs of Ménière's disease. Recently, it has become possible to visualize endolymphatic hydrops using MRI of the temporal bones. This publication presents an analysis of the current state of this topical aspect of the problem of diagnosing Ménière's disease. The purpose of this review is to conduct a comparative analysis of radiation methods for diagnosing Ménière's disease.

MATERIAL AND METHODS

The study included publications in English and Russian found in the PubMed, eLibrary database related to the diagnosis of Meniere's disease.

RESULTS

A comparative analysis of computed tomography of the temporal bones, magnetic resonance imaging of the temporal bones and diagnostic possibilities for detecting signs characteristic of Ménière's disease are presented. The most diagnostically significant method of studying Ménière's disease is identified.

CONCLUSION

MRI of the temporal bones with contrast enhancement is a promising method that can be used to develop an effective treatment algorithm.

Validation of inner ear MRI in patients with Ménière's disease by comparing endolymphatic hydrops from histopathologic specimens

Intravenous gadolinium-enhanced inner-ear magnetic resonance imaging (IV-Gd inner-ear MRI) has been used to visualize endolymphatic hydrops (EH) in clinical diagnosis of Ménière's disease (MD). However, lack of histological validation has led to several concerns regarding how best to interpret the resulting images. Here, we compared hydropic changes in temporal bone specimens with the results of IV-Gd inner-ear MRI in patients with MD. Histopathologic images of temporal bones from 37 patients with MD and 10 healthy controls were collected from the National Temporal Bone Bank of the Massachusetts Eye and Ear Infirmary in the United States. The EH ratios in the vestibule and cochlea were calculated from temporal bones using the methods used for IV-Gd inner-ear MRI, and the degree to which the saccular and utricular hydrops contributed to vestibular hydrops was measured. The presence of hydropic change in each semicircular canal was assessed using temporal bone images and compared with IV-Gd inner-ear MRI scans of 74 patients with MD. Based on human temporal bone imagery, the EH ratios in the cochlea and the vestibule on the affected side were 0.314 and 0.757, respectively. In the healthy control group, the ratio was 0.064 for the cochlea and 0.289 for the vestibule; these values were significantly different from those for the affected side of MD patients. The values for the affected ear were similar to the ratios from the IV-Gd inner-ear MRI scans in MD patients. In the vestibule, saccular hydrops were more common than utricular hydrops. The average EH ratios in the saccule and utricle were 0.513 and 0.242, respectively. No significant hydropic change from each of three semicircular canals was evident in temporal bone histopathology. However, herniation of otolithic organs (saccule or utricle) into the lateral semicircular canal was found in 44.4% of the patients, with saccular herniation (24.8%) more common than utricular herniation (16.7%). Although IV-Gd inner-ear MRI might not reflect fully the results of actual histopathology due to the limited resolution of MRI and image-processing techniques, the measured EH ratios from temporal bone specimens and IV-Gd inner-ear MRI scans were similar. Hydropic change in the three semicircular canals was not significant at either the ampullated or nonampullated end. Canal invasion of vestibular hydrops seen on MRI also appeared in temporal bone histopathology, and saccular invasion was dominant.

A Synchrotron and Micro-CT Study of the Human Endolymphatic Duct System: Is Meniere's Disease Caused by an Acute Endolymph Backflow?

Background: The etiology of Meniere's disease (MD) and endolymphatic hydrops believed to underlie its symptoms remain unknown. One reason may be the exceptional complexity of the human inner ear, its vulnerability, and surrounding hard bone. The vestibular organ contains an endolymphatic duct system (EDS) bridging the different fluid reservoirs. It may be essential for monitoring hydraulic equilibrium, and a dysregulation may result in distension of the fluid spaces or endolymphatic hydrops. Material and Methods: We studied the EDS using high-resolution synchrotron phase contrast non-invasive imaging (SR-PCI), and micro-computed tomography (micro-CT). Ten fresh human temporal bones underwent SR-PCI. One bone underwent micro-CT after fixation and staining with Lugol's iodine solution (I2KI) to increase tissue resolution. Data were processed using volume-rendering software to create 3D reconstructions allowing orthogonal sectioning, cropping, and tissue segmentation. Results: Combined imaging techniques with segmentation and tissue modeling demonstrated the 3D anatomy of the human saccule, utricle, endolymphatic duct, and sac together with connecting pathways. The utricular duct (UD) and utriculo-endolymphatic valve (UEV or Bast's valve) were demonstrated three-dimensionally for the first time. The reunion duct was displayed with micro-CT. It may serve as a safety valve to maintain cochlear endolymph homeostasis under certain conditions. Discussion: The thin reunion duct seems to play a minor role in the exchange of endolymph between the cochlea and vestibule under normal conditions. The saccule wall appears highly flexible, which may explain occult hydrops occasionally preceding symptoms in MD on magnetic resonance imaging (MRI). The design of the UEV and connecting ducts suggests that there is a reciprocal exchange of fluid among the utricle, semicircular canals, and the EDS. Based on the anatomic framework and previous experimental data, we speculate that precipitous vestibular symptoms in MD arise from a sudden increase in endolymph pressure caused by an uncontrolled endolymphatic sac secretion. A rapid rise in UD pressure, mediated along the fairly wide UEV, may underlie the acute vertigo attack, refuting the rupture/K+-intoxication theory.

Correlation between magnetic resonance imaging classification of endolymphatic hydrops and clinical manifestations and audiovestibular test results in patients with definite Ménière's disease

OBJECTIVES

The purpose was to evaluate magnetic resonance imaging (MRI) classification of endolymphatic hydrops with clinical features, audiological and vestibular tests in patients with definite unilateral Ménière's disease (MD).

METHODS

Thirty-eight patients were enrolled in this study. The severity of the main clinical symptoms, audiovestibular tests, and MRI, performed 4 hours after intravenous injection of gadobutrol to visualize inner ear compartments, were evaluated. Endolymphatic space dilatation was assessed using Barath and Bernaerts grading systems, and the correlation between the grade of the hydrops and clinical features was evaluated.

RESULTS

Using the Barath system, cochlear hydrops was visualized in 81.6% of affected ears, while vestibular was 63.2%. Sensitivity increased to 94.7% using Bernaerts' modification. Vestibular hydrops involving the utricle was present only among patients with cochlear and saccular endolymphatic space dilatation. There was a significant relationship between the hearing level and the vestibular hydrops degree in the Bernaerts scale. The grade of the hydrops correlated neither with the duration of MD nor with the severity of main clinical symptoms. Our study proved MRI to be a sensitive diagnostic tool in MD. The endolymphatic hydrops' grade correlates with the hearing level, which confirms endolymphatic space dilatation's role in hearing loss.

CONCLUSIONS

In our study, two similar MRI grading systems were used; however, several differences were found compared to one another. The Bernaerts scale was more sensitive than the Barath scale, and several relationships between the radiological and clinical data were found. Therefore, several MRI evaluating scales and correlating them with the clinical features are needed. The increased perilymphatic enhancement of the cochlea and an extra low-grade vestibular hydrops distinguished in the Bernaerts scale may increase MD diagnosis sensitivity. Magnetic resonance findings in MD support the clinical diagnosis and may help to understand MD pathophysiology better. This study adds to the knowledge and diagnostics in MD for healthcare to improve patients' treatment.

The "hype" of hydrops in classifying vestibular disorders: a narrative review

Background

Classifying and diagnosing peripheral vestibular disorders based on their symptoms is challenging due to possible symptom overlap or atypical clinical presentation. To improve the diagnostic trajectory, gadolinium-based contrast-enhanced magnetic resonance imaging of the inner ear is nowadays frequently used for the in vivo confirmation of endolymphatic hydrops in humans. However, hydrops is visualized in both healthy subjects and patients with vestibular disorders, which might make the clinical value of hydrops detection on MRI questionable.

Objective

To investigate the diagnostic value of clinical and radiological features, including the in vivo visualization of endolymphatic hydrops, for the classification and diagnosis of vestibular disorders.

Methods

A literature search was performed in February and March 2019 to estimate the prevalence of various features in healthy subjects and in common vestibular disorders to make a graphical comparison between healthy and abnormal.

Results

Of the features studied, hydrops was found to be a highly prevalent feature in Menière’s disease (99.4%). Though, hydrops has also a relatively high prevalence in patients with vestibular schwannoma (48.2%) and in healthy temporal bones (12.5%) as well. In patients diagnosed with (definite or probable) Menière’s disease, hydrops is less frequently diagnosed by magnetic resonance imaging compared to the histological confirmation (82.3% versus 99.4%). The mean prevalence of radiologically diagnosed hydrops was 31% in healthy subjects, 28.1% in patients with vestibular migraine, and 25.9% in patients with vestibular schwannoma. An interesting finding was an absolute difference in hydrops prevalence between the two diagnostic techniques (histology and radiology) of 25.2% in patients with Menière’s disease and 29% in patients with vestibular schwannoma.

Conclusions

Although the visualization of hydrops has a high diagnostic value in patients with definite Menière’s disease, it is important to appreciate the relatively high prevalence of hydrops in healthy populations and other vestibular disorders. Endolymphatic hydrops is not a pathognomic phenomenon, and detecting hydrops should not directly indicate a diagnosis of Menière’s disease. Both symptom-driven and hydrops-based classification systems have disadvantages. Therefore, it might be worth to explore features “beyond” hydrops. New analysis techniques, such as Radiomics, might play an essential role in (re)classifying vestibular disorders in the future.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10278-8) contains supplementary material, which is available to authorized users.

Current status on researches of Meniere's disease: a review

Background: Meniere's disease (MD) is a complex and multifactorial inner ear disease. The etiology of MD is unclear. Significant progress had been made in diagnosis and treatment. Complete cure for this disease is still impossible.Objectives: This review covers the updated research results in MD in the past decades.Material and methods: Recent publications were critically reviewed.Results: The relationship between Endolymphatic hydrops and Meniere symptoms requires further study. Direct visualization of EH is achieved by special sequences of inner ear MRI. Appearance of EH could be observed in MD patients both in symptomatic and asymptomatic ears. Visualization of EH in vivo might make a great substantial improvement in diagnose of MD. The first goal of the management of MD is to reduce the attack frequency. Several safe and effective medical and surgical therapies are practiced to help patients to control vertigo and preserve hearing.Conclusions and significance: There has been no major breakthrough in the pathogenesis research of MD in recent years. Visualization of EH in vivo might make a great substantial improvement in diagnose of MD. Clinicians still have few effective ways to alleviate the progress of the disease.

[Efficacy of semicircular canal occlusion in the treatment of fifteen pateints with Meniere's disease]

Objective:To investigate the long-term efficacy of semicircular canal occlusion in the treatment of refractory Meniere's disease. Method:Fifteen patients with Meniere's disease who underwent semicircular canal occlusion were reviewed. The preoperative and postoperative frequency of vertigo ,quality of life, hearing and tinnitus level were compared. All patients were followed for more than 24 months. Result:Postoperatively, vertigo was controlled effectively in all 15 cases, and the control rate was 100%, of which 11 cases were completely controlled（Grade A） and 4 cases were basically controlled（Grade B）. The improvement rate of quality of life was 100%. The hearing worse in 4 cases（26.7%） and stabilized in 11 cases（73.3%）. The tinnitus was relieved in 7 cases（46.7%）, unchanged in 7 cases（46.7%） and aggravated in 1 case（6.7%）. Conclusion:Semicircular canal occlusion can effectively control the vertigo symptoms of refractory Meniere's disease and improve the quality of life. The long-term efficacy of semicircular canal occlusion is definite, but there is a risk of hearing loss.