Kyoshiro Yamakawa, MD, and temporal bone histopathology of Meniere's patient reported in 1938. Commemoration of the centennial of his birth

Stratification of patients with Menière's disease based on eye movement videos recorded from the beginning of vertigo attacks and contrast-enhanced MRI findings

Purpose

Diagnosis of Menière's disease (MD) relies on subjective factors and the patients diagnosed with MD may have heterogeneous pathophysiologies. This study aims to stratify MD patients using two objective data, nystagmus videos and contrast-enhanced magnetic resonance imaging (CE-MRI).

Methods

This is a retrospective cross-sectional study. According to the Japan Society for Equilibrium Research criteria (c-JSER), adults diagnosed with definite MD and who obtained videos recorded by portable nystagmus recorder immediately following vertigo attacks and underwent CE-MRI of the inner ear were included (ss = 91). Patients who obtained no nystagmus videos, who had undergone sac surgery, and those with long examination intervals were excluded (n = 40).

Results

The gender of the subjects was 22 males and 29 females. The age range was 20-82 y, with a median of 54 y. Endolymphatic hydrops (EH) were observed on CE-MRI in 84% (43 patients). Thirty-one patients had unilateral EH. All of them demonstrated EH on the side of the presence of cochlear symptoms. The number of patients who had both nystagmus and EH was 38. Five patients only showed EH and 5 patients only exhibited nystagmus, while 3 patients did not have either. Of the 43 nystagmus records, 32 showed irritative nystagmus immediately after the vertigo episode. The direction of nystagmus later reversed in 44% of cases over 24 h.

Conclusion

Patients were stratified into subgroups based on the presence or absence of EH and nystagmus. The side with cochlear symptoms was consistent with EH. The c-JSER allows for the diagnosis of early-stage MD patients, and it can be used to treat early MD and preserve hearing; however, this approach may also include patients with different pathologies.

Potential Application of Hydrops MR Imaging: A Systematic Review

BACKGROUND

Diagnostic dilemma between clinical Meniere's disease and radiological endolymphatic hydrops (EH) has emerged since the introduction of hydrops magnetic resonance imaging (MRI). The aim of this study is to explore the potential application of hydrops MRI on diagnosing the EH.

METHODS

This review was developed from peer-reviewed articles published in those journals listed on journal of citation reports. The MEDLINE database of the US National Library of Medicine, Scopus, and Google Scholar were used to collect articles based on the guidelines (PRISMA 2020 statement) for reporting reviews.

RESULTS

Initially, 470 articles were retrieved from 1983 to 2023, and 80 relevant articles were ultimately selected. The sensitivity (69%-92%) and specificity (78%-96%) values varied from each laboratory for detecting EH via hydrops MRI, probably due to candidate selection and the grading system employed.

CONCLUSION

The application of hydrops MRI allows (1) differentiation between EH and sudden sensorineural hearing loss; (2) determination of the affected side of EH; and (3) confirmation of the diagnosis of EH concomitant with other disorders. Notably, not all differentials for EH can be visualized on MR images. One of the existing gaps to be filled is that updated hydrops MRI fails to identify distortion, that is, rupture, collapse, fistula, or fibrosis of the inner ear compartments, akin to what histopathological evidence can demonstrate. Hence, enhanced ultrahigh resolution of hydrops MRI is required for demonstrating fine structures of the inner ear compartments in the future.

Spinning Through History: Evolution of the Concept of Vestibular Migraine

Vestibular migraine represents a growing public health problem, imposing enormous societal burdens in the form of patient suffering, loss of productivity, and direct healthcare costs. This raises the question of how we developed our ideas about vestibular migraine and how these ideas shape how we treat it. This review walks through the history of how our conceptualization of migraine and vestibular symptoms evolved, starting with clinical observations in ancient times, inclusion under the umbrella of Meniere's disease, and then separation from Meniere's disease with its own identity. Tradition, clinical observations, and diagnostic criteria developed by professional societies have played prominent roles in building our current concept of vestibular migraine. A review of the ideas that have shaped our current conception of vestibular migraine may help us to see which ones have stood the test of time and which ones should continue to evolve. As in other disciplines, we study history in medicine to be inspired, warned, and sometimes, to be freed.

[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.

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.

Change in endolymphatic hydrops 2 years after endolymphatic sac surgery evaluated by MRI

OBJECTIVE

This study was performed to determine whether endolymphatic sac surgery improves vestibular and cochlear endolymphatic hydrops 2 years after sac surgery and to elucidate the relationship between the degree of improvement of endolymphatic hydrops and the changes in vertigo symptoms, the hearing level, and the summating potential/action potential ratio (-SP/AP ratio) by electrocochleography (ECochG) in patients with Ménière's disease (MD).

METHODS

Twenty-one patients with unilateral MD who underwent sac surgery were included in this study. All patients underwent gadolinium-enhanced magnetic resonance imaging (Gd-MRI) before and 2 years after sac surgery. We evaluated the difference in vestibular and cochlear endolymphatic hydrops between before and after surgery in both ears and compared these findings with the frequency of vertigo attacks, hearing level, and ECochG findings.

RESULTS

In affected ears, the presence of vestibular endolymphatic hydrops and the frequency of vertigo attacks significantly decreased after surgery. However, affected ears showed no significant improvement in the presence of cochlear endolymphatic hydrops or the -SP/AP ratio by ECochG; there was also no significant improvement or deterioration in the hearing level.

CONCLUSION

The present findings suggest that sac surgery reduces vestibular endolymphatic hydrops and prevents aggravation of cochlear endolymphatic hydrops, and these changes lead to a reduction of vertigo attacks and suppress the progression of hearing impairment associated with vertigo attacks.

Evaluation of endolymphatic hydrops using 3-T MRI after intravenous gadolinium injection

Aim of this work is to establish evaluation criteria for identifying endolymphatic hydrops in the vestibule and cochlea using a magnetic resonance imaging (MRI) scanner. This is a retrospective diagnostic study. We evaluated 70 ears of 35 unilateral Ménière's disease patients. We performed 3-T MRI 4 h after intravenous gadolinium injection. Otologists manually traced the outline of vestibule, cochlea, and endolymphatic space of the vestibule and cochlea on two-dimensional fluid-attenuated inversion-recovery (2D-FLAIR) images. The traced area was measured, and rates of endolymphatic space to the vestibule and cochlea were calculated. The same otologists judged whether the low signal intensity area of the cochlea was at the edge of the cochlea. For measuring the rate of endolymphatic space to the vestibule, when the cut-off value was 30%, the presence of endolymphatic hydrops was determined with sensitivity of 87.1% and specificity of 94.3%. In contrast, the rate of endolymphatic space to the cochlea produced low accuracy. Therefore, when the presence of endolymphatic hydrops in the cochlea was judged by whether the low signal intensity area in the cochlea was at the edge of cochlea, endolymphatic hydrops could be detected with sensitivity of 91.4% and specificity of 94.3%. We were able to identify endolymphatic hydrops in the vestibule when the rate of endolymphatic space to the vestibule was greater than 30%, and could detect endolymphatic hydrops in the cochlea when a low signal intensity area was located at the edge of the cochlea in 2D-FLAIR images. Level of evidence 4.

Assessment of endolymphatic hydrops and otolith function in patients with Ménière's disease

Ménière's disease is associated with hydrops of the inner ear endolymphatic space, and histopathologically, the cochlea and vestibule are usually involved. We used gadolinium-enhanced magnetic resonance imaging and measured cervical and ocular vestibular evoked myogenic potentials and the gain in the utricular induced linear vestibulo-ocular reflex to test the hypothesis that vestibular hydrops in Ménière's disease patients is associated with otolith organ dysfunction. We evaluated 21 patients diagnosed with unilateral definitive Ménière's disease using gadolinium magnetic resonance imaging to detect endolymphatic hydrops in the cochlea and vestibule. Cervical and ocular vestibular evoked myogenic potentials and the gain in utricular induced linear vestibulo-ocular reflex during eccentric rotation were measured to assess otolith organ function. For eccentric rotation, patients were rotated while displaced from the axis of rotation, while linear acceleration stimulated the utricle and induced the vestibulo-ocular reflex. Magnetic resonance imaging revealed vestibular hydrops in 14 of 20 patients (70%). Among the 14 patients, ten (71%) had abnormal cervical and three (21%) had abnormal ocular vestibular evoked myogenic potentials. Four patients (4/21, 19%) had abnormal linear vestibulo-ocular reflexes, three of whom also had abnormal ocular vestibular evoked myogenic potentials. Overall, 16 of 17 patients had normal linear vestibulo-ocular reflexes and normal ocular vestibular evoked myogenic potentials. Vestibular endolymphatic hydrops in Ménière's disease patients caused otolith organ dysfunction, mainly in the saccule. The number of Ménière's disease patients with abnormal ocular vestibular evoked myogenic potentials was low (19%), and they also had abnormal utricular induced linear vestibulo-ocular reflexes.

Effects of body tilt on multifrequency admittance tympanometry

INTRODUCTION

Hydrops and abnormalities of inner fluid pressure are involved in some otologic diseases such as Ménière's disease (MD). However, demonstrating abnormal perilymphatic or endolymphatic pressure is challenging. Multifrequency tympanometry studies in MD patients demonstrated an increase of the width of conductance tympanograms (outside an attack) compared with controls. To confirm that the increase in conductance width is caused by hyperpressure and not hypopressure in these patients tested outside an attack, we assessed the effect of changes in inner ear fluid pressure caused by body tilt on the results of multifrequency admittancemetry tympanograms.

MATERIALS AND METHODS

A multifrequency tympanometry including conductance (G) tympanogram at 2 kHz and resonance frequency measurements were performed in 20 volunteers (40 ears) free of otologic or neurologic disease. The measures were collected in three different positions: vertical, supine, and Trendelenburg positions.

RESULTS

Changes in inner ear fluid pressure caused by body tilt induced an increase in the width of G tympanograms. In the vertical position, the mean value was 141.7 ± 56.5 daPa; in the supine position, it increased to 158 ± 58.3 daPa; and increased even more in the Trendelenburg position (20 degrees), with a mean of 184 ± 69.6 daPa (p < 0.01). Resonance frequency also increased in the Trendelenburg position.We conclude that the increased width of G tympanograms in MD patients outside an attack may be caused by an increase in inner ear fluid pressure.

Characterization of neuronal cell death in the spiral ganglia of a mouse model of endolymphatic hydrops

HYPOTHESIS

Spiral ganglion neurons (SGN) in the Phex male mouse, a murine model of postnatal endolymphatic hydrops (ELH) undergo progressive deterioration reminiscent of human and other animal models of ELH with features suggesting apoptosis as an important mechanism.

BACKGROUND

Histologic analysis of the mutant's cochlea demonstrates ELH by postnatal Day (P) 21 and SGN loss by P90. The SGN loss seems to occur in a consistent topographic pattern beginning at the cochlear apex.

METHODS

SGN were counted at P60, P90, and P120. Semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR), quantitative PCR, and immunohistochemical analyses of activated caspase-3, caspase-8, and caspase-9 were performed on cochlear sections obtained from mutants and controls. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling assay (TUNEL) was carried out on 2 mutants and 2 controls.

RESULTS

Corrected SGN counts in control mice were greater in the apical turn of the cochleae at P90 and P120, respectively (p < 0.01). Increased expression of activated caspase-3, caspase-8, and caspase-9 was seen in the mutant. At later time points, activated caspase expression gradually declined in the apical turns and increased in basal turns of the cochlea. Quantitative and semiquantitative PCR analysis confirmed increased expression of caspase-3, caspase-8, and caspase-9 at P21 and P40. TUNEL staining demonstrated apoptosis at P90 in the apical and basal turns of the mutant cochleae.

CONCLUSION

SGN degeneration in the Phex /Y mouse seems to mimic patterns observed in other animals with ELH. Apoptosis plays an important role in the degeneration of the SGN in the Phex male mouse.

In vivo visualization of endolyphatic hydrops in patients with Meniere's disease: correlation with audiovestibular function

Our objective is to determine whether the degree of endolymphatic hydrops as it is detected in vivo in patients with definite Meniere's disease correlates with audiovestibular function. In this prospective study, 37 patients with definite Meniere's disease according to AAO-HNS criteria were included. Intratympanic contrast enhanced temporal bone MRI was performed using a 3D FLAIR protocol. The degree of endolymphatic hydrops in the cochlea and the vestibulum was graded on a Likert scale (0-3). The degree of hydrops was then analyzed with respect to its correlation with audiometric hearing levels, electrocochleographic SP/AP ratios, interaural amplitude ratios of vestibular evoked myogenic potentials and degree of horizontal semicircular canal paresis on caloric irrigation. There was a significant correlation between the degree of hydrops on the one hand and the averaged hearing level at 0.25-1 and 0.5-3 kHz and the vestibular evoked myogenic potential interaural amplitude ratio on the other hand. A trend toward a correlation was noticed between the hydrops and the caloric response, no correlation was noticed between the hydrops and the SP/AP ratio. The degree of endolymphatic hydrops correlates with a progressive loss of auditory and sacculus function in patients with Meniere`s disease.

Contemporary perspectives on the pathophysiology of Meniere's disease: implications for treatment

PURPOSE OF REVIEW

Meniere's disease is characterized by episodic vertigo, fluctuating hearing loss, aural fullness and tinnitus. Endolymphatic hydrops, found on post-mortem examination, is the histologic hallmark. Recent research suggests that endolymphatic hydrops results from cytochemical perturbations of unknown etiology that lead to disturbance of the normal endolymphatic fluid homeostasis. This consequent hydropic state or the associated cytochemical perturbations appears to create a neurotoxic environment that ultimately leads to spiral ganglion cell death likely via the apoptotic mechanism. This review highlights some of the recent advances in the understanding of the pathophysiology of endolymphatic hydrops and progressive cochleovestibular deterioration, with emphasis placed on its potential therapeutic implications.

RECENT FINDINGS

Recent evidence supports that endolymphatic hydrops is possibly an epiphenomenon, and is preceded by perturbation of the normal ionic transport regulatory mechanisms. Furthermore, chronic cochleovestibular deterioration appears to be the result of an excitotoxic response to chronic hydrops. A recently described animal model, the Phex mouse, carrying a mutation in the Phex Hyp-Duk gene, provides a novel insight to genetically regulated postnatal endolymphatic hydrops and a useful tool to expand our understanding.

SUMMARY

Despite encouraging recent advances, there are considerable challenges that remain in the development of targeted therapeutic interventions that may offer new avenues of neuroprotection in known cases of Meniere's disease. These advances will hopefully provide pharmacotherapeutic interventions aimed at preventing progressive cochleovestibular dysfunction.

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.

Menière's disease: evolution of a definition

In 1861 Prosper Menière separated patients with episodic vertigo, hearing loss and tinnitus from a group previously described as having apoplectiform cerebral congestion. He suggested the cause was disease within the semicircular canals (Menière, 1861). Over the years it became apparent that within this group there were a number of patients with characteristic signs and symptoms and in 1938 a pathological correlate was found in the form of endolymphatic hydrops. Descriptions such as Menière's 'disease', Menière's 'syndrome' and Menière's 'symptom complex' led to a confusing array of terms for this condition and monitoring of treatment results became difficult. In response to this in 1972 the American Academy of Ophthalmology and Otolaryngology Committee on Hearing and Equilibrium published a clear definition of Menière's disease and criteria for the reporting of treatment results, it was updated in 1985 and again in 1995. We describe the changes that have taken place as the definition of Menière's disease has evolved.