Meniere's disease

Imaging endolymphatic space of the inner ear in vestibular migraine

BACKGROUND

Vestibular migraine (VM), the most frequent episodic vertigo, is difficult to distinguish from Ménière's disease (MD) because reliable biomarkers are missing. The classical proof of MD was an endolymphatic hydrops (EH). However, a few intravenous gadolinium-enhanced MRI studies of the inner ear (iMRI) also revealed an EH in VM. The major questions were the frequency and distribution characteristics of EH in VM for diagnostic use.

METHODS

In a prospective case-control study of 200 participants, 75 patients with VM (49 females; mean age 46 years) and 75 with MD (36 females; mean age 55 years), according to the Bárány and International Headache Society, and 50 age-matched participants with normal vestibulocochlear testing (HP), were enrolled. Analyses of iMRI of the endolymphatic space included volumetric quantification, stepwise regression, correlation with neurotological parameters and support vector machine classification.

RESULTS

EH was maximal in MD (80%), less in VM (32%) and minimal in HP (22%). EH was milder in VM (mean grade 0.3) compared with MD (mean grade 1.3). The intralabyrinthine distribution was preferably found in the vestibulum in VM, but mainly in the cochlea in MD. There was no interaural lateralisation of EH in VM but in the affected ear in MD. The grade of EH in the vestibulum was correlated in both conditions with the frequency and duration of the attacks.

CONCLUSION

Three features of the iMRI evaluation were most supportive for the diagnosis of VM at group and individual levels: (1) the bilateral manifestation, (2) the low-grade EH and (3) the intraaural distribution.

Angular Trajectory of the Vestibular Aqueduct in a Cohort of Chinese Patients with Unilateral Ménière's Disease: Association with Other Imaging Indices and Clinical Profiles

OBJECTIVE

We aimed to investigate the association between the angular trajectory of the vestibular aqueduct (ATVA) with other radiological parameters of temporal bone and clinical characteristics in patients with Ménière's disease (MD).

METHODS

A total of 125 unilateral MD patients and 118 controls were enrolled. Computer tomography (CT)-based radiological parameters included ATVA, vestibular aqueduct (VA) visibility, VA morphology, the vertical part of the posterior semicircular canal-the posterior fossa distance (PPD), and peri-VA pneumatization. The clinical characteristics of MD patients included gender, age of diagnosis/onset, disease duration, migraine history, clinical staging, and the results of audio-vestibular tests. The radiological parameters and clinical characteristics in MD patients were compared.

RESULTS

Compared with control ears, ATVA ≥ 140° was more prevalent and ATVA ≤ 120° was less frequent in the MD-affected side. For the MD-affected side, MD patients with ATVA ≥ 140° exhibited more severe VA invisibility and obliteration and higher male preponderance than those with ATVA ≤ 120°. Other radio-clinical features did not differ between these two subgroups.

CONCLUSION

In the current study, ATVA ≥ 140°, an indicator of a hypoplastic endolymphatic sac, was found in approximately one-third of the affected and unaffected ears of patients with MD, as well as in a minority of controls. This suggests that the indices may be a predisposing factor rather than a specific marker for the MD ear. The male preponderance in MD patients with hypoplastic ES suggests a gender difference in the anatomical factors for MD pathogenesis.

Differentiating Definite and Probable Ménière Disease: A Comprehensive Evaluation of Audio-Vestibular Function Testing Combined with Inner Ear MRI

OBJECTIVES

To evaluate the differences between audio-vestibular function testing and inner ear gadolinium magnetic resonance imaging (MRI) in distinguishing definite Ménière disease (DMD) and probable Ménière disease (PMD), and to provide a reference for early clinical diagnosis and intervention.

METHODS

A total of 116 patients diagnosed with DMD (n = 80) and PMD (n = 36) were enrolled. The differences in the results of pure tone audiometry, caloric test, and tympanic injection of gadolinium for contrast-enhanced MRI between the two groups were compared and analyzed. Parameters that could differentiate between the two conditions were identified, and the sensitivity and specificity and the area under the curve (AUC) of individual and combined indices in the differential diagnosis of DMD and PMD were evaluated.

RESULTS

The hearing threshold and hearing asymmetry rate of the DMD group were significantly higher than those of the PMD group (p < 0.001), 98.8% and 30.6%, respectively. The abnormal rates of canal paresis (CP) and severity of endolymphatic hydrops in the DMD group were higher than those in the PMD group (p < 0.05). When combined with high-frequency hearing thresholds, hearing asymmetry, hearing curve type, endolymphatic hydrops, and abnormal CP, the diagnostic accuracy of DMD was improved compared to using high-frequency alone (p < 0.05).

CONCLUSION

This study showed that PMD and DMD may represent two different stages in the development of MD disease. The comprehensive assessment of audio-vestibular function testing and inner ear MRI proves beneficial for early diagnosis, potentially contributing to the preservation of inner ear function.

Neuroimaging Insights: Structural Changes and Classification in Ménière's Disease

OBJECTIVES

This study aimed to comprehensively investigate the neuroanatomical alterations associated with idiopathic Ménière's disease (MD) using voxel-based morphometry and surface-based morphometry techniques. The primary objective was to explore nuanced changes in gray matter volume, cortical thickness, fractal dimension, gyrification index, and sulcal depth in MD patients compared with healthy controls (HC). Additionally, we sought to develop a machine learning classification model utilizing these neuroimaging features to effectively discriminate between MD patients and HC.

DESIGN

A total of 55 patients diagnosed with unilateral MD and 70 HC were enrolled in this study. Voxel-based morphometry and surface-based morphometry were employed to analyze neuroimaging data and identify structural differences between the two groups. The selected neuroimaging features were used to build a machine learning classification model for distinguishing MD patients from HC.

RESULTS

Our analysis revealed significant reductions in gray matter volume in MD patients, particularly in frontal and cingulate gyri. Distinctive patterns of alterations in cortical thickness were observed in brain regions associated with emotional processing and sensory integration. Notably, the machine learning classification model achieved an impressive accuracy of 84% in distinguishing MD patients from HC. The model's precision and recall for MD and HC demonstrated robust performance, resulting in balanced F1-scores. Receiver operating characteristic curve analysis further confirmed the discriminative power of the model, supported by an area under the curve value of 0.92.

CONCLUSIONS

This comprehensive investigation sheds light on the intricate neuroanatomical alterations in MD. The observed gray matter volume reductions and distinct cortical thickness patterns emphasize the disease's impact on neural structure. The high accuracy of our machine learning classification model underscores its diagnostic potential, providing a promising avenue for identifying MD patients. These findings contribute to our understanding of MD's neural underpinnings and offer insights for further research exploring the functional implications of structural changes.

Understanding Factors That Cause Benign Paroxysmal Positional Vertigo, Ménière Disease, and Vestibular Neuritis: A Two-Sample Mendelian Randomization Study

OBJECTIVES

Vertigo is a prevalent clinical symptom, frequently associated with benign paroxysmal positional vertigo (BPPV), Ménière disease (MD), and vestibular neuritis (VN), which are three common peripheral vestibular disorders. However, there is a relative lack of research in epidemiology and etiology, with some existing studies presenting discrepancies in their conclusions. We conducted a two-sample Mendelian randomization (MR) analysis to explore potential risk and protective factors for these three peripheral vestibular disorders.

DESIGN

Based on genome-wide association studies, we executed a univariable MR to investigate the potential associations between 38 phenotypes and MD, BPPV, and VN. We used the inverse variance weighted method as the primary MR result and conducted multiple sensitivity analyses. We used false discovery rate (FDR) correction to control for type I errors. For findings that were significant in the univariable MR, a multivariable MR analysis was implemented to ascertain direct effects. In addition, we replicated analyses of significant results from the univariable MR to enhance the robustness of our analyses.

RESULTS

For BPPV, both alcohol consumption (odds ratio [OR] = 0.57, 95% confidence interval [CI] = 0.43 to 0.76, FDR Q = 0.004) and educational attainment (OR = 0.77, 95% CI = 0.68 to 0.88, FDR Q = 0.003) were found to decrease the risk. The genetic prediction analysis identified major depression (OR = 1.75, 95% CI = 1.28 to 2.39, FDR Q = 0.008) and anxiety (OR = 5.25, 95% CI = 1.79 to 15.42, FDR Q = 0.036) increased the risk of MD. However, the impact of major depression on MD could be influenced by potential horizontal pleiotropy. Systolic blood pressures (OR = 1.03, 95% CI = 1.02 to 1.04, FDR Q = 4.00 × 10 -7 ) and diastolic blood pressures (OR = 1.05, 95% CI = 1.03 to 1.07, FDR Q = 2.83 × 10 -6 ) were associated with an increased risk of VN, whereas high-density lipoprotein (OR = 0.77, 95% CI = 0.67 to 0.89, FDR Q = 0.009) and urate (OR = 0.75, 95% CI = 0.63 to 0.91, FDR Q = 0.041) reduces the risk of VN. Only the relationship between urate and VN was not replicated in the replication analysis. Multivariable MR showed that the protective effect of education on BPPV was independent of Townsend deprivation index. The protective effect of high-density lipoprotein against VN was independent of triglycerides and apolipoprotein A1. The risk impacts of systolic and diastolic blood pressures on VN exhibited collinearity, but both are independent of chronic kidney disease and estimated glomerular filtration rate. The impacts of anxiety and severe depression on MD demonstrated collinearity.

CONCLUSIONS

Our study identified the risk association between systolic and diastolic blood pressure with VN and the protective influence of high-density lipoprotein on VN, which may support the vascular hypothesis underlying VN. Furthermore, we observed an elevated risk of MD associated with anxiety. The potential protective effects of education and alcohol consumption on BPPV need further exploration in subsequent studies to elucidate specific mechanistic pathways. In summary, our MR study offers novel insights into the etiology of three peripheral vestibular diseases from a genetic epidemiological standpoint.

Gray-tone appearances on 4-hour delayed gadolinium-enhanced magnetic resonance imaging indicate severe inner ear pathology and symptoms in sudden sensorineural hearing loss

Objective

Hybrid of reversed image of positive endolymph signal and negative image of perilymph signal (HYDROPS) in delayed gadolinium-enhanced magnetic resonance imaging (MRI) typically depicts normal inner ear as "white-tone" and endolymphatic hydrops as "black-transparent" appearances, whereas ears with auditory and vestibular disorders are occasionally depicted as "gray-tone." This study aimed to investigate the pathological basis of sudden sensorineural hearing loss (SSNHL) patients with "gray-tone" appearances on HYDROPS.

Methods

Delayed gadolinium-enhanced MRI examinations were conducted on 29 subjects with unilateral SSNHL. We mainly analyzed positive perilymph image (PPI) and positive endolymph image (PEI), which were components HYDROPS.

Results

On PPI, signal intensity (SI) values extracted from the cochlear and vestibular region of interest (ROI) were higher in the SSNHL ears with dizziness/vertigo symptom at the first visit compared to the healthy ear. Additionally, the PPI/PEI enhancement pattern in the vestibule was associated with a high prevalence of hearing and vestibular deteriorations at the first visit and poor hearing improvement after treatment.

Conclusion

Enhancement on PPI/PEI may result from leakage of gadolinium into the inner ear following breakdown of the blood-labyrinth barrier, with high SI being correlated with the amount of leakage. Particularly, a significant leakage into the endolymphatic space, defined as PPI+/PEI+, indicates severe inner ear pathology. Ultimately, we emphasize that the "gray-tone" appearance in the inner ear on HYDROPS comprises enhancements on both PPI and PEI and propose a new classification for evaluating SSNHL Peri- and Endolymphatic image Enhancement pattern in Delayed gadolinium-enhanced MRI (SPEED).

Level of Evidence

4.

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.

Hydrops regression after vestibular denervation - longitudinal magnetic resonance study in patients with severe Meniere's disease treated with vestibular neurectomy

OBJECTIVES

The aim was to evaluate endolymphatic hydrops in patients with severe Ménière's disease (MD) before and after vestibular neurectomy to verify if vestibular denervation results in hydrops regression.

METHODS

Magnetic resonance imaging was performed after intravenous gadolinium injection in twenty patients with unilateral definite MD before and after the vestibular neurectomy. Clinical symptoms and audiovestibular tests were evaluated. Follow-up intervals ranged from 18 to 35 months after the surgery.

RESULTS

Endolymphatic hydrops were visualized in all patients in the preoperative scans. After the vestibular neurectomy, all patients presented a complete resolution of vertigo episodes. Regression of the endolymphatic hydrops was observed in 35% and 15% of cases analyzing cochlea and vestibule, respectively. In 71.43% of patients with utricular herniation into the lateral semicircular canal, withdrawal of the hernia was visualized. Asymmetrical contrast enhancement in the cochlea regressed in 17.64% of cases. Analyzing all the parameters collectively, in 60% of patients, partial regression of at least one of the radiological signs was confirmed in the follow-up examination. No progression of the endolymphatic hydrops was visualized after the surgery in either the cochlea or the vestibule.

CONCLUSIONS

Vestibular neurectomy is an effective treatment, eliminating vertigo attacks and improving the quality of life in patients with MD. Magnetic resonance imaging of the inner ear allows visualization of changes in endolymphatic hydrops degree after treatment. Regression of the endolymphatic hydrops after vestibular neurectomy suggests that vestibular denervation may effectively halt the progression of the endolymphatic space dilatation and result in hydrops regression.

Intratympanic injections of emulsion-like dispersions to augment cinnarizine amount in a healthy rabbit inner ear model

Aim: To investigate eutectic liquid-based emulsion-like dispersions for intratympanic injections to augment cinnarizine permeability across round window membrane in a healthy rabbit inner ear model.Methods: Two-tier systematic optimization was used to get the injection formula. The drug concentrations in perilymph and plasma were analyzed via. Ultra-performance liquid chromatography-tandem mass spectrometry method after 30-, 60-, 90- and 120-min post intratympanic injection time points in rabbits.Results: A shear-thinning behavior, immediate drug release (∼98.80%, 10 min) and higher cell viability (>97.86%, 24 h) were observed in dispersions. The cinnarizine level of 8168.57 ± 1236.79 ng/ml was observed in perilymph at 30 min post intratympanic injection in rabbits.Conclusion: The emulsion-like dispersions can augment drug permeability through round window membrane.

MRI-confirmed cochlear artery infarct clinically diagnosed in a patient with sickle cell disease: a case report

PURPOSE

To corroborate the vascular etiology of sudden sensorineural hearing loss (SNHL) utilizing magnetic resonance imaging (MRI).

PATIENT

A 24-year-old male with a history of sickle cell disease experienced sudden SNHL and right horizontal nystagmus, without accompanying vertigo.

INTERVENTION

Audiometric evaluation revealed left-sided SNHL, predominantly affecting high frequencies. Video head impulse testing demonstrated isolated dysfunction of the left posterior semicircular canal. An urgent brain MRI identified a recent punctiform ischemic stroke in the frontal region. A subsequent MRI, conducted with a 4-hour delay and post-contrast enhancement, highlighted a hyperintense signal within the left cochlear region and the left posterior semicircular canal.

CONCLUSION

The investigative results substantiate an infarction in the territory of the cochlear artery, precipitated by a vaso-occlusive event, thereby reinforcing the vascular hypothesis of cochleovestibular artery syndrome. This case underscores the congruence between clinical observations and delayed post-contrast MRI findings.

Meniere's Disease and Statins: Is There an Association? A Single Institution Study

Meniere's disease (MD) is a complex inner ear disease related to endolymphatic hydrops and with multiple other etiologies suggested including autoimmunity and vascular insufficiency. Statins are lipid-lowering medications with additional effects including reduction of oxidative stress and inflammation. We performed a cross-sectional study comparing patients with MD on statins to those not on statins to see if there is any difference in disease activity (major vertigo spells) and hearing stage utilizing linear and logistic regression. Our analysis showed no difference in the average number of major vertigo spells per month (β = .07, P = .9) between statin users and nonusers; however, statin users were found to have lower odds of worse hearing (odds ratio = 0.46, P = .047). Further studies are needed to confirm our results.

Association Between Vestibular Aqueduct Morphology and Meniere's Disease

OBJECTIVE

To investigate the relationship between vestibular aqueduct (VA) morphology and Meniere's disease (MD) using ultrahigh-resolution computed tomography (U-HRCT).

METHODS

Retrospective data were collected from 34 patients (40 ears) diagnosed with MD in our hospital who underwent temporal bone U-HRCT with isotropic 0.05-mm resolution, magnetic resonance with gadolinium-enhanced, and pure-tone audiometry; 34 age- and sex-matched controls (68 ears) who underwent U-HRCT were also included. VA patency was qualitatively classified as locally not shown (grade 1), locally faintly shown (grade 2), or clearly shown throughout (grade 3). The width of the outer orifice and VA length and angle were quantitatively measured. Differences in VA morphology between the MD and control groups were analyzed. The correlations between VA morphology and the degrees of hearing loss and endolymphatic hydrops (EH) were also analyzed.

RESULTS

VA was classified as grades 1-3 in 11, 17, and 12 ears in the MD group and 5, 26, and 37 ears in the control group, respectively. The patency differed significantly between the groups (p < 0.01). The width of the outer orifice and length of VA were significantly smaller in the MD group than those in the control group (p < 0.05). Both VA patency and length were correlated with the degree of EH in the cochlea and the vestibule (p < 0.05). No difference was found between VA morphology and the degree of hearing loss (p > 0.05).

CONCLUSION

The morphological characteristics of VA were found to be associated with the occurrence of MD and the degree of EH.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3349-3354, 2024.

Lymphatic Vessels in the Inner Ear of Patients With Meniere Disease: A Novel Pathological Finding

Background

Meniere disease, characterized by intermittent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus, and aural pressure, is a common cause of vertigo in humans. The pathogenesis of Meniere disease remains unknown. The current study aimed to describe a novel pathological change discovered in the inner ears of patients with Meniere disease who underwent labyrinthectomy.

Methods

This retrospective case-control study was conducted with 21 patients with MD who underwent labyrinthectomy. A total of 15 patients diagnosed with acoustic neuroma or glomus jugular tumor were review over the same period of time as control. The clinical information of the patients and the pathological features of the membrane are described.

Results

The new pathological tissue was a morbid membrane structure sealing the round window, characterized by the formation of lymphatic capillaries. Histochemical and immunofluorescent staining was positive for D2-40, LYVE-1, podoplanin, and PROX1, which are the classical markers of the lymphatic vessels. Transmission electron microscopy revealed that the lymph capillaries lacked a typical basement membrane and that their ends were blind, composed of a single layer of endothelial cells with valval connection structures between adjacent capillary epithelial cells.

Conclusion

This is the first report of lymphatic vessels in the human inner ear, and this pathological structure is a completely new discovery. The lymphatic vessels may develop due to inflammation or decompensation of pressure in the inner ear, suggesting that the inner ear can reactively form lymphatic vessels in some inflammation and fluid flow-dependent pathological conditions. The current findings help in improving our understanding of the pathogenesis of Meniere disease.

Mendelian randomization analysis does not reveal a causal association between migraine and Meniere's disease

Background

According to observational research, migraine may increase the risk of Meniere's disease (MD). The two have not, however, been proven to be causally related.

Methods

Using Mendelian random (MR) analysis, we aimed to evaluate any potential causal relationship between migraine and MD. We extracted single-nucleotide polymorphisms (SNPs) from large-scale genome-wide association studies (GWAS) involving European individuals, focusing on migraine and MD. The main technique used to evaluate effect estimates was inverse-variance weighting (IVW). To assess heterogeneity and pleiotropy, sensitivity analyses were carried out using weighted median, MR-Egger, simple mode, weighted mode, and MR-PRESSO.

Results

There was no discernible causative link between genetic vulnerability to MD and migraine. The migraine dose not increase the prevalence of MD in the random-effects IVW method (OR = 0.551, P = 0.825). The extra weighted median analysis (OR = 0.674, P = 0.909), MR-Egger (OR = 0.068, P = 0.806), Simple mode (OR = 0.170, P = 0.737), and Weighted mode (OR = 0.219, P= 0.760) all showed largely consistent results. The MD dose not increase the prevalence of migraine in the random-effects IVW method (OR = 0.999, P = 0.020). The extra weighted median analysis (OR = 0.999, P = 0.909), MR-Egger (OR = 0.999, P = 0.806), Simple mode (OR = 0.999, P = 0.737), and Weighted mode (OR = 1.000, P = 0.760).

Conclusion and significance

This Mendelian randomization study provides casual evidence that migraine is not a risk factor for MD and MD is also not a risk factor for migraine.

Semicircular canal and vestibular plugging in patients with Meniere's disease: a preliminary study

BACKGROUND

Therapeutic options are limited for patients with intractable Meniere's disease who present with recurrent episodes of vertigo and drop attacks.

AIMS/OBJECTIVES

To investigate the effectiveness and safety of simultaneous semicircular canal plugging and vestibular plugging in the treatment of Meniere's disease with drop attacks.

MATERIAL AND METHODS

This was a single-center study with a 6-month post-operative follow-up. It included five patients with intractable Meniere's disease who presented with recurrent vertigo and drop attacks. All patients underwent surgery of semicircular canal plugging and vestibular plugging. The main outcome measures were vertigo control, drop attack control, hearing, and vestibular function; they were evaluated pre- and post-operatively.

RESULTS

Of the five patients, none had a recurrence of drop attacks; four had no recurrence of vertigo, and one patient had one episode of vertigo. Two patients had residual hearing before surgery, which was preserved postoperatively. All patients showed altered results in vestibular tests.

CONCLUSIONS

Semicircular canal plugging and vestibular plugging appear to be an effective treatment for intractable Meniere's disease presenting with recurrent vertigo and drop attacks. More studies are needed to confirm these results.

SIGNIFICANCE

This novel surgical procedure can control vestibular symptoms of Meniere's disease while hopefully preserving the hearing function.

Blood-labyrinth barrier breakdown in Meniere's disease

OBJECTIVE

We compared the signal intensity ratio (SIR) of the cochlear basal turn between Meniere's disease and healthy controls to investigate potential damage of the blood-labyrinth barrier in Meniere's disease.

METHODS

Thirty patients diagnosed with unilateral definite Meniere's disease and 24 healthy controls were enrolled. 3D-FLAIR scan was conducted to assess the grades of endolymphatic hydrops in Meniere's patients while measuring the SIR of cochlear basal turns in both groups. The differences of bilateral SIR between Meniere's disease and healthy control were compared, and the correlation between the SIR on affected ear in Meniere's disease and the grades of cochlear and vestibular hydrops were analyzed.

RESULTS

SIR of affected ear in Meniere's disease exhibited significant increase compared to that of unaffected ear. No significant difference was observed in SIR between the two ears in the healthy control. Furthermore, the SIR of unaffected side in Meniere's disease was higher than that of both ears in healthy controls. The SIR in affected ear of Meniere's disease exhibited positive correlation with hydrops in both cochlea and vestibula.

CONCLUSION

The permeability of blood-labyrinth barrier is increased in Meniere's disease, in combination with the typical criteria of Meniere's disease it may be a good biological marker. Destruction of blood-labyrinth barrier may be one of the causes of endolymphatic hydrops in Meniere's disease.

Unveiling the Role of Oxidative Stress in Cochlear Hair Cell Death: Prospective Phytochemical Therapeutics against Sensorineural Hearing Loss

Hearing loss represents a multifaceted and pervasive challenge that deeply impacts various aspects of an individual's life, spanning psychological, emotional, social, and economic realms. Understanding the molecular underpinnings that orchestrate hearing loss remains paramount in the quest for effective therapeutic strategies. This review aims to expound upon the physiological, biochemical, and molecular aspects of hearing loss, with a specific focus on its correlation with diabetes. Within this context, phytochemicals have surfaced as prospective contenders in the pursuit of potential adjuvant therapies. These compounds exhibit noteworthy antioxidant and anti-inflammatory properties, which hold the potential to counteract the detrimental effects induced by oxidative stress and inflammation-prominent contributors to hearing impairment. Furthermore, this review offers an up-to-date exploration of the diverse molecular pathways modulated by these compounds. However, the dynamic landscape of their efficacy warrants recognition as an ongoing investigative topic, inherently contingent upon specific experimental models. Ultimately, to ascertain the genuine potential of phytochemicals as agents in hearing loss treatment, a comprehensive grasp of the molecular mechanisms at play, coupled with rigorous clinical investigations, stands as an imperative quest.

The Association Between Choroidal Thickness and Meniere's Disease: A Cross-Sectional Study

OBJECTIVE

To evaluate and compare choroidal thickness (CT) between patients with Meniere's disease (MD) and a control group.

METHODS

This case-control analytical study was conducted on 37 subjects with MD and 37 healthy subjects. Subfoveal CT (SCT), large choroidal vessel (LCV) layer thickness, and mean subfoveal LCV thickness/mean SCT ratio were measured using enhanced-depth imaging optical coherence tomography (EDI-OCT) in the eyes on the MD side (ipsilateral), the contralateral eyes, and the control group.

RESULTS

A statistically significant difference was observed in the mean SCT values between the ipsilateral and control groups after adjustment for age, sex, and migraine (p = 0.04). Moreover, there was a statistically significant difference between the mean subfoveal LCV thickness values and the mean subfoveal LCV thickness/mean SCT ratio between the ipsilateral and control groups (p = 0.006, and p < 0.001, respectively). Patients with a duration of disease over three years had a greater mean subfoveal LCV thickness/mean SCT ratio (67.35 ± 11.56 and 60.66 ± 11.27, respectively), which was statistically insignificant (p = 0.08).

CONCLUSION

We found a thicker choroid and Haller layer, and a greater subfoveal LCV thickness/SCT ratio on the MD side compared to the controls. Furthermore, patients with a greater duration of disease had a lower subfoveal LCV thickness/SCT ratio. These findings may reflect the role of the trigeminal vascular system (TVS) and neurovascular pathophysiology in MD patients. More extensive studies are required to reach more definitive conclusions about the association between CT and MD.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1889-1893, 2024.

Impact of endolymphatic hydrops on the function of the horizontal canal during caloric stimulation in Ménière's disease

PURPOSE

When a dizzy patient with episodic vertigo has an abnormal caloric and a normal video head impulse test (vHIT), this caloric-vHIT dissociation provides vital information for a diagnosis of Ménière's disease (MD). Endolymphatic hydrops (EH), a histological marker of MD, is hypothesized to be involved in the caloric-vHIT dissociation in MD through hydropic duct distension of the horizontal semicircular canal (SC). This study was designed to determine the impact of EH on the function of horizontal SC during caloric stimulation.

METHODS

Caloric test and vHIT were used to evaluate the function of horizontal SC every six months, annual magnetic resonance imaging (MRI) was used to evaluate the degree of EH size in the vestibule, and monthly vertigo and hearing evaluation was done for 12 months. EH shrinkage was defined as the size change of vestibular EH from significant to none.

RESULTS

Among 133 MD patients evaluated for eligibility, 67 patients with caloric-vHIT dissociation entered the study. Fifteen participants had EH shrinkage (G-I), while 52 participants had no remarkable EH change (G-II). Average values (IQR) of the maximum slow phase velocity in G-I and G-II were 29.6 (13.0-34.0) and 25.9 (17.3-31.3), respectively, at baseline, 26.1 (9.0-38.0) and 23.6 (18.0-28.3) at 12 months. Two-factor repeated-measures ANOVA showed no significant differences between the groups (P = 0.486). The values of vestibulo-ocular reflex gain of the horizontal SC in G-I and G-II remained above 0.8 during the study period.

CONCLUSIONS

EH detected by MRI shows limited correlation with caloric stimulation results.

Effect of long-term betahistine treatment on the clinical outcomes of patients with cochlear Meniere's disease

BACKGROUND

Many studies have discussed the betahistine treatment for Meniere's disease (MD). However, regarding cochlear MD, there is no consensus on the long-term betahistine treatment.

AIMS/OBJECTIVES

This study aims to investigate the relationship between the betahistine treatment duration in patients with cochlear MD and their clinical outcomes.

MATERIAL AND METHODS

We enrolled 78 patients with 96 ears who were diagnosed with cochlear MD and received the treatment for more than 6 months. Outcomes included the hearing status, frequency of acute hearing loss attack, and whether the disease progressed to MD. Clinical characteristics including age, sex, side of affected ear, treatment duration of betahistine and trichlormethiazide, and pre-treatment hearing level was recorded from medical charts.

RESULTS

Comparing the clinical characteristics by outcomes, the average betahistine treatment duration was the independent factor for hearing status of four-tone average (p = 0.01) and low-tone average (p = 0.03). Patients with average betahistine treatment duration of at least 277 days per year had higher odds ratio for improvement of the hearing status of four-tone and low-tone average.

CONCLUSIONS

For patients with cochlear MD, regular and long-term betahistine treatment can benefit their hearing outcome in the low- and medium-frequency.

Symptom networks analysis among people with Meniere's disease: Application for nursing care

Objectives

This study aimed to explore and visualize the relationships among multiple symptoms in patients with Meniere's disease (MD) and aid clinical nurses in the design of accurate, individualized interventions.

Methods

This study included 790 patients with MD at the Eye and ENT Hospital of Fudan University from October 2014 to December 2021. A self-designed symptom checklist was used to assess 15 MD-related symptoms and construct contemporaneous networks with all 15 symptoms in R software. Qgraph package and Fruchterman-Reingold layout were used for network visualization. Bootstrapping methods were performed to assess network accuracy and stability, and three centrality indices were adopted to describe relationships among symptoms.

Results

Symptom networks showed good accuracy and stability. "Anxiety and nervousness"(98.2%), "aural fullness"(84.4%) and "tinnitus"(82.7%) were the common symptom in MD patients, while "tinnitus", "aural fullness" and "decline in word recognition", were more serious. MD patients with longer disease duration had higher prevalence and severity for all symptoms (P < 0.05). Symptom networks showed good accuracy and stability. "Decline in word recognition," "fatigue," and "anxiety and nervousness" were at the center of the symptom networks, which had the largest strength values and closeness. "Decline in word recognition," "headache," and "spatial discrimination and poor orientation" were the symptoms with the highest betweenness with the strongest bridging effect. The ≥1-year disease group exhibited higher centralities for "drop attack" and "anxiety and nervousness," and a lower centrality for "headache" compared with the <1-year disease group.

Conclusions

The symptom networks of MD patients with varying disease durations were revealed. Clinicians and nurses must provide precision interventions tailored to modifying symptom severity and centrality. Nursing interventions should focus on word recognition issues and associated discomfort in MD patients with multiple symptoms.

High jugular bulb in patients with non-thrombotic internal jugular venous and transverse sinus stenosis: Clues to pathogenesis

AIMS

Conventional theories for jugular bulb (JB) formation are insufficient to explain the high proportion of high JB in adult patients. We aimed to study features of high JB in patients with non-thrombotic internal jugular venous stenosis (IJVS) and/or transverse sinus stenosis (TSS) to explore the pathogenesis of high JB formation.

METHODS

We retrospectively enrolled consecutive patients with the diagnosis of non-thrombotic IJVS and/or TSS. The relationship between IJVS and/or TSS and high JB was explored. Logistic regression analysis was performed to identify potential independent risk factors for high JB.

RESULTS

A total of 228 patients were included in the final analyses. The proportions of IJVS, dominant-side IJVS, and non-TSS in dominant-side high JB subgroup were higher than those in nondominant-side high JB subgroup (83.3% vs. 62.5%, p < 0.001; 72.2% vs. 18.3%, p < 0.001; 43.5% vs. 29.2%, p = 0.02). Heights of JBs on dominant sides in IJVS subgroup and non-TSS subgroup were higher than those in non-IJVS subgroup and TSS subgroup (12.93 ± 2.57 mm vs. 11.21 ± 2.76 mm, p < 0.001; 12.66 ± 2.71 mm vs. 11.34 ± 2.73 mm, p = 0.003). Multivariate logistic regression indicated an independent association between dominant-side IJVS and dominant-side high JB (odds ratio, 29.40; 95% confidence interval, 11.04-78.30; p < 0.001).

CONCLUSION

IJVS and asymmetric transverse sinus were independently and positively associated with high JB, especially dominant-side IJVS with dominant-side high JB, indicating a potential hemodynamic relationship between IJVS and high JB formation. Conversely, TTS might impede high JB formation.

Development and validation of prediction model to estimate vertigo risk after endolymphatic sac decompression in Meniere's disease: a retrospective cohort study

PURPOSE

To study the efficacy predictors of endolymphatic sac decompression (ESD) in Meniere's disease (MD), and to establish and verify the prediction model of vertigo after ESD in patients with MD.

METHODS

The retrospective cohort data of 56 patients with unilateral MD who underwent ESD surgery were recorded. A stepwise regression method was used to select optimal modeling variables, and we established a logistic regression model with the outcome of vertigo after ESD. The bootstrap method was used for internal validation.

RESULTS

Potential predictors included sex, age, follow-up duration, disease course, attack duration, frequency of attack, pure-tone threshold average (PTA) of the patient's speech frequency, audiogram type, glycerin test results, MD subtype, and 10-year atherosclerotic cardiovascular disease risk classification. Using the stepwise regression method, we found that the optimal modeling variables were the audiogram type and PTA of the patient's speech frequency. The prediction model based on these two variables exhibited good discrimination [area under the receiver operating characteristic curve: 0.72 (95% confidence interval: 0.57-0.86)] and acceptable calibration (Brier score 0.21).

CONCLUSION

The present model based on the audiogram type and PTA of the patient's speech frequency was found to be useful in guidance of ESD efficacy prediction and surgery selection.

Association of Head Injury, Neck Injury or Acoustic Trauma on Phenotype of Ménière's Disease

The aim of the present study was to investigate adverse effects of head injury, neck trauma, and chronic noise exposure on the complaint profile in people with Ménière's disease (MD). The study used a retrospective design. Register data of 912 patients with MD from the Finnish Ménière Federation database were studied. The data comprised case histories of traumatic brain injury (TBI), neck trauma and occupational noise exposure, MD specific complaints, impact related questions, and the E-Qol health-related quality of life instrument. TBI was classified based on mild, moderate, and severe categories of transient loss of consciousness (TLoC). The mean age of the participants was 60.2 years, the mean duration of the disease was 12.6 years, and 78.7% were females. Logistic regression analysis, linear correlation, and pairwise comparisons were used in evaluating the associations. 19.2% of the participants with MD had a history of TBI. The phenotype of participants with TBI was associated with frequent vestibular drop attacks (VDA), presyncope, headache-associated vertigo, and a reduction in the E-QoL. Logistic regression analysis explained the variability of mild TBI in 6.8%. A history of neck trauma was present in 10.8% of the participants. Neck trauma associated with vertigo (NTwV) was seen in 47 and not associated with vertigo in 52 participants. The phenotype of NTwV was associated with balance problems, VDA, physical strain-induced vertigo, and hyperacusia. Logistic regression analysis explained 8.7% of the variability of the complaint profile. Occupational noise exposure was recorded in 25.4% of the participants and correlated with the greater impact of tinnitus, hyperacusis, and hearing loss. Neither the frequency, duration, or severity of vertigo or nausea were significantly different between the baseline group and the TBI, NTwV, or noise-exposure groups. The results indicate that TBI and NTwV are common among MD patients and may cause a confounder effect.

NADPH Oxidase 3: Beyond the Inner Ear

Reactive oxygen species (ROS) were formerly known as mere byproducts of metabolism with damaging effects on cellular structures. The discovery and description of NADPH oxidases (Nox) as a whole enzyme family that only produce this harmful group of molecules was surprising. After intensive research, seven Nox isoforms were discovered, described and extensively studied. Among them, the NADPH oxidase 3 is the perhaps most underrated Nox isoform, since it was firstly discovered in the inner ear. This stigma of Nox3 as "being only expressed in the inner ear" was also used by me several times. Therefore, the question arose whether this sentence is still valid or even usable. To this end, this review solely focuses on Nox3 and summarizes its discovery, the structural components, the activating and regulating factors, the expression in cells, tissues and organs, as well as the beneficial and detrimental effects of Nox3-mediated ROS production on body functions. Furthermore, the involvement of Nox3-derived ROS in diseases progression and, accordingly, as a potential target for disease treatment, will be discussed.

Exploring the Significance of Vitamin D Levels as a Biomarker in Ear Diseases: A Narrative Review

This narrative review examines the role of vitamin D as a biomarker in ear disorders, including benign paroxysmal positional vertigo (BPPV), otitis media, bell's palsy, Meniere's disease, and hearing loss. PubMed, The Cochrane Library, and Google Scholar were utilized to conduct a comprehensive literature search, and findings were combined from studies from 2014 to 2024. As highlighted in this review, there is a consistent association between vitamin D deficiency and an increased risk and recurrence of disease especially in BPPV and otitis media. Its importance as a prognostic biomarker is emphasized in Bell's palsy, where higher levels of deficiencies in vitamin D are associated with higher grades of severity on the House Brackmann grading system. Vitamin D deficiency can also lead to sensorineural hearing loss due to its receptors present in the inner ear or its effect on calcium metabolism. Serum levels of vitamin D have also been shown to influence treatment outcome of sensorineural hearing loss. The role of vitamin D in Meniere's disease is unclear as no cause has been identified for the increase in endolymphatic fluid. The findings of this review emphasize the importance of serum vitamin D as a biomarker in ear disorders and advocate for more studies to be conducted to assess the importance of optimal dosing of vitamin D for the progression and outcome of these diseases.

Role of conventional MD staging in modern era of hydrops MR imaging

Objective/Hypothesis

This study correlated stage of Meniere's disease (MD) with MR imaging of endolymphatic hydrops (EH) to assess the role of MD staging in modern era.

Study Design

Retrospective study.

Methods

Fifty-four MD patients (60 ears) underwent an inner ear test battery and were further confirmed by MR imaging. Sixty MD ears were divided into stages I-IV, and hydrops MR images at each stage were compared.

Results

Hydrops MRI demonstrated that EH at the cochlea with respective Grades 0/I/II were 3/7/1 ears for stage I, 0/5/3 ears for stage II, 1/6/26 ears for stage III and 0/2/6 ears for stage IV. Significant relationship was not identified between MD stage and grades of cochlear hydrops. Similarly, no significant relationship was shown between MD stage and grades of vestibular (saccular/utricular) hydrops. The optimal cutoff value of four-tone average for predicting severe type (Grade II-III) cochlear/vestibular EH was 48 dB, which was within the stage III. Hence, prevalence of severe type (Grade II) cochlear EH in stages III (79%) and IV (75%) was significantly higher than stages I (9%) and II (38%). Similarly, severe type saccular/utricular EH in stages III (64%) and IV (75%) also showed significantly higher than stages I (18%) and II (25%).

Conclusion

Although conventional MD staging fails to correlate with the grades of EH on hydrops MRI, late-stage MD may indicate heightened EH severity in the cochlea and vestibule.

Level of Evidence

4.

Enhancing the therapeutic potential of intravenous glycerol for Meniere's disease: Robust results from an extensive patient cohort

INTRODUCTION

Meniere's disease (MD) is an idiopatic condition characterized by recurrent attacks of vertigo, hearing loss, tinnitus, and aural fullness, affecting quality of life. Intravenous glycerol has shown potential as a therapeutic option. This study evaluates its efficacy in a larger patient cohort.

MATERIALS AND METHODS

Retrospective study with 168 patients having unilateral MD unresponsive to dietary restrictions. Intravenous 10 % glycerol with 0.9 % sodium chloride was administered for six months. Audio-vestibular assessments and questionnaires were used.

RESULTS

Significant improvements in vertigo control observed. 7.1 % achieved complete control, and 58.3 % had substantial control. Quality of life measures improved, and audiometry thresholds remained unchanged. No major adverse events reported.

DISCUSSION

Intravenous glycerol effectively controlled vertigo and improved MD patients' quality of life. Limitations include lack of a control group and a relatively short-term follow-up. Future prospects include randomized controlled trials and optimization of treatment protocols.

CONCLUSION

Intravenous glycerol shows promise as a therapeutic option for MD, with notable improvements in vertigo control and quality of life. Further research is needed for validation and optimization.

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.

Identifying Predictors of Treatment Response in Meniere's Disease: A Clinical Severity Staging System

OBJECTIVE

Identify clinically important factors associated with conservative treatment response in Meniere's disease and incorporate these factors into a composite clinical severity staging system.

STUDY DESIGN

Retrospective cohort.

SETTING

Tertiary academic medical center.

METHODS

Adult patients newly diagnosed with Meniere's disease between January 1, 2016 and December 31, 2019 were eligible. Patients with previous treatment for Meniere's disease, prior otologic surgery, or a lack of follow-up data were excluded. Treatment-responsive patients were managed with only conservative therapies (eg, dietary modifications, diuretics) and unresponsive patients underwent more intensive therapies (eg, intratympanic procedures, surgical interventions).

RESULTS

Of 78 patients included in the study, 49 (63%) were responsive to conservative therapies and 29 (37%) were not. Responsive patients had higher proportions of no or mild vertigo (24%, 95% confidence interval [CI]: 3.1%-45.8%) and none or mild comorbidity (27%, 95% CI: 9.2%-44.7%) and a lower proportion of hearing loss (19%, 95% CI: 5.6%-32.4%) compared to unresponsive patients. Conjunctive consolidation of these 3 factors was performed to develop a three-stage system with a treatment response gradient ranging from 100% to 64% to 18% for stage 1 (n = 11), stage 2 (n = 56), and stage 3 (n = 11), respectively.

CONCLUSIONS

This study identified decreased vertigo severity, reduced comorbidity burden, and absence of hearing loss as factors associated with conservative treatment response in Meniere's disease. A composite clinical severity staging system including these 3 factors can be used to optimize treatment selection and promote patient-centered management of Meniere's disease.

Interstitial Fluidopathy of the Central Nervous System: An Umbrella Term for Disorders with Impaired Neurofluid Dynamics

Interest in interstitial fluid dynamics has increased since the proposal of the glymphatic system hypothesis. Abnormal dynamics of the interstitial fluid have been pointed out to be an important factor in various pathological statuses. In this article, we propose the concept of central nervous system interstitial fluidopathy as a disease or condition in which abnormal interstitial fluid dynamics is one of the important factors for the development of a pathological condition. We discuss the aspects of interstitial fluidopathy in various diseases, including Alzheimer's disease, Parkinson's disease, normal pressure hydrocephalus, and cerebral small vessel disease. We also discuss a method called "diffusion tensor image analysis along the perivascular space" using MR diffusion images, which is used to evaluate the degree of interstitial fluidopathy or the activity of the glymphatic system.

Efficacy and preservation of hearing with low-dose gentamicin in unilateral meniere's disease: A clinical symptomatology-based study

PURPOSE

Meniere's disease (MD), a disorder of the inner ear, presents numerous therapeutic challenges, and intratympanic (IT) gentamicin has been proposed for intractable cases. However, controversy regarding dosage and method persists. The purpose of this study was to assess the efficacy and safety of low-dose IT gentamicin on vertigo attacks in MD using a clinical symptomatology-based method, wherein administration was repeated only if vertigo attacks recurred, with a 2-week interval between injections.

MATERIALS AND METHODS

This study included 88 patients with unilateral intractable MD. All patients received one to five IT injections with 0.5 ml of 10 mg of gentamicin (80 mg/2 ml) with an interval of 2 weeks between injections. Vertigo attacks were evaluated before and after therapy and categorized into classes A-F according to the 2015 Equilibrium Committee criteria. Audiovestibular assessments, including Pure Tone Audiometry and Vestibulo-Ocular Reflex evaluations, were performed.

RESULTS

Before treatment, patients had an average of 4.4 vertigo attacks/month; after treatment, this average decreased to 0.52. The majority of patients (57 %) reached Class A or B vertigo control with five or fewer gentamicin injections. VOR gain was slightly affected on the healthy side and significantly reduced on the affected side. No hearing deterioration was found in any of the treated patients.

CONCLUSIONS

Low-dose IT gentamicin administration based on clinical symptomatology can produce a satisfactory control of vertigo attacks after treatment. This protocol primarily affected the vestibular function, as demonstrated by the significant reduction in VOR gain on the affected side, while avoiding cochlear damage. The lack of adverse events and preservation of hearing underscore the safety and efficacy of this method. These findings have significant clinical implications, suggesting that a low-dose, clinical symptomatology-based gentamicin treatment regimen could be an effective and safe strategy for managing unilateral Meniere's disease in a larger population.

MRI can help differentiate Ménière's disease from other menieriform diseases

It is difficult to distinguish other pathologies mimicking Ménière's disease (MD) clinically. This study aims to investigate the differences of imaging findings and features between MD and other menieriform diseases via intravenous gadolinium-enhanced magnetic resonance imaging (MRI). 426 patients with menieriform symptoms, including MD, vestibular migraine (VM), and vestibular schwannoma (VS), underwent 3D-FLAIR and 3D-T2WI MRI 6 h after the intravenous gadolinium injection. MR images were analyzed for inner ear morphology, perilymphatic enhancement (PE), EH and other abnormalities. EH was observed at a higher rate in MD patients (85.71%) than patients with other menieriform diseases (VM group = 14.75%, VS group = 37.50%). The prevalence of unilateral EH as well as both cochlear and vestibular EH showed significant differences between MD and VM groups. The prevalence of cochlear EH (I and II) and vestibular EH (II and III) was different between MD and VM groups. The prevalence of PE was higher in MD than VM group. The degrees of cochlear and vestibular hydrops were higher in the definite than probable MD group (P < 0.05). Using these imaging features, MRI can be used to help differentiate MD from other menieriform diseases.

Ménière's disease and allergy: Epidemiology, pathogenesis, and therapy

The etiology of Ménière's disease (MD) remains controversial. Allergies are potential extrinsic factors that, in conjunction with underlying intrinsic factors, may cause MD. The link between allergies and MD was first described in 1923. For nearly a century, studies have demonstrated a possible link between allergies and MD, even though a causal relationship has not been definitively determined. Previous reviews have mainly focused on clinical epidemiology studies of patients. In this review, we shed light on the association between allergies and MD not only in terms of its epidemiology, but also from an immunology, pathophysiology, and immunotherapy perspective in both patients and animal models. Patients with MD tend to have a high risk of comorbid allergies or an allergy history, showing positive allergy immunology characteristics. Other MD-related diseases, such as migraine, may also interact with allergies. Allergy mediators such as IgE may worsen the symptoms of MD. Deposits of IgE in the vestibular end organs indicate the ability of the inner ear to participate in immune reactions. Allergic challenges can induce vertigo in animals and humans. Anti-allergy therapy plays a positive role in patients with MD and animal models of endolymphatic hydrops.

Does labyrinthectomy have an impact on hearing in the contralateral ear during long-term follow-up?

OBJECTIVE

To quantify contralateral hearing outcomes after labyrinthectomy for unilateral Ménière's disease (MD).

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary neurotology referral center.

PATIENTS

Labyrinth removal for the management of MD or translabyrinthine (TLAB) acoustic neuroma resection between 2008 and 2012.

MAIN OUTCOME MEASURE

Long-term hearing changes via pure tone averages (PTA).

RESULTS

Upon comparison of low-frequency PTA (250, 500, 1000 Hz), MD patients experienced a greater degree of hearing loss during the follow-up period when compared to the TLAB lab group (7.54 ± 2.11 dB vs 2.39 ± 1.10 dB, p = 0.035). This difference as attributable to 12 (28.6 %) MD patients experiencing a ≥30 dB increase in low-frequency PTA, whereas none (0.0 %) of the TLAB surpassed this threshold.

CONCLUSIONS

At 10 years post-labyrinthectomy there is a heightened risk for MD patients to develop low-frequency sensorineural hearing loss. Clinicians should monitor for audiometric changes through regular testing in the decade following labyrinth removal.

Findings of Intravenous Gadolinium Inner Ear Magnetic Resonance Imaging in Patients With Acute Low-Tone Sensorineural Hearing Loss

OBJECTIVES

Acute low-tone sensorineural hearing loss (ALHL) is thought to have a different etiology from that of idiopathic sudden sensorineural hearing loss. We hypothesized that endolymphatic hydrops (EH) in the inner ear organ contributes to ALHL, even in patients without vertigo. This study investigated the presence of EH in ALHL and compared the clinical characteristics of patients with or without EH.

METHODS

We retrospectively reviewed 38 patients diagnosed with ALHL without vertigo from January 2017 to March 2022. EH was measured in all patients using inner ear magnetic resonance imaging (MRI). In addition, we selected patients who showed only mid- or high-frequency hearing loss and had available MRI data as a control group and compared the ALHL and control groups.

RESULTS

After treatment, the pure-tone average at low frequencies significantly improved compared to the initial hearing (P<0.001). Hearing recovery was observed in 63.1% of patients; however, the recovery rate did not differ based on the treatment method. During the follow-up period, six patients (15.8%) progressed to Meniere's disease, and 18 (47.4%) experienced recurrence. In the ALHL group, the cochlear hydrops ratio on the affected side (0.34±0.09) was significantly higher than on the contralateral side (0.29±0.12) (P=0.005), and most patients showed hydrops in the apex area of the cochlea. Compared with the control group (0.25±0.15), the ALHL group showed a significantly higher cochlear hydrops ratio (P=0.043). The correlation analysis showed a tendency for hearing thresholds at low frequencies to increase as the hydrops ratio increased, albeit without statistical significance.

CONCLUSION

The cochlear hydrops ratio, especially in the apex area on the affected side, was significantly higher in patients with ALHL, suggesting that EH in the cochlea contributes to the pathogenesis of ALHL.

Functional reorganization of intranetwork and internetwork connectivity in patients with Ménière's disease

Ménière's disease (MD) is associated with functional reorganization not only in the auditory or sensory cortex but also in other control and cognitive areas. In this study, we examined intranetwork and internetwork connectivity differences between 55 MD patients and 70 healthy controls (HC) in 9 well-defined resting-state networks. Functional connectivity degree was lower in MD compared to HC in 19 brain areas involved in the somatomotor, auditory, ventral attention, default mode, limbic, and deep gray matter networks. In addition, we observed lower intranetwork connectivity in the auditory, ventral attention, and limbic networks, as well as lower internetwork connectivity between the somatomotor and limbic networks, and between the auditory and somatomotor, deep gray matter, and ventral attention networks, and between the deep gray matter and default mode network. Furthermore, we identified 81 pairs of brain areas with significant differences in functional connectivity between MD patients and HC at the edge level. Notably, the left amygdala's functional connectivity degree was positively correlated with MD's disease stage, and the ventral attention network's intranetwork connectivity was positively correlated with the healthy side vestibular ratio. Our findings suggest that these functional network reorganization alterations may serve as potential biomarkers for predicting clinical progression, evaluating disease severity, and gaining a better understanding of MD's pathophysiology. Large-scale network studies using neuroimaging techniques can provide additional insights into the underlying mechanisms of MD.

Speech Perception in Ménière Disease

Introduction  Ménière disease (MD) affects the inner ear, comprising the cochlea and semicircular canals. Symptoms include severe incapacitating vertigo, nausea, vomit, aural fullness, and sensorineural hearing loss - in which speech discrimination and intelligibility are impaired and can be quantified with speech audiometry. Objective  To investigate the influence of the stimuli presentation level in speech audiometry and the quality of life in adults with and without a diagnosis of MD. Method  Two groups were formed with nine individuals each - one with and the other without MD. The Speech Recognition Percentage Index was researched with stimuli presented above the self-reported comfort level or 5 dB below the discomfort level. Dizziness Handicap and Tinnitus Handicap Inventories were administered to individuals with tinnitus and vertigo complaints. Results  Speech recognition was better in the study group with higher presentation levels, as 75% of the sample improved their performance. The presence of vertigo significantly impacted the quality of life of individuals in the study group. Conclusion  Speech recognition improves with higher presentation levels. Also, MD impacts the quality of life, especially regarding limitations caused by vertigo.

Analytical Quality by Design-Driven RP-HPLC Method Conditions to Concomitantly Determine Cinnarizine and Morin Hydrate in Combined Drug Solution and Dual Drug-Loaded Formulations

BACKGROUND

The replacement of traditional oils with a camphor and menthol-based eutectic mixture is done to prepare oil-less emulsion-like dispersions for co-delivery of cinnarizine (CNZ) and morin hydrate (MH) for managing Meniére's disease (MD). Since two drugs are loaded into the dispersions, the development of a suitable reverse phase-high performance liquid chromatography (RP-HPLC) method for their simultaneous analysis becomes inevitable.

OBJECTIVE

By applying the analytical quality by design (AQbD) approach, the RP-HPLC method conditions were optimized for the concomitant determination of two drugs.

METHODS

The systematic AQbD started with identifying critical method attributes (CMA) through an Ishikawa fishbone diagram, risk estimation matrix, and risk priority number-based failure mode effect analysis followed by screening using fractional factorial design and optimization by face-centered central composite design. The concomitant determination of two drugs by the optimized RP-HPLC method condition was substantiated via specificity checking using combined drug solution, drug entrapment efficiency, and in vitro release of the two drugs from emulsion-like dispersions.

RESULTS

The AQbD optimized RP-HPLC method conditions revealed the retention time for CNZ and MH at 5.017 and 5.323, respectively. The studied validation parameters were found within the ICH-prescribed limits. Exposing the individual drug solutions to acidic and basic hydrolytic conditions yielded extra chromatographic peaks for MH, probably due to the degradation of MH. The DEE % values of 87.40 ± 4.70 and 74.79 ± 2.94, respectively, were noticed for CNZ and MH in emulsion-like dispersions. More than 98% CNZ and MH release was occurred from emulsion-like dispersions within 30 min post-dissolution in artificial perilymph.

CONCLUSIONS

Overall, the AQbD approach could be helpful for systematic optimization of RP-HPLC method conditions to estimate concomitantly other therapeutic moieties.

HIGHLIGHTS

The proposed article shows the successful application of AQbD for the optimization of RP-HPLC method conditions to concomitantly estimate CNZ and MH in combined drug solution and dual-drug-loaded emulsion-like dispersions.

Bilateral Low-Frequency Hearing Impairment After Microvascular Decompression Surgery

BACKGROUND

Hearing impairment is an important complication of microvascular decompression (MVD). In patients after MVD, we have occasionally noted slight to moderate hearing deterioration at low frequencies that is difficult to detect using pure tone average.

OBJECTIVE

To assess the incidence and features of low-frequency hearing impairment (LF-HI) after MVD and evaluate its associated factors.

METHODS

This single-center, retrospective observational study assessed the audiometric outcome of 270 patients who underwent MVD between January 2015 and December 2020. Preoperative and postoperative hearing levels were compared for each frequency. LF-HI was defined as a hearing deterioration of ≥15 dB at 125, 250, or 500 Hz. The incidence, symptoms, and associated factors of LF-HI were analyzed.

RESULTS

Statistical analysis of the patients overall demonstrated slight but significant decreases in the hearing level after MVD at lower frequencies on both the operative and contralateral sides. Eighty-one patients (30.0%) had LF-HI: 49 on the operative side, 24 on the contralateral side, and 8 on both sides, while pure tone average was worsened in 5 patients (1.8%). Subjective symptoms, including hearing deterioration, ear fullness, tinnitus, and dizziness, developed in 10.4% of the patients with LF-HI but improved subsequently within several weeks. "Older age" and "operative side" were associated with LF-HI.

CONCLUSION

Decreases in lower-frequency hearing levels in both the ipsilateral and contralateral (nonoperative) ears were observed after trigeminal neuralgia and hemifacial spasm surgery. LF-HI does not cause permanent symptoms but may be a noteworthy phenomenon, possibly involved in the contralateral hearing loss encountered occasionally after other types of posterior cranial fossa surgery.

The effect of vestibular rehabilitation in Meniere's disease: a systematic review and meta-analysis of clinical trials

BACKGROUND

Meniere's disease (MD) is a complex disease that can severely affect the quality of life. In this systematic review and meta-analysis, we aimed to investigate the effect of vestibular rehabilitation (VR) versus control/other interventions on the quality of life in patients with MD.

METHODS

We searched six electronic databases (PubMed/MEDLINE, Web of Science, EMBASE, Scopus, ProQuest, CENTRAL) from inception to September 30, 2022 with no language restriction for publications comparing the effect of VR with control/ other interventions in patients with MD. The primary outcome was quality of life assessed by dizziness handicap inventory (DHI).

RESULTS

Overall, three studies with a total of 465 patients were included in the meta-analysis. All the included studies reported immediate-term DHI scores. A medium effect (standardized mean difference [SMD] = - 0.58, 95% confidence interval [CI] - 1.12; - 0.05) was observed favoring the use of VR to improve DHI scores in patients with MD in the immediate term. Moreover, there was severe heterogeneity in immediate DHI scores among the included studies (χ2 = 22.33, P = 0.00, I2 = 82.1%).

CONCLUSIONS

VR rehabilitation can improve the quality of life in patients with MD immediately after treatment. Since all the included studies had a high risk of bias and none had long-term follow-ups, further high-quality research is required to determine the short-, intermediate-, and long-term effects of VR compared to control/other interventions.

The role of serum osmolality in Meniere's disease with acute sensorineural hearing loss

OBJECTIVE

This study investigated the role of serum osmolality in Meniere's disease (MD) patients with acute sensorineural hearing loss (SNHL).

DESIGN

Retrospective study.

STUDY SAMPLES

Twenty definite MD patients with acute unilateral SNHL were treated with an osmotic diuretic (Isosorbide, 100 mL daily) and assigned to Group A. Another 20 age- and sex-matched definite MD patients with acute SNHL were not given Isosorbide and assigned to Group B. Both groups underwent audiometry and blood examination for serum osmolality before and after treatment.

RESULTS

Group A revealed a significant increase in serum osmolality after treatment. The optimal cut-off values for increased serum osmolality in Group A were +1.5 mOSM/L for predicting hearing improvement at frequencies of 250-1000 Hz, and +2.5 mOSM/L at 2000-4000 Hz. Comparing increased levels of serum osmolality (> +2.0 vs. ≤ +2.0 mOSM/L), Isosorbide dosing at 3.0 L vs. 1.0 L, significantly differed in the odds ratio (OR). Isosorbide at a total dosage of 3.0 L thus improves the hearing threshold by >10 dB at frequencies of 250-2000 Hz.

CONCLUSION

The Isosorbide at a total dosage of 3.0 L may increase serum osmolality by > +2.0 mOSM/L, and improve the hearing threshold for hydropic ears at least >10 dB at low- and mid-frequencies.

Histamine and Its Receptors in the Mammalian Inner Ear: A Scoping Review

BACKGROUND

Histamine is a widely distributed biogenic amine with multiple biological functions mediated by specific receptors that determine the local effects of histamine. This review aims to summarize the published findings on the expression and functional roles of histamine receptors in the inner ear and to identify potential research hotspots and gaps.

METHODS

A search of the electronic databases PubMed, Web of Science, and OVID EMBASE was performed using the keywords histamine, cochlea*, and inner ear. Of the 181 studies identified, 18 eligible publications were included in the full-text analysis.

RESULTS

All four types of histamine receptors were identified in the mammalian inner ear. The functional studies of histamine in the inner ear were mainly in vitro. Clinical evidence suggests that histamine and its receptors may play a role in Ménière's disease, but the exact mechanism is not fully understood. The effects of histamine on hearing development remain unclear.

CONCLUSIONS

Existing studies have successfully determined the expression of all four histamine receptors in the mammalian inner ear. However, further functional studies are needed to explore the potential of histamine receptors as targets for the treatment of hearing and balance disorders.

Pitfalls of Using T2-contrast Enhancement Techniques in 3D-FLAIR to Detect Endolymphatic Hydrops

PURPOSE

To determine whether T2-contrast enhancement techniques can be used to diagnose endolymphatic hydrops, we compared fluid signal artifacts with and without T2-contrast enhancement techniques in 3D fluid-attenuated inversion recovery (3D-FLAIR).

METHODS

We prepared a custom-made phantom consisting of eight tubes half-filled with saline. Images were obtained using four 3D-FLAIR: without T2-contrast enhancement (Normal), with non-selective T2-inversion recovery (T2-IR), and two with non-selective T2 preparation IR (T2-prep). Scans were performed with and without rice covering the phantom to simulate minimal and severe B0-inhomogeneity conditions. The average signal intensity (SI) values of eight saline tubes were compared between the four sequences and between each other. Comparisons were performed for all measurement slices and the central 10 slices. The images using T2-contrast enhancement technique were obtained from a volunteer and a patient suspected of Meniere's disease.

RESULTS

The Normal sequence SI for all slices was significantly lower than that for the other sequences, with smaller standard deviation (SD) and no outliers. Several outliers were detected in the other sequences. The SDs and outliers were larger without rice than with rice. When the central 10 slices with rice, the T2-IR had a significantly higher SI with more outliers compared with the Normal sequence. The T2-prep had no outliers and SIs that were comparable to those of the Normal sequence. However, without rice, the T2-IR and T2-prep sequences had significantly higher SIs with outliers and larger SDs compared to the Normal sequence. In the corresponding images, the Normal sequence achieved excellent fluid suppression, whereas the T2-IR and T2-prep sequences showed high-signal artifacts. Imperfect fluid suppressions were observed in the volunteer image and the endolymphatic hydrops on the post-gadolinium image differed in size and shape in the non-injected T2-IR in the patient image.

CONCLUSION

T2-contrast enhancement techniques should be used with caution in 3D-FLAIR for diagnosing endolymphatic hydrops.

The effect of vascular risk factors on the efficacy of endolymphatic sac decompression surgery for Meniere's disease: a retrospective cohort study

Objectives

This study aimed to investigate the effect of vascular risk factors on the outcomes of endolymphatic sac decompression (ESD) surgery in patients with Meniere's disease.

Methods

The study included 56 patients with Meniere's disease, who had undergone unilateral ESD surgery. The patients' vascular risk factors were assessed based on the preoperative 10-year atherosclerotic cardiovascular diseases risk classification. Those with no or low risk were defined as the low-risk group, while those with medium, high, or very high risk were defined as the high-risk group. The correlation between the vascular risk factors and ESD efficacy was evaluated by the comparison of vertigo control grade between the two groups. The functional disability score was also assessed to investigate whether ESD improved the quality of life in Meniere's disease patients with vascular risk factors.

Results

After ESD, 78.95 and 81.08% of patients from the low-risk and high-risk groups, respectively, demonstrated at least grade B vertigo control; no statistically significant difference was observed (p = 0.96). The postoperative functional disability scores in both groups were significantly lower compared with those before surgery (p < 0.01), with a median decrease of two (1, 2) points in both groups. No statistically significant difference between the two groups was observed (p = 0.65).

Conclusion

Vascular risk factors have little effect on the efficacy of ESD in patients with Meniere's disease. Patients with one or more vascular risk factors can still experience a not poor vertigo control and improved quality of life after ESD.

Magnetic Targeting of Gadolinium Contrast to Enhance MRI of the Inner Ear in Endolymphatic Hydrops

OBJECTIVES

1. Determine the feasibility and efficiency of local magnetic targeting delivery of gadolinium (Gad) contrast to the inner ear in rodents. 2. Assess any potential ototoxicity of magnetic targeting delivery of Gad in the inner ear. 3. Study the utility of magnetic targeting delivery of Gad to visualize and quantify endolymphatic hydrops (EH) in a transgenic mouse model.

STUDY DESIGN

Controlled in vivo animal model study.

METHODS

Paramagnetic Gad was locally delivered to the inner ear using the magnetic targeting technique in both rat and mouse models. Efficiency of contrast delivery was assessed using magnetic resonance imaging (MRI). Ototoxicity of Gad was examined with histology of the cochlea and functional audiological tests. The Phex mouse model was used to study EH, hearing loss, and balance dysfunction. Magnetic targeting delivery of Gad contrast was used in the Phex mouse model to visualize the effects of EH using MRI.

RESULTS

Magnetic targeting improved the delivery of Gad to the inner ear and the technique was reproducible in both rat and mouse models. The delivery method did not result in microstructural damage or any significant hearing loss in a normal animal. Magnetic targeting of Gad in the Phex mouse model allowed detailed visualization and quantification of EH.

CONCLUSION

This study provided the first evidence of the effectiveness and efficiency of the local magnetic targeting delivery of gadolinium contrast to the inner ear and its application to the visualization and quantification of EH. Laryngoscope, 133:914-923, 2023.

Correlating atmospheric pressure and temperature with Meniere attack

OBJECTIVE

This paper correlated the Meniere attack with meteorological parameters i.e. atmospheric pressure, temperature, relative humidity and rainfall, to investigate which parameters that trigger the Meniere attack.

METHODS

During the past three years, totally 283 (2015), 351 (2016) and 319 (2017) patients with Meniere's disease (MD) were encountered at a clinic of the university hospital, accounting for 13%, 17% and 16% incidence in relation to overall annual neurotological cases, respectively. The onset of Meniere attack was then correlated with meteorological parameters.

RESULTS

The mean seasonal incidence of Meniere attack in relation to overall seasonal neurotological cases in 2015-2017 were 14.8 ± 2.8% (spring), 17.5 ± 2.2% (summer), 16.0 ± 1.8 % (autumn) and 12.8 ± 2.0% (winter), indicating that summer season had a higher incidence of Meniere attacks than winter season. Onset of Meniere attacks correlated significantly with the atmospheric pressure (r = -0.4484, p = 0.0061) and temperature (r = 0.4736, p = 0.0035), and the atmospheric pressure was highly negatively correlated with the temperature (r = -0.9421, p < 0.0001). In contrast, no correlation was identified between the onset of Meniere attacks and relative humidity or rainfall. The atmospheric pressure in the same month with typhoon compared with that without typhoon revealed a median reduction of 13.1 hectopascal.

CONCLUSION

Atmospheric pressure and temperature are correlated with the onset of Meniere attack. Summer season has a higher incidence of Meniere attack than winter season, likely because low atmospheric pressure in summer may aggravate endolymphatic hydrops, especially when accompanied by typhoons in the northwest Pacific region.

Tinnitus, Aural Fullness, and Hearing Loss in a Patient with Acoustic Neuroma and Pituitary Macroadenoma

We report the case of a 51-year-old woman with multiple otologic and vestibular symptoms. She presented with two different types of tinnitus in her right ear, vertigo, and fluctuating aural symptoms in the left ear. She also complained of disequilibrium; chronic headache; hyperhidrosis; amenorrhea; insomnia; broadened hands and feet; and widened, thickened, and stubby fingers. The patient underwent careful collection of medical history, otomiscroscopy, pure tone audiometry, tympanometry, reflex threshold measurements, vestibular assessments, blood tests, magnetic resonance imaging (MRI), and cone beam computed tomography (CBTC) of the head. The audiogram showed: (1) a mild low-to-mid frequency conductive hearing loss, and a sharply sloping sensorineural hearing loss above 4000 Hz in the right ear; (2) a mild low-frequency sensorineural hearing loss in the left ear. MRI with 3D FLAIR sequences detected an acoustic neuroma (7.4 mm × 5.2 mm) in the middle-third of the right internal auditory canal, a pituitary macroadenoma (13 mm × 10 mm × 10 mm) and left saccular hydrops. The CBCT scan documented an outbreak of otosclerosis (3 mm) around the fissula ante fenestram in the right ear. Therefore, acoustic neuroma (right ear), growth hormone-secreting macroadenoma of the pituitary gland, Menière’s disease (left ear), and otosclerosis (right ear) were diagnosed/strongly suspected. A watch-and-wait strategy was adopted for acoustic neuroma and otosclerosis, while transsphenoidal surgery was successfully performed to remove the pituitary macroadenoma. This case report confirms that multiple otologic disorders can occur simultaneously in the same patient, requiring prompt audiological and imaging evaluations.

A bibliometric and visualization study of Meniere's disease: Current status and global hotspots and emerging trends

BACKGROUND

Meniere's disease (MD) is a clinical condition characterized by endolymphatic hydrops. Persistent symptoms negatively affect patients mood, and the underlying etiology remains unclear. It is necessary to comprehensively understand the relevant publications, review the history and current status of research, and analyze hotspots and frontiers of research on MD.

METHODS

We retrieved literature on Meniere's disease from 2003 to 2022 from the Web of Science database and extracted the data. Data visualization and analysis was conducted using Cite Space, VOS viewer, an online web tool, and Microsoft Office Power Point 2019.

RESULTS

In total, 2847 publications were analyzed. The number of annual publications was relatively stable, with an accelerated upward trend over the past 5 years. The country with the most publications was USA (751, 26.38%), while the University of Munich contributed more publications than any other institution (117, 4.11%). The article titled "Diagnostic criteria for Meniere's disease" by Lopez-Escamez J et al in 2015 was the most cited and co-cited publication, and also had the top co-cited references with the strongest citation bursts. Naganawa S was the author with the most publications (85, 2.99%). The top 3 journals and co-cited journals were Otology Neurotology, Acta Oto Laryngologica, and Laryngoscope. Recently, the key theme words were "sensorineural hearing loss," "therapy," "intratympanic injection method," "vestibular-evoked myogenic potentials," "vestibular migraine," "magnetic resonance imaging," and "meniere's disease."

CONCLUSIONS

The US has the largest number of publications and research institutions, many European countries have high-quality journals, and Japan has the highest number of scholars. The international opinion on Meniere's disease is relatively uniform. The stepped-therapy for MD is scientific and clear. Intratympanic injection of steroids and intratympanic injection of gentamicin are commonly used, but steroids are considered safer. Saccular dysfunction may be more common in patients with MD than in those with utricular dysfunctions. It is worth paying attention to study the relationship between MD and vestibular migraine through headache. Progress in magnetic resonance imaging technology is still required for the imaging diagnosis of MD.