Diagnostic and therapeutic strategies for Meniere's disease of the Japan Society for Equilibrium Research

Early and certain Ménière's disease characterization of predictors of endolymphatic hydrops

Introduction

Ménière's disease (MD) is characterized by fluctuating sensorineural hearing loss, tinnitus, aural fullness, and episodic vertigo. Although endolymphatic hydrops (EH) is recognized as a pathognomonic finding, the relationship between clinical presentation, disease duration, and EH severity remains controversial, especially in early-stage MD. This study aimed to determine the impact of disease onset, temporal variables, and clinical phenotypes on EH severity and audiovestibular performance in a cohort with very early MD.

Methods

We evaluated 80 patients diagnosed with certain MD, with symptom duration of less than 3 years. All underwent 3T MRI with 3D-real-IR sequences for EH evaluation, graded using cochlear (HCAFF), vestibular (HVAFF), and volumetric vestibular ratio (RELAFF). Multiple regression and correlation analyses were used to examine relationships between EH and clinical time markers (TD1, TS1, TR1, TR2), phenotypes, onset patterns, and audiovestibular outcomes (PTA, cVEMP, oVEMP, vHIT). Statistical significance was set at p < 0.05.

Results

All patients exhibited some degree of EH, with 92.5% showing both cochlear and vestibular involvement. No significant correlations were found between time variables and EH severity. However, TS1 and TD1 were significantly associated with PTA in the affected ear (r = 0.277, p = 0.017 and r = 0.318, p = 0.006, respectively). Multinomial regression revealed that vestibular and complete onset patterns predicted more severe vestibular hydrops (HVAFF II and III: p = 0.019 and p = 0.020, respectively). The delayed phenotype was significantly associated with higher RELAFF values (p = 0.032), worse PTA in the affected ear (p = 0.005), and abnormal cVEMP responses (p = 0.002). No associations were found between phenotype or onset form and hydrops in general.

Discussion

In very early MD, clinical time variables do not predict EH severity but correlate with hearing loss severity. The pattern of disease onset significantly impacts vestibular hydrops, whereas age correlates with cochlear EH, likely reflecting age-related hearing vulnerability. Phenotypic differences influence audiovestibular outcomes but not EH presentation. These findings highlight the diagnostic and prognostic utility of early symptom characterization and the need for standardization in defining disease duration in MD research.

Comparison of gadolinium-enhanced MRI of the inner ear with definite Meniere's disease in the detection of endolymphatic hydrops between intratympanic and intravenous injection

OBJECTIVE

We aimed to compare the success rate of the inner-ear visualization and actual endolymphatic hydrops (EH) detection rate of gadolinium-enhanced MRI in ears with definite Meniere's disease (dMD) with intratympanic versus intravenous injection.

METHODS

122 ears with dMD were included and divided into the intratympanic (IT) administration and intravenous (IV) groups. 38 ears in the IT group were evaluated by 3D-real IR and 3D-FLAIR sequence scans 24 h after injection of 8-fold diluted gadolinium. 84 ears in IV group were evaluated by i3D-real IR sequence scans 4 h after intravenous gadolinium administration. The success rate and the detection rate of EH were evaluated and analysed.

RESULTS

The i3D-real IR sequence in the IV group had a higher success rate (100%) than did the 3D-real IR (76.32%) and 3D-FLAIR (84.21%) sequences in the IT group. The actual EH detection rate in the IV group (98.81%) was significantly higher than that for the 3D-real IR (76.32%), 3D-FLAIR (78.95%) or 3D-real IR + 3D-FLAIR (84.21%) sequences in the IT group. The presence of EH could not accurately be assessed in 15.79% of ears in the IT group due to weak perilymph enhancement. After exclusion of these ears, the IT and IV groups showed similar EH detection rates.

CONCLUSION

The insufficient success rate of IT method reduced its actual EH detection rate. Using i3D-real IR, the IV method offers the higher success and actual EH detection rates, which provides a reference to the individualized choice of gadolinium-enhanced MRI.

Direct Visualization of Tracer Permeation into the Endolymph in Human Patients Using MR Imaging

PURPOSE

The endolymph of the inner ear, vital for balance and hearing, has long been considered impermeable to intravenously administered gadolinium-based contrast agents (GBCAs) due to the tight blood-endolymph barrier. However, anecdotal observations suggested potential GBCA entry in delayed heavily T2-weighted 3D-real inversion recovery (IR) MRI scans. This study systematically investigated GBCA distribution in the endolymph using this 3D-real IR sequence.

METHODS

Forty-one patients suspected of endolymphatic hydrops (EHs) underwent pre-contrast, 4-h, and 24-h post-contrast 3D-real IR imaging. Signal intensity in cerebrospinal fluid (CSF), perilymph, and endolymph was measured and analyzed for temporal dynamics of GBCA uptake, correlations between compartments, and the influence of age and presence of EH.

RESULTS

Endolymph showed a delayed peak GBCA uptake at 24h, contrasting with peaks in perilymph and CSF at 4h. Weak to moderate positive correlations between endolymph and CSF contrast effect were observed at both 4 (r = 0.483) and 24h (r = 0.585), suggesting possible inter-compartmental interactions. Neither the presence of EH nor age significantly influenced endolymph enhancement. However, both perilymph and CSF contrast effects significantly correlated with age at both time points.

CONCLUSION

This study provides the first in vivo systematic confirmation of GBCA entering the endolymph following intravenous administration. Notably, endolymph uptake peaked at 24h, significantly later than perilymph and CSF. The lack of a link between endolymph contrast and both perilymph and age suggests distinct uptake mechanisms. These findings shed light on inner ear fluid dynamics and their potential implications in Ménière's disease and other inner ear disorders.

Visualization of Vestibular Aqueduct and Endolymphatic Hydrops in Meniere's Disease With 3D-Real IR

OBJECTIVES

To investigate the association between the vestibular aqueduct (VA) and endolymphatic hydrops (EH) in patients with Meniere's disease (MD) using three-dimensional real inversion recovery (3D-real IR) sequences.

METHODS

This retrospective study included patients diagnosed with unilateral MD who underwent computed tomography (CT) and 3D-real IR sequencing. The VA course was identified on CT, and its visibility was assessed using a 3D-real IR sequence. The presence and severity of the cochlear and vestibular EH were evaluated. VA visualization was classified as Grade 0, whereas nonvisualization was classified as Grade 1. Differences in VA visibility between the affected and unaffected ears were compared, and correlations between VA visibility and EH severity were analyzed. Finally, the diagnostic efficacy of various MD indicators was assessed.

RESULTS

A total of 56 patients with unilateral MD were analyzed. The incidence rates of cochlear or vestibular EH were higher in the affected ear group than in the unaffected ear group (p < 0.001). The rates of nonvisualization of the VA in the affected and unaffected ears were 91.1% and 41.1%, respectively, with a statistically significant difference (χ2 = 31.226, p < 0.001). The VA visualization status was positively correlated with vestibular and cochlear EH (p < 0.001). The area under the curve for diagnosing MD using combined VA nonvisualization and EH was 0.876, which was significantly higher than that obtained using EH alone (Z = 3.414, p = 0.001).

CONCLUSION

VA visibility on 3D-real IR sequences may assist in the diagnosis of MD and associated EH.

LEVEL OF EVIDENCE: 3

The impact of 3D real-IR delayed post gadolinium MRI parameterisation on the diagnostic performance and optimal descriptor selection in Ménière's disease

OBJECTIVES

To compare the performance and optimal combination of MRI descriptors used for the diagnosis of Ménière's disease (MD) between a real-IR sequence with "zero-point" endolymph (ZPE), and an optimised real-IR sequence with negative signal endolymph (NSE).

MATERIALS AND METHODS

This retrospective single-centre cross-sectional study evaluated delayed post-gadolinium ZPE and NSE real-IR MRI in consecutive patients with Ménièriform symptoms (8/2020-10/2023). Two observers assessed 14 MRI descriptors. "Definite MD" (2015 criteria) and "all MD" ears (wider clinical criteria) were compared to controls. Cohen's kappa and risk ratios (RR) were evaluated for each descriptor. Forward stepwise logistic regression established which combination of descriptors best predicted MD.

RESULTS

The study included 132 patients (57 men; mean age 57.7 ± 13.6), with 87 "all MD" (56 "definite") and 39 control ears. The NSE sequence demonstrated increased perilymph SNR, and improved both diagnostic performance and reliability for 9/14 descriptors. However, ZPE demonstrated superior diagnostic performance for the best descriptor of "saccule absent, large as or confluent with the utricle" (RR 6.571, ZPE; 6.300, NSE) and that of "asymmetric perilymphatic enhancement" (RR 3.628, ZPE; 2.903, NSE). Both sequences combined these two descriptors in the optimal predictive model for "definite MD", with "grade 2 cochlear hydrops" also significant for NSE. ZPE and NSE descriptor combinations both correctly classified 95.8% of ears. The ZPE descriptor combination performed better for "all MD" (ZPE, AUC-ROC 0.914; NSE, AUC-ROC 0.893).

CONCLUSION

Parameter optimisation with NSE Real-IR influenced the optimal selection of MRI descriptors but did not improve their diagnostic performance in definite MD.

KEY POINTS

Question Delayed post-gadolinium ZPE (FLAIR) and NSE (REAL-IR) sequences are widely applied for diagnosing MD, but their relative benefits remain unclear. Findings Optimised NSE sequences improve perilymphatic depiction and influence the selection of the optimal MRI descriptors, but do not improve diagnostic performance. Clinical relevance Radiologists may continue to apply either ZPE or NSE sequences since they offer similar diagnostic abilities, but the choice of the sequence will influence which MRI features should be evaluated to support the diagnosis of MD.

Effect of vestibular rehabilitation treatment (VRT) on patients with unsteadiness after intratympanic gentamicin in Menière's disease: protocol for a randomised controlled trial

INTRODUCTION

Menière's disease (MD) is a multifactorial disease characterised by recurring vertigo, tinnitus and fluctuating sensorineural hearing loss as typical clinical symptoms. For patients with MD with poor response to non-invasive treatments, it is recommended to use intratympanic gentamicin treatment. The destruction of vestibular organs by gentamicin may cause residual vestibular symptoms, notably unsteadiness. However, most previous clinical studies paid little attention to this issue. Currently, vestibular rehabilitation treatment (VRT) has been proven to be an effective method for controlling vestibular symptoms and has been applied to patients with various vestibular diseases. The aim of this study is to investigate the efficacy of VRT versus usual care in MD patients who experience persistent unsteadiness for 1 month after intratympanic gentamicin treatment, in order to understand whether VRT has a positive impact on balance maintenance and vertigo control in patients with MD.

METHODS AND ANALYSIS

Randomised, assessor-blinded, controlled clinical trials will be used to compare the efficacy of balance function before and after VRT. Patients with MD who experience chronic unsteadiness for 1 month after intratympanic gentamicin treatment will be recruited and receive VRT, mainly including gaze stability training, gait rehabilitation, vestibular habituation training, etc. The outcomes assessments will be conducted at baseline and at eighth week and sixth month post-randomisation. The primary outcome will be the improvements in vestibular function quantified through the Functional Gait Assessment. The secondary outcomes will include sensory organisation test, vestibular laboratory tests (video head impulse test, caloric test and vestibular evoked myogenic potentials), Menière's disease outcomes questionnaire, visual vertigo analogue scale and vestibular activities and participation measure.

ETHICS AND DISSEMINATION

This trial received ethical approval from the Institutional Review Board of Eye and ENT Hospital of Fudan University (reference number 2024020). The study results will be disseminated via peer-reviewed journals and conferences.

TRIAL REGISTRATION NUMBER

NCT06143462.

The impact of endolymphatic hydrops on wideband acoustic immittance and otoacoustic emissions in guinea pigs

Background

Inner ear disorders, such as EH, commonly lead to hearing loss and vestibular dysfunction. EH is particularly prevalent in various inner ear diseases, including Meniere's disease. We aimed to evaluate the effects of EH on WAI and OAEs.

Objective

This study explores the potential of wideband acoustic immittance (WAI) and otoacoustic emissions (OAEs) for the early detection of changes in acoustic transmission associated with vasopressin-induced endolymphatic hydrops (EH) in a guinea pig model.

Methods

We induced EH in guinea pigs via daily intraperitoneal injections of arginine vasopressin over 14 consecutive days. Auditory function was assessed using Auditory Brainstem Responses (ABR), while changes in sound energy transmission were measured using WAI and Distortion Products Otoacoustic Emissions (DPOAE).

Results

Increased ABR thresholds in EH models were statistically significant (p < 0.05). After 14 days of EH induction, absorbance at 1 kHz significantly increased, whereas it significantly decreased at 4 kHz and 6 kHz (p < 0.05). DPOAE measures, both magnitude and phase, showed no significant changes (p > 0.05).

Conclusion

WAI demonstrates greater sensitivity than DPOAE in the early detection of acoustic transmission alterations in EH models, suggesting its utility as a diagnostic tool in early-stage inner ear disorders.

Circadian rhythm disruptions exacerbate inner ear damage in a murine endolymphatic hydrops model

Meniere's disease (MD) is an inner ear disease characterized by endolymphatic hydrops (EH). Maintaining a regular daily routine is crucial for MD patients. However, the relationship between circadian rhythms and MD remains unclear. Therefore, we investigated the effect of circadian rhythm on endolymphatic hydrops and its underlying mechanisms. Mice with endolymphatic hydrops were subjected to chronic jet lag (CJL) conditions to simulate the MD patients under circadian rhythm disruptions. We assessed whether this disruption would exacerbate inner ear damage with endolymphatic hydrops. RNA-seq of the inner ear and bioinformatic analysis were performed. Then, the expression of PER2, AQP2, AQP4, AQP5, and BDNF were assessed, and the morphological changes were evaluated in the inner ear. Our findings showed circadian rhythm disruption affected the cochlear internal clock genes in the inner ear, particularly in mice with EH. EH mice under CJL conditions exhibited exacerbated hearing impairment and an increased severity of EH. GO enrichment analysis revealed that the regulation of fluid homeostasis and neurotransmitter release at synapses were significantly enriched. Disruption of circadian rhythms disturbed the expression pattern of PER2, reduced BDNF levels, and affected the expression of aquaporins in the cochlea. Moreover, the disruption of circadian rhythm compromised inner hair cell synapses and auditory nerve fibers. This study indicated that disruption of circadian rhythms may exacerbate inner ear damage in endolymphatic hydrops mice by affecting the aquaporins and compromising synapses and auditory nerves in the inner ear. BDNF and PER2 may play a central role in these pathophysiological processes.

Hearing loss rather than vestibular loss identifies patient subgroups with different outcomes in Meniere's disease

OBJECTIVE

This study investigates the relationship between Meniere's disease (MD) duration and both hearing thresholds and vestibular dysfunction.

DESIGN

Retrospective cohort study. First, the relationships between MD duration and pure-tone audiometry thresholds for each frequency, the canal paresis (CP) ratio, and the vestibulo-ocular reflex (VOR) gain were analysed. Second, clinical characteristics, CP values, and VOR gains were compared between patient groups with low and high hearing thresholds to determine whether they exhibited different clinical presentations.

STUDY SAMPLE

The study included 69 patients diagnosed with unilateral MD within a duration of 10 years. A hearing dataset from 306 MD Spanish patients was used to cluster patients according to the hearing profile overtime.

RESULTS

The thresholds at 250-2000 Hz frequencies increased with the duration of the disease. Conversely, vestibular function tests were not related to the duration of MD. Additionally, no statistically significant differences were observed in clinical characteristics, CP values, or VOR gain between patient groups with low and high hearing thresholds.

CONCLUSIONS

Hearing loss involves all frequencies in most patients and hearing outcome, rather than vestibular loss, may define patient subgroups in MD. Moreover, not all patients with MD experience hearing loss progression as the duration of the disease increases.

Magnetic resonance imaging evaluation of cochlear and vestibular nerve calibre: a case-control study in Ménière's disease and endolymphatic hydrops

PURPOSE

To compare the calibre of the cochlear (CN), superior vestibular (SVN) and inferior vestibular (IVN) nerves on magnetic resonance imaging (MRI), both between Ménière's Disease (MD) ears and clinical controls, and between inner ears with and without endolymphatic hydrops (EH) on MRI.

METHODS

A retrospective case-control study evaluated patients undergoing MRI for suspected hydropic ear disease from 9/2017 to 8/2022. The CN, SVN, IVN and facial nerve (FN) diameters and cross-sectional areas (CSA) were measured on T2-weighted sequences whilst EH was evaluated on delayed post-gadolinium MRI. Absolute nerve calibre (and that relative to the FN) in unilateral definite MD ears (2015 Barany criteria) was compared to that in both asymptomatic contralateral ears and clinical control ears. Nerve calibre in ears with severe cochlear and vestibular EH was compared to ears without EH. t tests or Wilcoxon signed-rank test/Mann-Whitney U test were applied (p < 0.001).

RESULTS

173 patients (mean age 51.3 ± 15.1, 65 men) with 84 MD (62 unilateral) and 62 clinical control ears were studied. Absolute and relative CN dimensions were decreased in both MD ears (CSA and diameter) and the contralateral asymptomatic ears (CSA) when compared to clinical controls (p < 0.001). Absolute nerve dimensions were reduced in both severe vestibular EH (CN, IVN and SVN) and severe cochlear EH (CN) (p < 0.001), however this was not evident when adjusted according to facial nerve calibre.

CONCLUSION

There is decreased absolute CN calibre in both symptomatic and asymptomatic MD ears as well as ears with severe cochlear and vestibular EH on MRI.

Microbial alpha diversity in the intestine negatively correlated with disease duration in patients with Meniere's disease

Ménière's disease (MD) is characterized by loss of balance and hearing disorders. Although there is known to be endolymphatic hydrops involved in the pathological process, the pathogenesis of the disease is still largely unclear. Approximately half of patients with MD suffer from depressive symptoms and high levels of several stress hormones were observed in MD and depression, simultaneously. Recently, gut microbes have been shown to influence the function of the central nervous system in humans through their metabolites. We studied the intestinal microbiota of 10 patients with MD and 11 healthy donors (HD). Significant negative correlations were found between disease duration and alpha diversity indexes of gut microbes in patients with MD. The relative abundance of the species Butyricicoccus ambiguous taxa was increased in patients with MD compared with that of HD. In contrast, Oscillospiraceae UCG-002/UCG-005 ambiguous taxa and Anaerovoracaceae (Eubacterium) brachy group uncultured bacterium were increased in the relative abundance of HD than that of patients with MD. The relative abundance of the Butyricicoccus species was positively correlated with disease duration. Thus, these compositional alterations of gut microbes in patients with MD are associated with inner ear pathologies, such as endolymphatic hydrops, by changing the metabolite profiles in the intestine.

Is endolymphatic hydrops, as detected in MRI, a truly cochleocentric finding?

Introduction

The most common histopathological finding in Ménière's disease (MD) is endolymphatic hydrops (EH), which involves the dilation of the membranous labyrinth. The direct relationship between EH and MD is debated, although EH plays a crucial role in auditory and vestibular functional tests. MRI sequences such as 3D-FLAIR and 3D-real-IR are used to study EH, with the latter being more effective. This study aimed to examine whether the severity of EH detected by MRI is always more pronounced in the cochlea than in the vestibule, indicating a cochleocentric progression of the condition.

Methods

A retrospective longitudinal study was conducted at a tertiary care medical center from 2019 to 2023, involving patients diagnosed with unilateral Ménière's disease. All patients underwent MRI hydrops assessments (3D-REAL-IR sequences) using 3 Tesla magnets and gadobutrol contrast agent. EH was graded qualitatively and quantitatively for both ears using scales for cochlear endolymphatic hydrops (cEH) and vestibular endolymphatic hydrops (vEH). Volumetric measurements of the vestibule and endolymph were performed, and the vestibular endolymphatic ratio (vELR) was calculated. The degree of perilymphatic enhancement (PE) and endolymphatic herniation was also assessed. Patient data, including demographics, disease features, comorbidities, hearing loss, and vestibular function, were collected from medical records. Statistical analysis involved various tests to compare groups and evaluate correlations, using a significance level of p < 0.05. The study aimed to classify the patients into cochleocentric (CC) or non-cochleocentric (NCC) groups based on the difference in the severity of EH in both compartments.

Results

We included 137 patients, of whom 55 (40.15%) were classified as CC, and the remaining 82 (59.85%) were classified as NCC. The degree of vestibular EH (vEH) was more severe in the NCC group (p < 0.001), while cochlear EH (cEH) showed a moderate correlation with vEH. The mean vestibular endolymphatic ratio (vELR) was higher in the NCC group (80.5% ± 38%) compared to the CC group (55% ± 49.5%) (p < 0.0001). Vestibular herniation was more common in the NCC group, while vestibular perilymphatic enhancement was more prevalent in the CC group. Cardiovascular risk was associated with the CC group, while the NCC group reported more vestibular symptoms. Delayed Ménière's disease was linked to the CC group. The hearing loss and vestibular function tests did not show significant differences between the groups.

Discussion

In conclusion, our study found that endolymphatic hydrops (EH) was more severe in the vestibule than in the cochlea in nearly 60% of the cases, with a clinical correlation to the initial symptoms. However, no significant differences were observed in the auditory or vestibular function tests during the follow-up.V Previous studies have indicated that vestibular EH occurs early in Ménière's disease (MD) and subsequently progresses to the cochlea, a finding that challenges the traditional cochleocentric progression theory supported by experimental and clinical otopathology. MRI techniques have enhanced the detection of EH, revealing that the relative amount of endolymph is slightly higher in the vestibule than in the cochlea, thereby supporting the study's findings. We considered the important technical limitations in the MRI visualization of EH and suggested that advanced imaging techniques and volumetric quantification could enhance the classification of cochleocentric and non-cochleocentric groups. The clinical findings revealed that cardiovascular risk factors and delayed MD phenotypes were more common in the cochleocentric group, while the non-cochleocentric group exhibited poorer vestibular MRI results and a higher incidence of endolymph herniation into the semicircular canals.

Prognosis of asymptomatic endolymphatic hydrops in healthy volunteers: A five-year cohort study

Background

This study aimed to clarify the prognosis of asymptomatic endolymphatic hydrops (EH) in healthy volunteers via five-year follow-ups with inner ear magnetic resonance imaging (MRI).

Methods

Inner ear MRI was performed on 115 participants recruited as controls in a previous study on Meniere's disease. The endolymphatic space was visualized using Naganawa's method of contrast-enhanced MRI with intravenous gadolinium injection and evaluated using Nakashima's method of 2D imaging analysis.

Results

Cochlear or vestibular EH was present in 7.0% of participants (n = 8), with all cases being unilateral (laterality), moderate (severity), and asymptomatic (onset). Only cochlear-localized EH, only vestibular-localized EH, and both EH were present in 1.7% (n = 2) (C group), 4.3% (n = 5) (V group), and 0.9% (n = 1) (CV group) of participants, respectively. Conducting inner ear MRI after 5 years showed that EH had almost disappeared in two participants in the C and V groups (4/8, 50.0%). EH was still present in three participants in the V group and one in the CV group (4/8, 50.0%). One participant in the V group and another in the CV group presented with residual inner ear EH and developed typical symptomatic Meniere's disease (2/8, 25.0%).

Conclusions

Approximately 7% of healthy participants showed asymptomatic EH. Therefore, EH is not the definitive marker for making a diagnosis of Meniere's disease or the suitable predictor for the development of Meniere's disease. Among these participants, 25% maintained EH and subsequently developed typical Meniere's disease within the next 5 years. Schellong-positive participants maintained persistent EH in the inner ear, and participants with higher scores on the self-rating depression scale developed Meniere's symptoms after 5 years.

Level of evidence

2a.

Assessing the optimal MRI descriptors to diagnose Ménière's disease and the added value of analysing the vestibular aqueduct

OBJECTIVES

To evaluate the diagnostic performance and reliability of MRI descriptors used for the detection of Ménière's disease (MD) on delayed post-gadolinium MRI. To determine which combination of descriptors should be optimally applied and whether analysis of the vestibular aqueduct (VA) contributes to the diagnosis.

MATERIALS AND METHODS

This retrospective single centre case-control study evaluated delayed post-gadolinium MRI of patients with Ménièriform symptoms examined consecutively between Dec 2017 and March 2023. Two observers evaluated 17 MRI descriptors of MD and quantified perilymphatic enhancement (PLE) in the cochlea. Definite MD ears according to the 2015 Barany Society criteria were compared to control ears. Cohen's kappa and diagnostic odds ratio (DORs) were calculated for each descriptor. Forward stepwise logistic regression determined which combination of MRI descriptors would best predict MD ears, and the area under the receiver operating characteristic curve for this model was measured.

RESULTS

A total of 227 patients (mean age 48.3 ± 14.6, 99 men) with 96 definite MD and 78 control ears were evaluated. The presence of saccular abnormality (absent, as large as or confluent with the utricle) performed best with a DOR of 292.6 (95% confidence interval (CI), 38.305-2235.058). All VA descriptors demonstrated excellent reliability and with DORs of 7.761 (95% CI, 3.517-17.125) to 18.1 (95% CI, 8.445-39.170). Combining these saccular abnormalities with asymmetric cochlear PLE and an incompletely visualised VA correctly classified 90.2% of cases (sensitivity 84.4%, specificity 97.4%, AUC 0.938).

CONCLUSION

Either absent, enlarged or confluent saccules are the best predictors of MD. Incomplete visualisation of the VA adds value to the diagnosis.

CLINICAL RELEVANCE STATEMENT

A number of different MRI descriptors have been proposed for the diagnosis of Ménière's disease, but by establishing the optimally performing MRI features and highlighting new useful descriptors, there is an opportunity to improve the diagnostic performance of Ménière's disease imaging.

KEY POINTS

• A comprehensive range of existing and novel vestibular aqueduct delayed post-gadolinium MRI descriptors were compared for their diagnostic performance in Ménière's disease. • Saccular abnormality (absent, confluent with or larger than the utricle) is a reliable descriptor and is the optimal individual MRI predictor of Ménière's disease. • The presence of this saccule descriptor or asymmetric perilymphatic enhancement and incomplete vestibular aqueduct visualisation will optimise the MRI diagnosis of Ménière's disease.

Comparative analysis of vestibular endolymphatic hydrops grading methods and hearing loss in Ménière's disease: a retrospective MRI study using 3D-real inversion recovery sequence

PURPOSE

To compare the correlation between different grading methods of vestibular endolymphatic hydrops (EH) and the severity of hearing loss in Ménière's disease (MD), and evaluate the diagnostic value of these methods in diagnosing MD.

METHODS

This retrospective study included 30 patients diagnosed with MD from June 2021 to August 2023. All patients underwent inner ear MR gadolinium-enhanced imaging using three-dimensional (3D)-real inversion recovery sequences and pure-tone audiometry. The EH levels were independently evaluated according to the classification methods outlined by Nakashima et al. (Acta Otolaryngol Suppl 5-8, 2009. https://doi.org/10.1080/00016480902729827 ) (M1), Fang et al. (J Laryngol Otol 126:454-459, 2012. https://doi.org/10.1017/S0022215112000060 ) (M2), Barath et al. (Am J Neuroradiol 35:1387-1392, 2014. https://doi.org/10.3174/ajnr.A3856 ), (M3), Liu et al. (Front Surg 9:874971, 2022. https://doi.org/10.3389/fsurg.2022.874971 ), (M4), and Bernaerts et al. (Neuroradiology 61:421-429, 2019. https://doi.org/10.1007/s00234-019-02155-7 ) (M5), with a subsequent comparison of interobserver agreement. After achieving a consensus, an analysis was performed to explore the correlations between vestibular EH grading using different methods, the average hearing thresholds at low-mid, high-, and full frequencies and clinical stages. The diagnostic capabilities of these methods for MD were then compared.

RESULTS

The interobserver consistency of M2-M5 was superior to that of M1. The EH grading based on M4 showed a significant correlation with the average hearing thresholds at low-mid, high-, and full frequencies and clinical stages. M1, M2, M3, and M5 correlated with some parameters. A receiver operating characteristic curve analysis indicated that M5 significantly outperformed M1, M2, M3, and M4 in terms of diagnostic efficiency for MD.

CONCLUSION

M4 showed the strongest correlation with the degree of hearing loss in patients with MD, whereas M5 showed the highest diagnostic performance.

Correlation of endolymphatic hydrops and perilymphatic enhancement with the clinical features of Ménière's disease

OBJECTIVES

To use three-dimensional real inversion recovery (3D-real IR) MRI to investigate correlations between endolymphatic hydrops (EH) grades or the degree of perilymphatic enhancement (PE) and clinical features of Ménière's disease (MD), as previous findings have been inconsistent.

METHODS

A total of 273 consecutive patients with definite unilateral MD were retrospectively enrolled from September 2020 to October 2021. All patients underwent 3D-real IR and 3D-T2WI 6 h after intravenous gadolinium injection. MD-related symptom duration and vertigo frequency were recorded. EH grades were evaluated, the signal intensity ratio (SIR) was measured, and correlations between clinical features and EH, PE were assessed respectively.

RESULTS

The study included 123 males and 150 females, with a mean age of 53.0 years. A longer duration of vertigo was associated with higher cochlear EH grades, whereas the opposite was true for the duration of aural fullness. A longer time since vertigo onset was associated with higher vestibular EH grades; the opposite was true for the duration of individual vertigo attacks. The multiple regression analysis revealed that age, tinnitus duration, and vestibular EH were risk factors for SIR. Furthermore, the low-frequency hearing threshold (HT) was a risk factor for cochlear and vestibular EH, and the SIR.

CONCLUSION

The EH grade and SIR (an indicator for the quantitative evaluation of PE) were correlated with clinical features and HT of MD; thus, imaging can be a valuable tool in planning individualised treatment.

CLINICAL RELEVANCE STATEMENT

This study revealed that the grade of endolymphatic hydrops and degree of perilymphatic enhancement positively correlates with the length of time since onset of clinical symptoms and hearing thresholds in patients with Ménière's disease, facilitating the tailored treatment.

KEY POINTS

• Relationships between 3-dimensional real inversion recovery features and clinical symptoms in Ménière's disease are unknown. • Symptom duration and hearing thresholds correlated with endolymphatic hydrops grades and degree of perilymphatic enhancement. • MRI features correlate with MD severity; thus, imaging is valuable for planning tailored treatment.

New non-contrast MRI of endolymphatic hydrops in Ménière's disease considering inversion time

Objectives

Three-tesla MRI with gadolinium-based contrast agents is important in diagnosing Ménière's disease. However, contrast agents cannot be used in some patients. By using the compositional difference between the inner ear endolymph and perilymph, we performed basic and clinical research focused on potassium ions and protein to find the optimal parameters for visualizing endolymphatic hydrops on MRI without contrast. We then examined the relationship between severity stage and visualization rate of endolymphatic hydrops.

Methods

In phantom experiments simulating the endolymph and perilymph, we explored MRI parameters that could be used to separate endolymph from perilymph by gradually changing the inversion time. We then used these parameters to perform both new non-contrast MRI and contrast MRI on the same day in Ménière's disease patients, and we compared the visualization rates of endolymphatic hydrops under the two modalities. Fifty patients were selected from 478 patients with Ménière's disease of different severity stages; 12 patients had asthma and allergy to contrast agents.

Results

The higher the disease stage, the higher the endolymphatic hydrops visualization rate. The new non-contrast MRI gave significantly higher (p < .01) visualization rates of endolymphatic hydrops on the affected side in patients at Stage 3 or above than in Stages 1 and 2 combined.

Conclusion

New non-contrast MRI with parameters focusing on the endolymph-perilymph difference in the density of protons surrounding the potassium ions and protein can produce images consistent with endolymphatic hydrops. We believe that this groundbreaking method will be useful for diagnosing Ménière's disease in patients.

Evidence Level

Clinical studies are at evidence level 3 in non-randomized controlled trials.

Vestibular function is associated with immune inflammatory response

Association between vestibular function and immune inflammatory response has garnered increasing interest. Immune responses can lead to anatomical or functional alterations of the vestibular system, and inflammatory reactions may impair hearing and balance. Vestibular disorders comprise a variety of conditions, such as vestibular neuritis, benign paroxysmal positional vertigo, Meniere's disease, vestibular migraine, posterior circulation ischemia, and bilateral vestibular disease. Moreover, some patients with autoimmune diseases develop vestibulocochlear symptom. This paper offers an overview of prevalent vestibular diseases and discusses associations between vestibular dysfunction and immune diseases.

Reviewing Kampo medicine (Traditional Japanese Herbal Medicine) for otology/neurotology diseases

Kampo medicine, a traditional Japanese herbal medicine, is used for the treatment of otologic and neurotologic diseases in Japan and other Asian countries. However, only Japanese medical doctors can prescribe both Kampo and modern (Western) medicine. Since a medical doctor can perform not only the diagnosis but also Kampo treatment, it is expected that the quality of clinical studies on traditional herbal medicine is higher in Japan than that in other countries. However, there is no Kampo review written in English language for the treatment of otology/neurotology diseases. Herein, we would like to demonstrate evidence of Kampo treatment for otology/neurotology diseases according to previous studies in Japan.

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.

Tympanostomy tube placement for intractable Meniere's disease in the elderly

BACKGROUND

The treatment of refractory elderly Meniere's disease is a challenge.

AIM

To investigate the efficacy of tympanostomy tube placement in elderly patients with Meniere's disease.

METHODS

31 patients over 60 years old with Meniere's disease who had failed medical treatment and underwent tympanostomy tube placement. Vertigo control, hearing level, tinnitus, and ear fullness were recorded and analyzed preoperatively and postoperatively.

RESULTS

All patients completed a 6-month follow-up. At 6 months postoperatively,complete control, substantial control and limited control of vertigo were achieved in 10 (32%), 13 (42%), and 6 (19%) patients respectively. Two patients (6%) reported no substantial improvement. Twelve patients completed a 2-year follow-up. At 2 years postoperatively, complete control, substantial control and limited control of vertigo were achieved in 3 (25%), 5 (42%), and 1 (8%) patients respectively. Three (25%) patients showed no significant improvement in vertigo. The majority of patients reported significant improvement in the functional level scale, the Dizziness Handicap Inventory scores, and ear fullness at 6 months and 2 years postoperatively.

CONCLUSIONS AND SIGNIFICANCE

Tympanostomy tube placement may reduce vertigo attacks and improved the quality of life in elderly patients with Meniere's disease.

Relationship between stress levels and endolymphatic space volume in Meniere's disease

OBJECTIVES

Since the first report by Hallpike and Yamakawa in 1938, many more patients with Meniere's disease (MD) with endolymphatic hydrops (EHs) have been described. Mental/physical stress and a subsequent increase in the release of the anti-diuretic hormone (ADH) supposedly triggers MD. In the present study, to assess the relationship between stress and EHs, we conducted a series of stress-related questionnaires as well as a 3D endolymphatic space (ELS) analysis in patients with unilateral MD.

METHODS

We enrolled 76 patients with unilateral MD (uMD) as the active group and 75 patients with unilateral benign paroxysmal positional vertigo (uBPPV) as the control group; both underwent examinations between June 2014 and November 2019. All patients underwent 3-T magnetic resonance imaging (MRI) 4 h after intravenous gadolinium injection. We used the total fluid space (TFS), ELS, and ELS rate (ELS/TFS × 100), which is the percentage of the volume of the ELS relative to that of the TFS, for a precise evaluation of the ELS and EHs in MD. Stress was evaluated using the Self-Rating Depression Scale (SDS), the psychological Stress Response Scale (SRS), and the modified Dizziness Handicap Inventory (mDHI). Stress scores and blood ADH levels were compared across patient groups.

RESULTS

In patients with uMD, ELS rates significantly correlated with SRS scores on both the affected and the healthy side and with mDHI scores on the affected side, while the SDS and ADH showed no significant correlation with the ELS rates. Correlations were much stronger in the group with severe SDS and one with low ADH levels.

CONCLUSIONS

The present results indicate that stress may be involved in EHs development in uMD, not only in the ipsilateral but also the contralateral ear. They also suggest that patients with neuropsychiatric tendencies may develop EHs and MD in response to a stressful lifestyle.

Meniere's disease: Pathogenesis, treatments, and emerging approaches for an idiopathic bioenvironmental disorder

Meniere's disease (MD) is a severe inner ear condition known by debilitating symptoms, including spontaneous vertigo, fluctuating and progressive hearing loss, tinnitus, and aural fullness or pressure within the affected ear. Prosper Meniere first described the origins of MD in the 1860s, but its underlying mechanisms remain largely elusive today. Nevertheless, researchers have identified a key histopathological feature called Endolymphatic Hydrops (ELH), which refers to the excessive buildup of endolymph fluid in the membranous labyrinth of the inner ear. The exact root of ELH is not fully understood. Still, it is believed to involve several biological and bioenvironmental etiological factors such as genetics, autoimmunity, infection, trauma, allergy, and new theories, such as saccular otoconia blocking the endolymphatic duct and sac. Regarding treatment, there are no reliable and definitive cures for MD. Most therapies focus on managing symptoms and improving the overall quality of patients' life. To make significant advancements in addressing MD, it is crucial to gain a fundamental understanding of the disease process, laying the groundwork for more effective therapeutic approaches. This paper provides a comprehensive review of the pathophysiology of MD with a focus on old and recent theories. Current treatment strategies and future translational approaches (with low-level evidence but promising results) related to MD are also discussed, including patents, drug delivery, and nanotechnology, that may provide future benefits to patients suffering from MD.

Potential Theranostic Roles of SLC4 Molecules in Human Diseases

The solute carrier family 4 (SLC4) is an important protein responsible for the transport of various ions across the cell membrane and mediating diverse physiological functions, such as the ion transporting function, protein-to-protein interactions, and molecular transduction. The deficiencies in SLC4 molecules may cause multisystem disease involving, particularly, the respiratory system, digestive, urinary, endocrine, hematopoietic, and central nervous systems. Currently, there are no effective strategies to treat these diseases. SLC4 proteins are also found to contribute to tumorigenesis and development, and some of them are regarded as therapeutic targets in quite a few clinical trials. This indicates that SLC4 proteins have potential clinical prospects. In view of their functional characteristics, there is a critical need to review the specific functions of bicarbonate transporters, their related diseases, and the involved pathological mechanisms. We summarize the diseases caused by the mutations in SLC4 family genes and briefly introduce the clinical manifestations of these diseases as well as the current treatment strategies. Additionally, we illustrate their roles in terms of the physiology and pathogenesis that has been currently researched, which might be the future therapeutic and diagnostic targets of diseases and a new direction for drug research and development.

Delayed post gadolinium MRI descriptors for Meniere's disease: a systematic review and meta-analysis

OBJECTIVES

Delayed post-gadolinium magnetic resonance imaging (MRI) detects changes of endolymphatic hydrops (EH) within the inner ear in Meniere's disease (MD). A systematic review with meta-analysis was conducted to summarise the diagnostic performance of MRI descriptors across the range of MD clinical classifications.

MATERIALS AND METHODS

Case-controlled studies documenting the diagnostic performance of MRI descriptors in distinguishing MD ears from asymptomatic ears or ears with other audio-vestibular conditions were identified (MEDLINE, EMBASE, Web of Science, Scopus databases: updated 17/2/2022). Methodological quality was evaluated with Quality Assessment of Diagnostic Accuracy Studies version 2. Results were pooled using a bivariate random-effects model for evaluation of sensitivity, specificity and diagnostic odds ratio (DOR). Meta-regression evaluated sources of heterogeneity, and subgroup analysis for individual clinical classifications was performed.

RESULTS

The meta-analysis included 66 unique studies and 3073 ears with MD (mean age 40.2-67.2 years), evaluating 11 MRI descriptors. The combination of increased perilymphatic enhancement (PLE) and EH (3 studies, 122 MD ears) achieved the highest sensitivity (87% (95% CI: 79.92%)) whilst maintaining high specificity (91% (95% CI: 85.95%)). The diagnostic performance of "high grade cochlear EH" and "any EH" descriptors did not significantly differ between monosymptomatic cochlear MD and the latest reference standard for definite MD (p = 0.3; p = 0.09). Potential sources of bias were case-controlled design, unblinded observers and variable reference standard, whilst differing MRI techniques introduced heterogeneity.

CONCLUSIONS

The combination of increased PLE and EH optimised sensitivity and specificity for MD, whilst some MRI descriptors also performed well in diagnosing monosymptomatic cochlear MD.

KEY POINTS

• A meta-analysis of delayed post-gadolinium magnetic resonance imaging (MRI) for the diagnosis of Meniere's disease is reported for the first time and comprised 66 studies (3073 ears). • Increased enhancement of the perilymphatic space of the inner ear is shown to be a key MRI feature for the diagnosis of Meniere's disease. • MRI diagnosis of Meniere's disease can be usefully applied across a range of clinical classifications including patients with cochlear symptoms alone.

Long-term effects of middle ear pressure therapy with the EFET01 device in patients with Ménière's disease and delayed endolymphatic hydrops in Japan

BACKGROUND

Long-term efficacy of middle ear pressure therapy (MEPT) with the EFET01 device in patients in Japan with definitive Ménière's disease (MD) and delayed endolymphatic hydrops (DEH) was evaluated.

OBJECTIVE

To examine the effects of reducing vertigo attacks and improving hearing of MD and DEH patients by using MEPT with the EFET01 device for two years after treatment.

MATERIAL AND METHODS

A retrospective study was conducted of 32 MD patients and 2 DEH patients treated by MEPT with the EFET01 device from December 2018 to April 2021. According to Japan Society for Equilibrium Research (JSER) guidelines, patients were investigated for the frequency of vertigo attacks and change in hearing levels during a period of 6 months before to 18-24 months after start of treatment.

RESULTS

The frequency of vertigo attacks significantly decreased in both MD and DEH patients, and hearing level has remained stable in the majority of our patients after treatment.

CONCLUSION

Our study clarified that MEPT with the EFET01 device was effective in controlling vertigo symptoms of MD and DEH. It should be considered a safe option for patients failing medical treatment.

SIGNIFICANCE

The efficacy of MEPT with the EFET01 was shown over a 2-year follow-up period.

Improving diagnostic accuracy for probable and definite Ménière's disease using magnetic resonance imaging

PURPOSE

To determine whether magnetic resonance imaging (MRI) can improve diagnostic accuracy for definite and probable Ménière's disease (MD) based on perilymphatic enhancement (PE) and endolymphatic hydrops (EH).

METHODS

363 patients with unilateral MD (probable MD, n = 75 and definite MD, n = 288) were recruited. A three-dimensional zoomed imaging technique with parallel transmission SPACE real inversion recovery was performed 6 h after intravenous gadolinium injection to investigate the presence of PE and to evaluate the grading and location of EH. PE and EH characteristics were analyzed and compared between the probable and definite MD groups.

RESULTS

The cochlear and vestibular EH grading on the affected side was more severe in the definite MD group than that in the probable MD group (P < 0.001). The EH locations within the inner ear on the affected side also differed between the two groups (χ2 = 81.15, P < 0.001). The signal intensity ratio (SIR) on the affected side was significantly higher in the definite MD group than in the probable MD group (t = 2.18, P < 0.05). The assessment of the combination of PE and EH parameters within the inner ear revealed a higher area under the curve (AUC) in the definite MD group (0.82) compared with the AUCs of the parameters assessed alone.

CONCLUSION

The assessment of a combination of PE and EH parameters improved the diagnostic accuracy for probable and definite MD, suggesting that MRI findings may be clinically useful in the diagnosis of MD.

Monitoring pressure changes in the inner ear induced by middle ear pressure therapy with an EFET01 device in guinea pigs

BACKGROUND

As a low-cost, portable, handheld air pressure generation tool not requiring a ventilation tube, the EFET01 device has shown clinical effectiveness for intractable Ménière's disease (MD) patients in Japan. However, no animal studies have investigated changes in inner ear pressure (PI) when applying this device.

OBJECTIVE

To determine the PI properties in response to middle ear pressure therapy (MEPT) induced by the EFET01 in guinea pigs.

MATERIAL AND METHODS

In seven healthy guinea pigs, bi-phasic pressure pulses from -5 to 12 cm H2O were delivered to the external ear canal and transmitted to the middle and inner ear cavities with an intact tympanic membrane. Hydrostatic pressure change in the inner ear perilymphatic compartment was measured by a servo-controlled micropipette system.

RESULTS

From eight successful ears, pressure changes in the middle ear slightly decreased and were instantly transferred to the inner ear. The EFET01 produces a bi-phasic positive/negative pressure pulse, which is approximately twice as large as the monophasic pressure pulse.

CONCLUSION

Our study clarified the EFET01's ability to transmit pressure and verified its effectiveness in MD patients as observed in clinical studies.

SIGNIFICANCE

The PI properties in guinea pig response to MEPT with the EFET01 device were investigated.

Endolymphatic Hydrops on Magnetic Resonance Imaging May Be an Independent Finding on Aging in Neurotologic Patients

OBJECTIVE

To clarify whether age impacts the development of endolymphatic hydrops (ELH) in neurotologic patients. Documentation of ELH in living patients on magnetic resonance imaging (MRI) allows analysis of patient age and formation of ELH, which is impossible by means of postmortem temporal bone pathology.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Fifty patients (100 ears) with top 3 diagnoses of definite Menière's disease, delayed ELH, or probable Menière's disease.

INTERVENTIONS

Endolymph MRI after intravenous gadolinium injection and pure-tone audiometry.

MAIN OUTCOME MEASURES

Cochlear and vestibular ELH confirmed by MRI.

RESULTS

The prevalences of ears showing both cochlear and vestibular ELH were similar among age groups <30 years (30%), 30-59 years (25.9%), and ≥60 years (34.4%; p > 0.05; χ2 test). Using logistic regression modeling, mean hearing level at the six frequencies was positively associated with a higher risk of cochlear ELH (odds ratio, 1.3; 95% confidence interval, 1.1-1.5 per 10-dB increment). In the same regression model, age did not impact the outcome of cochlear ELH (odds ratio, 1.0; 95%confidence interval, 0.7-1.4 per 10-year increment). Age did not differ among ears with no ELH (mean ± standard deviation age, 48.6 ± 14.4 yr), ears with only cochlear ELH (59.3 ± 10.7 yr), ears with only vestibular ELH (50.4 ± 16.9 yr), or ears with both cochlear and vestibular ELH (51.5 ± 18.4 yr; p > 0.05, analysis of variance).

CONCLUSION

Chronological age was not associated with the formation of ELH. Aging per se may not be associated with the development of ELH in neurotologic patients.

A Novel MR Imaging Sequence of 3D-ZOOMit Real Inversion-Recovery Imaging Improves Endolymphatic Hydrops Detection in Patients with Ménière Disease

BACKGROUND AND PURPOSE

The detection rate of premortem MR imaging endolymphatic hydrops is lower than that of postmortem endolymphatic hydrops in Ménière disease, indicating that current MR imaging techniques may underestimate endolymphatic hydrops. Therefore, we prospectively investigated whether a novel high-resolution MR imaging technique, the 3D zoomed imaging technique with parallel transmission real inversion-recovery (3D-ZOOMit real IR), would improve the detection of endolymphatic hydrops compared with conventional 3D TSE inversion-recovery with real reconstruction.

MATERIALS AND METHODS

Fifty patients with definite unilateral Ménière disease were enrolled and underwent 3D-ZOOMit real IR and 3D TSE inversion-recovery with real reconstruction 6 hours after IV gadolinium injection. The endo- and perilymph spaces were scored separately. The contrast-to-noise ratio, SNR, and signal intensity ratio of the 2 sequences were respectively calculated and compared. The presence of endolymphatic hydrops was evaluated.

RESULTS

The endolymphatic space in the cochlea and vestibule was better visualized with 3D-ZOOMit real IR than with conventional 3D TSE inversion-recovery with real reconstruction (P < .001). There were differences between the 2 sequences in the evaluation of no cochlear hydrops and cochlear hydrops (both, P < .017). All contrast-to-noise ratio, SNR, and signal intensity ratio values of 3D-ZOOMit real IR images were statistically higher than those of conventional 3D TSE inversion-recovery with real reconstruction (all, P < .001).

CONCLUSIONS

The 3D-ZOOMit real IR sequences are superior to conventional 3D TSE inversion-recovery with real reconstruction sequences in visualizing the endolymphatic space, detecting endolymphatic hydrops, and discovering contrast permeability.

Vestibular migraine or Meniere's disease: a diagnostic dilemma

Meniere's disease (MD) represents one of the vertigo disorders characterized by triad symptoms (recurrent vertigo, fluctuating hearing loss, tinnitus or ear fullness). The diagnosis of MD relies on the accurate and detailed taking of medical history, and the differentiation between MD and vestibular migraine (VM) is of critical importance from the perspective of the treatment efficacy. VM is a highly prevalent vertigo condition and its typical symptoms (headache, vestibular symptoms, cochlear symptoms) mimic those of MD. Furthermore, the misdiagnosis in MD and VM could lead to VM patients mistakenly receiving the traumatic treatment protocol designed for MD, and sustaining unnecessary damage to the inner ear. Fortunately, thanks to the advances in examination technologies, the barriers to their differentiation are being gradually removed. These advances enhance the diagnostic accuracy of vertigo diseases, especially VM and MD. This review focused on the differentiation of VM and MD, with an attempt to synthesize existing data on the relevant battery of differentiation diagnosis (covering core symptoms, auxiliary tests [audiometry, vestibular tests, endolymphatic hydrops tests]) and longitudinal follow-up. Since the two illnesses are overlapped in all aspects, no single test is sufficiently specific on its own, however, patterns containing all or at least some features boost specificity.

Comparison between audio-vestibular findings and contrast-enhanced MRI of inner ear in patients with unilateral Ménière’s disease

Objective

The diagnosis of Ménière’s disease (MD), characterized by idiopathic endolymphatic hydrops (ELH), remains a clinical priority. Many ancillary methods, including the auditory and vestibular assessments, have been developed to identify ELH. The newly emerging delayed magnetic resonance imaging (MRI) of the inner ear after intratympanic gadolinium (Gd) has been used for identifying ELH in vivo. We aimed to investigate the concordance of audio-vestibular and radiological findings in patients with unilateral MD.

Methods

In this retrospective study, 70 patients with unilateral definite MD underwent three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequences following intratympanic application of Gd. Audio-vestibular evaluations were performed, including pure tone audiometry, electrocochleogram (ECochG), glycerol test, caloric test, cervical and ocular vestibular evoked myogenic potentials (VEMPs), and video head impulse test (vHIT). The relationship between imaging signs of ELH and audio-vestibular results was investigated.

Results

The incidence of radiological ELH was higher than that of neurotological results, including the glycerol test, caloric test, VEMPs, and vHIT. Poor or slight agreement was observed between audio-vestibular findings and radiological ELH in cochlear and/or vestibular (kappa values &lt;0.4). However, the pure tone average (PTA) in the affected side significantly correlated with the extent of both cochlear (r = 0.26795, p = 0.0249) and vestibular (r = 0.2728, p = 0.0223) hydrops. Furthermore, the degree of vestibular hydrops was also positively correlated with course duration (r = 0.2592, p = 0.0303) and glycerol test results (r = 0.3944, p = 0.0061) in the affected side.

Conclusion

In the diagnosis of MD, contrast-enhanced MRI of the inner ear is advantageous in detecting ELH over the conventional audio-vestibular evaluations, which estimates more than hydropic dilation of endolymphatic space.

Evaluation of changes in endolymphatic hydrops volume after medical treatments for Meniere's disease using 3D magnetic resonance imaging

OBJECTIVE

To elucidate the relationship between vertigo and EH volume after medical treatment, we investigated changes in endolymphatic hydrops (EH) volume using inner ear magnetic resonance imaging (ieMRI) in relation to clinical results for vertigo and hearing after administration of the anti-vertiginous medications betahistine, adenosine triphosphate (ATP), isosorbide (ISO), and saireito (SAI) for Meniere's disease (MD).

METHODS

We retrospectively enrolled 202 consecutive patients diagnosed with unilateral MD from 2015 to 2021 and assigned them to four groups: Group I (G-I), symptomatic oral medication with betahistine only (CONT); Group II (G-II), inner ear vasoactive oral medication (ATP); Group III (G-III), osmotic diuretic oral medication (ISO); and Group IV (G-IV), kampo oral medication (SAI). In total, 172 patients completed the planned one-year-follow-up, which included the assessment of vertigo frequency, hearing improvement, and changes in EH using ieMRI (G-I, n=40; G-II, n=42; G-III, n=44; G-IV, n=46). We constructed 3D MRI images semi-automatically and fused the 3D images of the total fluid space (TFS) of the inner ear and endolymphatic space (ELS). After fusing the images, we calculated the volume ratios of the TFS and ELS (ELS ratios).

RESULTS

One year after treatment, vertigo was controlled with zero episodes per month in 57.5% (23/40) of patients in G-I, 78.6% (33/42) in G-II, 81.8% (36/44) in G-III, and 82.6% (38/46) in G-IV (statistical significance: G-I<G-II=G-III=G-IV). Hearing improved by > 10 dB in 5.0% (2/40) of patients in G-I, 16.7% (7/42) in G-II, 18.2% (8/44) in G-III, and 21.7% (10/46) in G-IV (statistical significance: G-I=G-II=G-III=G-IV). ELS ratios were significantly reduced after treatment only in the vestibule for G-II, G-III, and G-IV when compared with G-I. Especially among patients with complete control of vertigo after treatment, ELS ratios were significantly reduced after treatment in the vestibule and total inner ear for G-II; in the cochlea, vestibule, and total inner ear for G-III; and in the cochlea, vestibule, and total inner ear for G-IV compared with G-I. However, there were no significant findings in the relationship between hearing results and changes in ELS ratios.

CONCLUSION

These results indicate that daily administration of anti-vertiginous medications including ATP, ISO, and SAI could be an effective treatment option for patients with MD at an early stage before it becomes intractable. Treatments to reduce EH might offer better control of vertigo rather than improve hearing.

Efficiency of a novel middle ear pressure device for intractable definite Meniere's disease and delayed endolymphatic hydrops after certification by the public health insurance system in Japan

BACKGROUND

Middle ear pressure therapy (MEPT) is effective in treating intractable vertigo in patients with definite Meniere's disease (MD) and delayed endolymphatic hydrops (DEH) refractory to conservative treatment. A novel middle ear pressure device, the EFET01^®, which requires no transtympanic ventilation tubes, was developed in Japan, approved by the Japanese Ministry of Health, Labour and Welfare, and has been used under Japanese national health insurance since September 2018.

OBJECTIVES

To examine short-term therapeutic effect of MEPT using the ETET01^® compared with previous clinical trial results.

METHODS

Patients selected according to Japan Society for Equilibrium Research (JSER) guidelines underwent MEPT using the EFET01 from September 2018 to July 2021, and 44 patients were enrolled in this retrospective study. Clinical data analysed at 4 months after the start of MEPT were compared with those of the previous clinical trial for the EFET01.

RESULTS

MEPT using the EFET01 showed the same therapeutic efficacy as that of the previous clinical trial, i.e. improvement in the intensity and frequency of vertigo with no effect on hearing, even under JSER guidelines for proper use of MEPT.

CONCLUSION

MEPT using the EFET01 provided an effective treatment option for intractable vertigo in patients with definite MD and DEH.

Consensus on MR Imaging of Endolymphatic Hydrops in Patients With Suspected Hydropic Ear Disease (Meniere)

Endolymphatic hydrops (EH) is considered the histological hallmark of Meniere's disease. Visualization of EH has been achieved by special sequences of inner ear magnetic resonance imaging (MRI) with a gadolinium-based contrast agent via intravenous or intratympanic administration. Although it has been applied for more than 10 years since 2007, a unified view on this technique has not yet been achieved. This paper presents an expert consensus on MRI of endolymphatic hydrops in the following aspects: indications and contra-indications for patient selection, methods of contrast-agent administration (intravenous or intratympanic), MRI sequence selection, the specific scanning parameter settings, and standard image evaluation methods and their advantages and disadvantages. For each part of this consensus, a comment is attached to elucidate the reasons for the recommendation.

Clinical application of MIIRMR as a salvage method in gadolinium-enhanced MRI after intra-tympanic injection

BACKGROUND

Three-dimensional fluid-attenuated inversion-recovery (3 D-FLAIR) and real inversion-recovery (3 D-real IR) sequences are used to detect endolymphatic hydrops (EH), but medium inversion-time inversion-recovery imaging with magnitude reconstruction (MIIRMR) may be more sensitive.

AIMS

We investigated the inner-ear visualisation success rate and EH detection rates of 3 D-FLAIR and 3 D-real IR, and whether salvage MIIRMR could improve EH detection.

MATERIALS AND METHODS

Fifty-one patients (102 ears) with episodic or chronic vestibular syndrome were injected intra-tympanically with 8-fold diluted gadolinium, and 3 D-FLAIR and 3 D-real IR images obtained 24-h post-injection. If 3 D-FLAIR inner-ear visualisation failed, additional MIIRMR was performed. The success and EH detection rate increase by MIIRMR was calculated. The diagnostic performance of combined MIIRMR + 3D-FLAIR + 3D-real IR for Meniere's disease (MD) was evaluated.

RESULTS

The success rates of 3 D-FLAIR and 3 D-real IR were 88.90% and 72.55%, respectively. MIIRMR increased the success and EH detection rates by 11.10% and 6.86%, respectively. In MD, MIIRMR increased these rates by 10.53% and 10.53%, respectively. 3 D-FLAIR + 3D-real IR + MIIRMR had 92.11% sensitivity, 79.68% specificity, 72.92% positive-predictive value, and 94.44% negative-predictive value for MD diagnosis.

CONCLUSION AND SIGNIFICANCE

MIIRMR can improve success and EH detection rates when 3 D-FLAIR fails. Combined MIIRMR + 3D-FLAIR + 3D-real IR is more valuable for diagnosing MD than conventional sequences.

Contrast-Enhanced Fluid-Attenuated Inversion Recovery in Neuroimaging: A Narrative Review on Clinical Applications and Technical Advances

While contrast-enhanced fluid-attenuated inversion recovery (FLAIR) has long been regarded as an adjunct sequence to evaluate leptomeningeal disease in addition to contrast-enhanced T1-weighted imaging, it is gradually being used for more diverse pathologies beyond leptomeningeal disease. Contrast-enhanced FLAIR is known to be highly sensitive to low concentrations of gadolinium within the fluid. Accordingly, recent research has suggested the potential utility of contrast-enhanced FLAIR in various kinds of disease, such as Meniere's disease, seizure, stroke, traumatic brain injury, and brain metastasis, in addition to being used for visualizing glymphatic dysfunction. However, its potential applications have been reported sporadically in an unorganized manner. Furthermore, the exact mechanism for its superior sensitivity to low concentrations of gadolinium has not been fully understood. Rapidly developing magnetic resonance technology and unoptimized parameters for FLAIR may challenge its accurate application in clinical practice. This review provides the fundamental mechanism of contrast-enhanced FLAIR, systematically describes its current and potential clinical application, and elaborates on technical considerations for its optimization. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 5.

A systematic quality appraisal of clinical practice guidelines for Ménière's disease using the AGREE II instrument

PURPOSE

To systematically appraise clinical practice guidelines for the diagnosis and treatment of Ménière's disease using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument.

MATERIALS AND METHODS

A systematic literature search was performed to identify guidelines pertaining to the diagnosis and treatment of Ménière's disease. Data were abstracted from guidelines that met inclusion criteria and appraised by four independent reviewers in the six domains of quality defined by the AGREE II. Domain scores reflecting quality in each domain were calculated. Intraclass correlation coefficients (ICC) were calculated across domains to qualify interrater reliability.

RESULTS

Six guidelines were found to meet inclusion criteria after a systematic literature search. Of the six clinical practice guidelines appraised using the AGREE II, the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guideline received the highest average score, with a mean of 90.7% spanning six quality domains. The guideline with the lowest average score across all domains was the European Position Statement on diagnosis and treatment of Ménière's disease, receiving an average score across domains of 34.6%. Overall quality scores of clinical practice guidelines for Ménière's disease had a standard deviation of 21.3%. Two guidelines met the quality threshold of > 60% in at least five domains, qualifying as 'high': AAO-HNS and National Institute for Health and Care Excellence. Average ICC across all six domains was 0.87, suggesting near total agreement between reviewers.

CONCLUSION

Ménière's disease remains a challenging entity to diagnose and treat; few existing clinical guidelines meet the standards of quality established by the AGREE II appraisal instrument.

Effects of transtympanic intermittent pressure therapy using a new tympanic membrane massage device for intractable Meniere's disease and delayed endolymphatic hydrops: a prospective study

BACKGROUND

The retrospective study showed that the effect of the middle ear pressure treatment by the tramstympanic membrane massage (TMM) device was similar to that of the Meniett device.

OBJECTIVES

The new TMM device named EFET device was prospectively evaluated in patients with Meniere's disease (MD) and delayed endolymphatic hydrops (DEH) and we compared the effects to the Meniett device.

MATERIALS AND METHODS

23 ears of 19 patients were treated with an EFET device, and 17 ears of 15 patients were treated with the Meniett device. All patients suffering from intractable MD and DEH were treated for 4 months. The insertion of a transtympanic ventilation tube was necessary for the Meniett device, but not the EFET device.

RESULTS

In patients treated by the EFET and Meniett devices, the frequency of vertigo significantly improved after treatment. The distribution of vertigo outcomes at 4 months after treatment did not differ between patients treated with the both devices.

CONCLUSIONS AND SIGNIFICANCE

Middle ear pressure treatment by the EFET device is effective and provides minimally invasive options for intractable MD and DEH like the Meniett device.

Investigation of endolymphatic hydrops positivity rates in patients with recurrent audiovestibular symptoms using inner ear magnetic resonance imaging

OBJECTIVES

This study aimed to investigate the endolymphatic hydrops (EH)-positivity rates among patients with recurrent audiovestibular symptoms using intravenous injection of gadolinium-enhanced inner ear magnetic resonance imaging (ieMRI).

METHODS

We reviewed 710 successive patients with recurrent audiovestibular symptoms at the Vertigo/Dizziness Center of Nara Medical University and other related hospitals, between May 2014 and April 2020. We performed ieMRI on 153 patients with unilateral recurrent cochleovestibular symptoms (rCV), 51 with recurrent vertigo symptoms (rVO), and 84 with unilateral recurrent cochlear symptoms (rCO).

RESULTS

EH was observed in 69.4% of the participants: 81.7% in the rCV group, 19.6% in the rVO group, and 77.4% in the rCO group. The participants were divided into two groups according to the disease duration: short-duration and long-duration groups. In the short-duration group (less than 4 years), EH was observed in 82.3%, 42.9%, and 71.4% of the patients in rCV, rVO, and rCO groups, respectively; in the long-duration group (more than 5 years), EH was observed in 81.1%, 10.8%, and 81.6% of the patients in rCV, rVO, and rCO groups, respectively.

CONCLUSIONS

The longer the duration of the disease, the larger the EH-positivity rates in patients with rCO, smaller in those with rVO, and unchanged in those with rCV. Although ieMRI could not detect EH with 100% accuracy in Ménière's disease, the present pathological statistics of patients with recurrent audiovestibular symptoms might be helpful in considering the pathology-based treatment strategy.

MR Imaging of Endolymphatic Hydrops in Five Minutes

In this study, we present images acquired by a fast-imaging method for the evaluation of endolymphatic hydrops after intravenous administration of a single dose of gadolinium-based contrast agent. We utilized the hybrid of reversed image of MR cisternography and a positive perilymph signal by heavily T2- weighted 3D-fluid attenuated inversion recovery-multiplied by T2 (HYDROPS2-Mi2) method combined with deep learning reconstruction denoising. The scan time for the fast protocol was approximately 5 mins, which is far shorter than previously reported scan times. The fast acquisition provides similar image quality and less motion artifacts compared to the longer method.