Restriction of salt, alcohol and coffee intake and Ménière's disease: insight from Mendelian randomization study.

Background: Restricting salt, caffeine, and alcohol intake is commonly recommended as a first-line treatment for patients with Ménière's disease (MD). However, it remains unclear whether these interventions effectively improve symptoms of MD. Therefore, we conducted a bidirectional two-sample Mendelian randomization (MR) analysis to evaluate the relationship between these dietary modifications and MD. Methods: Summary statistics for salt added to food, alcohol consumption, coffee consumption, and MD were sourced from the United Kingdom Biobank, GSCAN, and the FinnGen study, involving up to 941,280 participants. The main analyses were performed using the random-effects inverse-variance weighted (IVW) approach and were complemented by four additional methods. Multiple sensitivity analyses were performed to validate the findings, and both forward and reverse MR analyses were employed to address potential reverse causality bias. Results: The primary MR results using the IVW method revealed that salt added to food (OR = 0.719, 95% CI: 0.429-1.206; p = 0.211), alcohol consumption (OR = 0.834, 95% CI: 0.427-1.628; p = 0.595), and coffee consumption (OR = 0.852, 95% CI: 0.555-1.306; p = 0.461) were not significantly correlated with MD. In reverse analysis, no evidence of significant effect was found from MD to salt added to food (OR = 1.000, 95% CI: 0.993-1.007; p = 0.957), alcohol consumption (OR = 0.998, 95% CI: 0.987-1.008; p = 0.682), and coffee consumption (OR = 0.998, 95% CI: 0.985-1.011; p = 0.72). Conclusion: This MR analysis did not identify convincing evidence to support the idea that restricting salt, caffeine, and alcohol intake is beneficial for the treatment of MD.

Evaluating vertebrobasilar insufficiency and Meniere's disease: Insights from cervical vestibular evoked myogenic potential and video head impulse test.

Background and purpose:

This prospective study aimed to investigate diffe-rences in video head impulse test (vHIT) and cervical vestibular evoked myogenic poten-tial (cVEMP) findings between patients with vertebrobasilar insufficiency (VBI) and Meniere’s disease (MD) who experience episodic vertigo attacks.

A total of 27 patients with VBI and 37 patients with MD were enrolled into the study in a tertiary referral center. Inclusion criteria consisted of patients with a minimum of two previous vertigo attacks, unaccompanied by any neurological symptoms during an attack. All patients underwent horizontal canal h-vHIT and c-VEMP assessments following pure sound audiometric examinations. First, vHIT and cVEMP results for low and high flow sides in VBI patients were analyzed. Subsequently, data from the low-flow side in VBI patients and the affected side in MD patients were compared.

The mean vHIT values for low and high-flow volume sides in VBI patients were 0.68 and 0.88, respectively. In MD patients, mean vHIT values for affected and healthy sides were measured as 0.77 and 0.87, respectively. Abnormal results were observed in 66.7% of VBI patients and 51.4% of MD patients, with no statistically significant difference between the findings (p> 0.05). Upon examining the affected side, c-VEMP responses were absent in 41% of MD patients and 48% of VBI patients, with no statistically significant difference between the groups (p> 0.05).

vHIT and cVEMP assessments can be utilized as supplementary tools to radiologic investigations for the clinical diagnosis and follow-up of VBI. However, no significant differences were observed between vHIT and cVEMP findings in patients with MD and VBI.

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.

The relationship between dizziness and sleep: a review of the literature.

Background: The relation between vestibular disorders and (quality of) sleep is underexplored scientifically and the complex interactions between vestibular and sleep disorders are far from being well understood. Some studies have been conducted on the association between patients with vestibular disorders and (the occurrence of) sleep disorders, other studies have been published on the prevalence of dizziness complaints in patients with sleep disorders. The quality of sleep in patients with vestibular disorders generally receives little attention in clinical practice. Objective: To establish what is currently known about the mutual relationship between dizziness and sleep, and to assess whether or not there is evidence of causality with regard to this relationship. Methods: After systematically searching four literature database up until 1 April 2024, selected studies were summarized and evaluated through a (critical) review. Results: Ultimately, 42 studies were selected and evaluated. Patients with dizziness in general and patients with a specific vestibular disorder like Benign Paroxysmal Positional Vertigo, Vestibular Migraine, Meniere's disease, and vestibular hypofunction were significantly more likely to have sleep disorders than control groups. A causal relationship is not supported due to the nature of the studies. In patients with obstructive sleep apnea syndrome there were significantly more vestibular complaints, and more disorders in the vestibular system were identified. Conclusion: Dizziness complaints often co-exist with a sleep disorder. To what extent this sleep disorder influences dizziness is not clear. Paying attention to the quality of sleep in patients with a vestibular disorder seems to be important. In patients with OSAS, consideration should be given to vestibular complaints and dysfunction.

The relationship between endolymphatic hydrops features and hearing loss in Bilateral Meniere's disease.

BACKGROUND: This study aimed to investigate the relationship between the features of endolymphatic hydrops and hearing loss in patients with Bilateral Meniere's Disease. METHODS: A retrospective analysis was conducted on 77 patients diagnosed with Bilateral Meniere's Disease. The features of endolymphatic hydrops in the affected ear were evaluated through gadolinium-enhanced inner ear Magnetic resonance imaging. The Spearman correlation coefficient, paired t-tests, and Wilcoxon signed-rank tests were employed for data analysis. RESULTS: The analysis revealed a significant correlation between the degree of endolymphatic hydrops and hearing loss across all frequencies(0.125-8 kHz), including the cochlear, vestibular, and overall degree of endolymphatic hydrops. The strongest correlation between the overall degree of endolymphatic hydrops and hearing loss was observed at low frequencies (r = 0.571, p < 0.05), followed by mid-frequencies (r = 0.508, p < 0.05), and high-frequencies (r = 0.351, p < 0.05), with a correlation of r = 0.463, p < 0.05 for the staging of Meniere's disease. Affected Ears with endolymphatic hydrops both in the cochlea and vestibule exhibited more severe hearing loss and Meniere's disease staging compared to those with isolated endolymphatic hydrops within the same patient. CONCLUSIONS: The features of endolymphatic hydrops in patients with Bilateral Meniere's Disease were found to correlate with the severity of hearing loss and the staging of Meniere's disease.

Multiomic-based immune response profiling in migraine, vestibular migraine and Meniere's disease.

Migraine (MI) is the most common neurological disease, affecting with 20% of the world population. A subset of 25% of MI patients showcase concurrent vestibular symptoms, which may classify as vestibular migraine (VM). Meniere's disease (MD) is a complex inner ear disorder defined by episodes of vertigo associated with tinnitus and sensorineural hearing loss with a significant autoimmune/autoinflammatory contribution, which symptoms overlap with VM. Blood samples from 18 patients with MI (5), VM (5) and MD (8) and 6 controls were collected and compared in a case-control study. Droplet-isolated nuclei from mononuclear cells used to generate scRNAseq and scATACseq data sets from MI, VM and MD. MI and VM have no differences in their immune transcriptome; therefore, they were considered as a single cluster for further analyses. Natural Killer (NK) cells transcriptomic data support a polarisation triggered by Type 1 innate immune cells via the release of interleukin (IL)-12, IL-15 and IL-18. According to the monocyte scRNAseq data, there were two MD clusters, one inactive and one driven by monocytes. The unique pathways of the MI + VM cluster were cellular responses to metal ions, whereas MD monocyte-driven cluster pathways showed responses to biotic stimuli. MI and MD have different immune responses. These findings support that MI and VM have a Type 1 immune lymphoid cell response, and that there are two clusters of MD patients, one inactive and one Monocyte-driven.

The characteristics of three-dimensional real inversion recovery MRI sequence in delayed Meniere's disease.

BACKGROUND: Delayed Meniere's disease (DMD) is characterized by episodic vertigo occurring after a significant delay following longstanding sensorineural hearing loss. However, its pathogenesis and characteristics remain unclear. OBJECTIVES: To explore the characteristics of endolymphatic hydrops (EH) in DMD and investigate its pathology using MRI. MATERIALS AND METHODS: 17 patients diagnosed with DMD were included in this study. A 3D-real-IR MRI sequence was utilized to visualize and grade EH. The signal intensity of the basal cochlear turn was compared to that of the cerebellar white matter to calculate the CC ratio. A paired t-test was employed to assess the differences in the CC ratio between the affected and unaffected sides in patients with unilateral DMD. RESULTS: EH was present in 100% of cases on the affected side. Unilateral EH was seen in 82.4%, and bilateral EH in 23.5%. Vestibular EH without cochlear involvement occurred in 29.4%, and cochlear EH without vestibular involvement in 5.9%. The CC ratio was significantly higher on the affected side (p < 0.01). CONCLUSIONS AND SIGNIFICANCE: A significant grade of vestibular EH was observed in DMD, with bilateral EH being relatively common. The increased contrast on the affected side may reflect the underlying pathology in DMD patients.

The clinical manifestation and treatment of Meniere's Disease from the viewpoint of the water homeostasis of the inner ear.

Endolymphatic hydrops, a pathological feature of Ménière's disease, has been experimentally and clinically confirmed to be influenced by the blood circulation of vasopressin (VP). VP is a well-known hormonal regulator of water homeostasis. In addition, VP is influenced by various environmental changes, dehydration, fluctuation of atmospheric pressure, pregnancy, and other factors. Furthermore, VP is a key regulator of the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis is a major neuroendocrine system that controls reactions to emotional and physical stresses, as well as the sleep/wake cycle (circadian rhythm). Therefore, VP is susceptible to change via the HPA axis. This review considers possible mechanisms of the formation of endolymphatic hydrops from the perspective of the vasopressin-aquaporin 2 system.

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.

The role of selective serotonin reuptake inhibitors and tricyclic antidepressants in addressing reduction of Meniere's disease burden: A scoping review.

Objective: To assess the effect of selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) in reducing vertigo, tinnitus, and hearing loss among patients with Meniere's disease (MD). Data Sources: The following databases were utilized in this scoping review: Ovid Medline, PubMed-NCBI, CINAHL, Cochrane Library, Web of Science, and Clinicaltrials.gov. Method: Studies were identified through the following search phrases: "serotonin specific reuptake inhibitors" OR "tricyclic antidepressants" AND "Meniere's disease." References from included manuscripts were examined for possible inclusion of additional studies. Results: The literature search yielded 23 results, which were screened by three independent reviewers. Seventeen studies and three duplicates were excluded. An examination of references from the included studies yielded two additional publications. A total of four published studies assessing SSRIs and TCAs among 147 patients with MD were ultimately included. Four studies described significant reductions in vertigo attack frequency among patients treated with either SSRIs or TCAs compared to their pretreatment baseline. Three studies assessed the drugs' effects on hearing, of which none found a significant difference among patients treated with SSRIs or TCAs. One study found a significant decrease in patient-reported tinnitus following treatment with TCAs or SSRIs compared to their pretreatment baseline. Conclusions: Data exploring SSRIs and TCAs among patients with MD suggests that these medications may reduce the frequency of tinnitus and vertigo, although there was significant heterogeneity in outcome reporting. There remains a need for larger-scale prospective studies that emphasize objective data to evaluate their effectiveness in reducing common MD symptoms.

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.

Comparative efficacy of intratympanic gentamicin and intratympanic corticosteroid in the treatment of Meniere's disease: a systematic review and meta-analysis.

Purpose: We aimed to evaluate the efficacy of gentamicin compared to corticosteroids for the treatment of Meniere's disease. Methods: An extensive search was conducted in PubMed, Embase, and Web of Science until May 2024. For continuous outcomes, pooled effect estimates were determined by calculating the weighted mean difference (WMD), while for binary outcomes, the risk ratio (RR) was used, each accompanied by their respective 95% confidence intervals (CIs). Heterogeneity among the studies was assessed using Cochran's I 2 and Q statistics. Results: A total of 12 studies were selected, involving 694 patients. Our analysis found that the gentamicin group demonstrates superior vertigo control rates compared to the corticosteroid group (RR: 1.36, 95% CI: 1.13 to 1.65, p < 0.001). In subgroup analysis, the gentamicin group showed a higher vertigo control rates at 6 months compared to the corticosteroid group (RR: 1.69, 95% CI: 1.28 to 2.24, p < 0.001); however, there was no statistically significant difference between the two groups at 12 months (RR: 1.48, 95% CI: 0.88 to 2.49, p = 0.14). Regarding changes in pure tone average, the corticosteroid group was superior to the gentamicin group (WMD: 4.41, 95% CI: 3.31 to 5.52, p < 0.001). Conclusion: Our study suggests that the intratympanic gentamicin group achieves higher vertigo control rates, whereas the corticosteroid group demonstrates better improvement in pure tone averages. However, the high heterogeneity in vertigo control rates warrants caution. Larger sample-sized randomized controlled trials are needed to further validate these findings.

Neutrophil Extracellular Traps Affect Human Inner Ear Vascular Permeability.

The integrity of the blood-labyrinth barrier (BLB) is essential for inner ear homeostasis, regulating the ionic composition of endolymph and perilymph and preventing harmful substance entry. Endothelial hyperpermeability, central in inflammatory and immune responses, is managed through complex intercellular communication and molecular signaling pathways. Recent studies link BLB permeability dysregulation to auditory pathologies like acoustic trauma, autoimmune inner ear diseases, and presbycusis. Polymorphonuclear granulocytes (PMNs), or neutrophils, significantly modulate vascular permeability, impacting endothelial barrier properties. Neutrophil extracellular traps (NETs) are involved in diseases with autoimmune and autoinflammatory bases. The present study evaluated the impact of NETs on a BLB cellular model using a Transwell® setup. Our findings revealed a concentration-dependent impact of NETs on human inner ear-derived endothelial cells. In particular, endothelial permeability markers increased, as indicated by reduced transepithelial electrical resistance, enhanced dextran permeability, and downregulated junctional gene expression (ZO1, OCL, and CDH5). Changes in cytoskeletal architecture were also observed. These preliminary results pave the way for further research into the potential involvement of NETs in BLB impairment and implications for auditory disorders.

Predictive nomograms and an algorithm for managing patients with probable Meniere's disease.

PURPOSE: To explore the efficacy of diagnostic tests in accurately reclassifying patients initially diagnosed with probable Meniere's disease (MD) into either definite or non-MD categories. MATERIALS AND METHODS: A retrospective cohort study was conducted at a neurotology clinic between 1/2016 and 5/2022. Patients underwent a battery of tests, from which sensitivity, specificity, positive and negative predictive values, as well as positive and negative likelihood ratios, were calculated. Additionally, prediction nomograms were developed. RESULTS: Of the 69 patients, 25 (36.2 %) were initially classified as definite MD, 21 (30.4 %), probable MD, and 23 (33.4 %) non-MD. The mean follow-up was 3.5 years. The sensitivity of electrocochleography (ECochG) was the highest (92 %), with a negative likelihood ratio of 15 %. Magnetic resonance imaging (MRI) with MD-protocol had the highest specificity (100 %), with a positive likelihood ratio of 100 %. Videonystagmography, video head impulse test, and cervical vestibular-evoked myogenic potentials, had lower sensitivity and specificity. We were able to reclassify 18 (86 %) patients with probable MD: 12 (57 %) were diagnosed with definite MD, and 6 (29 %) were diagnosed with non-MD, consistent with their clinical course. CONCLUSIONS: The combination of ECochG and MRI with MD-protocol provides the most reliable approach to reclassify patients with Probable MD, ensuring a precise and accurate diagnosis. Vestibular tests express the functional status of the labyrinth and may not be reliable. Our findings provide valuable insights into clinical decision-making for patients with Probable MD and raise the consideration of additional diagnostic tests as supplementary to the existing clinical-only diagnosis criteria.

Labor market effects of rehabilitation for patients diagnosed with dizziness - a Danish nationwide register-based cohort study.

PURPOSE: Both vestibular neuronitis (VN) and Meniere's disease (MD) have great impact on quality of life and are associated with a significant number of sick leave days absent from work. The aim was to assess labor market participation rate one year after hospital diagnosis of VN and MD and the use of rehabilitation measures. STUDY DESIGN: Nationwide register-based cohort study including patients with VN (n = 1,341) and MD (n = 843) and control persons matched in 1:5 with a VN cohort control (n = 6,683) and MD cohort control (n = 4,209). RESULTS: Compared to control persons, VN patients were more likely to be single, have higher income, and a higher Charlson comorbidity index score. MD patients had a higher level of education and a higher Charlson index compared to control persons. One year after patients were diagnosed with VN, no significant difference in labor market participation was observed (p = 0.88). However, MD patients had a 10.4% reduced probability of possessing a full-time job one year after diagnosis compared to matched control persons (58.1 ± 0.5% vs. 68.5 ± 0.5%, p < 0.001). Both VN and MD patients consulted otorhinolaryngologists, general practitioners, and physiotherapists more than control persons both before and after the initial diagnosis (p < 0.01). In addition, MD patients also consulted psychologists more frequently before and after diagnosis of the disease (p < 0.01). CONCLUSION: Intrahospital diagnosed MD increases the risk of leaving the labor market in opposition to VN. Both MD and VN are associated with significant expenses to the Danish health care system from the use of public rehabilitation measures and medical consultations.

Do measures of gain asymmetry and catch-up saccades improve video head impulse test agreement with caloric results?

Objective: To investigate the relative sensitivity and agreement of caloric testing and video head impulse test (vHIT) across four groups of vestibular disorders. Methods: Caloric and vHIT results of 118 patients with either Ménière's disease, vestibular neuritis/labyrinthitis, vestibular migraine, or vestibular schwannoma were retrospectively analyzed. vHIT gain, gain asymmetry, and catch-up-saccades (≥100°/sec) were compared with reference limits of 91 controls. Results: Abnormal caloric results and vHIT gain were recorded in 57.6 % and 33.1 % of patients, respectively. Consideration of all three measures increased vHIT sensitivity to 43.2 %, and concordance with caloric results improved from 66.1 % to 70.3 %. A significant interaction effect confirmed the relationship between tests depended on the diagnosis (p = 0.013). Vestibular migraine and vestibular neuritis/labyrinthitis produced similar results on both tests, usually normal and abnormal respectively. Vestibular schwannoma produced more caloric abnormalities than vHIT gain but not compared with catch-up-saccades and gain asymmetry; Ménière's disease produced more caloric abnormalities than all vHIT measures. When vHIT was normal (all measures), a 37 % canal paresis was 90 % specific for Ménière's disease. Conclusions: Rates of vHIT catch-up-saccades and gain asymmetry can improve sensitivity and concordance with caloric testing, but this is disease-dependent. Significance: vHIT outcome measures are complementary to the caloric test and each other.

The dissociation between pathological caloric testing and a normal video head impulse test helps differentiate between Menière's disease, vestibular migraine, and other vestibular disorders: a confirmatory study in a large cohort of 2,101 patients.

Vestibular migraine (VM) and Menière's disease (MD) are characterized by episodes of vertigo of similar duration. It is well known that differentiation between both diseases is not always possible based only on the patient history, physical examination, and audiological testing. In addition, the quantification of the vestibular function can also be helpful since, among patients with MD, there is often a dissociation between a normal/pseudo-normal video head impulse test (vHIT) and reduced caloric testing. The goal of this confirmatory study was to determine the sensitivity, specificity, and positive and negative predictive values (PPV and NPV) of this dissociation to differentiate between MD and VM as well as between MD and other vestibular diseases. We performed a retrospective analysis of 2,101 patients. The examination group consisted of 1,100 patients; of these, 627 (57%) had MD according to the diagnostic criteria of the Bárány Society and 473 (43%) had VM. The comparison group consisted of 1,001 patients with other peripheral, central, or functional vestibular disorders. Statistical analysis revealed the following findings for the dissociation: MD vs. VM: specificity: 83.5%, sensitivity: 58.9%, PPV: 82.6%, and NPV: 60.5%, and MD vs. all other vestibular disorders (VM plus others): specificity: 83.5%, sensitivity: 58.9%, PPV: 60.3%, and NPV: 82.7%. The dissociation between a normal vHIT and a reduced caloric response is due to the high specificity and PPV suited for the differentiation between MD and VM. This part of the study confirms previous findings in a large cohort of patients. When it comes to differentiating between MD and all observed vestibular disorders, if there is no dissociation, the diagnosis of MD is unlikely.

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.

Spatial position changes in the semicircular canals may be the anatomical basis of Meniere's disease: a preliminary study based on ultra-high-resolution computed tomography (CT) and intelligent segmentation.

Background: Meniere's disease (MD) is an ear-related vestibular disorder accompanied by vertigo, hearing loss, and tinnitus. The anatomical structure and spatial position of the semicircular canals are important for understanding vestibular function and disease; however, research on MD and the effect of anatomical changes in the semicircular canals is limited. This study explored the relationship between the spatial location of the semicircular canals and MD using ultra-high-resolution computed tomography (U-HRCT) and intelligent segmentation. Methods: Isotropic U-HRCT images obtained from patients with MD and healthy controls (HCs) were retrospectively analyzed. We extracted the semicircular canal structures and extracted their skeleton. The plane of the skeleton of each semicircular canal was fitted separately. The mutual angles between the semicircular canals, and the angles between each semicircular canal and each plane of the coordinate system were measured. Results: Among 45 MD-affected ears (MDAEs), 33 MD-healthy ears (MDHEs), and 45 HC ears, the angle between the superior and lateral semicircular canals (LSCs) and the angle between the superior and posterior semicircular canals (PSCs) were larger in the MDAE and MDHE groups than the HC group (P<0.01), while the angle between the posterior and LSCs was smaller in the MDAE group than the HC group (P<0.001). The angles between the superior and PSCs and coronal plane (CP) of the coordinate system were significantly smaller in the MDAE and MDHE groups than the HC group (P<0.01); however, the angles between the LSC and axial plane and CP were significantly larger in the MDAE and MDHE groups than the HC group (P<0.001). Conclusions: Spatial position changes in the semicircular canals may be the anatomical basis of MD.

Clinical features of persistent postural-perceptual dizziness coexisting with Meniere's disease in comparison with Meniere's disease alone.

Background: Persistent postural-perceptual dizziness (PPPD) is a chronic vestibular syndrome often triggered by acute or episodic vestibular syndromes, such as Meniere's disease (MD). According to the diagnostic criteria, PPPD may coexist with other structural diseases, and the evidence of another active illness does not necessarily exclude PPPD diagnosis. However, persistent symptoms, even those meeting the PPPD criteria even long after Meniere's attack, are often overlooked as potential PPPD precipitated by MD. Some clinicians overlook PPPD in such patients, treating them solely for MD once diagnosed. Since a treatment strategy for PPPD is completely different from that for MD, this may result in the deprivation of adequate treatments. Objectives: To emphasize the importance of diagnosing PPPD coexisting with MD including not treating such patients solely for MD, and to compare the clinical features of PPPD and MD. Methods: Vestibular function tests, including canal paresis (CP)%, c- and o-vestibular myogenic potentials, vestibulo-ocular reflex-direction preponderance, and posturography and clinical symptom scales, including the Dizziness Handicap Inventory, Niigata PPPD Questionnaire, and Hospital Anxiety and Depression Scale, were compared between 105 PPPD patients with MD or other precipitants and 130 patients with MD alone. The clinical symptom scales were further compared between 23 patients with PPPD coexisting with MD and those with MD alone. Results: The CP% was significantly higher in patients with MD than in those with PPPD. However, the total and subscores of all three clinical symptom scales were higher in patients with PPPD than in those with MD. The total score on all clinical symptom scales was higher in patients with PPPD coexisting with MD than in those with MD alone. Conclusion: Persistent postural-perceptual dizziness development from a precipitating MD may be associated with more severe clinical symptoms. Thus, clinical symptom scales may be useful for detecting PPPD in patients with Meniere's disease.