Saccular otoconia as a cause of Ménière's disease: hypothesis based on two theories

Clinical features of secondary BPPV: A nation-wide multicenter study

BackgroundBenign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disorder, and its prevalence is substantial. While primary BPPV has been well studied, the understanding of secondary BPPV is still limited.ObjectiveTo investigate the prevalence and clinical characteristics of secondary BPPV in a national multicenter retrospective analysis.MethodsThe study involved a retrospective analysis of medical records from 17 institutions across South Korea, between January and June 2022. We evaluated clinical features, presumed etiologies, involvement of semicircular canals, response to canalith repositioning procedures (CRPs), presence of residual dizziness, recurrence, and results of auditory and vestibular function tests for both primary and secondary BPPV cases.ResultsOf the total 1363 BPPV cases, 14.5% (198 patients) were categorized as secondary BPPV. The most prevalent etiology for secondary BPPV was head trauma. Secondary BPPV was associated with a higher prevalence of comorbidities including diabetes and inner ear diseases. Patients with secondary BPPV demonstrated more frequent involvement of multiple semicircular canals, necessitated a greater number of CRPs for resolution, and experienced a higher incidence of residual dizziness compared to primary BPPV cases. Furthermore, secondary BPPV patients exhibited more frequent abnormalities in auditory and vestibular function tests.ConclusionsSecondary BPPV accounts for a significant proportion of BPPV cases, with distinct clinical characteristics compared to primary BPPV.

[Meniere's disease and vestibular migraine: differential diagnostics and treatment]

The article contains main information concerning Meniere's disease and vestibular migraine - two the most similar in clinical manifestations cochleovestibulopathies. It also examines the differences between them in the relation of audiological and vestibular manifestations, reflects the auditory and vestibular function according to the results of instrumental examination, in order to facilitate the differential diagnostics between the two disorders. Possible options and tactics for treating Meniere's disease and vestibular migraine are highlighted.

A review of Meniere's disease - reflection of published MRI, ECochG and newer otoconial theory from Aotearoa New Zealand

Vertigo, or the symptom of an hallucination of motion, is usually caused by disorders of the inner ear. Buried in the bone of the otic capsule, the inner ear is the most difficult human sensory organ to image and investigate. As an inner ear disorder, Meniere's disease (MD) is characterised as recurrent vertiginous attacks, fluctuating hearing loss which can be progressive, tinnitus and aural fullness. Post-mortem studies, and now MRI inner ear imaging, show an excess of endolymph or endolymphatic hydrops (ELH) which has been assumed to usually commence in the cochlea. However, the cause of the initial hydrops is still debated. This paper reflects on the research published in Ōtautahi Christchurch, Aotearoa New Zealand. There is evidence from post-mortem studies, electrophysiological test, and some inner ear imaging that endolymphatic obstruction from clumps of detached saccular otoconia may be a cause of MD.

Abnormal Rhomboid Lip and Choroid Plexus Should be Valued in Microvascular Decompression for Vestibulocochlear Diseases

BACKGROUND

Surgical outcomes for functional vestibulocochlear diseases vary, and the influencing factors are not fully understood. The role of a rhomboid lip (RL) and choroid plexus (CP) in microvascular decompression (MVD) of the vestibulocochlear nerve has not been studied. This study aims to evaluate the surgical efficacy of MVD for vestibulocochlear diseases, with and without addressing the RL and CP, to enhance our understanding of their etiology.

METHODS

A total of 15 patients who underwent MVD for the vestibulocochlear nerve between 2013 and 2022 were retrospectively identified and followed up. The patients were classified into 4 categories: vestibular paroxysmia (VP), benign positional paroxysmal vertigo (BPPV), and Meniere disease (MD). The fourth was a "tinnitus" group. The relief of symptoms, recurrence, satisfaction after surgery, available relevant imaging studies, and intraoperative observation data were evaluated.

RESULTS

Following MVD, 6 of the 7 patients in the VP group, the 1 patient in the BPPV group, and 1 of 2 patients in the MD group were completely relieved of vertigo. The seventh VP patient showed significant improvement. The 5 patients in the "tinnitus" group remained unchanged. Retrospectively, 4 patients from the VP, BPPV, and MD groups who underwent RL incision and CP excision were also free of vertigo, although vascular compression was not confirmed in these cases.

CONCLUSIONS

MVD is generally considered a useful treatment for VP and could also be effective in managing recurrent vertigo caused by BPPV and MD. Our results highlight the potential role of an abnormal RL and CP in the development of vertigo symptoms. Patients presenting with "tinnitus" require further investigation and might not be suitable for MVD.

Normal Serum Levels of Otolin-1 in Patients with Meniere Disease in Remission

Introduction  Degenerative changes in the otolithic organs have been theorized to be caused by the mechanical obstruction to endolymphatic flow, possibly resulting in endolymphatic hydrops (ELH). Otolin-1 is an otoconial matrix protein that crosses the blood labyrinth barrier and has been found in the serum of healthy and diseased patients. Objective  To measure the serum levels of Otolin-1 in Meniere disease (MD) patients and compared them with the healthy individuals. Methods  This pilot, cross-sectional study was performed at our tertiary care referral center to compare the serum Otolin-1 levels of healthy individuals with those of MD patients. The blood samples were obtained during patients' visit to the vertigo clinic following remission of an acute episode. The data was analyzed using the Stata/SE version 12.0 (StataCorp. College Station, TX, USA). Comparison between the serum Otolin-1 levels in the two groups was performed using the unpaired t -test. A p -value of 0.05 was considered to be statistically significant. Results  The participants were divided into two groups, with 31 MD patients, and 30 age and gender-matched members of the control group. The serum levels of Otolin-1 in MD patients (247.6, ± 44.2 pg/ml) were not found to be significantly different from those of the control group (236.2, ± 43.5 pg/ml) ( p  = 0.31). Conclusion  The current study reveals that the serum levels of Otolin-1 are not significantly different between the patients with MD in the interictal phase and the control group's healthy ones.

Association between Osteoporosis and Meniere's Disease: Two Longitudinal Follow-Up Cohort Studies

A high rate of Meniere's disease (MD) in patients with osteoporosis has been suggested. This research intended to estimate the bidirectional association of MD with osteoporosis. The ≥40-year-old population in the Korean National Health Insurance Service-Health Screening Cohort 2002-2019 was examined. In study I, 9529 patients with MD and 38,116 control I participants were analyzed for a previous history of osteoporosis. In study II, 65,858 patients with osteoporosis and 65,858 control II participants were analyzed for a previous history of MD. Stratified Cox proportional hazard models were applied to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) of MD for osteoporosis in study I and of osteoporosis for MD in study II. The rate of a prior history of osteoporosis was 13.3% for the MD group and 11.3% for the control I group. The patients with MD had a 1.12 times higher HR for previous osteoporosis (95% CI = 1.04-1.20). In study II, the rate or a prior history of MD was 3.7% for patients with osteoporosis and 2.0% for the control II group. The patients with osteoporosis had a 1.50 times higher HR for previous MD (95% CI = 1.40-1.61). Most subgroups according to age, sex, and comorbid conditions demonstrated consistent bidirectional associations between MD and osteoporosis. Adult patients with MD had a greater risk of osteoporosis. In addition, adult patients with osteoporosis also showed a higher risk of MD.

Prevalence of Endolymphatic Hydrops in Cochlear Implant Candidates with Idiopathic Profound Sensorineural Hearing Loss

OBJECTIVE

To determine the prevalence of endolymphatic hydrops (EH) in cochlear implant (CI) candidates with idiopathic profound sensorineural hearing loss (SNHL) and its influence on the preservation of audiovestibular function after cochlear implantation.

STUDY DESIGN

Prospective case series.

SETTING

Tertiary referral center.

PATIENTS

CI candidates with idiopathic progressive SNHL, but without classic EH-associated symptoms.

INTERVENTIONS

Delayed intravenous gadolinium-enhanced inner ear fluid-attenuated inversion recovery magnetic resonance imaging as well as pure-tone audiograms, video head impulse tests, and vestibular evoked myogenic potentials before and 4 weeks after cochlear implantation.

MAIN OUTCOME MEASURES

Prevalence of EH before cochlear implantation, audiovestibular function before and after surgery in hydropic and nonhydropic ears.

RESULTS

Thirty-two ears in 16 CI candidates were included. Nine ears (28%) with EH were detected. Although preoperative hearing thresholds, utricular function, and semicircular canal function were not different between the two groups, saccular function was reduced in hydropic ears. Ten subjects received a unilateral CI. Of these, 3 (30%) showed EH on the implanted side. There was no difference regarding postoperative hearing loss between the two groups, but the results point toward a higher vulnerability of hydropic ears with respect to loss of otolith function after cochlear implantation.

CONCLUSIONS

This is the first study showing that EH can be assumed in about one third of CI candidates with idiopathic profound SNHL, but no classic EH-associated symptoms. Preliminary results suggest that EH has no influence on the preservation of cochlear function but could be a risk factor for loss of otolith function after cochlear implantation.

Magnetic resonance imaging of the endolymphatic space in patients with benign paroxysmal positional vertigo: volume ratio and distribution rate of the endolymphatic space

BACKGROUND

Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disease. It is characterised by sudden onset short lived vertigo triggered by sudden changes in head position relative to gravity.

AIMS/OBJECTIVES

We aimed to perform a quantitative volumetric analysis of the inner ear endolymphatic space in patients with BPPV.

MATERIAL AND METHODS

This study included 67 patients with BPPV and 50 control subjects (CS). The endolymphatic space/total fluid space volume ratio (%) and the distribution rate of the inner ear components in the endolymphatic space (%) were measured using three-dimensional magnetic resonance imaging.

RESULTS

Differences in the endolymphatic space/total fluid space volume ratio of the inner ear, cochlea, vestibule, and semi-circular canals (SCCs) between the CS and BPPV groups were not significant. The endolymphatic space distribution rate of the vestibule in the BPPV group was significantly lower than that in the CS group, and the endolymphatic space distribution rate of SCCs in the BPPV group was significantly higher than that in the CS group.

CONCLUSIONS AND SIGNIFICANCE

Extended endolymphatic space in patients with BPPV did not exist. The otoconia released from the damaged utricles were considered to move with the endolymphatic flow toward SCCs.

Magnetic resonance imaging of endolymphatic hydrops in patients with unilateral Meniere's disease: volume ratio and distribution rate of the endolymphatic space

BACKGROUND

Endolymphatic hydrops (ELH), which is a pathological feature of Meniere's disease (MD), is characterized by an extended endolymphatic space (ELS).

AIMS/OBJECTIVES

We aimed to perform a quantitative volumetric analysis of inner-ear ELH in patients with unilateral MD (uMD).

MATERIAL AND METHODS

This study included 97 patients with definite uMD and 49 control subjects (CS). The ELS/total fluid space (TFS) volume ratio (%) and the distribution rate of the inner-ear components in the ELS (%) were measured using 3D magnetic resonance imaging and compared between patients with uMD and CS.

RESULTS

Compared to CS, patients with uMD had significantly higher mean ELS/TFS volume ratios for inner-ear components. The mean distribution rate of the inner-ear components in the ELS was not significantly different between the two groups.

CONCLUSIONS AND SIGNIFICANCE

In patients with uMD, ELH was noted to be spread throughout the entire inner ear and the endolymph was evenly distributed in the total ELS. These findings should be useful as a standard reference for further research.

Ductus Reuniens and Its Possible Role in Menière's Disease

OBJECTIVE

After 160 years the true underlying cause of Meniere's disease remains enigmatic. The aim of our study is to discuss the possible implication of an obstruction of the ductus reuniens as a cause in Menière's disease.

METHODOLOGY

We first conducted an historical study of the description of the ductus reuniens. We then reviewed the literature regarding ductus reuniens obstruction in animal experiments, human post-mortem studies and living ear imaging. We completed its description by modern microCT imaging. Limited knowledge on the fate of dislodged saccular otoconia is summarized. The possible implications for Meniere's attacks are discussed.

RESULTS

Victor Hensen was the first to describe the ductus reuniens in 1863. He described its length and width and predicted that saccular otoconia might enter the ductus and the cochlea. On microCT the narrowest width of the human ductus reuniens was 0.14 mm. The literature reports cochlear endolymphatic hydrops occurring after animal experimental obstruction of the duct. Human postmortem studies have confirmed saccular otoconial clumps entering the ductus and the cochlea. A postmortem study has shown sites of endolymphatic obstruction, and imaging speculates on blockages in ears with Meniere's disease. Dislodged utricular otoconia can be in clumps of otolithic membranes.

CONCLUSION

Blockages of the ductus reuniens and at other endolymphatic system sites appear to be a feature in Meniere's disease ears. The blockages have been postulated to be saccular otoconia either causing or aggravating hydrops. This could be consistent with observed nystagmus reversals during attacks as the endolymphatic sac attempts to clear the hydrops and the otoconia.

Three-dimensional visualization of the human membranous labyrinth: The membrana limitans and its role in vestibular form

The inner ear contains the end organs for balance (vestibular labyrinth) and hearing (cochlea). The vestibular labyrinth is comprised of the semicircular canals (detecting angular acceleration) and otolith organs (utricle and saccule, which detect linear acceleration and head tilt relative to gravity). Lying just inferior to the utricle is the membranous membrana limitans (ML). Acting as a keystone to vestibular geometry, the ML provides support for the utricular macula and acts as a structural boundary between the superior (pars superior) and inferior (pars inferior) portions of the vestibular labyrinth. Given its importance in vestibular form, understanding ML morphology is valuable in establishing the spatial organization of other vestibular structures, particularly the utricular macula. Knowledge of the 3D structure and variation of the ML, however, remain elusive. Our study addresses this knowledge gap by visualizing, in 3D, the ML and surrounding structures using micro-CT data. By doing so, we attempt to clarify: (a) the variation of ML shape; (b) the reliability of ML attachment sites; and (c) the spatial relationship of the ML to the stapes footplate using landmark-based Generalized Procrustes, Principal Component and covariance analyses. Results indicate a consistent configuration of three distinct bony ML attachments including an anterolateral, medial, and posterior attachment which all covary with bony structure. Our results set the stage for further understanding into vestibular and more specifically, utricular macula spatial configuration within the human head, offering the potential to aid in clinical and evolutionary studies which rely on a 3D understanding of vestibular spatial configuration.

Benign paroxysmal positional vertigo in Meniere's disease: systematic review and meta-analysis of frequency and clinical characteristics

There is a recognized association of Meniere's disease (MD) and benign paroxysmal positional vertigo (BPPV). However, the frequency and clinical characteristics of BPPV in MD are unclear. The aim of this review was to determine the mean frequency and clinical features of BPPV in MD. Three databases were searched: MEDLINE, PubMed and Google Academia. Studies reporting the frequency of BPPV in MD were pooled. A total of 4198 references were identified, of which 20 studies were considered eligible. The pooled frequency of BPPV in MD was 14% (95% CI 9-18%). It was 38% (95% CI 26-49%) in longitudinal studies and 8% (95% CI 6-11%) in cross-sectional ones. BPPV comorbid with MD was mostly observed in the ear affected by hydrops, in females, in patients with more advanced disease. Canalolithiasis of the horizontal semicircular canal was more common in patients with BPPV associated with MD than in idiopathic BPPV. BPPV in MD was more prone to recurrence and required more canal repositioning maneuvers.

Association Between Serum Vitamin D Level and Ménière's Disease

OBJECTIVES

Ménière's disease (MD) is a well-known inner ear disease; however, the etiopathogenesis is unknown. Several factors may be involved. Meanwhile, vitamin D is reported to have an important role in inner ear physiology. The aim of this study is to evaluate the relation between vitamin D deficiency and MD.

STUDY DESIGN

This matched case-control study compared serum vitamin D levels between patients with definite MD and those without it.

SETTING

The study was done between August 2018 and December 2019 at Ghaem University Hospital in Mashhad, Iran.

METHODS

Twenty-eight patients with definite MD were matched with a group of 84 healthy individuals, regarding age, sex, body mass index, and occupation (indoor vs outdoor). The serum level of vitamin D (25-hydroxyvitamin D3) was measured in both groups.

RESULTS

The mean ± SD vitamin D level was 18.9 ± 9.7 ng/mL in the case group and 25.2 ± 13.7 ng/mL in the control group (P = .027). There was a significant difference between the case and control groups according to the results of the conditional logistic regression model (P = .03; adjusted odds ratio, 0.96). In the MD group, 17 (60.7%) patients were vitamin D deficient, 6 (21.4%) insufficient, and only 5 (17.9%) sufficient.

CONCLUSIONS

The results of this study show that serum vitamin D level in MD is significantly lower than that of the control group. However, the role of vitamin D supplementation in the management of MD needs further study.

LEVEL OF EVIDENCE

4.

Intratympanic Steroid for Menière's Disease: A Systematic Review

OBJECTIVES

To investigate the beneficial effects and safety of intratympanic steroid installation compared with placebo in patients with Menière's disease.

METHODS

We performed a systematic literature search in MEDLINE and EMBASE for existing systematic reviews and individual randomized controlled trials (RCTs). Studies were included if they investigated the usage intratympanic steroids in patients aged 18 and above, with definite or probable Menière's disease. The quality of the identified existing reviews was assessed using the AMSTAR tool. The risk of bias in RCTs was assessed using the Cochrane Risk of Bias Tool and overall quality of the individual outcomes was evaluated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method.

RESULTS

The literature search provided four systematic reviews, from which one yielded a sufficient AMSTAR evaluation and subsequently provided three RCTs relevant for inclusion. Due to the lack of sufficient reporting of the data, quantitative synthesis was not applicable. In the qualitative synthesis for the primary outcome, the results from the RCTs showed that there was a slight indication of steroid treatment reducing the frequency of vertiginous attacks. No serious adverse events were reported. Based on the GRADE approach the quality for both findings is very low. No studies reported on the secondary outcomes.

CONCLUSION

The effect of intratympanic steroid treatment in Menière's disease is questionable. There is a great need for further research to sufficiently assess whether steroid treatment may be considered as a safe and effective treatment for patients with Menière's disease.

PET Visualized Stimulation of the Vestibular Organ in Menière's Disease

Introduction: The cortical metabolic activity in patients with Menière's disease has not been investigated. The aim of this study was to investigate the ¹⁸F-FDG cerebral uptake in Menière's patients compared to healthy controls. Method: Eight patients with right-sided Menière's disease and fourteen healthy controls underwent a video head impulse test (vHIT), test of utricular function with ocular vestibular evoked myogenic potentials (oVEMP) and three ¹⁸F-FDG-based PET examinations of the brain. Participants were seated in a self-propelled chair, injected with ¹⁸F-FDG and then exposed to 35 min of chair motion stimulation, followed by a PET scan. Two types of natural vestibular stimuli were applied, predominantly toward the right horizontal semicircular canal (angular acceleration) and right utriculus (linear acceleration). For baseline scans, participants were injected with ¹⁸F-FDG while seated without movement. Results: Analyses of baseline scans revealed decreased ¹⁸F-FDG-uptake in the medial part of Heschl's gyrus in the left hemisphere in patients with Menière's disease compared to healthy controls. During angular vestibular stimulation there was also a significantly decreased ¹⁸F-FDG uptake in the intersection between the medial part of Heschl's gyrus and the parietal operculum in the left hemisphere and bilaterally in the posterior part of insula. During linear stimulation, Menière's patients showed decreased ¹⁸F-FDG uptake in the medial part of Heschl's gyrus in the right hemisphere and also bilaterally in the posterior insula. In addition, decreased ¹⁸F-FDG uptake was seen in the thalamus during vestibular stimulation. Conclusion: Heschl's gyrus, the posterior part of insula, and thalamus have previously been shown to be core areas for processing vestibular inputs. Patients with Menière's disease solely differed from the healthy controls with lower cortical activity in these areas at baseline and during natural vestibular stimulation.

Simultaneous Presentation of Benign Paroxysmal Positional Vertigo and Meniere's Disease - Case Report

BACKGROUND

Benign paroxysmal positional vertigo (BPPV) is one of the most common clinical entities, which develops spontaneously in most of the cases, but it can be secondary as a result of different conditions such as head injuries, viral neurolabyrinthitis, Meniere's disease and vertebrobasilar ischemia. The aim of presenting this case is to point out to the need of taking a precise clinical history and performing Dix-Hallpike manoeuvre in all patients who complain about vertigo regardless of the previously diagnosed primary disease of the inner ear.

CASE PRESENTATION

A 63-year-old female patient presented with the classical triad of symptoms for Meniere's disease (fluctuating sensorineural hearing loss in the right ear, tinnitus and fullness in the same ear and rotary vertigo), two years later complained of brief episodes of vertigo linked to changes in head position relative to gravity. Dix-Hallpike manoeuvre showed a classical response in the head-hanging right position. Benign paroxysmal positional vertigo (BPPV) in the same ear was diagnosed in this patient. After treatment with Epley's canal repositioning manoeuvre for a few days, the symptoms of positional vertigo resolved.

CONCLUSION

The authors recommend complete audiological and otoneurological evaluation in all patients with vertigo for timely recognition/diagnosis of any inner ear associated pathology.