Therapeutic strategies in the treatment of Menière's disease: the Italian experience

Functional Level and Dynamic Posturography Results Two Years after Vestibular Neurectomy in Patients with Severe Meniere's Disease

Objectives: The aim of this study was to evaluate the functional outcomes and balance compensation in patients with severe Meniere's disease after vestibular neurectomy. Methods: Pre- and postoperative results were analyzed in twenty patients with unilateral Meniere's disease before and two years after vestibular neurectomy. Clinical evaluation was performed using a subjective grading scale proposed by the American Academy of Otolaryngology-Head and Neck Surgery and the Dizziness Handicap Inventory. Sensory organization test results were analyzed to assess the balance system before and after the surgery. Results: All patients reported a complete resolution of vertigo attacks after the vestibular neurectomy; 95% of patients reported functional level improvement according to a scale proposed by the American Academy of Otolaryngology-Head and Neck Surgery, and the average score decreased from 4.5 to 1.6. Clinical improvement, evaluated with the Dizziness Handicap Inventory, was present in all patients, with the average result decreasing from 81.7 to 16.4. Analyzing both grading systems, differences between pre- and postoperative results were statistically significant. No statistically significant differences were found between the sensory organization test results before and after vestibular neurectomy. Significant correlations were found between a patient's age and postoperative results of the Dizziness Handicap Inventory and posturography. Conclusions: Vestibular neurectomy is an effective vertigo treatment in patients with severe Meniere's disease with no clinical improvement despite conservative treatment. It results in subjective physical, functional, and emotional improvement, enabling patients to return to daily activities and work. An appropriate qualification of patients and comprehensive preoperative evaluation are essential to obtaining satisfactory clinical outcomes.

Selective Vestibular Neurectomy through the Presigmoid Retrolabyrinthine Approach in the Treatment of Meniere's Disease

BACKGROUND

Meniere's disease (MD) is a disabling disease, especially in patients who are refractory to medical therapy. Moreover, selective vestibular neurectomy (VN), in these selected cases, can be considered a surgical alternative which preserves hearing function and facial nerve.

METHODS

We retrospectively studied 23 patients with MD diagnosis and history of failed extradural endolymphatic sac surgery (ELSS) who underwent combined micro-endoscopic selective VN, between January 2019 and August 2023, via a presigmoid retrolabyrinthine approach. All patients were stratified according to clinical features, assessing preoperative and postoperative hearing levels and quality of life.

RESULTS

At the maximum present follow-up of 2 years, this procedure is characterized by a low rate of complications and about 90% vertigo control after surgery. No definitive facial palsy or hearing loss was described in this series. One patient required reintervention for a CSF fistula. Statistically significant (p = 0.001) difference was found between the preoperative and the postoperative performance in terms of physical, functional, and emotive scales assessed via the DHI questionnaire.

CONCLUSIONS

Selective VN via a presigmoid retrolabyrinthine approach is a safe procedure for intractable vertigo associated with MD, when residual hearing function still exists. The use of the endoscope and intraoperative neuromonitoring guaranteed a precise result, saving the cochlear fibers and facial nerve. The approach for VN is a familiar procedure to the otolaryngologist, as is lateral skull base anatomy to the neurosurgeon; therefore, the best results are obtained with multidisciplinary teamwork.

Blood-Labyrinth Barrier in Health and Diseases: Effect of Hormetic Nutrients

Significance: The stria vascularis, located in the inner ear, consists of three layers, one of which is the blood-labyrinth barrier (BLB). It is formed by endothelial cells, sealed together to prevent the passage of toxic substances from the blood to the inner ear, by pericytes and perivascular-resident macrophage-like melanocyte. Recent Advances: There are various causes that lead to hearing loss, and among these are noise-induced and autoimmune hearing loss, ear disorders related to ototoxic medication, Ménière's disease, and age-related hearing loss. For all of these, major therapeutic interventions include drug-loaded nanoparticles, via intratympanic or intracochlear delivery. Critical Issues: Since many pathologies associated with hearing loss are characterized by a weakening of the BLB, in this review, the molecular mechanisms underlying the response to damage of BLB cellular components have been discussed. In addition, insight into the role of hormetic nutrients against hearing loss pathology is proposed. Future Directions: BLB cellular components of neurovascular cochlear unit play important physiological roles, owing to their impermeable function against all ototoxic substances that can induce damage. Studies are needed to investigate the cross talk occurring between these cellular components to exploit their possible role as novel targets for therapeutic interventions that may unravel future path based on the use of hormetic nutrients. Antioxid. Redox Signal. 40, 542-563.

Systemic pharmacological interventions for Ménière's disease

BACKGROUND

Ménière's disease is a condition that causes recurrent episodes of vertigo, associated with hearing loss and tinnitus. A number of pharmacological interventions have been used in the management of this condition, including betahistine, diuretics, antiviral medications and corticosteroids. The underlying cause of Ménière's disease is unknown, as is the way in which these treatments may work. The efficacy of these different interventions at preventing vertigo attacks, and their associated symptoms, is currently unclear.

OBJECTIVES

To evaluate the benefits and harms of systemic pharmacological interventions versus placebo or no treatment in people with Ménière's disease.

SEARCH METHODS

The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 14 September 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in adults with definite or probable Ménière's disease comparing betahistine, diuretics, antihistamines, antivirals or systemic corticosteroids with either placebo or no treatment. We excluded studies with follow-up of less than three months, or with a cross-over design (unless data from the first phase of the study could be identified).  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were: 1) improvement in vertigo (assessed as a dichotomous outcome - improved or not improved), 2) change in vertigo (assessed as a continuous outcome, with a score on a numerical scale) and 3) serious adverse events. Our secondary outcomes were: 4) disease-specific health-related quality of life, 5) change in hearing, 6) change in tinnitus and 7) other adverse effects. We considered outcomes reported at three time points: 3 to < 6 months, 6 to ≤ 12 months and > 12 months. We used GRADE to assess the certainty of evidence for each outcome.  MAIN RESULTS: We included 10 studies with a total of 848 participants. The studies evaluated the following interventions: betahistine, diuretics, antivirals and corticosteroids. We did not identify any evidence on antihistamines.  Betahistine Seven RCTs (548 participants) addressed this comparison. However, we were unable to conduct any meta-analyses for our primary outcomes as not all outcomes were considered by every study, and studies that did report the same outcome used different time points for follow-up, or assessed the outcome using different methods. Therefore, we were unable to draw meaningful conclusions from the numerical results. Some data were available for each of our primary outcomes, but the evidence was low- or very low-certainty throughout. One study reported on the outcome 'improvement in vertigo' at 6 to ≤ 12 months, and another study reported this outcome at > 12 months. Four studies reported on the change in vertigo, but again all used different methods of assessment (vertigo frequency, or a global score of vertigo severity) or different time points. A single study reported on serious adverse events.  Diuretics Two RCTs addressed this comparison. One considered the use of isosorbide (220 participants), and the other used a combination of amiloride hydrochloride and hydrochlorothiazide (80 participants). Again, we were unable to conduct any meta-analyses for our primary outcomes, as only one study reported on the outcome 'improvement in vertigo' (at 6 to ≤ 12 months), one study reported on change in vertigo (at 3 to < 6 months) and neither study assessed serious adverse events. Therefore, we were unable to draw meaningful conclusions from the numerical results. The evidence was all very low-certainty.  Other pharmacological interventions We also identified one study that assessed antivirals (24 participants), and one study that assessed corticosteroids (16 participants). The evidence for these interventions was all very low-certainty. Again, serious adverse events were not considered by either study.

AUTHORS' CONCLUSIONS

The evidence for systemic pharmacological interventions for Ménière's disease is very uncertain. There are few RCTs that compare these interventions to placebo or no treatment, and the evidence that is currently available from these studies is of low or very low certainty. This means that we have very low confidence that the effects reported are accurate estimates of the true effect of these interventions. Consensus on the appropriate outcomes to measure in studies of Ménière's disease is needed (i.e. a core outcome set) in order to guide future studies in this area and enable meta-analyses of the results. This must include appropriate consideration of the potential harms of treatment, as well as the benefits.

The Effect of Endolymphatic Hydrops and Mannitol Dehydration Treatment on Guinea Pigs

Background

Endolymphatic hydrops (EH) is considered as the pathological correlate of Menière’s disease (MD) and cause of hearing loss. The mechanism of EH, remaining unrevealed, poses challenges for formalized clinical trials.

Objective

This study aims to investigate the development of hearing loss, as well as the effect of dehydration treatment on EH animal models.

Methods

In this study, different severity EH animal models were created. The laser Doppler vibrometer (LDV) and auditory brainstem responses (ABR) were used to study the effects of EH and the dehydration effects of mannitol. The LDV was used to measure the vibration of the round window membrane (RWM) reflecting the changes in inner ear impedance. ABR was used to evaluate the hearing changes. Furthermore, tissue section and scanning electron microscopy (SEM) observations were used to analyze the anatomical change to the cochlea and outer hair cells.

Results

The RWM vibrations decreased with the severity of EH, indicating an increase in the cochlear impedance. The dehydration therapy lowered the impedance to restore acoustic transduction in EH 10- and 20-day animal models. Simultaneously, the ABR thresholds increased in EH models and were restored after dehydration. Moreover, a difference in the hearing was found between ABR and LDV results in severe EH animal models, and the dehydration therapy was less effective, indicating a sensorineural hearing loss (SNHL).

Conclusion

Endolymphatic hydrops causes hearing loss by increasing the cochlear impedance in all tested groups, and mannitol dehydration is an effective therapy to restore hearing. However, SNHL occurs for the EH 30-day animal models, limiting the effectiveness of dehydration. Our results suggest the use of dehydrating agents in the early stage of EH.

Pharmacological, surgical and diagnostic innovations in Meniere's disease: a review

Meniere's disease is an inner ear disorder characterized by the presence of endolymphatic hydrops in the inner ear and symptomatology of recurrent and debilitating vertigo attacks, tinnitus, aural fullness, and fluctuating sensorineural hearing loss. Although many therapeutic options for MD have been proposed during years, no consensus has been reached by the scientific community. In the last decade, many therapeutic options have been proposed, as intratympanic steroid, intratympanic gentamicin, and intravenous glycerol. Recently, the role of the antisecretory factor in the diet of MD patients have been investigated. Surgery is recommended for intractable MD; some authors proposed new approaches including transcanal endoscopic infracochlear vestibular neurectomy, new marsupiliazation technique in sac surgery, and tenotomy of the stapedius and tensor tympani muscles.