Examination of betahistine bioavailability in combination with the monoamine oxidase B inhibitor, selegiline, in humans-a non-randomized, single-sequence, two-period titration, open label single-center phase 1 study (PK-BeST)

Background

Betahistine was registered in Europe in the 1970s and approved in more than 80 countries as a first-line treatment for Menière's disease. It has been administered to more than 150 million patients. However, according to a Cochrane systematic review of betahistine and recent meta-analyses, there is insufficient evidence to say whether betahistine has any effect in the currently approved dosages of up to 48 mg/d. A combination with the monoamine oxidase B (MAO-B) inhibitor, selegiline, may increase the bioavailability of betahistine to levels similar to the well-established combination of L-DOPA with carbidopa or benserazide in the treatment of Parkinson's disease. We investigated the effect of selegiline on betahistine pharmacokinetics and the safety of the combination in humans.

Methods

In an investigator-initiated prospective, non-randomized, single-sequence, two-period titration, open label single-center phase 1 study, 15 healthy volunteers received three single oral dosages of betahistine (24, 48, and 96 mg in this sequence with at least 2 days' washout period) without and with selegiline (5 mg/d with a loading period of 7 days). Betahistine serum concentrations were measured over a period of 240 min at eight time points (area under the curve, AUC0-240 min). This trial is registered with EudraCT (2019-002610-39) and ClinicalTrials.gov.

Findings

In all three single betahistine dosages, selegiline increased the betahistine bioavailability about 80- to 100-fold. For instance, the mean (±SD) of the area under curve for betahistine 48 mg alone was 0.64 (+/-0.47) h*ng/mL and for betahistine plus selegiline 53.28 (+/-37.49) h*ng/mL. The half-life time of around 30 min was largely unaffected, except for the 24 mg betahistine dosage. In total, 14 mild adverse events were documented.

Interpretation

This phase 1 trial shows that the MAO-B inhibitor selegiline increases betahistine bioavailability by a factor of about 80 to 100. No safety concerns were detected. Whether the increased bioavailability has an impact on the preventive treatment of Menière's disease, acute vestibular syndrome, or post-BPPV residual dizziness has to be evaluated in placebo-controlled trials.

Clinical trial registration

https://clinicaltrials.gov/study/NCT05938517?intr=betahistine%20and%20selegiline&rank=1, identifier: NCT05938517.

Transmyringeal ventilation tube insertion for unilateral Menière's disease: a protocol for a prospective, sham-controlled, double-blinded, randomized, clinical trial

Background

Menière’s disease is an idiopathic disorder characterized by recurrent episodes of vertigo lasting more than 20 min, unilateral sensorineural hearing loss, and tinnitus. If vertigo attacks occur frequently, the patient is usually severely incapacitated. Currently, there is no consensus on the treatment of Menière’s disease. The evidence regarding most treatment options is sparse due to a lack of randomized trials together with an often-spontaneous relief over time and a considerable placebo effect. Insertion of a transmyringeal tube is a simple and relatively safe, minimally invasive procedure and previous open-label trials have shown promising results.

Study design

This is a prospective, sham-controlled, double-blinded, randomized, clinical trial.

Aim

This trial aims to assess the effects of inserting a ventilation tube into the tympanic membrane compared with sham treatment for definite or probable unilateral Menière’s disease according to the criteria formulated by the Classification Committee of the Bàràny Society.

Outcomes

The primary outcome will be the number of spontaneous vertigo attacks lasting more than 20 min and time to treatment failure. In addition to the primary outcome, we will assess various secondary outcomes related to hearing, ear fullness, dizziness, and serious adverse events.

Sample size

An estimated 104 participants in total or 52 participants in each group will be necessary.

The primary analysis will be according to the intention-to-treat principle. The trial will be initiated in 2021 and is expected to end in 2025.

Trial status

ClinicalTrials.gov: NCT04835688. Registered on April 8, 2021.

Protocol version: 1.8, 26-09-2022. Date of first enrollment: October 1st, 2021. End of study: anticipated January 2025.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06777-w.

The Additional Value of Endolymphatic Hydrops Imaging With Intratympanic Contrast for Diagnostic Work-Up-Experience From a Neurotology Center in Austria

Objective: To illustrate the merit of hydrops imaging during clinical workup of dizziness and balance disorders. Background: Ever since the first description of in-vivo endolymphatic hydrops imaging in 2007, this diagnostic tool has been implemented in an increasing number of centers. The more experience in its clinical application is gathered, the more it is possible to critically assess its potential value for the diagnostic workup. This article intends to provide information about the experience of handling and utilization of endolymphatic hydrops imaging in one of the first centers in Austria. Methods: Retrospective analysis and review of clinical cases. Results: Based on our experience of endolymphatic hydrops imaging (EHI), which was established in cooperation between our departments of radiology and otorhinolaryngology in 2017, we have exclusively used intratympanic application of a contrast agent prior to magnetic resonance imaging, as this approach provides high quality imaging results. In 42.6% of cases, EHI could lead to the diagnosis of MD or HED. Since precise vestibular examination is still necessary, EHI is not a tool to replace the clinical examination but rather to add significantly to the interpretation of the results. Conclusion: Endolymphatic hydrops imaging represents a valuable, safe and well-applicable tool for evaluating cases with inconclusive clinical results. However, its potential additional diagnostic benefits rely on a correct indication based on prior thorough vestibular investigations.

Interpreting pendred syndrome as a foetal hydrops: Clinical and animal model evidence

BACKGROUND

Menière disease (MD) and SLC26A4 related deafness (Pendred syndrome (PS) or DFNB4) are two different inner ear disorders which present with fluctuating and progressive hearing loss, which could be a direct consequence of endolymphatic hydrops.

OBJECTIVE

To present similarities between both pathologies and explore how the concept of hydrops may be applied to PS/DFNB4.

METHODS

Review of the literature on MD, PS/DFNB4 and mouse model of PS/DFNB4.

RESULTS

MD and PS/DFNB4 share a number of similarities such as fluctuating and progressive hearing loss, acute episodes with vertigo and tinnitus, MRI and histological evidence of endolymphatic hydrops (although with different underlying mechanisms). MD is usually diagnosed during the fourth decade of life whereas PS/DFNB4 is congenital. The PS/DFNB4 mouse models have shown that biallelic slc26a4 mutations lead to Na+ and water retention in the endolymph during the perinatal period, which in turn induces degeneration of the stria vascularis and hearing loss. Crossing clinical/imagery characteristics and animal models, evidence seems to support the hypothesis of PS being a foetal hydrops.

CONCLUSIONS

When understanding PS/DFNB4 as a developmental hydrops, treatments used in MD could be repositioned to PS.

Comparison between high-resolution 3D-IR with real reconstruction and 3D-flair sequences in the assessment of endolymphatic hydrops in 3 tesla

BACKGROUND

The main sequences used to assess degree of endolymphatic hydrops (EH) are the 3D- inversion-recovery (IR) with real reconstruction and the 3D- fluid-attenuated inversion recovery (FLAIR).

OBJECTIVES

The purpose of this study is to describe and compare both sequences.

MATERIAL AND METHODS

Forty-two consecutive patients diagnosed with probable or definite Ménièr´s disease were referred for hydrops MR examination. Vestibular and cochlear EH in both sequences were read by two independent radiologists, unaware of the patient's clinical status. The primary study endpoint was the concordance in the hydrops detection and severity with both imaging sequences. This was assessed using the Cohen's kappa Κ statistic for disease grading and Pearson Χ² test to test the difference in detection rates of hydrops. Statistical significance was defined as two-sided p < .05.

RESULTS

We obtained an excellent overall concordance, with a kappa of 0.821, (p < .001) when comparing hydrops detection. The degree of concordance is higher in vestibular hydrops than in cochlear hydrops. The 3D-IR sequence detected more hydrops than the 3D FLAIR, (62 vs. 39.5%, p < .03).

CONCLUSION

The 3D-IR sequence seems to be superior to the 3D-FLAIR for the assessment of EH. Significance: The 3D-IR sequence should be considered as a standalone parameter for a shorter and optimized EH magnetic resonance imaging protocol.

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

PURPOSE

Ménière's disease (MD) is an inner ear disorder of unknown etiology, whose pathological substrate is the endolymphatic hydrops. Different treatments have been proposed; however, evidence of their effectiveness is lacking. The aim of this study was to evaluate by a questionnaire which medical and surgical treatments are used in Italy for the treatment of MD and to compare them with those proposed in other countries.

METHODS

An electronic questionnaire of 40 questions was formulated and sent to Italian otolaryngologist (ENT) divided into two groups: Group 1 ("generalists" 60.8%) and Group 2 ("neurotologist- NO" 39.2%).

RESULTS

One hundred and twenty five ENT replied. Treatment of the acute phase, apart from symptomatics, was based on diuretics that are prescribed by 83.5% of respondents, steroids, prescribed by 66.7%, and vasodilators, prescribed by 22%. In the intercritical phase, 87.2% of respondents recommended low-salt diet, 78.4% of respondents prescribed betahistine, and 52.8% diuretics. Statistical analysis did not show correlation neither with the declared specialization nor with the number of patients treated. In case of failure of medical treatment, IT gentamicin was suggested by 48.8% of the respondents and IT steroids by 40.8%. Statistical analysis showed that generalists prefer IT steroids and NO IT gentamicin (p 0.019). In case of failure of both medical treatment and IT treatment, vestibular neurectomy was indicated by 58.4% of the respondents, 6.4% indicated endolymphatic sac surgery, and 2.4% surgical labyrinthectomy.

CONCLUSION

In Italy, the treatment of MD stand on a gradual approach that starts from the dietary-behavioral changes and a pharmacological therapy based on betahistine. In refractory cases, IT treatment initially with steroids and, therefore, with gentamicin allows the control in vertigo in the majority of cases. In case of failure of IT treatment, VNS is the surgery of choice.

Imaging diagnostics: congenital malformations and acquired lesions of the inner ear

INTRODUCTION

Congenital malformations and acquired lesions of the inner ear are characterised by small structural changes in this region. In recent decades, treatment options have improved considerably. At the same time, there has been a great advancement in diagnostic methods, obtaining high-resolution labyrinth images. Currently, we use a 64-multislice computed tomography scanner in spiral mode (Brilliance 64 Phillips, Eindhoven, the Netherlands), with an overlap of 0.66 mm and an interval of 0.33 mm, 120 KV and 300 mA. The magnetic resonance images were taken with Signa HDxt 1.5 and 3.0 T units (GE Healthcare, Waukesha, WI, USA). We reviewed the radiological features of the lesions affecting the inner ear. They are classified as congenital (labyrinth malformation and statoacoustic nerve deficiencies) or acquired (otospongiosis, labyrinthitis, Ménière's disease, inner ear haemorrhage, intralabyrinthine schwannoma and endolymphatic sac tumour).

CONCLUSION

Magnetic resonance imaging and computed tomography play an essential role in diagnosing patients with inner ear pathology. The technique selected should be chosen depending on the clinical setting. In a generic way, tomography is the method of choice for the study of traumatic pathology or otospongiosis. When tumour or inflammatory pathology is suspected, magnetic resonance is superior. In cases of congenital malformation, both techniques are complementary.

The sense of coherence in patients with Menière's disease

OBJECTIVE

To investigate how the ability to adapt, measured by the sense of coherence (SOC), is related to specific complaints of Menière's disease (MD) and the disease specific and general health related quality of life (EQ-5D) and on disease specific impact of the disease (MD-impact).

METHODS

Postal survey, including a structured questionnaire on EQ-5D, SOC, symptoms, positive experiences, and the impact of MD, was sent to the members of the Finnish Menière Federation, reporting a diagnosis compatible with the condition. A sample of 547 members replied and were analyzed.

RESULTS

The SOC reflected the disabilities caused by symptoms of MD and psychosocial factors including verbal score scale (VSS) anxiety (p<0.01) and loss of vitality (p<0.001). Higher SOC scores were related to better scores in EQ-5D and lower scores in MD-impact. Positive attitudes consequential to MD were associated with higher SOC scores reflecting better control over the consequences of disease.

CONCLUSION

SOC is an element of patient's attitude toward illness and correlates with perceived good health. Patients with higher SOC scores are more content with their quality of life. Future research should focus on whether influencing modifiable psychological factors, such as positive attitudes, could improve adaptive ability in MD.