Steroids for idiopathic sudden sensorineural hearing loss

The Role of Platelet-Rich Plasma in the Management of Sensorineural Hearing Loss: Current Evidence and Emerging Trends

Sensorineural hearing loss (SNHL) is a common form of hearing impairment characterized by damage to the inner ear or auditory nerve, resulting in significant communication difficulties and reduced quality of life. Current treatment options, including hearing aids, cochlear implants, and corticosteroids, primarily focus on symptom management and do not address the underlying pathophysiological damage. Platelet-rich plasma (PRP), an autologous concentrate rich in platelets and growth factors, has emerged as a potential regenerative therapy due to its ability to promote tissue repair and cellular regeneration. This review provides a comprehensive overview of the role of PRP in the management of SNHL, examining the current evidence from preclinical and clinical studies. We discuss the mechanisms through which PRP may promote auditory tissue regeneration and repair, analyze its efficacy and safety profile, and explore innovative approaches and future directions in its application for SNHL. Despite promising preliminary findings, further research is needed to optimize PRP protocols, establish standardized treatment guidelines, and conduct large-scale randomized controlled trials to validate efficacy. This review aims to highlight the potential of PRP as a novel therapeutic strategy in treating SNHL and its possible integration into current clinical practices, offering new hope for patients with this debilitating condition.

[Role of intratympanic glucocorticoid treatment in sudden hearing loss]

Idiopathic sudden sensorineural hearing loss (ISSNHL) is one of the most common diseases in otolaryngology. Its etiology remains unknown. Furthermore, there is only a low level of evidence for the efficacy of established treatment modalities. In addition to systemic glucocorticoids, intratympanic corticosteroid treatment (ICT) has become increasingly important for treatment of ISSNHL. Different application strategies and treatment regimens have been described; however, uniform standards do not yet exist. ICT may be used for primary treatment as well as salvage therapy. Current data from meta-analyses show no benefit of intratympanic versus systemic primary therapy for sudden hearing loss (moderate evidence) but suggest a benefit of intratympanic secondary treatment over no treatment or placebo (high effect size, low evidence). Regarding combination of systemic and local glucocorticoid therapy in primary treatment of hearing loss, there may be a small benefit over systemic treatment alone (low effect size, low evidence).

The Effect of Rivaroxaban in the Complementary Therapy of Sudden Sensorineural Hearing Loss

Background

Due to the importance of sudden sensorineural hearing loss (SSNHL) and the possible role of blood coagulation in its mechanism and the likely therapeutic effect of anticoagulants and also the lack of studies in this field, this study aimed to evaluate the effect of rivaroxaban (RXA) in the treatment of this disease.

Materials and Methods

The present double-blind randomized clinical trial study was performed on 34 patients with SSNHL. Patients were randomly divided into two groups. In the first group, in addition to corticosteroid therapy (CST), RXA 10 mg tablets were used daily for 10 days (RXA group), and in the second group, only CST (CST group) treatment was prescribed. Hearing recovery was then assessed and recorded according to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria.

Results

This study showed that the grade of hearing recovery in the RXA group (58.8%) was higher than the CST group (47.1%), but this difference was not significant (P value >0.05). Also, RXA treatment increased the odds of hearing recovery, and this difference was not statistically significant (odd ratio (95% confidence interval)(OR (95% CI): 2.327 (0.180-18.082); P value = 0.518). In contrast, delay to treatment, more increased PTA (pure tone average (PTA)), and having vertigo reduced the odds of hearing recovery by 0.138-, 0.019-, and 0.069-fold, respectively (P value <0.05).

Conclusion

According to the results of this study, although the percentage of hearing recovery was higher in the RXA group, in general, the results of the two treatments were not significantly different.

Salvage therapy for refractory sudden sensorineural hearing loss (RSSNHL): a systematic review and network meta-analysis

OBJECTIVE

Approximately 30-50% of sudden sensorineural hearing loss (SSNHL) patients show poor response to systemic steroid therapy. Additionally, the most appropriate treatment for patients with refractory sudden sensorineural hearing loss (RSSNHL) is unknown. This study aimed to explore the best treatment for RSSNHL.

DESIGN

Using a frequentist contrast-based model and PRISMA guidelines, this study compared five salvage regimes: intratympanic injection of steroids (ITS), hyperbaric oxygen (HBO) therapy, post auricle steroid injection (PSI), ITS combined with HBO therapy, and continued systemic steroids.

STUDY SAMPLE

We searched the PubMed, EMBASE, Web of Science, and Cochrane Library databases for randomised controlled trials and cohort studies comparing treatment regimens for RSSNHL.

RESULTS

Compared with the control group (no additional treatment), PSI and ITS demonstrated significant improvements. The mean hearing gain was greater after PSI (11.1 dB [95% CI, 4.4-17.9]) than after ITS (7.7 dB [95% CI, 4.8-10.7]). When a restricted definition of RSSNHL was used, the ITS + HBO therapy showed the largest difference in improvement for pure tone average compared with the control group (14.5 dB [95% CI, 4.2-25.0]).

CONCLUSIONS

The administration of either PSI or ITS leads to the greatest therapeutic effect in patients with RSSNHL. However, a consensus on the definition of RSSNHL is needed.

Physiologic Effects of Microneedle-Mediated Intracochlear Dexamethasone Injection in the Guinea Pig

OBJECTIVES

Oral or intratympanic corticosteroids are commonly used to treat sudden sensorineural hearing loss (SSHL), tinnitus, and Meniere disease. Direct intracochlear delivery has been proposed to overcome the variability in bioavailability and efficacy of systemic or middle ear delivery. In this study, we aim to characterize the physiologic consequences of microneedle-mediated direct intracochlear injection of dexamethasone through the round window membrane (RWM).

METHODS

In Hartley guinea pigs (n = 5), a post-auricular incision followed by bullostomy was made to access the round window membrane. Using 100 μm diameter hollow microneedles, 1.0 μl of 10 mg/ml dexamethasone was injected through the RWM over 1 min. Compound action potential (CAP) and distortion product otoacoustic action emissions (DPOAE) were measured before perforation, at 1 h, and at 5 h following injection. CAP hearing thresholds were measured from 0.5 to 40 kHz, and DPOAE f2 frequencies ranged from 1.0 and 32 kHz. Repeated measures ANOVA followed by pairwise t-tests were used for statistical analysis.

RESULTS

ANOVA identified significant CAP threshold shifts at four frequencies (4, 16, 36, and 40 kHz) and differences in DPOAE at 1 frequency (6 kHz). Paired t-tests revealed differences between the pre-perforation and 1 h time point. By 5 h post injection, both CAP hearing thresholds and DPOAE recover and are not significantly different from baseline thresholds.

CONCLUSION

Direct intracochlear delivery of dexamethasone via microneedles results in temporary shifts in hearing thresholds that resolve by 5 hours, thus supporting microneedle technology for the treatment of inner ear disorders.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:388-392, 2024.

High-Dose Glucocorticoids for the Treatment of Sudden Hearing Loss

BACKGROUND: Systemic glucocorticoids are commonly used for primary therapy of idiopathic sudden sensorineural hearing loss (ISSNHL). However, the comparative effectiveness and risk profiles of high-dose over lower-dose regimens remain unknown. METHODS: We randomly assigned patients with sudden hearing loss of greater than or equal to 50 dB within 7 days from onset to receive either 5 days of high-dose intravenous prednisolone at 250 mg/d (HD-Pred), 5 days of high-dose oral dexamethasone at 40 mg/d (HD-Dex), or, as a control, 5 days of oral prednisolone (Pred-Control) at 60 mg/d followed by 5 days of tapering doses. The primary outcome was the change in hearing threshold (pure tone average) in the three most affected contiguous frequencies from baseline to day 30. Secondary outcomes included speech understanding, tinnitus, communication competence, quality of life, hypertension, and insulin resistance. RESULTS: A total of 325 patients were randomly assigned. Mean change in 3PTAmost affected hearing threshold from baseline to 30 days was 34.2 dB (95% CI, 28.4 to 40.0) in the HD-Pred group, 41.4 dB (95% CI, 35.6 to 47.2) in the HD-Dex group, and 41.0 dB (95% CI, 35.2 to 46.8) in the Pred-Control group (P=0.09 for analysis of variance). There were more adverse events related to trial medication in the HD-Pred (n=73) and HD-Dex (n=76) groups than in the Pred-Control group (n=46). CONCLUSIONS: Systemic high-dose glucocorticoid therapy was not superior to a lower-dose regimen in patients with ISSNHL, and it was associated with a higher risk of side effects. (Funded by the Federal Ministry of Education and Research [BMBF]; EudraCT number, 2015‐002602‐36.)

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.

Randomized, placebo-controlled study on efficacy, safety and tolerability of drug-induced defibrinogenation for sudden sensorineural hearing loss: the lessons learned

PURPOSE

Disturbance of cochlear microcirculation is discussed as final common pathway of various inner ear diseases. Hyperfibrinogenemia causing increased plasma viscosity is a possible factor for a critical reduction of cochlear blood flow that might lead to sudden sensorineural hearing loss (SSHL). The aim was to determine the efficacy and safety of drug-induced defibrinogenation by ancrod for SSHL.

METHODS

Double-blind, randomized, placebo-controlled, multicenter, parallel group, phase II (proof-of-concept) study (planned enrollment: 99 patients). Patients received an infusion of ancrod or placebo (day 1) followed by subcutaneous administrations (day 2, 4, 6). Primary outcome was the change in pure tone audiogram air conduction average until day 8.

RESULTS

The study was terminated early due to slow recruiting (31 enrolled patients: 22 ancrod, 9 placebo). A significant improvement of hearing loss was registered in both groups (ancrod: - 14.3 dB ± 20.4 dB, - 39.9% ± 50.4%; placebo: - 22.3 dB ± 13.7 dB, - 59.1% ± 38.0%). A statistically significant group-difference was not detected (p = 0.374). Placebo response of 33.3% complete and 85.7% at least partial recovery was observed. Plasma fibrinogen levels were reduced significantly by ancrod (baseline: 325.2 mg/dL, day 2: 107.2 mg/dL). Ancrod was tolerated well, no adverse drug reaction was of severe intensity, no serious adverse events occurred.

CONCLUSION

Ancrod reduced fibrinogen levels that support its mechanism of action. The safety profile can be rated positively. Since the planned number of patients could not be enrolled, no efficacy conclusion can be drawn. The high rate of placebo response challenges clinical trials for SSHL and needs to be considered in future investigations. Trial registrations This study was registered in the EU Clinical Trials Register, EudraCT-No. 2012-000066-37 at 2012-07-02.

Idiopathic sudden sensorineural hearing loss: effectiveness of salvage treatment with intratympanic dexamethasone or hyperbaric oxygen therapy in addition to systemic steroids

Background

The development of standardized treatments for idiopathic sudden sensorineural hearing loss (ISSNHL) is hampered by uncertainty over the etiology of this disorder. Systemic steroids are historically the primary therapy, with variable hearing outcomes. Over the last two decades, intratympanic steroids (ITS) and hyperbaric oxygen therapy (HBOT) have been proposed as salvage treatments in case of failure of systemic steroids. The present study aims to evaluate the effectiveness of these salvage treatments in addition to systemic steroids.

Methods

We performed a retrospective study on 75 consecutive patients with a diagnosis of ISSNHL who were admitted to the Department of Otorhinolaryngology of our hospital between December 2018 and December 2022. All patients received primary treatment with systemic steroids. In case of slight or no hearing recovery within the 5th day from the beginning of the therapy (T1), a salvage treatment with ITS or HBOT was proposed. Patients were divided into three groups according to the therapy received: systemic steroids (group A), systemic steroids + HBOT (group B), and systemic steroids + ITS (group C). Pure-tone average at 500, 1000, 2000, and 3000 Hz and the mean gain were evaluated at T1 and 3 months after the beginning of the salvage treatment (T2). The hearing recovery was assessed according to the Siegel's criteria.

Results

Sixty-two patients (31 men and 31 women, mean age 56 years) with failure of the primary treatment were definitively enrolled in the study: 34 (54.8%) in group A, 16 (25.8%) in group B, and 12 (19.4%) in group C. The ratio of patients responding to therapy was higher in group A (29.4%) than in groups B (18.75%) and C (16.7%). We did not find any statistically significant difference between groups in terms of mean hearing gain at T2 (17.4 ± 15.4 dB in group A vs. 18.6 ± 21.1 dB in group B and 15.7 ± 14.2 dB in group C, p = 0.9).

Conclusion

In our experience, ITS or HBOT associated with systemic steroids, as salvage treatment, did not show significant improvement in hearing outcomes. The evolution of ISSNHL, regardless of the treatment, remains unpredictable.

Postauricular versus systemic use of steroids for sudden hearing loss: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Sudden sensorineural hearing loss (SSNHL) can be debilitating and is one of the most common otological diseases. Steroids play an important role in its treatment. There are many ways to administer steroids, and the efficacy and safety of different administration routes remain unclear. This meta-analysis aimed to investigate the effect and safety of different types of steroid delivery administration for the treatment of SSNHL.

METHODS AND ANALYSIS

We searched the Weipu, Wanfang, Chinese Biomedical Literature, National Knowledge Infrastructure, Web of Science, Embase and PubMed databases for randomized controlled trials (RCTs) on glucocorticoid treatments for SSNHL to compare the efficacy of postauricular injection and systemic steroid administration. Review Manager 5.4 software was used for data synthesis, which included the recovery rate (RR) of reported hearing improvement and change level in pure-tone audiometry (PTA). Subgroup analyses were performed based on different drugs, basic treatment, initial PTA, drug administration methods, onset time, and treatment course. Stata 15.1 software was used for analyses of publication bias and sensitivity.

RESULTS

Our meta-analysis included 38 studies involving 3609 patients with SSNHL. In all included studies, the risk difference (RD) using reported improvement as an outcome measure was 0.12 for postauricular injection administration compared with systemic therapy (95% confidence interval [CI] = 0.008, 0.16, P < .00001, I2 = 59%). When examining PTA changes as an outcome measure (19 studies), the mean difference was 6.06 (95% CI = 3.96, 8.16, P < .00001, I2 = 70%). The RD for hearing improvement was compared among different factors, and the results showed that postauricular injection is superior to systemic steroid administration.

CONCLUSION

Postauricular injection may be safer and more effective treatment than systemic therapy as a treatment for SSNHL.

Clinical characteristics and prognosis of acute low-frequency hearing loss and ascending sensorineural sudden sensorineural hearing loss

Objective

The present study aimed to explore the pathogenesis of the ascending sudden sensorineural hearing (SSNHL) loss by comparing the clinical characteristics and prognosis of acute low-frequency hearing loss (ALFHL) and ascending SSNHL.

Methods

A total of 43 patients with ALFHL and 122 patients with ascending SSNHL were enrolled in this study. First, the prognosis of patients with ALFHL and ascending SSNHL were compared, and the prognostic factors of AFHL and ascending SSNHL were analyzed.

Results

Acute low-frequency hearing loss and ascending SSNHL have no remarkable difference in complete recovery rate. Compared to ascending SSNHL, ALFHL has younger onset age, female prevalence, lower hearing threshold, shorter time from onset to recovery, and a lower proportion of combined tinnitus. The PTA at admission and delay from onset to therapy were significantly related to the prognosis of patients with ascending SSNHL, while only delay from onset to therapy was significantly related to the prognosis of patients with ALFHL. The majority of patients with ascending SSNHL and ALFHL recovered completely within 10 days from onset.

Conclusion

Audiogram shape plays a critical role in the prognosis of SSNHL. Ascending SSNHL and ALFHL may share a common pathological mechanism.

Oral Corticosteroids for Teprotumumab-Related Hearing Loss: A Case Report

Teprotumumab is a novel insulin-like growth factor-1 receptor inhibitor approved for the treatment of thyroid eye disease, but growing reports of hearing loss require further investigation. To date, an effective protocol for managing hearing loss in this setting has not been determined. Here, we present the first report of the resolution of teprotumumab-related hearing loss with prompt oral prednisone. A 70-year-old woman on teprotumumab experienced sudden hearing loss and tinnitus after her first infusion. An audiogram demonstrated a mild down-sloping to moderately severe mixed conductive and sensorineural hearing loss that was promptly treated with prednisone 60 mg for 6 days with a 1-week gradual taper. An audiogram 3 weeks later demonstrated return of hearing to normal thresholds, and the whole teprotumumab treatment course was completed without further issue. This case highlights the importance of audiometric monitoring, prompt identification of hearing symptoms, and the potential for oral steroids to reverse teprotumumab-related hearing loss.

Diagnosis, differential diagnosis, and treatment for sudden sensorineural hearing loss: Current otolaryngology practices in China

Introduction

Although sudden sensorineural hearing loss (SSNHL) has been attempted to be understood for 70 years, diagnosis and treatment strategies still have strong heterogeneity worldwide, which are reflected in the guidelines issued by countries and the clinical practice of otolaryngologists.

Methods

Questionnaires were sent to registered otolaryngologists nationwide via an online questionnaire system. We investigated the current views and clinical practices of otolaryngologists in mainland China about the diagnosis, examination, and treatment strategies of SSNHL.

Results

Most otolaryngologists supported diagnostic classification via audiograms. Regional economic situation and hospital grade affected application strategies for differential diagnosis. Regarding corticosteroid therapy, 54.9% of respondents opted to discontinue the drug 5 days after systemic administration. Both intratympanic therapy and post-auricular injections were selected by more than half of the respondents as initial and salvage treatments.

Discussion

Chinese otolaryngologists exhibit heterogeneity in clinical practices for SSNHL, including distinct approaches to combination therapy and local application of steroids. This study pointed out Chinese doctors' similarities, differences, and unique strategies in diagnosing and treating SSNHL and analyzed the possible reasons to help the world understand the current otolaryngology practices in China.

Time from sudden sensory neural hearing loss to treatment as a prognostic factor

Introduction

The widely accepted treatment for sudden sensorineural hearing loss (SSNHL) is corticosteroid treatment (oral or intratympanic). The main goal of this work is to define the significance of the time between symptom onset and treatment initiation, as well as other prognostic factors, for hearing improvement.

Methods

This retrospective study included 666 patients treated for SSNHL. Demographic data, audiometry, treatment method, time since symptom onset, and associated symptoms were recorded for each patient. The patients were divided into five groups according to the treatment initiation time-half a week, one week, 2 weeks, 3 weeks, or 4 weeks and over-after symptom onset. The degree of improvement was assessed by comparing the audiometry at the beginning and the end of the treatment.

Results

The average period of hearing loss from symptom onset to treatment initiation was 10.8 days. Significant differences were found between the groups of half a week, one week, and 2 weeks and the groups of 3 weeks and 4 weeks and over (each separately, p < 0.001). No difference was found between the half-week, one-week, and two-week groups, nor was there a difference between the three-week and four-week-and-over groups. A correlation was found between the treatment initiation time in days and the degree of improvement in hearing for both speech recognition threshold (SRT) and discrimination, R = 0.26 p < 0.001 and R = 0.17 p < 0.001, respectively. No correlation was found for gender, age of the patients, comorbidities, or associated symptoms.

Conclusion

The threshold for treatment initiation time is up to 2 weeks, after which the amplitude of hearing improvement decreases significantly. The other prognostic factors measured were not found to be statistically significant predictors.

Pericytes of Stria Vascularis Are Targets of Cisplatin-Induced Ototoxicity: New Insights into the Molecular Mechanisms Involved in Blood-Labyrinth Barrier Breakdown

The stria vascularis (SV) contributes to cochlear homeostasis and consists of three layers, one of which contains the blood-labyrinthic barrier (BLB), with a large number of bovine cochlear pericytes (BCPs). Cisplatin is a chemotherapeutic drug that can damage the SV and cause hearing loss. In this study, cell viability, proliferation rate, cytotoxicity and reactive oxygen species production were evaluated. The protein content of phospho-extracellular signal-regulated kinases (ERK) 1/2, total ERK 1/2, phospho-cytosolic phospholipase A₂ (cPLA₂), total cPLA₂ and cyclooxygenase 2 (COX-2) and the release of prostaglandin E2 (PGE2) and vascular endothelial growth factor (VEGF) from BCPs were analyzed. Finally, the protective effect of platelet-derived growth factor (PDGF-BB) on BCPs treated with cisplatin was investigated. Cisplatin reduced viability and proliferation, activated ERK 1/2, cPLA₂ and COX-2 expression and increased PGE2 and VEGF release; these effects were reversed by Dexamethasone. The presence of PDGF-BB during the treatment with cisplatin significantly increased the proliferation rate. No studies on cell regeneration in ear tissue evaluated the effect of the PDGF/Dex combination. The aim of this study was to investigate the effects of cisplatin on cochlear pericytes and propose new otoprotective agents aimed at preventing the reduction of their vitality and thus maintaining the BLB structure.

Repurposable Drugs That Interact with Steroid Responsive Gene Targets for Inner Ear Disease

Corticosteroids, oral or transtympanic, remain the mainstay for inner ear diseases characterized by hearing fluctuation or sudden changes in hearing, including sudden sensorineural hearing loss (SSNHL), Meniere's disease (MD), and autoimmune inner ear disease (AIED). Despite their use across these diseases, the rate of complete recovery remains low, and results across the literature demonstrates significant heterogeneity with respect to the effect of corticosteroids, suggesting a need to identify more efficacious treatment options. Previously, our group has cross-referenced steroid-responsive genes in the cochlea with published single-cell and single-nucleus transcriptome datasets to demonstrate that steroid-responsive differentially regulated genes are expressed in spiral ganglion neurons (SGN) and stria vascularis (SV) cell types. These differentially regulated genes represent potential druggable gene targets. We utilized multiple gene target databases (DrugBank, Pharos, and LINCS) to identify orally administered, FDA approved medications that potentially target these genes. We identified 42 candidate drugs that have been shown to interact with these genes, with an emphasis on safety profile, and tolerability. This study utilizes multiple databases to identify drugs that can target a number of druggable genes in otologic disorders that are commonly treated with steroids, providing a basis for establishing novel repurposing treatment trials.

Pretreatment hearing grades and hearing recovery outcomes after primary hyperbaric oxygen treatment in patients with idiopathic sudden sensorineural hearing loss

INTRODUCTION

Previous studies suggest the effectiveness of hyperbaric oxygen treatment (HBOT) in idiopathic sudden sensorineural hearing loss (ISSNHL) but it is mostly used as an adjuvant and salvage treatment. This study evaluated the effect of primary HBOT according to pretreatment hearing grades and hearing recovery outcomes using modified Siegel's criteria in patients with ISSNHL.

METHODS

Fifty-nine ISSNHL patients treated with only HBOT were included. A pure-tone audiogram was recorded before and after a course of HBOT (90 min at 203 kPa daily for 20 days). Using the modified Siegel's criteria, patients were divided into groups according to hearing threshold before and after treatment.

RESULTS

Hearing thresholds were significantly lower after HBOT compared to pre-treatment values across all patients (P < 0.001) with a median value of recovery of 22.5 dB (interquartile range 12.5-33.7 dB). Significantly lower hearing threshold values were recorded at 500, 1,000, 2,000, and 4,000 Hz after treatment (P < 0.001). The greatest recovery was at 1,000 Hz, (change in median threshold = 32 dB) but without a significant difference compared to other frequencies (P = 0.10).

CONCLUSIONS

HBOT is a legitimate choice as the primary treatment for ISSNHL, especially if it is readily accessible, and if there are contraindications for corticosteroid therapy.

Intratympanic Administration of Dieckol Prevents Ototoxic Hearing Loss

OBJECTIVE

Systemic administration of dieckol reportedly ameliorates acute hearing loss. In this study, dieckol was delivered to the inner ear by the intratympanic route. The functional and anatomic effects and safety of dieckol were assessed using the rat ototoxicity model.

MATERIALS AND METHODS

Dieckol in a high-molecular-weight hyaluronic acid vehicle (dieckol+vehicle group) or vehicle without dieckol (vehicle-only group) were randomly delivered into 12 ears intratympanically. Ototoxic hearing loss was induced by intravenous administration of cisplatin, gentamicin, and furosemide. The hearing threshold and surviving outer hair cells (OHC) were enumerated. Biocompatibility was assessed by serial endoscopy of the tympanic membrane (TM), and the histology of the TM and the base of bulla (BB) mucosa was quantitatively assessed.

RESULTS

The hearing threshold was significantly better (difference of 20 dB SPL) in the dieckol+vehicle group than in the vehicle-only group. The number of surviving OHCs was significantly greater in the dieckol+vehicle group than in the vehicle-only group. There were no signs of inflammation or infection in the ear. The thickness of the TM and the BB mucosa did not differ between the two groups.

CONCLUSION

Intratympanic local delivery of dieckol may be a safe and effective method to prevent ototoxic hearing loss.

Unilateral, permanent hearing loss following severe COVID-19 infection

Hearing loss following COVID-19 infection has been scarcely reported in the literature.

A previously well middle-aged man presented to the emergency department with breathlessness and cough 8 days after testing positive for COVID-19 in the community. The patient was treated in the intensive care unit due to respiratory failure. Following extubation and step down to ward-level care 2 months later, the patient reported sudden left-sided hearing loss and tinnitus. Ear examination was unremarkable and pure tone audiometry revealed profound left sensorineural hearing loss. MRI of the internal acoustic meatus did not show any cerebellopontine lesions. Intravenous steroid therapy as well as oral steroids were not successful in improvement of hearing.

A few cases of COVID-19-associated sensorineural hearing loss have been reported; the majority report irreversible loss. Awareness of this phenomenon and early referral for specialist review and audiological assessment to attempt salvage of hearing can reduce hearing disability.

Intratympanic corticosteroids for sudden sensorineural hearing loss

BACKGROUND

Idiopathic sudden sensorineural hearing loss (ISSNHL) is common, and defined as a sudden decrease in sensorineural hearing sensitivity of unknown aetiology. Systemic corticosteroids are widely used, however their value remains unclear. Intratympanic injections of corticosteroids have become increasingly common in the treatment of ISSNHL.

OBJECTIVES

To assess the effects of intratympanic corticosteroids in people with ISSNHL.

SEARCH METHODS

The Cochrane ENT Information Specialist searched the Cochrane ENT Trials Register; CENTRAL (2021, Issue 9); PubMed; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials (search date 23 September 2021).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) involving people with ISSNHL and follow-up of over a week. Intratympanic corticosteroids were given as primary or secondary treatment (after failure of systemic therapy).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods, including GRADE to assess the certainty of the evidence. Our primary outcome was change in hearing threshold with pure tone audiometry. Secondary outcomes included the proportion of people whose hearing improved, final hearing threshold, speech audiometry, frequency-specific hearing changes and adverse effects.

MAIN RESULTS

We included 30 studies, comprising 2133 analysed participants. Some studies had more than two treatment arms and were therefore relevant to several comparisons. Studies investigated intratympanic corticosteroids as either primary (initial) therapy or secondary (rescue) therapy after failure of initial treatment. 1. Intratympanic corticosteroids versus systemic corticosteroids as primary therapy We identified 16 studies (1108 participants). Intratympanic therapy may result in little to no improvement in the change in hearing threshold (mean difference (MD) -5.93 dB better, 95% confidence interval (CI) -7.61 to -4.26; 10 studies; 701 participants; low-certainty). We found little to no difference in the proportion of participants whose hearing was improved (risk ratio (RR) 1.04, 95% CI 0.97 to 1.12; 14 studies; 972 participants; moderate-certainty). Intratympanic therapy may result in little to no difference in the final hearing threshold (MD -3.31 dB, 95% CI -6.16 to -0.47; 7 studies; 516 participants; low-certainty). Intratympanic therapy may increase the number of people who experience vertigo or dizziness (RR 2.53, 95% CI 1.41 to 4.54; 1 study; 250 participants; low-certainty) and probably increases the number of people with ear pain (RR 15.68, 95% CI 6.22 to 39.49; 2 studies; 289 participants; moderate-certainty). It also resulted in persistent tympanic membrane perforation (range 0% to 3.9%; 3 studies; 359 participants; very low-certainty), vertigo/dizziness at the time of injection (1% to 21%, 3 studies; 197 participants; very low-certainty) and ear pain at the time of injection (10.5% to 27.1%; 2 studies; 289 participants; low-certainty). 2. Intratympanic plus systemic corticosteroids (combined therapy) versus systemic corticosteroids alone as primary therapy We identified 10 studies (788 participants). Combined therapy may have a small effect on the change in hearing threshold (MD -8.55 dB better, 95% CI -12.48 to -4.61; 6 studies; 435 participants; low-certainty). The evidence is very uncertain as to whether combined therapy changes the proportion of participants whose hearing is improved (RR 1.27, 95% CI 1.15 to 1.41; 10 studies; 788 participants; very low-certainty). Combined therapy may result in slightly lower (more favourable) final hearing thresholds but the evidence is very uncertain, and it is not clear whether the change would be important to patients (MD -9.11 dB, 95% CI -16.56 to -1.67; 3 studies; 194 participants; very low-certainty). Some adverse effects only occurred in those who received combined therapy. These included persistent tympanic membrane perforation (range 0% to 5.5%; 5 studies; 474 participants; very low-certainty), vertigo or dizziness at the time of injection (range 0% to 8.1%; 4 studies; 341 participants; very low-certainty) and ear pain at the time of injection (13.5%; 1 study; 73 participants; very low-certainty).  3. Intratympanic corticosteroids versus no treatment or placebo as secondary therapy We identified seven studies (279 participants). Intratympanic therapy may have a small effect on the change in hearing threshold (MD -9.07 dB better, 95% CI -11.47 to -6.66; 7 studies; 280 participants; low-certainty). Intratympanic therapy may result in a much higher proportion of participants whose hearing is improved (RR 5.55, 95% CI 2.89 to 10.68; 6 studies; 232 participants; low-certainty). Intratympanic therapy may result in lower (more favourable) final hearing thresholds (MD -11.09 dB, 95% CI -17.46 to -4.72; 5 studies; 203 participants; low-certainty). Some adverse effects only occurred in those who received intratympanic injection. These included persistent tympanic membrane perforation (range 0% to 4.2%; 5 studies; 185 participants; very low-certainty), vertigo or dizziness at the time of injection (range 6.7% to 33%; 3 studies; 128 participants; very low-certainty) and ear pain at the time of injection (0%; 1 study; 44 participants; very low-certainty).  4. Intratympanic plus systemic corticosteroids (combined therapy) versus systemic corticosteroids alone as secondary therapy We identified one study with 76 participants. Change in hearing threshold was not reported. Combined therapy may result in a higher proportion with hearing improvement, but the evidence is very uncertain (RR 2.24, 95% CI 1.10 to 4.55; very low-certainty). Adverse effects were poorly reported with only data for persistent tympanic membrane perforation (rate 8.1%, very low-certainty).

AUTHORS' CONCLUSIONS

Most of the evidence in this review is low- or very low-certainty, therefore it is likely that further studies may change our conclusions.   For primary therapy, intratympanic corticosteroids may have little or no effect compared with systemic corticosteroids. There may be a slight benefit from combined treatment when compared with systemic treatment alone, but the evidence is uncertain. For secondary therapy, there is low-certainty evidence that intratympanic corticosteroids, when compared to no treatment or placebo, may result in a much higher proportion of participants whose hearing is improved, but may only have a small effect on the change in hearing threshold. It is very uncertain whether there is additional benefit from combined treatment over systemic steroids alone. Although adverse effects were poorly reported, the different risk profiles of intratympanic treatment (including tympanic membrane perforation, pain and dizziness/vertigo) and systemic treatment (for example, blood glucose problems) should be considered when selecting appropriate treatment.

The Otoprotective Effect of Ear Cryotherapy: Systematic Review and Future Perspectives

This systematic review investigates ear cooling and cryotherapy in the prevention and treatment of inner ear damage and disease, within the context of animal models and clinical studies. A literature search was carried out in the databases Pubmed and Cochrane Library. Ten studies were identified concerning the otoprotective properties of cryotherapy. Nine of these were rodent in vivo studies (mice, rats, gerbils, guinea pigs). One study involved human subjects and investigated cryotherapy in idiopathic sensorineural hearing loss. The studies were heterogeneous in their goals, methods, and the models used. Disorder models included ischemia and noise damage, ototoxicity (cisplatin and aminoglycoside), and CI-electrode insertion. All ten studies demonstrated significant cryotherapeutic otoprotection for their respective endpoints. No study revealed or expressly investigated otodestructive effects. While limited in number, all of the studies within the scope of the review demonstrated some degree of cryotherapeutic, otoprotective effect. These promising results support the conducting of further work to explore and refine the clinical applicability and impact of cryotherpeutics in otolaryngology.

Inner Ear Drug Delivery for Sensorineural Hearing Loss: Current Challenges and Opportunities

Most therapies for treating sensorineural hearing loss are challenged by the delivery across multiple tissue barriers to the hard-to-access anatomical location of the inner ear. In this review, we will provide a recent update on various pharmacotherapy, gene therapy, and cell therapy approaches used in clinical and preclinical studies for the treatment of sensorineural hearing loss and approaches taken to overcome the drug delivery barriers in the ear. Small-molecule drugs for pharmacotherapy can be delivered via systemic or local delivery, where the blood-labyrinth barrier hinders the former and tissue barriers including the tympanic membrane, the round window membrane, and/or the oval window hinder the latter. Meanwhile, gene and cell therapies often require targeted delivery to the cochlea, which is currently achieved via intra-cochlear or intra-labyrinthine injection. To improve the stability of the biomacromolecules during treatment, e.g., RNAs, DNAs, proteins, additional packing vehicles are often required. To address the diverse range of biological barriers involved in inner ear drug delivery, each class of therapy and the intended therapeutic cargoes will be discussed in this review, in the context of delivery routes commonly used, delivery vehicles if required (e.g., viral and non-viral nanocarriers), and other strategies to improve drug permeation and sustained release (e.g., hydrogel, nanocarriers, permeation enhancers, and microfluidic systems). Overall, this review aims to capture the important advancements and key steps in the development of inner ear therapies and delivery strategies over the past two decades for the treatment and prophylaxis of sensorineural hearing loss.

Delayed Recovery in Idiopathic Sudden Sensorineural Hearing Loss

Sudden hearing loss is an easily encountered disease in clinics, but its prognosis has not been completely elucidated. In the present study, we investigated the long-term prognosis of sudden hearing loss with 130 patients who were diagnosed based on strict criteria and provided uniform treatment. The patients with incomplete recovery were reevaluated after 2 months without receiving additional treatment. Hearing levels at different time points were compared. Moreover, the associated factors affecting the degree of hearing improvement over time were evaluated using stepwise multiple linear regression. After treatment, 73 out of the 130 (56.1%) patients attained incomplete recovery and were reevaluated after 2 months. Seventeen out of the seventy-three (23.3%) patients showed a grade promotion, fifty-four (74%) were constant, and two (2.7%) were aggravated. The mean interaural hearing differences (IHDs) showed significant improvement. Old age, poor initial IHD, and poor recovery grade were significantly associated with a profitable delayed hearing gain. Poorer hearing level at the time of onset might be a sign for slower recovery rather than a poorer prognostic factor. The treatment outcome of idiopathic sudden sensorineural hearing loss (ISSNHL) should be evaluated at least 2 months after treatment completion, and counseling is required due to the need for long-term follow-up in patients with ISSNHL.

Teprotumumab-associated chronic hearing loss screening and proposed treatments

We report a case of a woman in her 50s with chronic teprotumumab-associated sensorineural hearing loss. The patient presented with chronic thyroid eye disease with proptosis and diplopia despite systemic thyroid control and orbital decompression. She was started on teprotumumab but developed tinnitus after the third dose, followed by frank hearing loss after the fifth dose. Her audiogram showed bilateral mild to moderate-severe hearing loss, which was significantly worse compared with her baseline audiogram obtained prior to treatment. Teprotumumab was immediately stopped, however repeat audiogram 6 weeks later showed no improvement. Given potentially irreversible sensorineural hearing loss, we recommend close monitoring with regular audiometric testing before, during and after teprotumumab therapy and propose potential treatment to reverse its effects in the ear.

In silico Single-Cell Analysis of Steroid-Responsive Gene Targets in the Mammalian Cochlea

Background

Treatment of many types of hearing instability in humans, including sudden sensorineural hearing loss, Meniere's disease, and autoimmune inner ear disease, rely heavily on the utilization of corticosteroids delivered both by oral and transtympanic routes. Despite this use, there is heterogeneity in the response to treatment with corticosteroids in humans with these diseases. The mechanisms by which corticosteroids exert their effect and the cell types in which they exert their effects in the inner ear remain poorly characterized. In this study, we localize steroid-responsive genes to cochlear cell types using previously published transcriptome datasets from the mammalian cochlea.

Methods

Steroid-responsive genes were localized to specific cochlear cell types using existing transcriptome datasets from wild-type mammalian cochlea exposed to systemic and transtympanic steroids, as well as previously published single-cell and single-nucleus RNA-sequencing datasets from the mammalian cochlea. Gene ontology (GO) analysis of differentially expressed genes (DEGs) was performed using PANTHER to investigate cellular processes implicated in transtympanic vs. systemic steroid action in the cochlea.

Results

Steroid-responsive genes were localized to specific cell types and regions in the cochlea including the stria vascularis, organ of Corti, and spiral ganglion neurons (SGN). Analyses demonstrate differential prevalence of steroid-responsive genes. GO analysis demonstrated steroid-responsive DEGs in the SGN to be associated with angiogenesis, apoptosis, and cytokine-mediated anti-inflammatory pathways.

Conclusions

Single-cell and single-nucleus transcriptome datasets localize steroid-responsive genes to specific regions in the cochlea. Further study of these regionally-specific steroid-responsive genes may provide insight into the mechanisms of and clinical response to corticosteroids in diseases of hearing instability.

Sudden Sensorineural Hearing Loss and Why It’s an Emergency

This review shows the importance of sudden sensorineural hearing loss (SSNHL) as a significant cause of hearing loss that often goes under-recognized, especially by primary care physicians. Contrasted with conductive hearing loss, SSNHL involves inner ear damage. This work reviewed the diagnostic methods and treatments of SSNHL in the U.S. and Canada, including treatment options. It is imperative that primary care physicians and providers be able to recognize this condition early so that treatment may be initiated without delay as hearing loss can become permanent if not managed immediately.

Effectiveness of Various Treatments for Sudden Sensorineural Hearing Loss-A Retrospective Study

(1) Background: A retrospective clinical study was conducted to compare the effectiveness of different pharmacological and non-pharmacological regimens for treating sudden sensorineural hearing loss (SSNHL). (2) Methods: Adult patients (n = 130) diagnosed with sudden sensorineural hearing loss (SSNHL) and hospitalized between 2015 and 2020 were enrolled in this study. Depending on the treatment regimen applied, patients were divided into five groups. Inclusion criteria were as follows: (i) hearing loss of sudden onset; (ii) hearing loss of at least 30 dB at three consecutive frequencies; (iii) unilateral hearing loss; (iv) age above 18 years. Exclusion criteria were as follows: (i) no follow-up audiogram; (ii) bilateral hearing loss; (iii) recognized alternative diagnosis such as tumor, disorder of inner ear fluids, infection or inflammation, autoimmune disease, malformation, hematological disease, dialysis-dependent renal failure, postdural puncture syndrome, gene-related syndrome, mitochondrial disease; and (iv) age below 18 years. (3) Results: Complete recovery was found in 14% of patients (18/130) and marked improvement was found in 6% (8/130), giving an overall success rate of 20%. The best results were obtained in the second group (i.e., patients given intratympanic glucocorticoid + prolonged orally administered glucocorticoid) where the success rate was 28%. In general, the older the patient, the smaller the improvement in hearing, a correlation that was statistically significant. (4) Conclusions: In treating SSNHL, the highest rate of hearing recovery-28%-was in the group of patients given intratympanic corticoid plus prolonged treatment with orally administered glucocorticoid.

[Corticosteroids for acute sensorineural hearing loss treatment. The contemporary state of problem. Literature review. Part 1]

The article presents modern literary data relating to the expediency of the purpose of glucocorticosteroids in sudden sensorineural hearing loss (SSHL) of various genes. In detail, the radar molecular mechanisms and the anatomo-physiological features of the exposure to the inner ear, side effects, the introduction methods, their comparative efficacy and modern schemes of the SSHL.

Dexamethasone for Inner Ear Therapy: Biocompatibility and Bio-Efficacy of Different Dexamethasone Formulations In Vitro

Dexamethasone is widely used in preclinical studies and clinical trials to treat inner ear disorders. The results of those studies vary widely, maybe due to the different dexamethasone formulations used. Laboratory (lab) and medical grade (med) dexamethasone (DEX, C₂₂H₂₉FO₅) and dexamethasone dihydrogen phosphate-disodium (DPS, C₂₂H₂₈FNa₂O₈P) were investigated for biocompatibility and bio-efficacy in vitro. The biocompatibility of each dexamethasone formulation in concentrations from 0.03 to 10,000 µM was evaluated using an MTT assay. The concentrations resulting in the highest cell viability were selected to perform a bio-efficiency test using a TNFα-reduction assay. All dexamethasone formulations up to 900 µM are biocompatible in vitro. DPS-lab becomes toxic at 1000 µM and DPS-med at 2000 µM, while DEX-lab and DEX-med become toxic at 4000 µM. Bio-efficacy was evaluated for DEX-lab and DPS-med at 300 µM, for DEX-med at 60 µM, and DPS-lab at 150 µM, resulting in significantly reduced expression of TNFα, with DPS-lab having the highest effect. Different dexamethasone formulations need to be applied in different concentration ranges to be biocompatible. The concentration to be applied in future studies should carefully be chosen based on the respective dexamethasone form, application route and duration to ensure biocompatibility and bio-efficacy.

Virus-infection in cochlear supporting cells induces audiosensory receptor hair cell death by TRAIL-induced necroptosis

Although sensorineural hearing loss (SHL) is relatively common, its cause has not been identified in most cases. Previous studies have suggested that viral infection is a major cause of SHL, especially sudden SHL, but the system that protects against pathogens in the inner ear, which is isolated by the blood-labyrinthine barrier, remains poorly understood. We recently showed that, as audiosensory receptor cells, cochlear hair cells (HCs) are protected by surrounding accessory supporting cells (SCs) and greater epithelial ridge (GER or Kölliker's organ) cells (GERCs) against viral infections. Here, we found that virus-infected SCs and GERCs induce HC death via production of the tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). Notably, the HCs expressed the TRAIL death receptors (DR) DR4 and DR5, and virus-induced HC death was suppressed by TRAIL-neutralizing antibodies. TRAIL-induced HC death was not caused by apoptosis, and was inhibited by necroptosis inhibitors. Moreover, corticosteroids, the only effective drug for SHL, inhibited the virus-induced transformation of SCs and GERCs into macrophage-like cells and HC death, while macrophage depletion also inhibited virus-induced HC death. These results reveal a novel mechanism underlying virus-induced HC death in the cochlear sensory epithelium and suggest a possible target for preventing virus-induced SHL.

Association of Acute Upper Respiratory Tract Infections with Sudden Sensorineural Hearing Loss: A Case-Crossover, Nationwide, Population-Based Cohort Study

The etiology of sudden sensorineural hearing loss (SSNHL) has been unclear until now. Understanding its potential etiology is crucial for the development of preventive medicine. In this study, we investigated the association between acute upper respiratory tract infections (URIs) and SSNHL risk. We conducted a case-crossover study by using the longitudinal health insurance database derived from the National Health Insurance Research Database in Taiwan. Individual acute URI between the case and control periods was reviewed. Multivariable conditional logistic regression models were used to estimate the adjusted odds ratios (aORs) of SSNHL risk associated with acute URIs after adjustments for potential confounders. In total, 1131 patients with SSNHL between 2010 and 2013 fulfilled our inclusion criteria and were included. The aOR (95% confidence interval [CI]) for SSNHL was 1.57 (1.20-2.05) in relation to acute URIs one month before the index date. Moreover, the aORs (95% CIs) of the female and young to middle-aged (≤65 years) populations were 1.63 (1.13-2.36) and 1.76 (1.29-2.40), respectively. In addition, the association between SSNHL and acute URIs was decreased over time. The aOR for SSNHL was 1.25 (1.01-1.56) in relation to acute URIs three months before the index date. Acute URIs increase SSNHL risk and are a potential risk factor for SSNHL. The establishment of a feasible health policy for the prevention of acute URIs is crucial for SSNHL prevention, particularly in female, and young to middle-aged populations.

It's all about timing, early treatment with hyperbaric oxygen therapy and corticosteroids is essential in acute acoustic trauma

Background

Acute acoustic trauma (AAT) is an acute hearing impairment caused by intense noise-impact. The current management strategy for AAT with substantial hearing loss in the Dutch military is the combination therapy with corticosteroids and hyperbaric oxygen therapy (HBOT). In a previous study, early initiation of the combination therapy was associated with better outcomes. Therefore, we performed a new analysis to assess the difference in hearing outcome between patients in whom combination therapy was started within two days, versus after more than two days.

Methods

A retrospective analysis was performed on military patients diagnosed with AAT with substantial hearing loss who presented between February 2018 and March 2020. Absolute and relative hearing improvement between first and last audiograms were calculated for all affected frequencies (defined as loss of ≥20 dB on initial audiogram). We also determined the amount of patients who recovered to the level of Dutch military requirement, and performed speech discrimination tests.

Results

In this analysis, 30 male patients (49 ears) with AAT were included. The median age was 24.5 years (IQR 23-29). The median time to initiation of therapy with corticosteroids and HBOT were one and two days, respectively. HBOT was started within two days in 31 ears, and after more than two days in 18 ears. The mean absolute and relative hearing gains were 18.8 dB (SD 14.6) and 46.8% (SD 31.3) on all affected frequencies. The 100% discrimination/speech perception level improved from 64.0 dB to 51.7 dB (gain 12.3 dB ± 14.1). There was significantly more improvement in absolute and relative hearing improvement when HBOT was started in ≤2 days, compared to >2 days.

Conclusion

Our analysis shows results in favor of early initiation (≤2 days) of the combination treatment of HBOT and corticosteroids in patients with AAT.

Sudden Sensorineural Hearing Loss in Mild COVID-19: Case Series and Analysis of the Literature

Background: There is growing evidence of otoneurological involvement of SARS-CoV-2, such as tinnitus and balance disorders and smell and taste disorders, but HL in COVID-19 patients has still been marginally studied. Investigating the role of SARS-CoV-2 as an aetiological factor of Sudden Sensorineural Hearing Loss (SSNHL) may offer the opportunity to address treatment strategies to maximize clinical recovery and avoid side effects. Methods and results: For this purpose, we will present case studies of five patients who experienced SSNHL during COVID-19. Patients were selected from COVID-19 positive adult subjects with mild clinical presentation, admitted to the outpatient Ear Nose and Throat Department of Cardarelli Hospital due to the onset of SSNHL during the infection. All underwent a complete audio-vestibular investigation before and after SSNHL treatment protocol. Each patient is described with a detailed analysis. Conclusions: SSNHL could be an occasional symptom of COVID-19, even in mild manifestations of the disease. Our experience leads us to underline the value of promptly recognizing and addressing this and other uncommon symptoms, giving patients the opportunity to receive early treatment.

Systemic corticosteroids in coronavirus disease 2019 (COVID-19)-related smell dysfunction: an international view

The frequent association between coronavirus disease 2019 (COVID-19) and olfactory dysfunction is creating an unprecedented demand for a treatment of the olfactory loss. Systemic corticosteroids have been considered as a therapeutic option. However, based on current literature, we call for caution using these treatments in early COVID-19-related olfactory dysfunction because: (1) evidence supporting their usefulness is weak; (2) the rate of spontaneous recovery of COVID-19-related olfactory dysfunction is high; and (3) corticosteroids have well-known potential adverse effects. We encourage randomized placebo-controlled trials investigating the efficacy of systemic steroids in this indication and strongly emphasize to initially consider smell training, which is supported by a robust evidence base and has no known side effects.

Tympanic Membrane Perforation After Intratympanic Steroid Injection: A Systematic Review and Meta-analysis

OBJECTIVE

We investigated the incidence of tympanic membrane (TM) perforations induced after intratympanic steroid injection (ITSI) in patients with sudden sensorineural hearing loss (SSNHL) through a systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, and MEDLINE.

REVIEW METHODS

Primary database searches were performed, and 1901 records were identified. After removal of 1802 articles through abstract screening, the remaining 99 full-text journals were assessed for eligibility to be included in the study. Fifty-eight studies that used either ventilation tubing (VT) or tympanocentesis (TC) for ITSI were selected for analysis. The subjects were divided into VT and TC groups. The rate of TM perforation after ITSI in 2 groups, sites of ITSI, needle gauge, and influence on residual hearing were investigated.

RESULTS

The cohorts comprised patients who underwent VT (n = 257, 9.6%) and TC (n = 2415, 90.4%). The proportion of TM perforation after ITSI in each group was 0.073 (95% CI, 0.0469-0.1113) and 0.010 (95% CI, 0.0045-0.0215), respectively, which suggested that the VT group showed a significantly higher TM perforation rate than the TC group (P < .001). In the subgroup analyses, there was no significant difference in the odds ratio for the rate of TM perforation according to the injection site and needle gauge for TC. The proportion of surgical repair showed no significant difference between the 2 groups.

CONCLUSION

ITSI via VT may have a significantly higher risk of TM perforation than ITSI via TC, although those are relatively small overall. ITSI should be performed in the direction to minimize possible adverse effects.

Analysis of Pharmacokinetics in the Cochlea of the Inner Ear

Hearing loss affects >5% of the global population and therefore, has a great social and clinical impact. Sensorineural hearing loss, which can be caused by different factors, such as acoustic trauma, aging, and administration of certain classes of drugs, stems primarily from a dysfunction of the cochlea in the inner ear. Few therapeutic strategies against sensorineural hearing loss are available. To develop effective treatments for this disease, it is crucial to precisely determine the behavior of ototoxic and therapeutic agents in the microenvironment of the cochlea in live animals. Since the 1980s, a number of studies have addressed this issue by different methodologies. However, there is much less information on pharmacokinetics in the cochlea than that in other organs; the delay in ontological pharmacology is likely due to technical difficulties with accessing the cochlea, a tiny organ that is encased with a bony wall and has a fine and complicated internal structure. In this review, we not only summarize the observations and insights obtained in classic and recent studies on pharmacokinetics in the cochlea but also describe relevant analytical techniques, with their strengths, limitations, and prospects.

Hyperbaric oxygen for sudden hearing loss: Influence of international guidelines on practice in Australia and New Zealand

INTRODUCTION

Idiopathic sudden sensorineural hearing loss (ISSHL) is an otolaryngologic emergency. The Undersea and Hyperbaric Medicine Society (UHMS) revised practice guidelines in 2014 adding ISSHL to approved indications. This study investigated whether the UHMS guidelines influenced referral and practice in Australia and New Zealand.

METHODS

Retrospective review of 319 patient referrals in two time periods (five years prior to addition of ISSHL to indications (T-PRE) and three years post (T-POST)).

RESULTS

Seven of eight participating hyperbaric facilities provided data down to the level of the indication for HBOT for analysis. In T-PRE 136 patients were treated with HBOT for ISSHL, representing between 0% and 18% of the total cases to each facility. In the T-POST period 183 patients were treated for ISSHL, representing from 0.35% to 24.8% of the total patients in each facility. Comparison between the two periods shows the proportion of patients treated with ISSHL among all indications increased from 3.2% to 12.1% (P < 0.0009). One facility accounted for 74% (101/136) of ISSHL patients receiving HBOT in T-PRE and 63% (116/183) in T-POST. ISSHL case load at that facility increased from 18% to 24.8% (P = 0.009) after the UHMS guideline publication. Three of the seven units had a significant increase in referrals after the guideline change.

CONCLUSION

There remains equipoise regarding HBOT in the management of ISSHL. Only three out of seven units had a significant increase in ISSHL patients after the UHMS guidelines publication. Without well controlled RCTs to develop guidelines based on good evidence this is unlikely to change and practice variation will continue.

[Hormonal influence on hearing]

BACKGROUND

Hearing loss leads to impairments in communication, social interactions, and cognitive functions. This renders early treatment particularly important. A causal therapy is not yet available. Human and animal studies have shown that certain hormones can have a positive effect on hearing.

OBJECTIVE

This review provides an overview of the effects of various hormones on hearing and describes the potential benefit for future therapeutic approaches.

MATERIALS AND METHODS

A systematic literature review of reviews dealing with the effects of various hormones on hearing in humans and animals published in PubMed between 2015 and 2020 was conducted.

RESULTS

Hormones may mediate antiapoptotic effects on structure-relevant cells of the cochlea and auditory pathway, and may influence hair cell functionality or the electrolyte balance of the endo- and perilymph. Current research focuses on glucocorticoids; the mineral corticoid aldosterone; the sex hormones estrogen, progesterone, and testosterone; the growth hormones GH (growth hormone) and IGF‑1 (insulin-like growth factor 1); thyroid hormones; and insulin. Study results are still inconsistent at this time, but various hormones appear to represent a possible future treatment option for acute hearing loss. Long-term hormone treatment, which would be necessary particularly in the case of age-related hearing loss, does not currently represent a sensible course of action due to the side effect profile of the systemic treatment/lack of practicable topical application options.

CONCLUSION

The mode of action of hormones is complex. Whether they can be used in the future for individualized treatment of patients with acute hearing impairment requires further investigation.

Paediatric Sudden Sensorineural Hearing Loss: Pooled Analysis and Systematic Review

Sudden sensorineural hearing loss (SSNHL) is defined as hearing loss of ≥30 dB in one or both ears, developing within 3 days, affecting ≥3 contiguous frequencies. It is rare in children, but if untreated can cause significant morbidity. During the critical developmental period, it may cause lifelong social, behavioral, and mental sequelae. Currently, little guidance exists on prognosis and management within a pediatric population. A systematic literature review of pediatric SSNHL on PubMed, EMBASE, and the Cochrane CENTRAL database was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. A total of 620 papers met the Medical Subject Headings criteria, of which 14 met analysis criteria-13 were level 4 and 1 was level 2b evidence. A population of 732 individuals was analyzed. Most reported cases of pediatric SSNHL were idiopathic. Other etiologies included viral infection, trauma, ototoxic drugs, and structural abnormalities. Recovery was defined as any improvement in hearing after the initial loss, from "slight" to "complete." Recovery ranged from 20% to 100%, with a pooled rate of 56%. Systemic steroids were the mainstay of treatment, although salvage intratympanic steroid therapy had a role after the failure of systemic steroids. Children with bilateral SSNHL had poorer outcomes than those with unilateral loss, with 29% showing improvement. Two studies reported outcomes with no treatment, for which recovery rate was 7%. This analysis of SSNHL shows that 61% of children with unilateral and 29% of children with bilateral SSNHL demonstrate some recovery, a worse prognosis than adults. Multiple treatment regimens exist, although comparison is challenging owing to inconsistently reported improvement parameters.

Intratympanic administration of alpha-lipoic acid-loaded pluronic F-127 nanoparticles ameliorates acute hearing loss

We used antioxidant-containing nanoparticles (NPs) to treat acute hearing loss. Alpha-lipoic acid (ALA) served as the antioxidant; we employed Pluronic F127 to fabricate NPs. In vitro, ALA-NPs protected cells of the organ of Corti in HEI-OC1 mice, triggering nuclear translocation of NRF2 and increases in the levels of antioxidant proteins, including Nrf2, HO-1, SOD-1, and SOD-2. In vivo, the hearing of mice that received ALA-NP injections into the middle ear cavity was better preserved after induction of ototoxicity than in control animals. The cochlear Nrf2 level increased in test mice, indicating that the ALA-NPs protected hearing via the antioxidant mechanism observed in vitro. ALA-NPs effectively protected against acute hearing loss by activating the Nrf2/HO-1 pathway.

Clinical Features and Hearing Outcomes of Sudden Sensorineural Hearing Loss in Diabetic Patients

Background and Objectives

This study aimed to evaluate the clinical features and the clinical factors associated with prognosis of sudden sensorineural hearing loss (SSNHL) in diabetic patients.

Subjects and Methods

Forty-nine diabetic with unilateral SSNHL were retrospectively included. All patients received systemic high dose steroid therapy within one month after onset and had more than one month of follow-up audiogram. The basic characteristics of the patients, initial and follow-up audiograms, laboratory data, and methods of steroid treatment were collected.

Results

Compared to reference values in healthy subjects, 79%, 55%, and 45% of the patients had higher values of mean neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and lymphocyte-monocyte ratio (LMR), respectively. Older patients had significantly less degree of hearing loss, but they also had significantly worse hearing thresholds in the unaffected ear. After steroid treatment, less than half patients (47%) showed hearing recovery. Simultaneous intratympanic dexamethasone (ITD) injections with systemic steroid did not confer an additional hearing gain or an earlier recovery rate in diabetic patients with SSNHL. In the multivariate analysis, initial hearing thresholds of affected ear and timing of steroid treatment were significantly associated with hearing prognosis in diabetic patients with SSNHL.

Conclusions

Diabetic patients with SSNHL tended to have increased NLR, LMR, and PLR, which are reported to be associated with microvascular angiopathy. Simultaneous ITD injections to improve hearing recovery in diabetic patients with SSNHL seems unnecessary.

Acute sensorineural hearing loss as atypical presentation of typhoid fever in adult patient

Salmonella Typhi is the main cause of an acute febrile, sometimes fatal, multisystemic illness called typhoid fever. The diverse presentations of this disease make it a diagnostic challenge in some patients. Involvement of the neurological system, including cochleovestibular system, is very rare with less than a handful of reported cases. This case report describes the condition of a previously healthy 23-year-old Pakistani man with acute onset of hearing loss associated with fever, headache, and disorientation. The most likely differential diagnoses were bacterial or viral meningoencephalitis, and other bacterial infections, such as Rickettsial and spirochetal diseases. Salmonella Typhi grew on blood culture; thus, treatment with intravenous antibiotics and systemic steroids was provided with excellent response. Hearing loss gradually improved and almost completely resolved within 3 to 4 weeks.

Sudden sensorineural hearing loss - A contemporary review of management issues

Sudden sensorineural hearing loss (SSNHL) is an enigmatic entity, with obscure pathophysiology and debatable efficacy of the treatment agents used. An underlying cause is identified in only 10-15% of cases. The management of the remaining patients, classified as 'idiopathic', is empirical, and is conventionally with systemic steroids, vasodilator therapy, rheological agents, and antioxidants, to list a few amongst the host of the agents employed for the treatment. The availability of conflicting outcomes and lack of conclusive evidence has resulted in the propagation of consensus-based treatment protocols. In the present review, we discuss the various controversial issues and newer developments in the management of idiopathic SSNHL. The current review aims to present a narrative outlook of the updated evidence base available from PUBMED, augmented with relevant designated publications.

Efficacy and Safety of AM-111 in the Treatment of Acute Unilateral Sudden Deafness-A Double-blind, Randomized, Placebo-controlled Phase 3 Study

Objective:

To confirm the efficacy and safety of AM-111 (brimapitide), a cell-penetrating c-Jun N-terminal Kinase (JNK) inhibitor, in patients suffering from severe to profound acute unilateral idiopathic sudden sensorineural hearing loss (ISSNHL).

Study design:

Prospective, double-blind, randomized, placebo-controlled phase 3 study with follow-up visits on Days 3, 7, 28, and 91.

Setting:

Fifty-one European and Asian sites (tertiary referral centers, private ENT practices).

Patients:

Two hundred fifty-six patients aged 18 to 65 years presenting within 72 hours following ISSNHL onset with mean hearing loss ≥ 40 dB and mean threshold ≥ 60 dB at the 3 worst affected contiguous test frequencies.

Interventions:

Single-dose intratympanic injection of AM-111 (0.4 or 0.8 mg/ml) or placebo; oral prednisolone as reserve therapy if hearing improvement < 10 dB at Day 7.

Main outcome measures:

Hearing improvement to Day 28 was the primary efficacy endpoint; complete hearing recovery, frequency of reserve therapy used, complete tinnitus remission, improvement in word recognition were secondary endpoints. Safety was evaluated by the frequency of clinically relevant hearing deterioration and adverse events.

Results:

While the primary efficacy endpoint was not met in the overall study population, post-hoc analysis showed a clinically relevant and nominally significant treatment effect for AM-111 0.4 mg/ml in patients with profound ISSNHL. The study drug and the administration procedure were well tolerated.

Conclusions:

AM-111 provides effective otoprotection in case of profound ISSNHL. Activation of the JNK stress kinase, AM-111's pharmacologic target, seems to set in only following pronounced acute cochlear injury associated with large hearing threshold shifts.

Intratympanic versus intravenous corticosteroid treatment for sudden sensorineural hearing loss in diabetic patients: proposed study protocol for a prospective, randomized superiority trial

Background

Diabetes mellitus is associated with risk of sudden sensorineural hearing loss (SSNHL). Systemic and intratympanic corticosteroids are the two primary treatments for SSNHL in patients with diabetes mellitus. The benefit of intratympanic compared to systemic treatment is the reduced systemic steroid exposure and associated systemic adverse effects. Intratympanic corticosteroid administration may have potential benefits over standard systemic therapies.

Methods/design

The proposed study is a prospective, randomized superiority trial. A total of 96 patients (48 in each group) will be randomized into the experimental or control group. Patients in the experimental group will receive four 1-mL doses of 40 mg/mL of methylprednisolone over a 1-week period, with a dose administered every 2 days via tympanic membrane injection into the middle ear. The control group will be administered intravenous methylprednisolone (1 mg/kg/day, maximal dose 60 mg/day) for 5 days. The primary outcome for this study is the change in hearing threshold from the first audiogram to the 30-day follow-up audiogram. Secondary outcome measures will include pure-tone average (PTA) at 90-day follow up, visual analog tinnitus scale, visual analog vertigo scale, visual analog aural fullness scale, fasting blood glucose and 2-h postprandial blood glucose during treatment, and the change in glycosylated hemoglobin (HbA1C) levels. Vital signs and otological physical examination will be performed at each follow-up visit.

Discussion

The efficacy and safety of intratympanic methylprednisolone compared to intravenous methylprednisolone will be investigated in patients with diabetes mellitus and SSNHL. This trial may provide strong evidence for the efficacy and safety of intratympanic corticosteroid treatment and important clinical information for the treatment of patients with diabetes mellitus and SSNHL.

Trial registration

ChiCTR, ChiCTR1800015954. Registered on 2 May 2018, Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=25326.

[Topical drug administration to the inner ear. Modern state of the problem and development perspectives]

The work assessed modern methods of drug delivery through biological barriers to the lesion, in particular, through the most studied - skin. The main advantages and disadvantages of the existing methods for the topical administration of drugs into the inner ear - intra-imperial and intra-labyrinth delivery are analyzed. A brief review of medicinal substances for topical administration to the inner ear, both widely used (for example, aminoglycosides, steroid drugs) and undergoing clinical trials, is given. An assessment is made of the prospects for the use of transmembrane drug delivery to the inner ear using an electric field, which has a combined electro-creative and iontophoretic effect.

Medicines discovery for auditory disorders: Challenges for industry

Currently, no approved medicines are available for the prevention or treatment of hearing loss. Pharmaceutical industry productivity across all therapeutic indications has historically been disappointing, with a 90% chance of failure in delivering a marketed drug after entering clinical evaluation. To address these failings, initiatives have been applied in the three cornerstones of medicine discovery: target selection, clinical candidate selection, and clinical studies. These changes aimed to enable data-informed decisions on the translation of preclinical observations into a safe, clinically effective medicine by ensuring the best biological target is selected, the most appropriate chemical entity is advanced, and that the clinical studies enroll the correct patients. The specific underlying pathologies need to be known to allow appropriate patient selection, so improved diagnostics are required, as are methodologies for measuring in the inner ear target engagement, drug delivery and pharmacokinetics. The different therapeutic strategies of protecting hearing or preventing hearing loss versus restoring hearing are reviewed along with potential treatments for tinnitus. Examples of current investigational drugs are discussed to highlight key challenges in drug discovery and the learnings being applied to improve the probability of success of launching a marketed medicine.

Pentoxifylline versus Steroid Therapy for Idiopathic Sudden Sensorineural Hearing Loss with Diabetes

OBJECTIVES

To compare the efficacy of pentoxifylline with that of conventional steroid therapy in diabetic patients with idiopathic sudden sensorineural hearing loss (ISSNHL) and to compare blood sugar levels during hospitalization.

MATERIALS AND METHODS

Medical charts were retrospectively reviewed for all diabetic patients admitted to one institution for ISSNHL between 2000 and 2015. We analyzed 298 cases; 50 patients received pulse steroid treatment (steroid group) and 248 received intravenous administration of pentoxifylline only (pentoxifylline group). Hearing change was evaluated by comparing the initial hearing tests with follow-up hearing tests for up to 3 months. Blood sugar levels were also compared between the 2 groups.

RESULTS

At 3 months post-treatment, the degree of hearing recovery was similar between the 2 groups. The pure-tone average was improved from baseline by 17.9±21.2 dB in the steroid group and 18.9±20.7 dB in the pentoxifylline group (p=0.776); hearing recovery rates were also similar (40% vs 39.1%; p=0.826). During hospitalization, average fasting blood sugar levels were higher (203.9±92.0 vs 174.4±54.8 mg/dL; p=0.033) and acute hyperglycemia was more common (48.0% vs 33.1%; p=0.044) with steroid versus pentoxifylline treatment.

CONCLUSION

Hearing recovery rates did not significantly differ between steroid and pentoxifylline treatment in diabetic patients with ISSNHL, but pentoxifylline appeared to be associated with better blood sugar control.