Clinical Practice Guideline: Sudden Hearing Loss (Update) Executive Summary

Vestibular function assessment in Idiopathic sudden sensorineural hearing loss: a prospective study

PURPOSE

Idiopathic sudden sensorineural hearing loss (ISSHL) can cause acute damage not only to the auditory function, but also to the vestibular function in addition to damage to the hearing function. The aim of this study was to perform vestibular assessment using caloric test and video head impulse test in patients with idiopathic sudden sensorineural hearing loss. In addition, to evaluate the relationship of dizziness with vestibular tests and post-treatment responses of vestibular tests.

METHODS

This is an observational, longitudinal and prospective study, including patients diagnosed with idiopathic sudden sensorineural hearing. Patients were divided into two groups according to the presence of vestibular complaints at presentation: Group 1: Patients with vestibular complaints, Group 2: Patients without vestibular complaints. All subjects underwent pure tone audiometry (PTA) testing, cold caloric test and video head impulse test (vHIT) during their admission and on the 10th day, 3rd month, and 1st year of their follow-up outpatient clinic controls. A unilateral weakness (UW) in the caloric test response was quantified according to the Jongkees formula.

RESULTS

A positive and significant relationship was found between the degree of hearing loss according to the ASHA criteria pre-treatment and the level of improvement created according to Siegel criteria at the 10th day, 3rd month, 1st year after treatment (respectively p = 0.001, p = 0.001, p < 0.001). When both short-term and long-term results were evaluated after treatment, a positive improvement in the degree of hearing loss was observed. A statistically significant difference was observed between Groups 1 and 2 when the pre-treatment, at 10 days, 3 months and 1 year after treatment the caloric test UW value was compared (respectively p = 0.020, p = 0.004, p = 0.004, p = 0.004). A statistically significant difference was observed between Groups 1 and 2 when the pre-treatment, at 10 days, 3 months and 1 year after treatment vHIT lateral canal VOR value was compared (respectively p = 0.000, p = 0.001, p = 0.000, p = 0.004). When both short-term and long-term results were evaluated after treatment, a positive improvement was observed in both caloric test results and lateral vHIT VOR values. Pre-treatment, post-treatment 10th day, 3rd month, 1st year vHIT anterior and posterior canal VOR values were found to be VOR˃0.8 in all patients. No difference was observed in anterior and posterior canal VOR values.

CONCLUSION

Vertigo in patients with ISSHL "as objectively confirmed through caloric testing and vHIT" can be considered a sign of severe cochlear damage. Our study demonstrated a significantly increased risk of vestibular affect in patients with ISSHL, especially in the presence of vertigo. Thus, we conclude that the focus in ISSHL should not only be on the cochlea but also on the vestibular system.

Sound Exposure Promotes Intratympanic Drug Delivery to the Inner Ear

OBJECTIVE

To investigate the impact of sound exposure, with the resultant windows vibration on perilymphatic concentrations following intratympanic (IT) dexamethasone and gentamicin in an animal model.

STUDY DESIGN

Animal model blinded study.

SETTING

Animal facility of a tertiary medical center.

METHODS

Bilateral IT dexamethasone or gentamicin was applied to 15 tested rats. Following injections, each rat was exposed for 3 minutes to free field 30 dB sound pressure level (SPL), 512 vHz noise, with 1 external auditory canal plugged (contralateral control). Following noise exposure, perilymph was obtained from both ears. Drug concentrations were measured using ultrahigh-performance liquid chromatography-mass spectrometer.

RESULTS

For dexamethasone, the average (±SD) perilymphatic steroidal concentration was 0.417 µg/mL (±0.549) in the control ears versus 0.487 µg/mL (±0.636) in the sound-exposed ears (P = .008). The average (±SD) gentamicin perilymphatic concentration was 8.628 µg/mL (±2.549) in the sound-exposed ears, compared to 4.930 µg/mL (±0.668) in the contralateral control (nonsound exposed) ears. Sound exposure promoted steroidal and gentamicin diffusion to the inner ear by an averaged (±SD) factor of 1.431 and 1.730 (±0.291 and 0.339), respectively.

CONCLUSION

Low-intensity noise (30 dB SPL) was found to enhance dexamethasone phosphate and gentamicin diffusion to the inner ear (by an averaged factor of ∼1.4 and 1.7, respectively) in a murine model.

A single dose of AC102 restores hearing in a guinea pig model of noise-induced hearing loss to almost prenoise levels

Although sudden sensorineural hearing loss (SSNHL) is a serious condition, there are currently no approved drugs for its treatment. Nevertheless, there is a growing understanding that the cochlear pathologies that underlie SSNHL include apoptotic death of sensory outer hair cells (OHCs) as well as loss of ribbon synapses connecting sensory inner hair cells (IHCs) and neurites of the auditory nerve, designated synaptopathy. Noise-induced hearing loss (NIHL) is a common subtype of SSNHL and is widely used to model hearing loss preclinically. Here, we demonstrate that a single interventive application of a small pyridoindole molecule (AC102) into the middle ear restored auditory function almost to prenoise levels in a guinea pig model of NIHL. AC102 prevented noise-triggered loss of OHCs and reduced IHC synaptopathy suggesting a role of AC102 in reconnecting auditory neurons to their sensory target cells. Notably, AC102 exerted its therapeutic properties over a wide frequency range. Such strong improvements in hearing have not previously been demonstrated for other therapeutic agents. In vitro experiments of a neuronal damage model revealed that AC102 protected cells from apoptosis and promoted neurite growth. These effects may be explained by increased production of adenosine triphosphate, indicating improved mitochondrial function, and reduced levels of reactive-oxygen species which prevents the apoptotic processes responsible for OHC death. This action profile of AC102 might be causal for the observed hearing recovery in in vivo models.

The Effectiveness of Salvage Hyperbaric Oxygen Therapy Following Combined Steroid Therapy for Refractory Sudden Sensorineural Hearing Loss

OBJECTIVE

Hyperbaric oxygen therapy (HBOT) is an accepted treatment option for sudden sensorineural hearing loss (SSNHL), but it is still recommended in combination with corticosteroids. We investigated the efficacy of salvage HBOT in refractory SSNHL that does not respond to corticosteroid combination therapy.

METHODS

Eighty-four patients were included, who had unilateral SSNHL with an improvement of pure-tone average (PTA) less than 10 dB after using intratympanic plus systemic corticosteroids (combined therapy) as the initial therapy. The control group (n = 66) received no further treatment, and the HBOT group (n = 18) received additional treatment with HBOT (10 sessions in total with 2.5 atmospheres absolute for 1 hour).

RESULTS

No differences in PTA or WDS were found between the 2 groups. However, the mean hearing gain in the HBOT group (16.8 ± 4.49 dB) was significantly higher than that in the control group (4.45 ± 1.03 dB) (P = .015). The proportion of patients with hearing recovery (hearing gain of 10 dB or more) after treatment was significantly higher in HBOT group (38.9%) than in the control group (10.6%).

CONCLUSIONS

In patients with refractory SSNHL after steroid combined therapy, salvage HBOT showed a significant effect on hearing gain and recovery rate.

Knowledge of and Attitudes Toward Hearing Loss Among Primary Care Physicians in the Public Health Sector of Mauritius

Introduction  Primary care physicians are essential first points of contact for patients with hearing loss. Thus, knowledge of hearing loss and related aspects is essential to ensure the optimal management of individuals with suspected hearing loss. Objective  This study aimed to determine the knowledge of and attitudes toward hearing loss among primary care physicians in the public health sector in Mauritius. Methods  In this cross-sectional descriptive cohort study, 320 primary care physicians completed an online questionnaire adapted from previous questionnaires on knowledge of and attitudes toward hearing loss. Responses were analyzed using descriptive statistics and cross-sectional analyses. Results  Primary care physicians showed limited knowledge of hearing loss in areas such as early identification and intervention, professionals responsible for hearing assessments, and hearing tests used for assessing hearing sensitivity. However, the responses also showed positive attitudes toward hearing loss. Significant associations between knowledge of and attitudes toward hearing loss were obtained regarding the type of physician, length of practice, and department posted in. Ear, nose, and throat specialists, as well as pediatricians, demonstrated significantly higher scores for both knowledge of and positive attitudes toward hearing loss. Conclusions  The findings highlight a strong need for ongoing medical education to spread awareness about hearing loss among primary care physicians in the public health sector of Mauritius.

Machine Learning Models for Predicting Sudden Sensorineural Hearing Loss Outcome: A Systematic Review

BACKGROUND

Machine Learning models have been applied in various healthcare fields, including Audiology, to predict disease outcomes. The prognosis of sudden sensorineural hearing loss is difficult to predict due to the variable course of the disease. Hence, researchers have attempted to utilize ML models to predict the outcome of patients with sudden sensorineural hearing loss. The objectives of this study were to review the performance of these machine learning models and assess their applicability in real-world settings.

METHODS

A systematic search was conducted in PubMed, Web of Science and Scopus. Only studies that built machine learning prediction models were included, and studies that used algorithms such as logistic regression only for the purpose of adjusting for confounding variables were excluded. The risk of bias was assessed using the Prediction model Risk of Bias Assessment Tool (PROBAST).

RESULTS

After screening, a total of 7 papers were eligible for synthesis. In total, these studies built 48 ML models. The most common utilized algorithms were Logistic Regression, Support Vector Machine (SVM) and boosting. The area under the curve of the receiver operating characteristic curve ranged between 0.59 and 0.915. All of the included studies had a high risk of bias; hence there are concerns regarding their applicability.

CONCLUSION

Although these models showed great performance and promising results, future studies are still needed before these models can be applied in a real-world setting. Future studies should employ multiple cohorts, different feature selection methods, and external validation to further validate the models' applicability.

Differences in semicircular canal function in the video head impulse test in patients in the chronic stage of sudden sensorineural hearing loss with vertigo and vestibular neuritis

BACKGROUND

Sudden sensorineural hearing loss with vertigo (SHLV) and vestibular neuritis (VN) can result in prolonged dizziness.

OBJECTIVES

This study aimed to compare the video head impulse test (vHIT) of patients with SHLV and VN.

METHODS

Fifteen patients with SHLV and 21 patients with VN who visited the Vertigo/Dizziness Center of our hospital between December 2016 and February 2023 were included. vHIT was performed at the time of admission, and the VOR gain and catch up saccade (CUS) in the three types of semicircular canals (SCCs) were analyzed.

RESULTS

Pathologic vHIT results were observed most frequently in the posterior SCC (73%), followed by lateral (53%) and anterior (13%) SCCs in the SHLV group. In contrast, pathologic vHIT results were observed most frequently in the lateral SCC (100%), followed by the anterior (43%) and posterior SCC (24%) SCCs in the VN group. Pathological vHIT results in the lateral and posterior SCC showed significant differences between the two groups, but for anterior SCC, no significant differences were found.

CONCLUSIONS AND SIGNIFICANCE

Comparison of the two vHIT results revealed differences in the SCC dysfunction patterns. This may be due to the different pathophysiological mechanisms of the two vestibular disorders, which may result in prolonged vertigo.

Easing the Burden of Tinnitus: A Narrative Review for Exploring Effective Pharmacological Strategies

Many individuals seek medical attention for tinnitus, desiring relief from the distress caused by the condition; however, the treatment process is far from straightforward. The most effective treatments for chronic subjective tinnitus, such as tinnitus retraining therapy (TRT) and cognitive behavioral therapy (CBT), require considerable time and efforts. As a result, many of them express a desire for alleviation through medication. While it is true that medication is not generally recommended in treatment guidelines for chronic subjective tinnitus, in specific situations such as when accompanied by symptoms of depression or anxiety-drugs like antidepressants or anxiolytics may have a meaningful impact on symptom reduction. Additionally, medication can prove effective in certain specialized forms of tinnitus, such as typewriter tinnitus, as opposed to chronic subjective tinnitus. Although intratympanic dexamethasone injections for tinnitus have been reported to lack efficacy compared to a placebo, if patients perceive subjective satisfaction due to a placebo effect, it holds significance. From the perspective of patients suffering from tinnitus, even if the therapeutic mechanism is set aside, experiencing some degree of relief through certain medications can enhance compliance with evidence-based treatments like TRT and CBT.

Management of Sudden Sensorineural Hearing Loss in Multiple Sclerosis: A Comprehensive Case Report of a Patient with Bilateral Loss and Literature Review

In multiple sclerosis (MS), the occurrence of sudden sensorineural hearing loss (SSNHL) is considered rare, with reported cases predominantly being unilateral. Bilateral cases are even rarer. Here, we report a case of bilateral SSNHL in a 20-year-old male diagnosed with MS. The patient, undergoing corticosteroid therapy for the management of MS, additionally received an intratympanic dexamethasone injection; however, it could not achieve significant improvement. Subsequently, the systemic dosage was increased for one week, resulting in substantial hearing improvement in both ears after three months. A review of MS-related SSNHL cases from 1987 to 2022 revealed 39 ears in the literature, with only five ears showing no hearing recovery. A remarkable 87.2% exhibited restored hearing, presenting a more favorable prognosis compared with idiopathic SSNHL. Although there were slight variations in administration methods and duration, all documented treatment approaches involve systemic corticosteroids. In some instances, SSNHL manifested as the initial symptom of MS. When SSNHL occurs in MS, auditory brainstem response (ABR) tests may reveal prolonged abnormalities, making ABR testing effective in cases where MS is suspected following SSNHL. In conclusion, the treatment of MS-related SSNHL appears appropriate with systemic corticosteroids, showing a significantly superior prognosis compared with idiopathic SSNHL.

High-Dose Glucocorticoids for Treating Sudden Hearing Loss: Cart before the Horse?

Hearing impairment is the most common sensory deficit. It affects 2 to 3 of 1000 newborns and nearly 50% of adults 75 years of age and older in the United States.1 Idiopathic sudden sensorineural hearing loss (ISSNHL) is characterized by an abrupt hearing loss requiring immediate diagnosis and treatment. Systemic glucocorticoids are widely used as the primary treatment for ISSNHL,2 but no head-to-head comparisons of the effectiveness and risk profiles of high doses over a more commonly used lower dose of glucocorticoids have been conducted to inform standard-of-care practice.

Functional to structural plasticity in unilateral sudden sensorineural hearing loss: neuroimaging evidence

A cortical plasticity after long-duration single side deafness (SSD) is advocated with neuroimaging evidence while little is known about the short-duration SSDs. In this case-cohort study, we recruited unilateral sudden sensorineural hearing loss (SSNHL) patients and age-, gender-matched health controls (HC), followed by comprehensive neuroimaging analyses. The primary outcome measures were temporal alterations of varied dynamic functional network connectivity (dFNC) states, neurovascular coupling (NVC) and brain region volume at different stages of SSNHL. The secondary outcome measures were pure-tone audiograms of SSNHL patients before and after treatment. A total of 38 SSNHL patients (21 [55%] male; mean [standard deviation] age, 45.05 [15.83] years) and 44 HC (28 [64%] male; mean [standard deviation] age, 43.55 [12.80] years) were enrolled. SSNHL patients were categorized into subgroups based on the time from disease onset to the initial magnetic resonance imaging scan: early- (n = 16; 1-6 days), intermediate- (n = 9; 7-13 days), and late- stage (n = 13; 14-30 days) groups. We first identified slow state transitions between varied dFNC states at early-stage SSNHL, then revealed the decreased NVC restricted to the auditory cortex at the intermediate- and late-stage SSNHL. Finally, a significantly decreased volume of the left medial superior frontal gyrus (SFGmed) was observed only in the late-stage SSNHL cohort. Furthermore, the volume of the left SFGmed is robustly correlated with both disease duration and patient prognosis. Our study offered neuroimaging evidence for the evolvement from functional to structural brain alterations of SSNHL patients with disease duration less than 1 month, which may explain, from a neuroimaging perspective, why early-stage SSNHL patients have better therapeutic responses and hearing recovery.

Assessment of prognostic biomarkers in sudden sensorineural hearing loss: A systematic review and meta-analysis

Sudden sensorineural hearing loss (SSNHL) is defined as hearing loss of more than 30 dB in less than 72 h. SSNHL is a frequent complaint and an emergency in otolaryngology. Various biomarkers have been used to determine the prognosis of SSNHL. This systematic review and meta-analysis aims to evaluate the relationship between the different biomarkers and the prognosis of SSNHL. We searched English-language literature up to October 2022 in four databases, including PubMed, Google Scholar, Cochrane, and Science Direct. This search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. This study was reported in the International Prospective Register of Systematic Reviews (PROSPERO) database (ID = CRD42022369538). All studies examining the role of neutrophil to lymphocyte ratio (NLR) concluded that higher NLR is associated with a worse prognosis. The results of studies regarding the relationship between platelet to lymphocyte ratio (PLR) and tumor necrosis factor (TNF) are controversial. Other factors shown to be associated with SSNHL include Glycated hemoglobin (HbA1C), blood glucose, iron levels, serum endocan, salusin-beta, and bone turnover biomarkers. This meta-analysis showed that PLR, NLR, and neutrophils were significantly different between recovered and non-recovered patients. PLR, NLR, and neutrophil count are reliable tools to assess the prognosis of patients with SSNHL.

Clinical utility of inflammatory biomarkers in COVID-19-related sudden sensorineural hearing loss

BACKGROUND

The etiology and pathophysiological mechanisms of sudden sensorineural hearing loss (SSNHL) remain unclear, but it is generally believed to be associated with viral infections, vascular diseases, and autoimmune disorders. Considering that coronavirus disease 2019 (COVID-19) is promising candidates for SSNHL, we studied the immune cells changes by COVID-19 in patients with SSNHL.

METHODS

We collected data from 47 patients with SSNHL and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive. Patients were divided into ineffective or effective groups based on the degree of hearing recovery at discharge. Clinical information was collected and processed for both groups. Logistic regression models were used to determine the risk factors for an unfavorable prognosis in COVID-19-related SSNHL. Receiver operating characteristic (ROC) curves were used to estimate the predictive value.

RESULTS

There was statistically significant difference in C-reactive protein (CRP), auditory curve, degree decline, pretreatment hearing, posttreatment hearing, systolic blood pressure, diastolic blood pressure, total bilirubin, neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), indirect-bilirubin and platelet count between groups (p < 0.05). In the logistic regression model, high levels of SII and NLR were associated with treatment ineffectiveness, pre- and postcorrectively (both, p < 0.05). And ROC curve analysis showed higher AUC of 0.765 for SII, 0.697 for NLR,0.681 for CRP, and 0.553 for platelet-to-lymphocyte ratio (PLR) in predicting treatment outcomes.

CONCLUSION

The prognosis of COVID-19-related SSNHL was associated with inflammation. SII, NLR and CRP could serve as predictive markers of unfavorable outcomes in COVID-19-related SSNHL. SII may be considered an independent risk factor for poor prognosis in COVID-19-related SSNHL.

The prognostic value of peripheral blood parameters on all-frequency sudden sensorineural hearing loss

OBJECTIVE

To determine whether peripheral blood parameters have any predictive value for all-frequency Sudden Sensorineural Hearing Loss (SSNHL).

METHODS

We chose 78 individuals with all-frequency SSNHL who had been admitted to our department. They were divided into two groups: the effective group and the ineffective group. In patients with all-frequency SSNHL, the prognostic variables, including peripheral blood tests and clinical traits, were examined by a logistic regression analysis. In addition, the predictive value was carried out.

RESULTS

The effective rate of all-frequency SSNHL was 61.5%. Pre-treatment hearing level and the proportion of patients with diabetes were both significantly lower in the effective group than in the ineffective group (p = 0.024 and 0.000, respectively). The levels of fibrinogen and C-reactive protein were also significantly different between the two groups (p = 0.001 and 0.025, respectively). Pre-treatment hearing level and fibrinogen level both significantly impacted the prognosis of all-frequency SSNHL (p = 0.032 and 0.002, respectively), according to a logistic regression analysis. Furthermore, the prognosis was significantly predicted by both fibrinogen level and pre-treatment hearing level (p = 0.001 and 0.0002, respectively). The receiver operating characteristic curve showed that the fibrinogen level had a sensitivity of 85.4% and a specificity of 60.0% for predicting the prognosis of all-frequency SSNHL.

CONCLUSION

For the prognosis of all-frequency SSNHL, the fibrinogen level can be regarded as a useful predictor. The level of C-reactive protein, however, does not have a significant prognostic effect on predicting all-frequency SSNHL. Therefore, more attention should be devoted to the level of fibrinogen in the acute period of all-frequency SSNHL.

LEVEL OF EVIDENCE: 4

Analysis of Clinical Efficacy and Influencing Factors of Nerve Growth Factor (NGF) Treatment for Sudden Sensorineural Hearing Loss

Objective: This study aims to examine the clinical efficacy and prognostic factors associated with nerve growth factor (NGF) treatment for sudden sensorineural hearing loss (SSHL). Materials and methods: A retrospective analysis was conducted on the clinical data of 101 patients with moderate or more severe SSHL who underwent secondary treatment at Sun Yat-sen Memorial Hospital of Sun Yat-sen University between January 2019 and July 2020. Prior to treatment, all patients were assessed using Pure Tone Audiometry (PTA), auditory brainstem response, otoacoustic emission, temporal bone computed tomography, or inner ear magnetic resonance imaging. Fifty-seven patients received conventional systemic treatment and served as the control group, while 44 patients received NGF in conjunction with conventional systemic treatment, forming the experimental group. PTA results were compared between the two groups before treatment and at 1 week, 2 weeks, and 1 month post-treatment. Additionally, the impact of age, sex, affected side, hypertension, and other factors on patient prognosis was analyzed. Results: Both groups demonstrated significant PTA improvements following treatment, with a statistically significant difference (P < .05). The hearing recovery effective rate in the control group was 42.1%, while that of the experimental group reached 70.5%, with a statistically significant difference between the groups (P < .05). Most patients experienced notable hearing improvements 1 week after treatment, with some patients still showing progress 2 weeks post-treatment. Multifactor analysis revealed that hypertension and onset days were associated with treatment outcomes. Conclusion: Secondary treatment remains clinically significant for patients with SSHL who have not achieved a satisfactory response or show no clear improvement following initial treatment. The presence of hypertension and delayed treatment are negative factors related to treatment efficacy.

Research progress on the treatment and nursing of sensorineural hearing loss

This article provides a comprehensive review of the progress in the treatment and care of sensorineural hearing loss (SNHL), which is a common disease in the field of otolaryngology. In recent years, the incidence of SNHL has been on the rise due to factors such as fast-paced lifestyles, work pressure, and environmental noise pollution, which have a significant impact on the quality of life of patients. Therefore, the study of the treatment and care of SNHL remains a hot topic in the medical community. Despite significant advances in this field, there are still some challenges and limitations. For example, there is currently no single method that can completely cure SNHL, and the effectiveness of treatment may vary significantly among individuals. In addition, due to the complex etiology of SNHL, the prognosis of patients may vary greatly, requiring the development of personalized treatment plans and care strategies. To address these challenges, continuous research is needed to explore new treatment methods and care models to improve the quality of life of patients. In addition, there is a need for health education programs for the general public to raise awareness of SNHL and promote preventive measures to reduce its incidence. The ultimate goal is to ensure the sustainable development of the field of SNHL treatment and care, thus ensuring the health and well-being of affected individuals.

Etiological analysis of patients with sudden sensorineural hearing loss: a prospective case-control study

Sudden sensorineural hearing loss (SSNHL) is a multifactorial emergency disease. Until now, the etiology of SSNHL is still unknown. Previous studies regarding the etiology of SSNHL are clinical studies depending on clinical data collection and analysis. Due to the insufficient sample size or various selective bias in clinical studies, the results of these studies may be inaccurate. This prospective case-control study aimed at exploring the possible etiology and risk factors of SSNHL. We enrolled 255 SSNHL patients and 255 sex-, age- and residence-matched non-SSNHL subjects in the control group. Our study shows that there was no significant difference in the prevalence of comorbidities including hypertension and diabetes, as well as the incidence of smoking and drinking habits between the case and control groups (P > 0.05). In addition, the peripheral blood white blood cell count, neutrophil count, platelet-to-lymphocyte ratio (PLR) and fibrinogen level of the case group were significantly higher than those in the control group (P < 0.05). These findings suggest smoking, drinking, hypertension and diabetes may not be related to the onset of SSNHL. However, hypercoagulable state and inner ear vascular microthrombosis related to an elevated fibrinogen level might be the risk factors of the disease. In addition, inflammation play an important role of SSNHL onset.Trial Registration: Chinese Clinical Trial Registry. Registration number: ChiCTR2100048991.

Could the Audiometric Criteria for Sudden Sensorineural Hearing Loss Miss Vestibular Schwannomas?

OBJECTIVE

To investigate the likelihood of missing a vestibular schwannoma (VS) diagnosis in patients who present with a sudden hearing loss (SHL) that does not meet the most accepted audiometric criteria for sudden sensorineural hearing loss (SSNHL) (a decrease of ≥30 dB at three consecutive frequencies).

METHODS

All adult patients (>18 years) diagnosed with SHL of any severity in a tertiary care referral medical center between 2015 and 2020 and who underwent an MRI scan to rule out VS were included. Statistical analyses were conducted to evaluate the difference between the rate of VS among patients with an initial audiogram, which met the abovementioned criteria, and those who did not. Other audiometric criteria for SNHL were also evaluated (≥10 dB at ≥2 frequencies and ≥ 15 dB at one frequency).

RESULTS

Of the 332 patients included in the study, 152 met the audiometric criteria for SSNHL, and 180 did not. Both groups had a similar VS rate (8.6% vs. 8.9%, p = 0.914). Similar results were found when other audiometric criteria for asymmetric SNHL were analyzed. In a subgroup analysis of patients with VS-associated SSNHL, neither the tumor size nor the Koos classification was associated with any of the audiometric criteria systems.

CONCLUSION

There should be a high index of suspicion for the presence of VS in patients with an SHL of any severity.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:670-675, 2023.

The relationship between serum lipid and sudden sensorineural hearing loss

BACKGROUND

Hyperlipidemia may be part of the important mechanisms for the development of idiopathic sudden sensorineural hearing loss (ISSNHL).

AIMS

So the purpose of this study was to evaluate the relationship between changes in blood lipid levels and ISSNHL.

MATERIALS AND METHODS

We enrolled 90 ISSNHL patients in our hospital using a retrospective study design from 2019.1 to 2021.12. Blood levels of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL-C). Hearing recovery was analyzed using the chi-square test and one-way analysis of variance (ANONA). Univariate and multifactorial Logstic retrospective analyses to establish the relationship between LDL-C/HDL-C ratio and hearing recovery after adjustment for potential confounding factors.

RESULTS

In our study, 65 (72.2%) patients had their hearing recovered. All group analyses and three group analyses (i.e. Excluding the no-recovery group) found that LDL/HDL was on an upward trend from complete recovery to a slight recovery group and strongly associated with hearing recovery. Univariate and multivariate logistic regression analysis found high levels of LDL and LDL/HDL in the partial hearing recovery group, relative to the full hearing recovery group. Curve fitting intuitively demonstrates the influence of blood lipids on prognosis.

CONCLUSIONS

Our findings suggest that LDL. TC, TC/HDL, and LDL/HDL concentrations may be closely related to the pathogenesis of ISSNHL.

SIGNIFICANCE

Improving the relevant lipid test at the time of admission to the hospital has good clinical significance for improving the prognosis of ISSNHL.

Melatonin Alleviates the Oxygen-Glucose Deprivation/Reperfusion-Induced Pyroptosis of HEI-OC1 Cells and Cochlear Hair Cells via MT-1,2/Nrf2 (NFE2L2)/ROS/NLRP3 Pathway

Substantial evidence suggests that pyroptosis is involved in renal, cerebral, and myocardial ischemia-reperfusion injury. However, whether pyroptosis is involved in ischemia-reperfusion injury of cochlear hair cells has not been explored. In this study, we examined the effects of melatonin on the oxygen-glucose deprivation/reperfusion (OGD/R) of hair cell-like House Ear Institute-Organ of Corti 1 (HEI-OC1) cells and cochlear hair cells in vitro to mimic cochlear ischemia-reperfusion injury in vivo. We found that melatonin treatment protected the HEI-OC1 and cochlear hair cells against OGD/R-induced cell pyroptosis and reduced the expression level of ROS in these cells. However, these effects were completely abolished by the application of luzindole (a non-selective melatonin receptor blocker) and largely offset by the use of ML385 (an nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor). These findings suggest that melatonin alleviates OGD/R-induced pyroptosis of the hair cell-like HEI-OC1 cells and cochlear hair cells via the melatonin receptor 1A (MT-1) and melatonin receptor 1B (MT-2)/Nrf2 (NFE2L2)/ROS/NLRP3 pathway, which may provide credible evidence for melatonin being used as a potential drug for the treatment of idiopathic sudden sensorineural hearing loss in the future.

Analysis of clinical features and prognostic correlation factors of sudden sensorineural hearing loss in children

OBJECTIVE

This study aimed to investigate the clinical features and prognostic correlation factors of sudden sensorineural hearing loss in children (CSSNHL).

METHODS

From January 2016 to December 2021, the clinical data of hospitalized children presenting with sudden sensorineural hearing loss, including age, gender, the ear of onset, onset of treatment, concomitant symptoms, the degree of hearing loss, and audiogram curve type, were retrospectively collected and the effective rate of treatment and the factors affecting prognosis were statistically analyzed.

RESULTS

The effective rate of CSSNHL was 29.97%. Univariate analyses showed that the onset of treatment, the degree of hearing loss, audiogram curve type, and tinnitus were associated with prognosis (P < 0.05). Multivariate analyses showed that onset of treatment was correlated with prognosis (OR = 0.939, 95% CI = 0.911-0.969, P < 0.001). Compared with patients in the profound group, the therapeutic performance of the severe, moderate, and mild groups were significantly different (OR = 9.951, 11.264, 13.373, 95% CI = 2.311-42.856, 2.818-45.028, and 5.310-33.677, P < 0.05). Compared with patients with profound audiogram, ascending audiogram and flat audiogram were related to therapeutic performance (OR = 13.373 and 14.481, 95% CI = 5.310-33.677, 6.509-32.217, P < 0.001).

CONCLUSIONS

The prognosis of CSSNHL patients was related to the onset of treatment, the degree of hearing loss, and the audiogram curve type. Patients who received earlier treatment, had lighter hearing loss and the ascending and flat audiograms exhibited improved prognosis.

Inflammatory markers and the risk of idiopathic sudden sensorineural hearing loss: A Mendelian randomization study

Background

Observational studies suggest that inflammatory markers may increase the risk of idiopathic sudden sensorineural hearing loss (ISSHL). However, the causal relationship between the two has not been established. We sought to assess the possible causal effect between several genetically predicted inflammatory markers and ISSHL by Mendelian random (MR) analysis.

Methods

We extracted single nucleotide polymorphisms (SNPs) associated with C-reactive protein (CRP), Tumor necrosis factor-α (TNF-α), and fibrinogen from abstract data from the European Individual Large genome-wide association studies (GWAS). Genetic data for ISSHL were obtained from the FinnGen study (n = 196,592). Effect estimates were assessed using inverse variance weighting (IVW) as the primary method. Sensitivity analyses were performed using weighted median, MR-Egger, and MR-PRESSO to evaluate heterogeneity and pleiotropy.

Results

In the random-effects IVW approach, there was a significant causal relationship between genetic susceptibility to CRP levels and ISSHL (OR = 1.23, 95% CI = 1.02-1.49, P = 0.03). In contrast, genetic TNF-α and fibrinogen were not risked factors for ISSHL (OR = 1.14, 95% CI = 0.88-1.49, P = 0.30; OR = 0.74, 95% CI = 0.07-7.96, P = 0.30; OR = 1.05, 95% CI = 0.88-1.25, P = 0.59). All the above results were consistent after validation by different Mendelian randomization methods and sensitivity analyses.

Conclusion

This Mendelian randomization study provides causal evidence that CRP is a risk factor for ISSHL, while TNF-α and fibrinogen do not increase the risk for ISSHL Introduction.

Potential molecular mechanisms of Erlongjiaonang action in idiopathic sudden hearing loss: A network pharmacology and molecular docking analyses

Background

Idiopathic sudden hearing loss (ISHL) is characterized by sudden unexplainable and unilateral hearing loss as a clinically emergent symptom. The use of the herb Erlongjiaonang (ELJN) in traditional Chinese medicine is known to effectively control and cure ISHL. This study explored the underlying molecular mechanisms using network pharmacology and molecular docking analyses.

Method

The Traditional Chinese Medicine System Pharmacological database and the Swiss Target Prediction database were searched for the identification of ELJN constituents and potential gene targets, respectively, while ISHL-related gene abnormality was assessed using the Online Mendelian Inheritance in Man and Gene Card databases. The interaction of ELJN gene targets with ISHL genes was obtained after these databases were cross-screened, and a drug component-intersecting target network was constructed, and the gene ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes, and protein-protein interaction networks were analyzed. Cytoscape software tools were used to map the active components-crossover target-signaling pathway network and screened targets were then validated by establishing molecular docking with the corresponding components.

Result

Erlongjiaonang contains 85 components and 250 corresponding gene targets, while ISHL has 714 disease-related targets, resulting in 66 cross-targets. The bioinformatical analyses revealed these 66 cross-targets, including isorhamnetin and formononetin on NOS3 expression, baicalein on AKT1 activity, and kaempferol and quercetin on NOS3 and AKT1 activity, as potential ELJN-induced anti-ISHL targets.

Conclusion

This study uncovered potential ELJN gene targets and molecular signaling pathways in the control of ISHL, providing a molecular basis for further investigation of the anti-ISHL activity of ELJN.

Sudden Sensorineural Hearing Loss in the COVID-19 Pandemic: A Systematic Review and Meta-Analysis

INTRODUCTION

Accumulating data indicate that patients with COVID-19 could be affected by sudden sensorineural hearing loss (SSNHL). The aim of the study was to analyze the epidemiological and clinical trend of SSNHL occurrence during the COVID-19 pandemic by applying a systematic review and meta-analysis approach.

METHODS

PubMed, Scopus, Web of Science, ScienceDirect, and Cochrane databases were searched.

RESULTS

The seven included studies had adequate relevance to the topic and the quality was fair. The mean age at SSNHL onset ranged from 39.23 to 62.18 years during the pandemic year period (PYP); a meta-analysis of four studies comparing these data with those of previous periods in the same institutions found a younger age during the PYP (pooled mean -0.2848). The heterogeneity was high (76.1935%) and no frank asymmetry was observed in the funnel plot. The SARS-CoV-2 positivity rate of SSNHL patients ranged from 0% to 57.53%. Standard steroid treatments were applied without significant adverse effects. Comprehensively, hearing improvement was achieved for more than half of the cases. No studies reported long-term follow-up data.

CONCLUSIONS

Further prospective analyses on large series and a long-term follow up on COVID-related SSNHL cases are necessary to address the open questions regarding the causative link between COVID-19 infection and SSNHL.

Predictive factors for recovery in idiopathic sudden sensory neural hearing loss

Background

Idiopathic sudden sensorineural hearing loss (ISSNHL) is considered a clinical symptom of various conditions. Circulatory disorders, viral infection, labyrinthine membrane rupture, and autoimmune reactions are considered as the common causes, but the exact cause remains unestablished. Various drugs and methods have been used empirically for the treatment of ISSHL. The current study aimed at evaluation factors contributing to the success of standardized medical therapy in cases of ISSNHL.

Methods

In period between 2019 and 2021, a total 40 patients with ISSNHL were enrolled. All patients were subjected to history taking, physical and ENT evaluation. Patients were managed according to the recent guidelines for managing ISSNHL included systemic steroid and salvage therapy.

Results

Mean age of studied patients was 42.55 ± 13.14 years with range between 19 and 70 years. Out of the studied patients; 26 (65%) patients were males and 14 (35%) patients were females. Majority (80%) of patients had no comorbidities. Based on the current study, we found that only 12 (30%) patients were improved while 28 (70%) patients were not improved. It was found that majority (58.3%) of improved patients was females. Frequency of vertigo was significantly higher among patients who were not improved. Three (10.7%) patients of not-improved group and 5 (41.7%) patients of improved group had low lymphocyte:monocytes ratio.

Conclusion

Patients with ISSNHL, the presence of vertigo and late onset of presentation may carry a risk for poor prognosis. Multiple centers studies with large number of patients are warranted to confirm such findings.

Intratympanic Dexamethasone in Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss can be a frightening experience for the sufferer and needs immediate treatment. Systemic steroid therapy has been the mainstay of treatment of this condition but concerns about their side effects has led to their use by intratympanic injection. We studied the results of intratympanic dexamethasone (IT-Dexa) both as a primary therapy and as salvage treatment after failure of oral steroids. A total of 39 patients of SSNHL were studied prospectively. Of these 23 were given oral steroids. Ten of these showed no response and were treated with IT-Dexa 4 mg/ml twice a week for two weeks. In addition, 16 patients who reported later than two weeks or had concomitant medical disorders like diabetes and/or hypertension were treated with IT-Dexa. While oral steroids showed hearing improvement (≥ 10 dB) in 56.5% patients, the recovery rate was 62.5% and 80% in those treated primarily with IT-Dexa and as salvage therapy respectively. There was a negative correlation of delay in institution of treatment with hearing recovery. Conclusion: intratympanic dexamethasone is a safe and effective treatment and should be offered to patients as a primary treatment modality and also as salvage therapy after failure of oral steroids. For best results the treatment should be started at the earliest.

Is Idiopathic Sudden Sensorineural Hearing Loss Seasonal?

OBJECTIVE

To investigate the circannual rhythm (seasonal incidence) of idiopathic sudden sensorineural hearing loss (ISSNHL).

METHODS

Data were retrieved from the medical files of an original cohort of all consecutive patients with ISSNHL in a tertiary medical center between 2012 and 2020. A systematic literature search of "MEDLINE" via "PubMed," "Embase," and "Web of Science" on comparable published cases was performed. A Google Trends analysis of the term [sudden hearing loss] and related terms between 2014 and 2020 was also performed.

RESULTS

Most of the published series (9/12) reported the highest ISSNHL incidence in the spring and the lowest in the winter (8/12). In our local series, the incidence during the winter was significantly lower than that for the other seasons by a factor of 0.69 (95% confidence interval, 0.65-0.77; p = 0.041; r = 0.36). Google Trends data showed no significant correlation between the calendric month and the incidence of ISSNHL in any of the analyzed countries ( p = 0.873, r2 = 0.029).

CONCLUSION

The ISSNHL incidence was lowest during the winter season in our cohort and reported for other cohorts worldwide. Google Trends-based model analysis did not determine any circannual rhythm.

Safety and audiological outcome in a case series of tertiary therapy of sudden hearing loss with a biodegradable drug delivery implant for controlled release of dexamethasone to the inner ear

Background

Intratympanic injections of glucocorticoids have become increasingly common in the treatment of idiopathic sudden sensorineural hearing loss (ISSHL). However, due to their fast elimination, sustained applications have been suggested for local drug delivery to the inner ear.

Materials and methods

The study is based on a retrospective chart review of patients treated for ISSHL at a single tertiary (university) referral center. We included patients who were treated with a solid, biodegradable, poly(D,L-lactic-co-glycolic acid) (PLGA)-based drug delivery system providing sustained delivery of dexamethasone extracochlear into the round window niche (n = 15) or intracochlear into scala tympani (n = 2) for tertiary therapy of ISSHL in patients without serviceable hearing after primary systemic and secondary intratympanic glucocorticoid therapy. We evaluated the feasibility and safety through clinical evaluation, histological examination, and functional tests [pure-tone threshold (PTA), word recognition scores (WRS)].

Results

With adequate surgical preparation of the round window niche, implantation was feasible in all patients. Histologic examination of the material in the round window niche showed signs of resorption without relevant inflammation or foreign body reaction to the implant. In patients where the basal part of scala tympani was assessable during later cochlear implantation, no pathological findings were found. In the patients with extracochlear application, average preoperative PTA was 84.7 dB HL (SD: 20.0) and 76.7 dB HL (SD: 16.7) at follow-up (p = 0.08). The preoperative average maximum WRS was 14.6% (SD: 17.9) and 39.3% (SD: 30.7) at follow-up (p = 0.11). Six patients (40%), however, reached serviceable hearing. The two patients with intracochlear application did not improve.

Conclusion

The extracochlear application of the controlled release system in the round window niche and – based on limited observations - intracochlear implantation into scala tympani appears feasible and safe. Due to the uncontrolled study design, conclusions about the efficacy of the treatment are limited. These observations, however, may encourage the initiation of prospective controlled studies using biodegradable controlled release implants as drug delivery systems for the treatment of inner ear diseases.

Probability of clinically significant hearing recovery following salvage intratympanic steroids for sudden sensorineural hearing loss in the ‘real world’

Objective

This study aimed to determine the probability of hearing recovery in patients with idiopathic sudden sensorineural hearing loss following salvage intratympanic steroids

Method

A retrospective review of all patients receiving salvage intratympanic steroid injections for idiopathic sudden sensorineural hearing loss was performed (January 2014 to December 2019). Twenty-two patients were identified, of whom 15 met inclusion criteria. Pre- and post-treatment audiograms were compared with the unaffected ear. Hearing recovery was categorised based on American Academy of Otolaryngology Head and Neck Surgery criteria.

Results

Only 1 patient out of 15 (6.7 per cent) made a partial recovery, and the remainder were non-responders. The median duration of time between symptom onset and first salvage intratympanic steroid treatment was 52 days (range, 14–81 days). No adverse reactions were observed.

Conclusion

‘Real world’ patients with idiopathic sudden sensorineural hearing loss present differently to those in the literature. Sudden sensorineural hearing loss should be diagnosed with care and intratympanic steroid injections initiated early if considered appropriate. Patients should make an informed decision on treatment based on prognostic factors and local success rates.

Sudden sensorineural hearing loss as the initial symptom in patients with acoustic neuroma

Background

Previous studies have shown that patients with acoustic neuroma (AN) sometimes present with sudden sensorineural hearing loss (SSNHL) as an initial symptom. The purpose of this research was to investigate the clinical characteristics, diagnosis, and treatment of AN in patients initially diagnosed with SSNHL.

Materials and methods

We reviewed retrospectively the medical records of all patients who were treated as SSNHL initially and were later diagnosed with AN after undergoing magnetic resonance imaging (MRI) at our hospital between 2008 and 2021. Patient demographics, associated complaints (mostly tinnitus and vertigo), the severity of hearing loss, audiogram configurations, auditory brainstem response (ABR), and MRI examination were reviewed and analyzed. In addition, treatment outcomes and management protocols were also included in this study.

Results

A total of 10 (0.7%, 10/1,383) patients presented with SSNHL as the initial symptom and were diagnosed as AN by MRI finally. Of the 10 patients enrolled in this study, four were men and six were women. The average age at the time of diagnosis of SSNHL was 46.2 ± 13.16 years. These patients exhibited varying severity of hearing loss and a variety of audiogram configurations. All patients showed an abnormal ABR. According to the Koos grading standard, there were 5 grade I (intracanalicular [IAC]) tumors, 3 grade II tumors, and 2 grade III tumors. The treatment outcome revealed that 2 patients exhibited recovery of the average hearing of impaired frequency by more than 15 dB, and 6 patients showed no recovery. Furthermore, four patients were referred to undergo surgical treatment after being diagnosed with AN, 1 patient accepted stereotactic radiation therapy, and the remaining 5 patients were on a “wait and scan” strategy.

Conclusion

The hearing loss of patients with AN presented with SSNHL may improve with drug treatment. Hearing recovery for SSNHL does not exclude the presence of AN, and all patients initially diagnosed with SSNHL should undergo MRI and ABR to prevent misdiagnosis and delays in potential treatment.

Digging into the Role of Inflammatory Biomarkers in Sudden Sensorineural Hearing Loss Diagnosis and Prognosis: A Systematic Review and Meta-Analysis

Background and Objectives: Sudden Sensorineural Hearing Loss (SSNHL) is a quite common clinical finding in otolaryngology. Most cases are classified as idiopathic and there is a dearth of information on factors able to predict the response to treatment and hearing recovery. The main aim of this systematic review and meta-analysis was to assess and critically discuss the role of circulating inflammatory biomarkers in SSNHL. Materials and Methods: A search was conducted of the English literature published between 1 January 2009 and 7 July 2022 on Pubmed, Scopus, Web of Science, ScienceDirect, and Cochrane following PRISMA guidelines. Results: A total of 256 titles were retrieved from the search. After full-text screening and application of inclusion/exclusion criteria, 13 articles were included. Twelve out of thirteen studies reported significant differences in biomarkers values in SSNHL patients, of which Tumor Necrosis Factor alpha (TNF-α) and C-reactive Protein (CRP) were the most analyzed. Our meta-analysis for CRP’s mean values in SSNHL groups vs. controls showed significantly higher CRP levels with a pooled overall difference of 1.07; confidence interval (CI) at 95%: 0.03; 2.11. For TNF-α, discordant results were found: three studies showed significantly higher levels in SSNHL patients vs. controls, whereas other three investigations showed lower levels in the SSNHL groups (overall pooled difference 1.97; 95% CI: −0.90; 4.84). A high between-study heterogeneity was found. Conclusions: This systematic review pointed out that, although there exists a growing literature in the field of circulatory biomarkers identification in SSNHL, there is a high heterogeneity of results and low quality of evidence. CRP resulted to be higher in SSNHL patients than in controls, while TNF-α showed more heterogeneous behavior. The data reported herein needs to be confirmed in well-designed prospective multicenter randomized studies, with the objective of improving SSNHL treatment and outcome and thereby reducing the social burden of hearing loss.

Thromboelastography Predicting the Prognosis of Sudden Sensorineural Hearing Loss

OBJECTIVES

To explore the association between thromboelastography and the clinical features as well as the prognosis of sudden sensorineural hearing loss (SSNHL).

DESIGN

Single-centre, retrospective study.

SETTING

A hospital in China PARTICIPANTS: In total, 133 patients presenting with SSNHL within 2 weeks before the study, who did not receive treatment.

MAIN OUTCOME MEASURES

The patients' medical history was collected. Audiological, imaging, and haematological examinations were performed before treatment. Patients with abnormal thromboelastography were re-examined 1 week after treatment, and efficacy was evaluated 1 month after treatment. The chi-squared test and binary logistic regression analysis were used to analyse the association between factors, such as vertigo, degree and type of hearing loss, vestibular function, inner ear MRI results, thromboelastography, and efficacy of treatment.

RESULTS

Thromboelastography was correlated with prognosis (P=0.049) and degree (P=0.030) and type of hearing loss (P=0.013) in patients with SSNHL. The R (P=0.002) and angle values (P=0.010) correlated with prognosis. The MA (P=0.022) and G values (P=0.020) correlated with the degree of hearing loss. The R (P=0.033) value correlated with inner ear MRI results, and the ΔG (P=0.010) value correlated with fibrinogen levels. ΔThromboelastography (P=0.032) was correlated with the prognosis of patients with abnormal thromboelastography results. Logistic regression analysis showed that thromboelastography correlated with prognosis (P=0.013), and Δthromboelastography correlated with the prognosis of patients with abnormal thromboelastography results (P=0.013) and vertigo (P=0.016).

CONCLUSION

Thromboelastography is an independent risk factor affecting the prognosis of SSNHL with the R and angle values playing a major role.

Correlation Between the Prognosis of Sudden Total Deafness and the Peripheral Blood Inflammation Markers

Objective

To analyze the correlation between prognosis of sudden total deafness (STD) and peripheral blood inflammation markers including white blood cell count (WBC), monocytes, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), fibrinogen (FIB).

Methods

125 patients with STD who were hospitalized in our department from 2014 to 2019 were enrolled. The general physical conditions, clinical manifestations, pure tone audiometry, imaging examination, and peripheral blood inflammation markers were collected, and all patients were divided into effective and ineffective two groups according to the degree of hearing recovery at the time of discharge. Then binary logistic regression was used to analyze the correlation between multiple factors and prognosis, meanwhile the receiver operating characteristic (ROC) curve was used to evaluate the predictive value of the above prognostic factors.

Results

Compared with the ineffective group, patients in the effective group were younger and have higher PLR level and lower FIB levels. Age and PLR are independent prognostic factors. Taking age ≤ 56 years old, PLR >142.6 as the standard to predict the prognosis of patients with STD has the largest AUC with the potential effective rate reaching 78.1%.

Conclusions

Age and PLR are independent prognostic factors for patients with STD. The younger the age and the higher the PLR, the better the prognosis. Clinically, the prognosis of patients with STD can be evaluated by the patient's age and PLR level, which is of great significance to predict the prognosis of patients with STD.

The protective effects of systemic dexamethasone on sensory epithelial damage and hearing loss in targeted Cx26-null mice

Mutations in the GJB2 gene (encoding Connexin26(Cx26)) are the most common cause of hereditary deafness, accounting for about a quarter of all cases. Sensory epithelial damage is considered to be one of the main causes of deafness caused by GJB2 gene mutation. Dexamethasone (DEX) is widely used in the treatment of a variety of inner ear diseases including sudden sensorineural hearing loss (SSNHL), noise-induced hearing loss (NIHL), and deafness caused by ototoxic drugs. Whether DEX has a direct therapeutic effect on hereditary deafness, especially GJB2-related deafness, remains unclear. In this study, we revealed that DEX can effectively prevent hair cell death caused by oxidative stress in cochlear explants. Additionally, two distinct Cx26-null mouse models were established to investigate whether systemic administration of DEX alleviate the cochlear sensory epithelial injury or deafness in these models. In a specific longitudinally Cx26-null model that does not cause deafness, systemic administration of DEX prevents the degeneration of outer hair cells (OHCs) induced by Cx26 knockout. Similarly, in a targeted-Deiter's cells (DCs) Cx26-null mouse model that causes deafness, treatment with DEX can almost completely prevent OHCs loss and alleviates auditory threshold shifts at some frequencies. Additionally, we observed that DEX inhibited the recruitment of CD45-positive cells in the targeted-DCs Cx26-null mice. Taken together, our results suggest that the protective effect of dexamethasone on cochlear sensory epithelial damage and partially rescue auditory function may be related to the regulation of inner ear immune response in Cx26 deficiency mouse models.

Resveratrol Ameliorates Lipopolysaccharide-Induced Sudden Sensorineural Hearing Loss in In Vitro Model through Multitarget Antiapoptotic Mechanism Based on Network Pharmacology and Molecular Docking

Objective

To explore the effects of resveratrol (RSV) on hair cell apoptosis caused by sudden sensorineural hearing loss (SSNHL) and its effect on lipopolysaccharide-induced apoptosis of HEI-OC1 cells.

Methods

We used the network pharmacology method to screen molecules related to RSV for the treatment of SSNHL and analyzed these molecules and their enriched biological processes and signaling pathways through Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis. We selected hub genes related to apoptosis using protein-protein interaction (PPI) analysis for in vitro and molecular docking verification.

Results

Eighty overlapping genes were identified as potential targets for RSV treatment of SSNHL. Further GO analysis showed that the biological processes were mainly related to toxicity, cell proliferation, and lipopolysaccharide reactions. KEGG analysis showed that the AGE-RAGE signaling pathway in diabetic complications, Kaposi's sarcoma-associated herpesvirus infection, FoxO signaling pathway, PI3K-Akt signaling pathway, and other inflammatory signaling pathways were concentrated. AKT1, STAT3, JUN, TNF, TP53, MAPK3, CASP3, and VEGFA were screened as HUB genes using PPI analysis. The apoptosis-related proteins TNF, CASP3, AKT1, and TP53 were selected for in vitro experiments, which showed that mRNA was significantly different before and after RSV intervention, confirming that the corresponding protein receptors could bind well with RSV.

Conclusion

RSV mainly affects the prognosis of SSNHL through anti-inflammatory effects and may improve hair cell apoptosis caused by inflammatory factors through multitargeted interventions involving TNF, CASP3, AKT1, and TP53.

Clinical Features and Influencing Factors for the Prognosis of Patients With Sudden Deafness

Backgrounds

Studies on risk factors influencing the prognosis of patients with sudden onset deafness are lacking.

Methods

From March 2018 to March 2021, 500 patients, from the Tongde Hospital in Zhejiang Province, with sudden onset deafness were enrolled. We collected clinical information from the hospital medical records, including certain demographic characteristics, information related to sudden-onset deafness, and laboratory parameters. Univariate and multivariate analyses were performed to determine independent prognostic risk factors for patients with sudden deafness. Additionally, we also employed orthogonal partial least squares discriminant analysis (OPLS-DA) to analyze the data of these enrolled patients.

Results

The baseline clinical characteristics of the enrolled patients were analyzed. Based on their prognoses, the included patients were divided into the overall effective and ineffective groups. Between these two groups, the univariate and multivariate analyses were performed. Age, type of hearing curve at the initial diagnosis, acute phase, and sudden deafness site were found to be independently associated with the prognoses of patients with sudden deafness (all P < 0.05). Through the OPLS-DA, the sudden deafness site was found to be an indicator with the highest predictive power.

Conclusions

Age, type of hearing curve at the initial diagnosis, acute phase, and sudden deafness site were all independently correlated with the prognoses of patients with sudden deafness and, therefore, need to be emphasized.

Efficacy of steroid treatment for sudden sensorineural hearing loss in patients with vestibular schwannoma

BACKGROUND

Sudden sensorineural hearing loss (SSNHL) has several aetiologies and may be a presenting symptom of vestibular schwannoma (VS).

OBJECTIVES

The aim of this study was to investigate the recovery rate after steroid treatment and the prognostic factors of SSNHL with VS.

MATERIALS AND METHODS

This was a retrospective observational study wherein 32 patients with VS who presented with SSNHL were analysed at a tertiary referral centre. Hearing gain and prognostic factors were the main outcome measures for steroid treatment intervention.

RESULTS

Among the 1698 patients presenting with SSNHL, VS was found in 43 (2.5%) patients. Eleven cases (34.3%) showed good recovery, with significant improvements in the pure-tone audiometry values. Even though age was a significant factor, there were no associations between steroid response and initial hearing level, presence of vertigo, tumour size, and tumour extension.

CONCLUSIONS AND SIGNIFICANCE

Our study showed that hearing recovery of SSNHL does not exclude a VS diagnosis. We suggest that steroid treatment be considered in patients with VS presenting SSNHL.

Association between human papillomavirus infection and sudden sensorineural hearing loss: A nationwide population-based cohort study

BACKGROUND

While the etiology of sudden sensorineural hearing loss (SSNHL) remains unclear, viral infection has been suggested as a possible cause. Human papillomavirus (HPV) might trigger immune-mediated reaction and induce inflammatory cytokines which are injurious to the cochlea. This study aimed to investigate the association between HPV infection and the risk of developing SSNHL using a nationwide population-based data set.

METHODS

In this study, we used the population-based National Health Insurance Research Database of Taiwan to enroll 49,247 individuals with HPV infection from January 1st, 2000, to December 31st, 2013, and compared with a control group of 98,494 individuals who had never been diagnosed with HPV infection (at a 1:2 ratio matched by age, sex, index year, and comorbidities) in relation to the risk of subsequent SSNHL. The primary outcome was the time from the index date to the date when the first diagnosis of SSNHL occurred, death, withdrawal from the National Health Insurance Program, or the end of the study. Cox model with frailty was conducted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), relative to comparison group. Sensitivity analyses were performed to validate our findings.

FINDINGS

The adjusted hazard ratio (aHR) of developing SSNHL was 1.37 (95% CI, 1.07-1.74) after adjustment for demographic characteristics, comorbidities, and medications. Sensitivity analyses showed consistent positive association. In our sub-group analysis, a significantly higher effect of HPV on SSNHL was noted in the patients with a previous diagnosis of cerebrovascular disease, compared with those without cerebrovascular disease (aHR: 4.59 versus 1.27, p-value for interaction = 0.024).

INTERPRETATION

HPV infections are associated with higher risk of subsequent SSNHL in the Taiwanese population. More research is needed to examine the causality and to determine the potential efficacy of specific precautions.

FUNDING

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

A case of sudden mixed hearing loss in SARS-CoV-2

The current global pandemic caused by coronavirus has uncovered multiple symptoms, including sudden hearing loss in either one or both ears, with different outcomes. We present a 68-year-old female with sudden onset bilateral hearing loss, fever, generalized body weakness, and gastrointestinal disturbances. She tested positive for severe acute respiratory syndrome coronavirus 2, was isolated, and was treated with a variety of medications for 5 days before being discharged home to self-isolate. The audiological assessment revealed both sensorineural and conductive hearing loss with a progressive favorable outcome on follow-up visits, with resolution occurring approximately 2 months after the onset. The majority of cases have reported sensorineural hearing loss. However, this case is one of the few that has reported mixed hearing loss. This report highlights an alternate clinical feature of the coronavirus that requires a comprehensive audiological examination by clinicians to ensure proper identification and treatment.

Hearing Dysfunction After Treatment With Teprotumumab for Thyroid Eye Disease

PURPOSE

To characterize the frequency, severity, and resolution of hearing dysfunction in patients treated with teprotumumab for thyroid eye disease (TED).

DESIGN

Prospective observational case series.

METHODS

Ophthalmic examination and adverse event assessment, including otologic symptoms, were performed at baseline, after infusions 2, 4, and 8, and at 6-month follow-up in consecutive patients who received at least 4 teprotumumab infusions. Laboratory test results were collected at baseline and during treatment. Audiometry, patulous eustachian tube (PET) testing, and otolaryngology evaluation were obtained for patients with new or worsening otologic symptoms, with a subset obtaining baseline and posttreatment testing.

RESULTS

Twenty-seven patients were analyzed (24 females, 3 males, average 56.3 years old). Twenty-two patients (81.5%) developed new subjective otologic symptoms, after a mean of 3.8 infusions (SD 1.8). At 39.2-week average follow-up after the last infusion, most patients with tinnitus (100%), ear plugging/fullness (90.9%), and autophony (83.3%) experienced symptom resolution, whereas only 45.5% (5 of 11) of patients with subjective hearing loss/decreased word comprehension experienced resolution. Six patients underwent baseline and posttreatment audiometry, 5 of whom developed teprotumumab-related sensorineural hearing loss (SNHL) and 1 patient also developed PET. Three of the 5 patients with teprotumumab-related SNHL had persistent subjective hearing loss at last follow-up. A prior history of hearing loss was discovered as a risk factor for teprotumumab-related SNHL (P = .008).

CONCLUSIONS

Hearing loss is a concerning adverse event of teprotumumab, and its mechanism and reversibility should be further studied. Until risk factors for hearing loss are better understood, we recommend baseline audiometry with PET testing and repeat testing if new otologic symptoms develop. Screening, monitoring, and prevention guidelines are needed.

Sudden hearing loss and vestibular disorders during and before COVID-19 pandemic: An audiology tertiary referral centre experience

PURPOSE

During the Coronavirus disease 2019 (COVID-19) pandemic a reduction in the diagnosis of many otorhinolaryngological and audiological disorders has been widely reported. The main aim of this investigation was to evaluate the impact of COVID-19 outbreak on the incidence of acute hearing and vestibular disorders.

MATERIALS AND METHODS

A retrospective analysis was performed of all patients evaluated in an audiology tertiary referral centre for acute cochleo-vestibular impairment between March 1st 2020 and February 28th 2021 (Pandemic Year Period, PYP). Results were compared to patients presenting with the same disorders during two previous periods (March 1st 2019 to February 29th 2020 and March 1st 2018 to February 28th 2019; First Precedent Year Period, FPYP and Second Precedent Year Period, SPYP, respectively).

RESULTS

The annual incidence of total acute audio-vestibular disorders (number of annual diagnoses divided by total number of annual audiological evaluations) was 1.52% during the PYP, 1.31% in FPYP and 1.20% in SPYP. Comparison between the pandemic period and previous periods did not show a significant difference (p > 0.05). The overall incidence of SSNHL and combined acute cochlear-vestibular involvement was significantly higher during the PYP compared to the previous periods (p = 0.022).

CONCLUSIONS

There were no differences in the absolute number of acute audio-vestibular disorders during the pandemic compared to previous periods. Although not significant, the SSNHL during the pandemic appeared worse in terms of pure-tone average with a higher incidence of associated vestibular involvement. Further studies are needed to clarify the role of SARS-CoV-2 on audio-vestibular disorders incidence and pathophysiology.

Clinical features and prognostic factors of children with profound sudden sensorineural hearing loss

OBJECTIVE

To investigate the clinical features and factors affecting the prognosis of children with profound sudden sensorineural hearing loss (SSNHL).

METHODS

We retrospectively analyzed the clinical data of 147 children with profound SSNHL who received inpatient treatment at our department from January 2016 to January 2021. All children were administered with systemic steroid therapy and/or intratympanic steroid (ITS) treatment for 2 weeks. Statistical analyses were performed for the clinical features, treatment effectiveness, and factors affecting the prognosis using SPSS 23.0.

RESULTS

The median age of the study population was 8 (6-10) years. The median treatment onset time was 8 (4-20) days. The most common concomitant symptom was tinnitus (45.58%). Laboratory findings showed that the percentages of children with abnormal leukocytes was 25.85%, abnormal platelet counts was 17.01%, abnormal cytomegalovirus IgG antibodies was 36.73% and abnormal Epstein-Barr (EB) virus IgG antibodies was 41.50%. The overall recovery rate of the treatment was 20.04%. The univariate analysis showed that age, treatment onset time, tinnitus, and ITS treatment were associated with the prognosis (p < 0.05). Regarding laboratory findings, the neutrophil count, lymphocyte count, and neutrophil-to-lymphocyte ratio differed significantly between the effective and invalid treatment effect groups (p < 0.05). The multivariable logistic regression analysis showed that treatment onset time [odds ratio (OR) = 0.936, 95% confidence interval (CI): 0.881-0.994] and ITS treatment (OR = 0.174, 95% CI: 0.044-0.0687) correlated with hearing recovery (p < 0.05).

CONCLUSION

In this study, the earlier the treatment start time of children with profound SSNHL, the better was the prognosis. Further, ITS could be an effective treatment option.

Accelerated Long-Term Hearing Loss Progression After Recovery From Idiopathic Sudden Sensorineural Hearing Loss

Background and Introduction: Idiopathic sudden sensorineural hearing loss (ISSNHL) is characterized by rapid onset, typically unilateral presentation, and variable recovery. This case-control observational study aimed to improve patient counseling by objectively characterizing long-term hearing loss progression following ISSNHL, using sequential audiometry in the largest-to-date cohort of patients with ISSNHL.

Methods: Patients diagnosed with ISSNHL at a tertiary referral hospital from 1994 through 2018 with sequential audiometry were studied. Case controls with sensorineural hearing loss (SNHL) were matched by age, sex, baseline hearing status, and frequency of sequential audiometry. Hearing loss progression was quantified using Kaplan–Meier (K–M) analysis to account for variable follow-up duration. A subgroup analysis was performed by age, sex, preexisting comorbidities, ISSNHL-associated symptoms, ISSNHL treatment, and degree of post-ISSNHL hearing recovery.

Results: A total of 660 patients were identified with ISSNHL. In patients with post-ISSNHL recovery to good hearing [pure tone average (PTA) <30 dB and word recognition score (WRS) > 70%], median time to progression to non-serviceable (PTA > 50 dB or WRS <50%) SNHL was 16.4 years. In patients with incomplete post-ISSNHL hearing recovery, contralateral ears were also at significantly higher risk of SNHL progression over the following 12-year period. Male sex was associated with increased risk of SNHL progression [odds ratio (OR) 3.45 male vs. female] at 5-year follow up. No other subgroup factors influenced the likelihood of SNHL progression.

Discussion and Conclusion: Patients should be counseled on continued risk to long-term hearing after stabilization of hearing post-ISSNHL, with particular emphasis on greater risk to the contralateral ear in those with incomplete ipsilateral recovery.

Utilizing Single Cell RNA-Sequencing to Implicate Cell Types and Therapeutic Targets for SSNHL in the Adult Cochlea

OBJECTIVE

To identify genes implicated in sudden sensorineural hearing loss (SSNHL) and localize their expression in the cochlea to further explore potential pathogenic mechanisms and therapeutic targets.

STUDY DESIGN

Systematic literature review and bioinformatics analysis.

DATA SOURCES

The following sources were searched from inception through July 2, 2020: PubMed-NCBI, MEDLINE, Embase, CINAHL, Cochrane Library, ClinicalTrials.gov, OpenGrey, GreyNet, GreyLiterature Report, and European Union Clinical Trials Registry. PubMed-NCBI and MEDLINE were additionally searched for human temporal bone histopathologic studies related to SSNHL.

METHODS

Literature review of candidate SSNHL genes was conducted according to PRISMA guidelines. Existing temporal bone studies from SSNHL patients were analyzed to identify the most commonly affected inner ear structures. Previously published single-cell and single-nucleus RNA-Seq datasets of the adult mouse stria vascularis, as well as postnatal day 7 and 15 mouse cochlear hair cells and supporting cells, were utilized for localization of the SSNHL-related genes curated through literature review.

CONCLUSIONS

We report 92 unique single nucleotide polymorphisms (SNPs) in 76 different genes that have been investigated in relation to SSNHL in the literature. We demonstrate that a subset of these genes are expressed by cell types in the adult mouse stria vascularis and organ of Corti, consistent with findings from temporal bone studies in human subjects with SSNHL. We highlight several potential genetic targets relevant to current and possible future SSNHL treatments.

Dual Viscosity Mixture Vehicle for Intratympanic Dexamethasone Delivery Can Block Ototoxic Hearing Loss

Clinically there is no effective method to prevent drug induced hearing loss in patients undergoing chemotherapy and anti-tuberculosis therapy. In this study, we developed an intratympanic (IT) local drug delivery vehicle featuring hyaluronic acid-based dual viscosity mixture encapsulation of dexamethasone (D), named dual-vehicle + D, and assessed its protective effect in ototoxic hearing loss. We assessed the residence time, biocompatibility, and treatment outcome of the novel vehicle compared with the current standard of care vehicle (saline) and control conditions. The hearing threshold and hair cell count were significantly better in the dual-vehicle + D group compared to the other two groups. The final hearing benefit in the dual-vehicle group was approximately 25–35 dB, which is significant from a clinical point of view. Morphologic evaluation of the cochlear hair cells also supported this finding. Due to the high viscosity and adhesive property of the vehicle, the residence time of the vehicle was 49 days in the dual-vehicle + D group, whereas it was less than 24 h in the saline + D group. There was no sign of inflammation or infection in all the animals. From this study we were able to confirm that dual viscosity mixture vehicle for IT D delivery can effectively block ototoxic hearing loss.

Vestibular functions in patients with idiopathic sudden sensorineural hearing loss and its relation to prognosis

OBJECTIVE

Because of the anatomically close relationship between the cochlea and the vestibular organs, cochlear function disorders may be accompanied by vestibular disorders. This study aimed to evaluate vestibular functions in patients with idiopathic sudden sensorineural hearing loss using VEMP, caloric test, and VNG test battery and its relation to prognosis.

MATERIALS AND METHODS

For this study, 42 patients aged 18-55 years with idiopathic sudden sensorineural hearing loss and 30 volunteers who had no hearing and balance problems were included. Audiometry, cVEMP, oVEMP, caloric tests, and VNG tests were performed. Moreover, the effects of age, sex, time of admission, degree and configuration of hearing loss, accompanying vertigo, tinnitus, and ear fullness on improvement in hearing were evaluated.

RESULTS

Of the 42 patients in the study group, 26 (56.52%) were male, 20 (43.48%) were female, and the mean age was 41.54 ± 12.23 years. Of the 30 individuals in the control group, 19 (63.3%) were male, 11 (36.7%) were female, and the mean age was 39.53 ± 13.03 years. There was no significant difference in the incidence of sudden sensorineural hearing loss in terms of sex and age, and the prognosis was better for female patients. Early admission to treatment was a factor of good prognosis; profound hearing loss, bilateral hearing loss and vertigo were factors of poor prognosis. Prognosis was better in patients with rising type audiogram configuration, while the prognosis was worse in patients with flat, descending and total hearing loss. Tinnitus and ear fullness had no effect on the prognosis. No anomalies were observed in VNG findings. Moreover, abnormal caloric response was higher in patients with profound hearing loss and total hearing configuration. Shortening was observed in cVEMP / oVEMP P1 and N1 latency after treatment. Furthermore, there was an improvement in abnormal responses after treatment.

CONCLUSION

In this study, vestibular function was affected in patients with idiopathic sudden sensorineural hearing loss. The present study can help the development of a clinical strategy in the evaluation of the vestibular system in idiopathic SSNHL, patient follow-up, patient information, and the implementation of vestibular rehabilitation. Note that additional studies involving larger patients series are required.