Sudden sensorineural hearing loss

Relevant Research of Inflammatory Cytokines Spectrum in Peripheral Blood of Sudden Hearing Loss

OBJECTIVE

To investigate whether there is a correlation between the inflammatory state and the pathogenesis and clinical features of sudden hearing loss (SHL) by studying the expression of inflammation-related cytokines in the peripheral blood of patients with SHL.

METHODS

In this work, we analyzed the cytokine profiles of 48 analytes in 38 patients with SHL compared to 38 healthy donors using a multiplex immunoassay. This study used appropriate statistical methods to screen for inflammatory cytokines associated with the pathogenesis of SHL, to analyze their network correlation, and to analyze the relationship between clinical features of SHL and inflammatory cytokines.

RESULTS

Several cytokines, including CTACK, Eotaxin, HGF, INF-α2, IFN-β, IL-1β, IL-1ra, IL-2Rα, IL-4, IL-7, IL-8, IL-9, IL-10, IL-12(p40), IL-13, MIG, β-NGF, SCF, and TNF-α, exhibited significantly higher levels in the peripheral blood of the SHL group compared to the control group. An inflammatory network composed of multiple cytokines, including IL-1β, is a risk factor for the development of SHL.

CONCLUSION

This study identified several inflammatory cytokines with elevated expression, which may be linked with the onset of SHL. The results of this study also provide a basis for the theoretical hypothesis of inflammation in SHL.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:3293-3301, 2024.

Intratympanic Gels for Inner Ear Disorders: A Scoping Review of Clinical Trials

OBJECTIVE

Intratympanic injections are a safe, well tolerated procedure routinely performed by ENT's specialists. Intratympanic injections of gels have the potential to deliver therapeutics into the cochlea through the round window membrane prolonging the release of drugs in the inner ear compartment. Aim of the present review is to summarize clinical trials testing pharmacological treatments for inner ear pathologies through intratympanic gel formulations.

DATA SOURCES

Online databases (Google scholar and PubMed) and registers (Clinicaltrials.gov and Euclinicaltrial) were used to identify clinical trials performed between 1990 and 2022.

REVIEW METHODS

PRISMA criteria have been followed. Clinical trials testing gel formulations administered through local intratympanic injections and targeting inner ear disorders were included. All the reports were identified by the authors working in pairs sequentially selecting only studies respecting the inclusion criteria.

RESULTS

A total of 45 clinical studies have been noticed; the gels for intratympanic injection are in the form of poloxamers or hyaluronic acid combinations; the trials found target different kind of inner ear disorders: acquired-stable SNHL, tinnitus, acute sudden SNHL, Meniere disease, cisplatin induced ototoxicity and hearing preservation in patients undergoing cochlear implant surgery.

CONCLUSION

Few studies listed do not provide the specific kind of gel formulation used but only report the intratympanic delivery vehicle as "gel" or "thermogel". Multiple clinical studies have been targeting several forms of inner ear disorders by injecting different compounds through poloxamer and hyaluronic acid formulations. Larger and more advanced clinical stages are necessary to confirm the efficacy of these chemical compounds.

Paradoxical Embolism in Juveniles and Young Adults With Severe-to-Profound Sudden Sensorineural Hearing Loss

Objective: Paradoxical embolism from right-to-left shunting is a common cause of cryptogenic stroke in the young. Circulatory ischemia of the cochlea is closely connected with severe-to-profound sudden sensorineural hearing loss. This study aimed to explore the role of paradoxical embolism in severe-to-profound sudden sensorineural hearing loss in juveniles and young adults. Methods: From August 2021 to September 2022, consecutive outpatients under 35 years of age with severe-to-profound sudden hearing loss were included in the study. Routine auditory electrophysiological testing and contrast transcranial Doppler ultrasonography (c-TCD) were conducted, and the results were retrospectively analyzed. Results: Seven patients (age: 19.4 ± 6.5 years) were enrolled, including 5 juveniles and 2 young adults. Three patients had severe deafness, and 4 patients had profound deafness. Right-to-left shunting was detected in all patients through c-TCD. Patent foramen ovale was found in 2 patients while pulmonary arteriovenous fistula was found in 1 patient through contrast transthoracic echocardiography or cardiac catheterization. No patients had precipitating factors for sudden sensorineural hearing loss, and none had abnormalities on head magnetic resonance imaging. Six patients underwent whole-exome sequencing, and no known deafness gene variant was detected. After standard treatment for 1 month, 2, 3, and 2 patients had complete, slight, and no hearing recovery, respectively. Conclusions: Paradoxical embolism is a possible cause of severe-to-profound sudden sensorineural hearing loss in juveniles and young adults. In young patients, c-TCD is an effective screening tool to detect right-to-left shunting, while contrast transthoracic echocardiography is a complementary examination to c-TCD.

Prevalence of perilymphatic fistula in patients with sudden-onset sensorineural hearing loss as diagnosed by Cochlin-tomoprotein (CTP) biomarker detection: its association with age, hearing severity, and treatment outcomes

PURPOSE

To determine the prevalence of perilymphatic fistula (PLF) in sudden-onset sensorineural hearing loss (SSNHL) patients by employing the Cochlin-tomoprotein (CTP) detection test, a specific diagnostic marker for perilymph. We also analyzed the clinical characteristics associated with hearing outcomes in this cohort.

METHODS

A total of 74 eligible patients were prospectively enrolled. Following myringotomy, middle ear lavage (MEL) samples underwent the CTP test to identify perilymph leakage. Intratympanic dexamethasone (IT-DEX) therapy was administered, and hearing outcomes were assessed. Control groups comprised patients with chronic otitis media (n = 40) and non-inflammatory middle ears (n = 51) with concurrent MEL sample collection.

RESULTS

CTP was positive in 16 (22%) patients. No control samples showed positive results. Multiple regression analysis indicated that age and pre-treatment hearing levels significantly contributed to the CTP value. We found a positive correlation between CTP values, age, and pre-treatment pure-tone averages. Notably, CTP values in SSNHL cases aged 60 and above were significantly higher than in those below 60 years. Patients with positive CTP had significantly worse recovery rates after IT-DEX treatment.

CONCLUSION

This study is the first prospective investigation demonstrating a positive relationship between CTP values, age, and hearing severity in SSNHL, indicating that PLF might be the essential cause of SSNHL, particularly in the elderly. Our findings suggest that IT-DEX may be less effective for PLF-associated SSNHL. Future research could reveal that PLF repair surgery is a viable treatment strategy for SSNHL. This study was registered under the UMIN Clinical Trials Registry (UMIN000010837) on 30/May/2013.

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.

Causal role of immune cell phenotypes in idiopathic sudden sensorineural hearing loss: a bi-directional Mendelian randomization study

Background

A growing body of evidence suggests that immunological processes have a significant role in developing idiopathic sudden sensorineural hearing loss (SSHL). However, few studies have examined the association between immune cell phenotype and SSHL using Mendelian Randomization (MR).

Methods

The online genome-wide association studies (GWAS) database was used to compile data from GWAS covering 731 immunophenotypes and SSHL. Inverse variance weighted (IVW) analysis was primarily used for MR study, and single nucleotide polymorphisms (SNPs) associated with immunophenotypes served as dependent variables. A sensitivity study and the false discovery rate (FDR) correction were used to examine the MR hypothesis. In addition, the possibility of reverse causality between immunophenotype and SSHL was validated by reverse MR. Reverse MR was analyzed in a manner consistent with forward MR.

Results

After FDR correction and sensitivity analysis, we screened 7 immunophenotypes, including IgD+ CD38dim %lymphocyte (95% CI: 1.0019, 1.0742, p = 3.87 × 10-2, FDR = 1.15 × 10-2); Unsw mem AC (95% CI: 1.004, 1.2522, p = 4.23 × 10-2, FDR = 2.25 × 10-2); CD86+ myeloid DC AC (95% CI: 1.0083, 1.1147, p = 2.24 × 10-2, FDR = 4.27 × 10-2); CD33dim HLA DR- AC (95% CI: 1.0046, 1.0583, p = 2.12 × 10-2, FDR = 4.69 × 10-2); SSC-A on CD8br (95% CI: 1.0028, 1.1461, p = 4.12 × 10-2, FDR = 4.71 × 10-2); CD45RA- CD4+ %T cell (95% CI: 1.0036, 1.0503, p = 2.32 × 10-2, FDR = 4.82 × 10-2); DP (CD4+CD8+) AC (95% CI: 1.011, 1.2091, p = 2.78 × 10-2, FDR = 4.97 × 10-2). There was a strong causal relationship with SSHL onset, and the reliability of the results was verified. Furthermore, the immunological cell profile and SSHL did not appear to be closely associated, as shown by reverse MR analysis.

Conclusion

Our study provides more support for the current hypothesis that immunophenotypes and the pathophysiology of SSHL are closely associated. Further validation is needed to assess the role of these immunophenotypes in SSHL.

The acute vestibular syndrome: prevalence of new hearing loss and its diagnostic value

OBJECTIVES

To assess the prevalence of new hearing losses in patients with acute vestibular syndrome (AVS) and to start to evaluate its diagnostic value for the differentiation between peripheral and central causes.

DESIGN

We performed a cross-sectional prospective study in AVS patients presenting to our Emergency Department (ED) from February 2015 to November 2020. All patients received an MRI, Head-impulse test, Nystagmus test and Test of skew ('HINTS'), caloric testing and a pure-tone audiometry.

RESULTS

We assessed 71 AVS patients, 17 of whom had a central and 54 a peripheral cause of dizziness. 12.7% had an objective hearing loss. 'HINTS' had an accuracy of 78.9% to diagnose stroke, whereas 'HINTS' plus audiometry 73.2%. 'HINTS' sensitivity was 82.4% and specificity 77.8% compared to 'HINTS' plus audiometry showing a sensitivity of 82.4% and specificity of 70.4%. The four patients with stroke and minor stroke had all central 'HINTS'. 55% of the patients did not perceive their new unilateral hearing loss.

CONCLUSIONS

We found that almost one-eighth of the AVS patients had a new onset of hearing loss and only half had self-reported it. 'HINTS' plus audiometry proved to be less accurate to diagnose a central cause than 'HINTS' alone. Audiometry offered little diagnostic accuracy to detect strokes in the ED but might be useful to objectify a new hearing loss that was underestimated in the acute phase. Complete hearing loss should be considered a red flag, as three in four patients suffered from a central cause.

Signaling pathways regulating the immune function of cochlear supporting cells and their involvement in cochlear pathophysiology

The inner ear, including the cochlea, used to be regarded as an immune-privileged site because of its immunologically isolated environment caused by the blood-labyrinthine barrier. Cochlear resident macrophages, which originate from the yolk sac or fetal liver during the embryonic stage and are maintained after birth, are distributed throughout various regions of the cochlear duct. Intriguingly, these cells are absent in the organ of Corti, where hair cells (HCs) and supporting cells (SCs) are located, except for a limited number of ionized calcium-binding adapter molecule 1 (Iba1)-positive cells. Instead, SCs exert glial functions varying from a quiescent to an emergency state. Notably, SCs acquire the nature of macrophages and begin to secrete inflammatory cytokines during viral infection in the organ of Corti, which is ostensibly unprotected owing to the lack of general resident macrophages. This review provides an overview of both positive and negative functions of SCs enabled to acquire macrophage phenotypes upon viral infection focusing on the signaling pathways that regulate these functions. The former function protects HCs from viral infection by inducting type I interferons, and the latter function induces HC death by necroptosis, leading to sensorineural hearing loss. Thus, SCs play contradictory roles as immune cells with acquired macrophage phenotypes; thereby, they are favorable and unfavorable to HCs, which play a pivotal role in hearing function.

The construction and validation of prognostic prediction model for sudden sensorineural hearing loss in middle-aged and elderly people

OBJECTIVE

Idiopathic sudden sensorineural hearing loss (ISSNHL), as an otologic emergency, is commonly encountered and its prevalence has been climbing every year recently. To our knowledge, the prognosis of middle-aged and elderly patients is worse than that of young patients. Previous researches mainly focused on the adult population, which was considered as prognostic models who performed hearing recovery in ISSNHL. However, few studies regarding the middle-aged and elderly population who are regarded as prognostic models have been reported. Therefore, we aim to construct and validate a nomogram-based prognostic prediction model, which can provide a reference for the prognostic assessment in the middle-aged and elderly patients with ISSNHL.

METHOD

A total of 371 middle-aged and elderly ISSNHL patients who were admitted to the Department of Otolaryngology-Head and Neck Surgery, Yanbian Hospital, Yanbian University, from April 2018 to April 2023 were enrolled in the study. All subjects were randomly divided into two groups including training group (n = 263) and validation group (n = 108). Lasso regression and multi-factor logistic regression were jointly utilized to screen out prognosis-related independent risk factors and establish a nomogram-based risk prediction model. The accuracy and clinical application value of the model were evaluated by combining the Bootstrapping method and k-fold cross-validation, plotting the receiver operating characteristic  (ROC)  curve, calculating the area under the ROC curve (AUC), plotting the decision curve analysis (DCA), and the calibrating curve.

RESULT

We used the method of lasso regression combined with multivariate logistic regression and finally screened out eight predictors (including age, number of affected ears, degree of hearing loss, type of hearing curve, duration of disease, presence of vertigo, diabetes, and lacunar cerebral infarction) that were included into the nomogram. The C-index were 0.823 [95% CI (0.725, 0.921)] and 0.851 [95% CI (0.701, 1.000)], and the AUC values were 0.812 and 0.823 for the training and validation groups, respectively. The calibration curve for the validation group was approximately conformed to that for the modeling group, indicating favorable model calibration. The DCA results revealed the modeling group (3%-86%) and the validation group (2%-92%) showed significant net clinical benefit under the majority of thresholds.

CONCLUSION

This study developed and validated a nomogram-based prognostic prediction model which based on the eight independent risk factors mentioned above. The predictors are conveniently accessible and may assist clinicians in formulating individualized treatment strategies.

A Comprehensive Study on Sudden Deafness for Analyzing Their Clinical Characteristics and Prognostic Factors

Background: To study the factors associated with the prognosis of patients with sudden deafness to facilitate clinical treatment and improve efficacy. Methods: A total of 414 patients with sudden deafness treated in Zhenjiang First People's Hospital from January 2020 to December 2022 were chosen. Relevant data were gathered and the effectiveness of treatment was assessed by comparing hearing test results before and after hospital admission and divided into effective and ineffective groups, and the effectiveness of each factor was analyzed using univariate analysis, Spearman's correlation analysis, and multifactor logistic regression. Results: The 2 groups had significant differences in age, presence of tinnitus, degree of hearing loss, and triglyceride levels. Spearman's rank correlation analysis showed a negative correlation between hearing threshold of at least 81 dB at 250 to 8000 Hz, the low-density lipoprotein (LDL), triglyceride levels, and the prognosis (r < 0, P < .001). A positive correlation exists between high-density lipoprotein levels and prognosis (r > 0, P < .001). Receiver operating characteristic curve showed LDL level, age, and time since disease onset appears to be highly predictive. Multivariable logistic regression analysis showed that age >47 years, LDL >2.93 mmol/L, and time to presentation >10 days after disease onset are at higher risk for poor prognosis. Conclusion: Factors that influence the prognosis of patients with sudden deafness include age, tinnitus symptoms, high LDL levels, and the type of hearing curve. Early intervention and targeted treatment should be given to high-risk patients to improve the outcome of sudden deafness in clinical practice.

The Importance of Lassa Fever and Its Disease Management in West Africa

Lassa virus (LASV) is a zoonotic pathogen endemic throughout western Africa and is responsible for a human disease known as Lassa fever (LF). Historically, LASV has been emphasized as one of the greatest public health threats in West Africa, with up to 300,000 cases and 5000 associated deaths per year. This, and the fact that the disease has been reported in travelers, has driven a rapid production of various vaccine candidates. Several of these vaccines are currently in clinical development, despite limitations in understanding the immune response to infection. Alarmingly, the host immune response has been implicated in the induction of sensorineural hearing loss in LF survivors, legitimately raising safety questions about any future vaccines as well as efficacy in preventing potential hearing loss. The objective of this article is to revisit the importance and prevalence of LF in West Africa, with focus on Nigeria, and discuss current therapeutic approaches and ongoing vaccine development. In addition, we aim to emphasize the need for more scientific studies relating to LF-associated hearing loss, and to promote critical discussion about potential risks and benefits of vaccinating the population in endemic regions of West Africa.

Exploring functional connectivity alterations in sudden sensorineural hearing loss: A multilevel analysis

Sudden sensorineural hearing loss (SSNHL) constitutes an urgent otologic emergency, marked by a rapid decline of at least 30 dB across three consecutive frequencies within 72 h. While previous studies have noted brain region alterations encompassing both auditory and non-auditory areas, this research examines functional connectivity changes across integrity, network, and edge levels in SSNHL. The cohort included 184 participants: 107 SSNHL patients and 77 age- and sex-matched healthy controls. Our investigation comprises: (1) characterization of overall functional connectivity degree across 55 nodes in nine networks (p < 0.05, corrected for false discovery rate), exposing integrity level changes; (2) identification of reduced intranetwork connectivity strength within sensory and attention networks (somatomotor network, auditory network, ventral attention network, dorsal attention network) in SSNHL individuals (p < 0.05, Bonferroni corrected), and reduced internetwork connectivity across twelve distinct subnetwork pairs (p < 0.05, FDR corrected); (3) revelation of increased internetwork connectivity in SSNHL patients, primarily spanning dorsal attention network, fronto parietal network, default mode network, and limbic network, alongside widespread reductions in connectivity patterns among the nine distinct resting-state brain networks. The study further uncovers negative correlations between SSNHL duration and intranetwork connectivity of the auditory network (p < 0.001, R = -0.474), and between Tinnitus Handicap Inventory (THI) scores and internetwork connections linking auditory network and dorsal attention network (p < 0.001, R = -0.331). These observed alterations provide crucial insights into the neural mechanisms underpinning SSNHL and extend our comprehension of the brain's network-level responses to sensory loss. By unveiling the intricate interplay between sensory deprivation, adaptation, and cognitive processes, this study lays the groundwork for future research targeting enhanced diagnosis, treatment, and rehabilitation approaches for individuals afflicted by SSNHL.

Comparison of Batroxobin Versus the Combination of Batroxobin and Intratympanic Dexamethasone Injection in the Treatment of Sudden Sensorineural Hearing Loss

Introduction: Sudden sensorineural hearing loss (SSNHL) manifests as an abrupt decline in hearing by at least 30 dB within a 3 day period. Intratympanic dexamethasone injection (ITDI) has gained recognition as a potential treatment for SSNHL. This study aims to investigate the efficacy of combining batroxobin with ITDI (Bat and ITDI) in treating SSNHL patients and its influence on peripheral blood inflammatory indicators. Methods: SSNHL patients were retrospectively categorized into the control group (treated with Bat) and the observation group (treated with Bat and ITDI). The study involved analyzing clinical baseline data, evaluating clinical efficacy, and comparing the total effective rates among SSNHL patients with different audiometric curve types in the observation group. Routine blood tests were performed on peripheral blood samples to calculate the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), and to determine C-reactive protein (CRP) levels. Adverse reactions and complications were closely monitored. Results: Following treatment, both groups displayed improvements in hearing, with the observation group exhibiting a significantly higher total effective rate (75.90%) than the control group (59.78%). For patients with 3 distinct types of sudden hearing loss (high-frequency, flat-frequency, total deafness), Bat and ITDI treatment demonstrated increased total effective rate for patients with different sudden hearing loss types (high-frequency, flat-frequency, and total deafness). Both groups experienced reduced peripheral blood CRP levels and the NLR/PLR values, with the observation group demonstrating lower values. Additionally, across the 4 audio metric subtypes, the levels of peripheral blood CRP, NLR, and PLR decreased in SSNHL patients, and the observation group had a lower incidence of adverse reactions compared to the control group. Conclusions: Bat and ITDI emerge as notably more effective for SSNHL patients, displaying potential for reducing peripheral blood inflammatory indicator levels and mitigating the incidence of adverse reactions or complications, thereby enhancing safety.

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.)

Recovery From Idiopathic Sudden Sensorineural Hearing Loss: Association With Cardiovascular Disease Risk

PURPOSE

The purpose of this study is to investigate the association between cardiovascular disease (CVD) risk factors and idiopathic sudden sensorineural hearing loss (ISSNHL) disease severity and recovery.

METHOD

A retrospective medical chart review was performed on 90 patients (n = 48 men; Mage = 59.8 years, SD = 15.8) evaluated for ISSNHL. Major CVD risk factors (current tobacco smoking, diabetes, total cholesterol ≥ 240 mg/dl or treatment, and hypertension [systolic blood pressure [BP]/diastolic BP ≥ 140/ ≥ 90 mmHg or treatment]) determined two CVD risk groups: lower (no major risk factors) and higher (one or more risk factors). Two pure-tone averages (PTAs) were computed: PTA0.5,1,2 and PTA3,4,6,8. Complete recovery of ISSNHL was defined as PTAinitial - PTAfollow-up ≥ 10 dB. Logistic regression estimated the odds of ISSNHL recovery by CVD risk status adjusting for age, sex, body mass index, noise exposure, and treatment.

RESULTS

Most patients (67.8%) had one or more CVD risk factors. Severity of initial low- and high-frequency hearing loss was similar between CVD risk groups. Recovery was 53.2% for PTA0.5,1,2 and 32.9% for PTA3,4,6,8. With multivariable adjustment, current/former smoking was associated with lower odds of PTA0.5,1,2 recovery (OR = 0.27; 95% CI [0.08, 0.92]). Neither higher CVD risk status nor individual CVD risk factors had a significant association with recovery. For every one-unit increase in Framingham Risk Score, odds of PTA3,4,6,8 recovery were 0.95 times lower (95% CI [0.90, 1.00]) after accounting for age, sex, body mass index, noise exposure, and treatment/time-to-treatment grouping (p = .056).

CONCLUSIONS

The prognosis of low-frequency ISSNHL recovery is worse among current/former smokers than nonsmokers. Other CVD risk factors and aggregate risk are not significantly related to recovery.

Video head impulse test for the assessment of vestibular function in patients with idiopathic sudden sensorineural hearing loss without vertigo

OBJECTIVE

Idiopathic sudden sensorineural hearing loss may be accompanied by dizziness without true vertigo. This study used the video head impulse test to evaluate vestibular function in idiopathic sudden sensorineural hearing loss patients who described experiencing dizziness and not true vertigo.

METHODS

A prospective study was conducted of 30 consecutive patients diagnosed with idiopathic sudden sensorineural hearing loss with dizziness without true vertigo. A comparison of the video head impulse test results of the patients who complained of dizziness (symptomatic group) with a group of patients with idiopathic sudden sensorineural hearing loss and no dizziness (asymptomatic) was performed.

RESULTS

Nine patients (30 per cent) were symptomatic. Two of those patients had abnormal video head impulse test findings. Seven patients in the asymptomatic group (7 out of 21, 33 per cent) presented with abnormal video head impulse test results. No significant difference in vestibular function between the two groups was detected by the video head impulse test.

CONCLUSION

The site of insult in patients with idiopathic sudden sensorineural hearing loss without true vertigo is usually limited to the cochlea or the cochlear nerve.

Intratympanic Triamcinolone or Dexamethasone in Sudden Sensory Neural Hearing Loss: A Randomized Clinical Trial

Sudden sensorineural hearing loss (SSNHL) is a condition in which a person experiences a rapid loss of hearing, often in one ear. The cause of SSNHL is not always clear, but it is thought to be related to issues with the inner ear, auditory nerve, or other parts of the hearing pathway. Intratympanic injection is a treatment method for SSNHL in which a medication (corticosteroids) is injected directly into the middle ear space through the tympanic membrane. This randomized clinical trial was conducted in two hospitals in Tehran, Iran. Patients with SSNHL were randomized (using the 4-block method) and included in this study. 0.5 cc of dexamethasone or triamcinolone was injected via a 25-gauge spinal needle into the cone of light of tympanic membrane. This procedure was repeated six times. In the present study, the rate of response to treatment was compared in the two groups of triamcinolone and dexamethasone, which showed that in the group where intratympanic injection of dexamethasone was performed, 70.9% of patients responded to treatment (48.4% had a complete response and 22.5% had a partial response), and in the group receiving intratympanic triamcinolone, 72.5% responded to the treatment and improved, 50% showed a complete response and 22.5% showed a partial response, and no significant difference was found in the statistical analysis of the two groups. Also, the comparison of audiometric parameters (SDS and SRT) did not show any significant difference before and after the treatment based on the treatment group, and the treatment response was found in the same group. No significant differences were noted in terms of outcome. Intratympanic dexamethasone injection was associated with a 70.9% response and triamcinolone injection with a 72.5% response.

A case of sudden hearing loss in a patient with chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia is a myeloid stem cell disease characterized by an abnormal production and accumulation of monocytic cells in association with other signs of myeloproliferation. Extramedullary manifestations of CMML are common and can affect the spleen, liver skin, and lymph nodes. However, otologic manifestations are extremely rare and could have occurred from either direct leukemic infiltration, hemorrhage of the cochlea, labyrinth, leukostasis, or infection. There is no standard treatment protocol for sensorineural hearing loss in CMML patients. More research is needed to improve the understanding of the pathogenesis of this condition, in order to provide better treatment options.

A Comparative Study Using Vestibular Mapping in Sudden Sensorineural Hearing Loss With and Without Vertigo

OBJECTIVE

To investigate the impairment patterns in peripheral vestibular organs in sudden sensorineural hearing loss (SSNHL) with and without vertigo.

STUDY DESIGN

Retrospective study.

SETTING

Single tertiary medical center.

METHODS

Data from 165 SSNHL patients in a tertiary referral center from January 2017 to December 2022 were retrospectively analyzed. All patients underwent a video head impulse test, vestibular evoked myogenic potential test, and pure-tone audiometry. Hierarchical cluster analysis was performed to investigate vestibular impairment patterns. The prognosis of the hearing was determined using American Academy of Otolaryngology-Head and Neck Surgery recommendations.

RESULTS

After excluding patients with vestibular schwannoma and Meniere's disease, 152 patients were included in this study. A total of 73 of 152 patients were categorized as SSNHL with vertigo (SSNHL_V) and showed an independent merge of the posterior semicircular canal (PSCC) in cluster analysis. A total of 79 of 152 patients were categorized as SSNHL without vertigo (SSNHL_N) and showed an independent merge of saccule in cluster analysis. The PSCC (56.2%) and saccule (20.3%) were the most frequently impaired vestibular organs in SSNHL_V and SSNHL_N, respectively. In terms of prognosis, 106 of 152 patients had partial/no recovery and showed an independent merge of the PSCC in cluster analysis. A total of 46 of 152 patients had a complete recovery and showed an independent merge of the saccule in cluster analysis.

CONCLUSION

A tendency of isolated PSCC dysfunction was seen in SSNHL_V and partial/no recovery. A tendency of isolated saccular dysfunction was seen in SSNHL_N and complete recovery. Different treatments might be needed in SSNHL depending on the presence of vertigo.

Correlation between right-to-left shunt and sudden sensorineural hearing loss: protocol for a case-control study

BACKGROUND AND PURPOSE

Sudden sensorineural hearing loss (SSNHL) is a neurological and otolaryngological emergency during which rapid diagnosis and early treatment are of great importance. Clinical experience indicates that a considerable number of patients with SSNHL have concurrent right-to-left shunt (RLS). With limited reports, the association between SSNHL and RLS is yet unclear and there is a need for large observational studies to explore their latent relationship.

METHODS AND ANALYSIS

This proposed study is a prospective, observational case-control study. A total of 194 eligible participants matched in age and sex will be divided equally into two groups: 97 patients with SSNHL included in the case group and 97 individuals without SSNHL in the control group. Medical evaluations, including clinical characteristics, laboratory examination, audiological examination and ultrasonography examination, will be performed in all subjects. The primary outcome of the study is the difference in RLS rates between the groups. Differences in patent foramen ovale rates and other measured variables will be further assessed. A conditional logistic regression as a correlation analysis will be used to evaluate the relationship between RLS and SSNHL.

DISCUSSION

This study may provide evidence on the correlation between RLS and SSNHL in order to enrich the aetiology of SSNHL.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Ethics Committee of Peking University Shenzhen Hospital. A written informed consent form will be signed and dated by the participants and the researchers before the study begins. The results will be disseminated in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ChiCTR2200064067.

Idiopathic Sudden Sensorineural Hearing Loss, But Not Compatible With the Classical Definition

BACKGROUND AND PURPOSE

 The purpose of this study was to raise awareness for patients who did not meet the audiometric criteria of idiopathic sudden sensorineural hearing loss (SSNHL) but complained of acute hearing loss.

MATERIALS AND METHODS

Medical records of patients who were diagnosed with SSNHL from October 2021 to March 2023 were examined retrospectively. Among 223 patients with SSNHL, 40 cases with atypical SSNHL and fitting in the criteria were included in the study. The patients who were included in this study were the ones who were given one bolus dose of IV systemic steroid (250 mg methylprednisolone with a proton pump inhibitor) and betahistine 2x24 mg po for a month. Pure tone audiometry was performed during the initial visit, on the fifth day, and at the end of the one-month usage of betahistine tablets. Hearing levels on the 250, 500, 1,000, 2,000, 4,000, and 8,000 Hz of the affected ear were compared with those of the contralateral ear. Hearing improvement was calculated as the hearing gain (in decibels) on the control audiograms and the resolution of the patients' complaints.

RESULTS

These patients were suffering from idiopathic SSNHL with minimal hearing impairment. A total of 36 of the cases had hearing recovery on the fifth-day audiogram, and the remaining four patients showed hearing improvement on the first-month audiogram. The changes between the initial and the control audiogram values were found to be statistically significant (p<0.001). Additionally, these patients showed distinctive characteristics, such as being younger than the classical SSNHL population, lacking systemic diseases (diabetes or hypertension), and having good unaffected hearing.

CONCLUSION

Although there have been lots of studies to understand the pathophysiology, prognostic factors, and treatment options for SSNHL, atypical SSNHL patients have been underestimated and generally excluded from studies, and there have been a small number of studies on this issue. These patients might be accepted as having mild hearing loss. However, when the nerve injury is proven by audiograms, it is hard to decide what to do due to the lack of a treatment approach. This study is important as it focuses on atypical SSNHL cases. Further studies with larger group patients or prospective randomized-controlled group studies are needed to define these patients and decide how to treat this type of acute nerve dysfunction.

Reassessment of oxidative stress in idiopathic sudden hearing loss and preliminary exploration of the effect of physiological concentration of melatonin on prognosis

Background and purpose

The pathogenesis of idiopathic sudden sensorineural hearing loss (ISSNHL) is still unclear, and there is no targeted treatment. This research aimed to verify the role of oxidative stress in ISSNHL and explore whether melatonin has a protective effect on hearing.

Materials and methods

A total of 43 patients with ISSNHL and 15 healthy controls were recruited to detect the level of melatonin, reactive oxygen species (ROS), and total antioxidant capacity (TAC) in the blood and compared before and after treatment. Multivariate logistic regression models were performed to assess the factors relevant to the occurrence and improvement of ISSNHL.

Results

The patients with ISSNHL showed significantly higher ROS levels than controls (4.42 ± 4.40 vs. 2.30 ± 0.59; p = 0.031). The levels of basal melatonin were higher (1400.83 ± 784.89 vs. 1095.97 ± 689.08; p = 0.046) and ROS levels were lower (3.05 ± 1.81 vs. 5.62 ± 5.56; p = 0.042) in the effective group as compared with the ineffective group. Logistic regression analysis showed that melatonin (OR = 0.999, 95% CI 0.997-1.000, p = 0.049), ROS (OR = 1.154, 95% CI 1.025-2.236, p = 0.037), and vertigo (OR = 3.011, 95% CI 1.339-26.983, p = 0.019) were independent factors associated with hearing improvement. Besides, the level of melatonin (OR = 0.999, 95% CI 0.998-1.000, p = 0.023) and ROS (OR = 3.248, 95% CI 1.109-9.516, p = 0.032) were associated with the occurrence of ISSNHL.

Conclusion

Our findings may suggest oxidative stress involvement in ISSNHL etiopathogenesis. The level of melatonin and ROS, and vertigo appear to be predictive of the effectiveness of hearing improvement following ISSNHL treatment.

Altered static and dynamic intrinsic brain activity in unilateral sudden sensorineural hearing loss

Introduction

Sudden sensorineural hearing loss (SSHL) is a critical otologic emergency characterized by a rapid decline of at least 30 dB across three consecutive frequencies in the pure-tone audiogram within a 72-hour period. This audiological condition has been associated with alterations in brain cortical and subcortical structures, as well as changes in brain functional activities involving multiple networks. However, the extent of cerebral intrinsic brain activity disruption in SSHL remains poorly understood. The aimed of this study is to investigate intrinsic brain activity alterations in SSHL using static and dynamic fractional amplitude of low-frequency fluctuation (fALFF) analysis.

Methods

Resting-state functional magnetic resonance imaging (fMRI) data were acquired from a cohort of SSHL patients (unilateral, n = 102) and healthy controls (n = 73). Static and dynamic fALFF methods were employed to analyze the acquired fMRI data, enabling a comprehensive examination of intrinsic brain activity changes in SSHL.

Results

Our analysis revealed significant differences in static fALFF patterns between SSHL patients and healthy controls. SSHL patients exhibited decreased fALFF in the left fusiform gyrus, left precentral gyrus, and right inferior frontal gyrus, alongside increased fALFF in the left inferior frontal gyrus, left superior frontal gyrus, and right middle temporal gyrus. Additionally, dynamic fALFF analysis demonstrated elevated fALFF in the right superior frontal gyrus and right middle frontal gyrus among SSHL patients. Intriguingly, we observed a positive correlation between static fALFF in the left fusiform gyrus and the duration of hearing loss, shedding light on potential temporal dynamics associated with intrinsic brain activity changes.

Discussion

The observed disruptions in intrinsic brain activity and temporal dynamics among SSHL patients provide valuable insights into the functional reorganization and potential compensatory mechanisms linked to hearing loss. These findings underscore the importance of understanding the underlying neural alterations in SSHL, which could pave the way for the development of targeted interventions and rehabilitation strategies aimed at optimizing SSHL management.

Hyperbaric oxygen therapy as an adjunct to corticosteroid treatment in sudden sensorineural hearing loss: a retrospective study

Background

A retrospective clinical study was conducted to test the impact of including hyperbaric oxygen therapy in the treatment of patients with sudden sensorineural hearing loss (SSNHL).

Materials and methods

A total of 63 adult patients with sudden sensorineural hearing loss diagnosed between 2015 and 2023 were divided into two groups: 36 patients treated with intratympanic glucocorticoid and orally administered glucocorticoid who also underwent hyperbaric oxygen therapy and 27 patients treated with intratympanic glucocorticoid and prolonged orally administered glucocorticoid (without hyperbaric oxygen therapy). An audiological evaluation was performed using pure-tone audiometry.

Results

Average hearing gain as measured by pure tone average was 12.5 dB HL (+/- 19.9 dB HL) in the patients treated with steroids combined with HBOT, and was 14.1 dB HL (+/- 17.9 dB) in the patients treated with steroids alone. Successful treatment (complete recovery or marked improvement) was observed in 27.8% of the patients in the first group and in 25.5% in the second group. There was no statistically significant difference between the groups.

Conclusion

Both groups of patients-those treated with glucocorticoids and those treated with glucocorticoids and HBOT-had similar hearing outcomes. A prospective, controlled, and randomized study would provide more reliable knowledge about the efficacy of HBOT in treating SSNHL.

Impact of environmental noise exposure as an inducing factor on the prognosis of sudden sensorineural hearing loss: a retrospective case-control study

Objective

The study aimed to evaluate the clinical characteristics and prognostic factors associated with unilateral sudden sensorineural hearing loss (SSNHL) related to environmental noise exposure before its onset.

Methods

A total of 50 unilateral SSNHL patients exposed to environmental noise before onset (case group) and 924 unilateral SSNHL patients without any exposure to obvious inducing factors before onset (control group) were enrolled between January 2018 and October 2022. We retrospectively analyzed differences between both groups using the chi-square test, Fisher's exact tests, independent t-tests, and Mann-Whitney U-tests as appropriate before and after propensity score matching (PSM) based on sex, age, and initial pure-tone average (PTA). Prognostic factors for the case group were analyzed using univariate and multivariate logistic analyses between the effective and ineffective groups.

Results

Before PSM, significant differences were noted in age, sex, time to treatment, the proportion of combined diabetes mellitus, initial PTA, hearing gain, the incidence of vertigo or aural fulness, the rate of vestibular dysfunction or inner ear MRI abnormalities, the effective rate, the glucose and homocysteine levels, and the proportion of audiogram curve types (P < 0.05) between both groups. After PSM, compared to the control group, a longer time to treatment (Z= -3.02, P < 0.05), higher final PTA (Z= -2.39, P < 0.05), lower hearing gain (Z= -3.46, P < 0.05), lower rate of vestibular dysfunction (χ² = 55.1, P < 0.001), and lower effective rate (χ² = 4.87, P < 0.05) were observed in the case group. There was a significant difference between the audiogram curve types in both groups (χ² = 14.9, P < 0.05). Time to treatment (95% confidence interval: 0.692-0.965, P < 0.05) and final PTA (95% confidence interval: 0.921-0.998, P < 0.05) were associated with the clinical outcomes for the case group.

Conclusion

Unilateral SSNHL patients exposed to environmental noise triggers before onset showed a poorer effective rate and a lower rate of vestibular dysfunction than those who were not. The time to treatment and final PTA were associated with the prognosis of these patients.

Neurofilament Expression as a Biomarker of Post-COVID-19 Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSHL) affects a patient's quality of life and requires rapid treatment. The etiology is viral, vascular, and autoimmune, even though, in most cases, it remains idiopathic SSHL. Since 2019, several different complications have been identified following COVID-19 infection. The post-COVID-19 ENT manifestations reported in the literature are sore throat, headache, pharyngeal erythema, nasal obstruction, rhinorrhea, upper respiratory tract infection, and tonsil enlargement. Cases of SSHL, vestibular neuronitis, and audio-vestibular disorders (such as tinnitus, dizziness, and vertigo) have also been reported, albeit in a smaller percentage of patients. We reported our experience of a case of post-COVID-19 SSHL in the absence of any other type of post-COVID symptoms or brain and internal auditory canal magnetic resonance imaging and magnetic resonance angiography modifications. We aimed to identify a serological biomarker of sudden sensorineural hearing loss, and we also dosed and monitored the value of the serum neurofilament light (NfL). the best of our knowledge, this is the first report that associates SSHL and the serological increase in NfL as a potential biomarker of neuronal-disease-related damage.

Extracellular ATP accelerates cell death and decreases tight junction protein ZO-1 in hypoxic cochlear strial marginal cells in neonatal rats

In the cochlear, extracellular ATP (eATP) plays an important role in both physiological and pathological processes, but its role in the hypoxic cochlear remains unclear. The present study aims to investigate the relationship between eATP and hypoxic marginal cells (MCs) in the stria vascularis in cochlear. Combining various methodologies, we found that eATP accelerates cell death and decreases tight junction protein zonula occludens-1 (ZO-1) in hypoxic MCs. Flow cytometry and western blot analyses revealed an increase in apoptosis levels and suppression of autophagy, indicating that eATP causes additional cell death by increasing the apoptosis of hypoxic MCs. Given that autophagy inhibits apoptosis to protect MCs under hypoxia, apoptosis is probably enchanced by suppressing autophagy. Interleukin-33(IL-33)/suppression of tumorigenicity-2(ST-2)/matrix metalloprotein 9(MMP9) pathway activation was also observed during the process. Further experiments involving the use of additional IL-33 protein and an MMP9 inhibitor indicated that this pathway is responsible for the damage to the ZO-1 protein in hypoxic MCs. Our study revealed the adverse effect of eATP on the survival and ZO-1 protein expression of hypoxic MCs, as well as the underlying mechanism.

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.

Application of CNN and ANN in assessment the effect of chemical components of biological nanomaterials in treatment of infection of inner ear and environmental sustainability

Nanoparticles (NPs) are a promising alternative to antibiotics for targeting microorganisms, especially in the case of difficult-to-treat bacterial illnesses. Antibacterial coatings for medical equipment, materials for infection prevention and healing, bacterial detection systems for medical diagnostics, and antibacterial immunizations are potential applications of nanotechnology. Infections in the ear, which can result in hearing loss, are extremely difficult to cure. The use of nanoparticles to enhance the efficacy of antimicrobial medicines is a potential option. Various types of inorganic, lipid-based, and polymeric nanoparticles have been produced and shown beneficial for the controlled administration of medication. This article focuses on the use of polymeric nanoparticles to treat frequent bacterial diseases in the human body. Using machine learning models such as artificial neural networks (ANNs) and convolutional neural networks (CNNs), this 28-day study evaluates the efficacy of nanoparticle therapy. An innovative application of advanced CNNs, such as Dense Net, for the automatic detection of middle ear infections is reported. Three thousand oto-endoscopic images (OEIs) were categorized as normal, chronic otitis media (COM), and otitis media with effusion (OME). Comparing middle ear effusions to OEIs, CNN models achieved a classification accuracy of 95%, indicating great promise for the automated identification of middle ear infections. The hybrid CNN-ANN model attained an overall accuracy of more than 0.90 percent, with a sensitivity of 95 percent and a specificity of 100 percent in distinguishing earwax from illness, and provided nearly perfect measures of 0.99 percent. Nanoparticles are a promising treatment for difficult-to-treat bacterial diseases, such as ear infections. The application of machine learning models, such as ANNs and CNNs, can improve the efficacy of nanoparticle therapy, especially for the automated detection of middle ear infections. Polymeric nanoparticles, in particular, have shown efficacy in treating common bacterial infections in children, indicating great promise for future treatments.

Related factors to the coping style of patients with sudden sensorineural hearing loss

BACKGROUND

Coping style can affect the patient's physical and mental health management. Therefore this study aimed to identify factors related to the coping style of young and middle-aged sudden sensorineural hearing loss (SSNHL) patients to provide reference for clinical nursing practice.

METHODS

A cross-sectional study was conducted on young and middle-aged SSNHL patients hospitalized in the otolaryngology departments of four hospitals in Suzhou City, China. A paper-based self-administered questionnaire investigated the patient's coping style and related factors. Multiple linear stepwise regression analysed the effective related factors in patients' coping styles.

RESULTS

Among 872 patients, 866 completed the survey, with an average age of 37.27 y. Factors related to the coping style of these patients included gender, chronic diseases, history of trauma, social support and type D personality (p<0.05). Female patients adopt more negative coping styles than male patients. Patients with chronic diseases or a history of trauma had more positive coping styles. Higher social support scores were related to improvements in coping style. Patients with type D personality were more likely to adopt negative coping styles.

CONCLUSIONS

This study suggests that psychological assessment of patients, chronic diseases, history of trauma, social support and type D personality may benefit the understanding of these patients' coping styles and, as a consequence, may improve their stress management.

Is There an Association between Concurrent Epstein-Barr Virus Infection and Sudden Hearing Loss?-A Case-Control Study in an East Asian Population

Viral infection serves as the crucial etiology for the development of sudden sensorineural hearing loss (SSNHL). We aimed to investigate whether there is an association between concurrent Epstein-Barr virus (EBV) infection and SSNHL in an East Asian population. Patients who were older than 18 years of age and met the criteria of sudden hearing loss without an identifiable etiology were enrolled from July 2021 until June 2022, followed by the serological testing of IgA antibody responses against EBV-specific early antigen (EA) and viral capsid antigen (VCA) with an indirect hemagglutination assay (IHA) and real-time quantitative polymerase chain reaction (qPCR) of EBV DNA in serum before the treatment was initiated. After the treatment for SSNHL, post-treatment audiometry was performed to record the treatment response and degree of recovery. Among the 29 patients included during enrollment, 3 (10.3%) had a positive qPCR result for EBV. In addition, a trend of poor recovery of hearing thresholds was noted for those patients with a higher viral PCR titer. This is the first study to use real-time PCR to detect possible concurrent EBV infection in SSNHL. Our study demonstrated that approximately one-tenth of the enrolled SSNHL patients had evidence of concurrent EBV infection, as reflected by the positive qPCR test results, and a negative trend between hearing gain and the viral DNA PCR level was found within the affected cohort after steroid therapy. These findings indicate a possible role for EBV infection in East Asian patients with SSNHL. Further larger-scale research is needed to better understand the potential role and underlying mechanism of viral infection in the etiology of SSNHL.

Analysis of NFKB1 and NFKB2 gene expression in the blood of patients with sudden sensorineural hearing loss

OBJECTIVES

Sudden Sensorineural Hearing Loss (SSNHL) is an increasingly common health problem today. Although the direct mortality rate of this disorder is relatively low, its impact on quality of life is enormous; this is why accurate identification of pathogenesis and influencing factors in the disease process can play an essential role in preventing and treating the disease. Acute inflammation, which leads to chronic inflammation due to aberrant expression of inflammation-mediating genes, may play a significant role in the pathogenesis of the disease. The essential Nuclear factor kappa B (NF-kB) pathway genes, NFKB1 and NFKB2, serve as prothrombotic agents when expressed abnormally, compromising the cochlea by disrupting the endolymphatic potential and causing SSNHL.

METHODS

This study investigates the expression levels of NFKB1 and NFKB2 in peripheral blood (PB) through a quantitative polymerase chain reaction in 50 Iranian patients with SSNHL, and 50 healthy volunteers were of the same age and sex as controls.

RESULTS

As a result, NFKB2 expression levels in patients were higher than in controls, regardless of sex or age (posterior beta = 0.619, adjusted P-value = 0.016), and NFKB1 expression levels did not show significant differences between patients and controls. The expression levels of NFKB1 and NFKB2 had significantly strong positive correlations in both SSNHL patients and healthy individuals (r = 0.620, P = 0.001 and r = 0.657, P 0.001, respectively), suggesting the presence of an interconnected network.

CONCLUSION

NFKB2 has been identified as a significant inflammatory factor in the pathophysiology of SSNHL disease. Inflammation can play an essential role in developing SSNHL, and our findings could be used as a guide for future research.

Nomogram for predicting the prognostic role in idiopathic sudden sensorineural hearing loss

PURPOSE

A nomogram model was constructed to assist in early prediction of idiopathic sudden sensorineural hearing loss (ISSHL) prognosis. Additionally, this study contributed to evaluating and analyzing the usefulness of the nomogram model in ISSHL clinical intervention.

METHODS

A retrospective analysis was performed concerning 355 ISSHL patients who were hospitalized between June 2021 and August 2022. Single-factor analysis was used to filter variables, which were subsequently used for multivariate analysis to construct a nomogram. The discriminative capability and clinical usefulness of the predictive model were estimated by calculating the area under the curve (AUC), calibration curve, and decision curve analysis (DCA).

RESULTS

Hearing loss type, duration from onset to treatment, vertigo, periauricular paresthesia, and batroxobin use were included in the nomogram for ISSHL. The predictive model showed fair discrimination values (AUC =0.764; 95%CI: 0.715-0.813) and was well-calibrated, the C-index was 0.746 (95%CI: 0.715-0.793) in the internal validation. DCA indicated that the model was also clinically beneficial when the threshold range was between 0.246 and 0.840.

CONCLUSIONS

The nomogram prediction model may have potential clinical practicability in effectively assisting clinicians in predicting ISSHL prognosis and optimizing treatment protocols.

Thymosin beta-4 - A potential tool in healing middle ear lesions in adult mammals

Acute tympanic membrane perforations primarily occur due to injury or infection in humans. In acute cases, nearly 80-94 % of the perforations heal spontaneously. In chronic cases, non-surgical treatment becomes significantly limited, and the perforation can be restored only by myringoplasty. In addition to classical grafts such as the fascia or cartilage, promising results have been reported with various biological materials including silk or acellular collagen. However, despite of all the efforts, healing remains insufficient. Consequentially, a need for substances which actively promote tympanic cell migration and proliferation is deemed essential. In our study, we utilized Thymosin beta-4 (TB4), a 43aa peptide possessing many regenerative properties in various organ systems. Our aim was to reveal the impact of externally administered TB4 regarding impairments of the middle ear, particularly the tympanic membrane. We harvested tympanic membranes from adult mice and treated these with TB4 or PBS on both collagen gel matrixes and in the form of floating, ex vivo explants. Cell migration and proliferation was measured, while immunocytochemical analyses were performed to determine cell type and the nature of the targeted molecules. We discovered the peptide affects the behavior of epidermal and epithelial cells of the tympanic membrane in vitro. Moreover, as our initial results imply, it is not the differentiated, yet most likely the local epidermal progenitor cells which are the primary targets of the molecule. Our present results unveil a new, thus far undiscovered field regarding clinical utilization for TB4 in the future.

Future Pharmacotherapy for Sensorineural Hearing Loss by Protection and Regeneration of Auditory Hair Cells

Sensorineural hearing loss has been a global burden of diseases for decades. However, according to recent progress in experimental studies on hair cell regeneration and protection, clinical trials of pharmacotherapy for sensorineural hearing loss have rapidly progressed. In this review, we focus on recent clinical trials for hair cell protection and regeneration and outline mechanisms based on associated experimental studies. Outcomes of recent clinical trials provided valuable data regarding the safety and tolerability of intra-cochlear and intra-tympanic applications as drug delivery methods. Recent findings in molecular mechanisms of hair cell regeneration suggested the realization of regenerative medicine for sensorineural hearing loss in the near future.

Clinical Profiles and Prognoses of Adult Patients with Full-Frequency Sudden Sensorineural Hearing Loss in Combination Therapy

We aimed to characterize the clinical profiles and short-term outcomes of adult patients with full-frequency idiopathic sudden sensorineural hearing loss (ISSNHL) treated uniformly with combination therapy, and to determine the prognostic predictors for the combination therapy. A total of 131 eligible cases hospitalized in our department from January 2018 to June 2021 were retrospectively reviewed. All enrolled cases received a standardized combination therapy employing intravenous methylprednisolone, batroxobin, and Ginkgo biloba extract during the 12 days of hospitalization. The clinical and audiometric profiles were compared between recovered patients and their unrecovered counterparts. The overall recovery rate was 57.3% in the study. Accompanying vertigo (odds ratio = 0.360, p = 0.006) and body mass index (BMI, odds ratio = 1.158, p = 0.016) were two independent predictors of hearing outcomes of the therapy. The male gender and cigarette-smoking history were marginally associated with good hearing prognosis (p = 0.051 and 0.070, respectively). Patients with BMI ≥ 22.4 kg/m² had a better chance of hearing recovery (p = 0.02). Conclusions: Accompanying vertigo and low BMI (<22.4 kg/m²) were independently associated with poor prognosis for full-frequency ISSNHL in combination therapy. Male gender and cigarette-smoking history might be considered positive effects on hearing prognosis.

Glucocorticoid receptor (NR3C1) genetic polymorphisms and the outcomes of sudden sensorineural hearing loss

BACKGROUND

The glucocorticoid receptor gene (NR3C1) encodes the receptor to which cortisol and other glucocorticoids bind. Steroids in either oral, intratympanic, or intravascular forms are the treatment of choice for sudden sensorineural hearing loss (SSNHL), but the outcome varies. The outcomes of SSNHL have been investigated for related factors, including age, initial hearing loss severity and pattern, vertigo, genetic variations, and the time between onset and treatment. The objective of the present study was to analyze the association of genetic polymorphisms of NR3C1 with the outcomes of SSNHL.

MATERIALS AND METHODS

We conducted a comparison study of 93 cases with a poor outcome (control) and 100 cases with a good outcome (case) in SSNHL patients. Six single nucleotide polymorphisms (SNPs) were selected. The genotypes were determined using TaqMan technology.

RESULTS

The heterozygous AT genotype of rs17100289 was associated with a poor outcome in comparison with the major homozygous AA genotype after adjustments for age and sex (OR = 0.50; 95% CI 0.26-0.95; P = 0.035) in SSNHL patients. The CT genotype of rs4912912 was also associated with a poor outcome compared with the major homozygous TT genotype after the adjustments (OR = 0.47; 95% CI 0.24-0.92; P = 0.026).

CONCLUSION

These results suggest that NR3C1 genetic polymorphisms may influence the outcomes of SSNHL.

Sudden Hearing Loss Following Vaccination Against COVID-19

Importance

Spontaneous adverse reaction reports of sudden hearing loss have been observed, and a population-based cohort study conducted in Israel showed an increase in the incidence of sudden sensorineural hearing loss (SSNHL) following vaccination with messenger RNA COVID-19 vaccine BNT162b2 (Pfizer-BioNTech). However, in this setting, the possibility of confounding remained.

Objective

To assess a potential association between COVID-19 vaccinations and SSNHL.

Design, Setting, and Participants

This register-based country-wide retrospective cohort study of 5.5 million Finnish residents was conducted from January 1, 2019, to April 20, 2022, and included all individuals who were identified from the population information system who were alive or born during the study period except individuals who had SSNHL during 2015 to 2018 according to specialized care derived diagnosis codes for SSNHL (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision [ICD-10] code H91.2) as a primary or secondary diagnosis.

Exposures

The a priori primary risk period was 0 to 54 days following each COVID-19 vaccination. The risk periods for different vaccine doses did not overlap so that a later vaccine exposure ended the previous risk period. The secondary risk period was from 55 days following each COVID-19 vaccination until a subsequent COVID-19 vaccination. A secondary analysis included a risk time from 0 to 54 days following a positive polymerase chain reaction test result for SARS-CoV-2.

Main Outcomes and Measures

The incidences of SSNHL following COVID-19 vaccination were compared with the incidences before the COVID-19 epidemic in Finland. The Poisson regression model included calendar time, age, sex, diabetes, cardiovascular disease, other chronic diseases, and the number of visits in primary health care.

Results

For the 5.5 million Finnish residents included in the study, the comparison time comprised 6.5 million person-years, the primary risk time of 1.7 million person-years, and the secondary risk time of 2.1 million person-years. Before the COVID-19 epidemic in Finland, 18.7/100 000 people received a diagnosis of SSNHL annually. The study data suggested no increased risk for SSNHL following any COVID-19 vaccination. In particular, adjusted incidence rate ratios with 95% confidence intervals for the BNT162b2 vaccine's 3 doses were 0.8 (95% CI, 0.6-1.0), 0.9 (95% CI, 0.6-1.2), and 1.0 (95% CI, 0.7-1.4), respectively. There was no association between SARS-CoV-2 infection and an increased incidence of SSNHL.

Conclusions and Relevance

The results of this cohort study show no evidence of an increased risk of SSNHL following COVID-19 vaccination. The study accounted for previous disease and other potential confounding factors. These results are based on diagnosis codes in specialized care but still need to be verified in settings that are capable of evaluating the degree of hearing loss.

The Optimized Protocol of Hyperbaric Oxygen Therapy For Sudden Sensorineural Hearing Loss

OBJECTIVE

This study aimed to determine the optimal protocol of hyperbaric oxygen therapy (HBOT) according to various treatment settings for sudden sensorineural hearing loss (SSNHL).

METHODS

A 112 patients with SSNHL were enrolled in this prospective study. All patients were treated with systemic steroid therapy, intratympanic steroid therapy, and HBOT. According to the pressure and duration of HBOT (10 sessions in total), the patients were divided into three groups: group 1, 2.5 atmospheres absolute (ATA) for 1 h; group 2, 2.5 ATA for 2 h; and group 3, 1.5 ATA for 1 h. The pure-tone average (PTA), word discrimination score (WDS), and mean gain were compared.

RESULTS

A total of 105 patients completed the 3-month follow-up, and 6 patients were excluded. Differences among groups were found in PTA, WDS, and mean gain. In the post-hoc analysis, group 3 had significantly lower WDS and mean gain than groups 1 and 2; however, group 2 showed no significant differences from group 1. The proportion of patients with hearing recovery after treatment was significantly higher in group 1 (57.6%) and group 2 (58.8%) than in group 3 (31.3%).

CONCLUSIONS

When HBOT (10 sessions) was combined with corticosteroids as the initial therapy for SSNHL, a higher pressure (1.5 ATA vs. 2.5 ATA) provided better treatment results; however, increasing the duration (1 h vs. 2 h) under 2.5 ATA did not result in a significant difference. Therefore, HBOT for SSNHL may be performed at 2.5 ATA for 1 h in 10 sessions. Laryngoscope, 133:383-388, 2023.

Comparison of Intratympanic Steroid and Hyperbaric Oxygen Salvage Therapy Hearing Outcomes in Idiopathic Sudden Sensorineural Hearing Loss: A Retrospective Study

OBJECTIVES

Systemic steroids are the most common first-line therapy in sudden sensorineural hearing loss (SSNHL), with significant improvement in hearing outcomes in over 60% of patients. It is unknown why 40% of patients do not respond to systemic steroid therapy. Salvage treatment includes intratympanic steroids (ITS) and hyperbaric oxygenation (HBO) therapy, with inconsistent results reported. This study aimed to compare the results of ITS and HBO therapy in patients with SSNHL that previously failed systemic steroid therapy.

DESIGN

This is a comparative retrospective nonrandomized interventional cohort study, enrolling 126 patients with SSNHL. Out of these, 35 patients received HBO therapy, 43 patients received ITS, and 48 patients did not receive any second-line therapy (control group). Pure-tone audiograms were performed before and after the salvage therapy in the IT and HBO groups and at the same time interval in the control group. Study variables included age, time until therapy initiation, tinnitus status, and hearing outcomes, with a cutoff criteria of cumulative >30 dB improvement on all frequencies indicating recovery.

RESULTS

ITS and HBO therapy were associated with statistically significant hearing recovery at all frequencies compared to systemic steroids. The results show an average hearing improvement of 13.6 dB overall frequencies (250 to 8000 Hz) after ITS therapy and 7.4 dB in HBO therapy in comparison to the control group. Presence of significant hearing improvement positively correlated with age, ITS therapy, and HBO therapy. Presence of tinnitus before therapy was negatively correlated with hearing improvement. Patients with tinnitus present at the start of therapy improve 4.67 dB less on average compared to those without tinnitus. ITS therapy significantly reduced tinnitus compared to the other two treatment options. Patients with tinnitus present before therapy significantly improve hearing at low frequencies, compared to the control group.

CONCLUSIONS

ITS and HBO therapy show superior hearing results compared to observation alone after failed oral steroid therapy for SSNHL. ITS shows an additional positive impact on tinnitus reduction and shows superior hearing outcomes after salvage therapy.

Characteristics and prognostic analysis of simultaneous bilateral sudden sensorineural hearing loss

Objective

To evaluate the clinical characteristics of simultaneous bilateral sudden sensorineural hearing loss (Si-BSSNHL) as well as its prognostic factors.

Methods

Patients with Si-BSSNHL who were admitted to the Department of Otology Medicine between December 2018 and December 2021 were enrolled in the case group. Propensity score matching (PSM) for sex and age was used to select the control group, which included people who had unilateral sudden sensorineural hearing loss (USSNHL) during the same time period. Hearing recovery, audiological examinations, vestibular function assessments, laboratory tests, and demographic and clinical manifestations were analyzed for intergroup comparisons. Binary logistic regressions were used for both univariate and multivariate analyses of Si-BSSNHL prognostic factors.

Results

Before PSM, the Si-BSSNHL and USSNHL groups differed significantly (p < 0.05) in terms of time from onset to treatment, initial pure-tone average (PTA), final PTA, hearing gain, audiogram curve type, proportion of tinnitus, high-density lipoprotein level, homocysteine level, and effective rate. After PSM, significant differences were also observed in time from onset to treatment, initial PTA, final PTA, hearing gain, total and indirect bilirubin levels, homocysteine level, and effective rate between the two groups (p < 0.05). There was a significant difference in the classification of therapeutic effects between the two groups (p < 0.001). For prognostic analysis, the audiogram curve type was significantly different between the effective group and the ineffective groups of Si-BSSNHL (p = 0.01), in which the sloping type was an independent risk factor for the prognosis of the right ear in Si-SSNHL (95% confidence interval, 0.006-0.549, p = 0.013).

Conclusion

Patients with Si-BSSNHL had mild deafness, elevated total and indirect bilirubin and homocysteine levels, and poorer prognosis than those with USSNHL. Audiogram curve type was linked to the therapeutic effect of Si-BSSNHL, and the sloping type was an independent risk factor for a poor prognosis in the right ear of Si-SSNHL.

Myosin Mutations and Sudden Sensorineural Hearing Loss: Results of Whole Exome Sequencing

OBJECTIVE

Idiopathic sudden sensorineural hearing loss (ISSNHL) affects 66,000 patients per year in the United States. Genetic mutations have been associated with progressive hearing loss; however, genetic mutations associated with ISSNHL have not been identified.

METHODS

A prospective cohort study of adults older than 18 years presenting with ISSNHL at a tertiary academic medical center. Whole exome sequencing (WES) was conducted using Genome Analysis Toolkit best practices. An automated diagnostic screen employing a variety of models for pathogenicity was conducted across all genes with no specific targets. Candidate pathogenic variants were reviewed by a team of geneticists and clinicians. Variants were crossed-referenced with 92 known hearing loss associated genes.

RESULTS

Twenty-nine patients with SSNHL were screened using WES. The average age of patients was 53 ± 17.1 years, and most patients were White (62%) and men (55%). The mean pure tone average was 64.8 ± 31.3 dB for the affected ear. Using a 0.1% allele frequency screen, 12 (41%) cases had a mutation in any of the nine selected myosin genes. When we restrict to singletons (allele frequency = 0%), 21% (n = 6) of cases have qualifying variants, whereas only 3.8% (n = 481) of 12,577 healthy controls carry qualifying variants (p < 0.01). Most mutations (80%) were missense mutations. Of the novel mutations, one was a frameshift mutation, and two were a stop-gained function. Three were missense mutations.

CONCLUSION

Myosin mutations may be associated with ISSNHL. However, larger population screening is needed to confirm the association of myosin mutation with ISSNHL and steroid responsiveness.

Epidemiology of idiopathic sudden sensorineural hearing loss in the era of big data

OBJECTIVES

Idiopathic sudden sensorineural hearing loss (ISSNHL) is a medical emergency, and delayed treatment can have permanent sequelae. However, the etiology of ISSNHL is diverse and unclear; thus, it is idiopathic. To develop an insight into this condition, patients with ISSNHL must be clearly identified. We propose an operational definition for the unambiguous identification of ISSNHL patients. Patients are identified through suggested definitions, and prevalence and general information are investigated.

METHODS

A retrospective study of patients with ISSNHL was performed using the Health Insurance and Review Assessment-National Patient Sample from 2009 to 2016. To present a new operational definition, a systematic review was conducted for studies on ISSNHL from January 2007 to June 2021. After constructing several operant definitions using the conditions that can specify patients with ISSNHL in big data, we compared each definition to propose an operational definition.

RESULTS

The important conditions required to classify patients with ISSNHL using big data were the International Classification of Diseases (ICD)-10 code, number of pure tone audiometry (PTA) tests, and whether steroids were prescribed. Among them, those who had undergone PTA tests more than twice could be clearly identified as patients with ISSNHL.

CONCLUSION

As the use of big data becomes smoother, research using national medical data is being conducted; however, the results of the studies may vary depending on how a patient with ISSNHL is classified. Clear identification of patients with ISSNHL will be beneficial for better management of this condition.

Better late than never: initial experience of intra-arterial pulsed-urokinase-injection as a salvage therapy for refractory sudden sensorineural hearing loss

BACKGROUND AND PURPOSE

Cochlear vascular micro-thrombosis has been hypothesized as one of the pathogenic mechanisms for sudden sensorineural hearing loss (SSNHL) refractory to regular management. This study aimed to evaluate the feasibility and safety of intra-arterial pulsed-injection urokinase (IAPU) as a salvage therapy for SSNHL after the failure of conventional therapy.

METHODS

We retrospectively reviewed our patient database to identify refractory SSNHL patients between November 2017 and July 2020. Study outcomes before and after the IAPU therapy were compared between IAPU and conventional therapy groups.

RESULTS

Sixty-seven moderate-profound SSNHL patients (29 in IAUP group, 38 in control group) were included in this study. Compared to the control group, patients in the IAPU group showed more significant improvement in pure tone average (PTA) (34.2 ± 23.5 vs. 10.7 ± 13.1, p < 0.001) and degree of hearing recovery (total: 20.7% vs. 5.3%, partial: 24.1% vs. 10.5%, mild: 27.6% vs. 13.2% and non: 27.6% vs. 71.1%) 2 weeks after admission. In the IAPU group, a significant improvement of PTA (86.6 ± 11.5 vs. 54.6 ± 20.1 dB, p < 0.005) was observed on the first day after IAPU treatment.

CONCLUSION

In carefully selected SSNHL cases with a highly suspected vascular origin, IAPU is a safe and effective therapy when conventional treatments have failed. Despite the encouraging findings of our work, large studies are needed to better investigate the strengths and limitations of this salvage therapy.

Diagnostic value and prognostic significance of MRI findings in sudden sensorineural hearing loss

Purpose

Materials and Methods

Results

Conclusion

Lay Summary

Level of Evidence

Salvage intratympanic steroid therapy for sudden sensorineural hearing loss: our real-life experience in 32 patients

Objective

To examine the role of salvage intratympanic steroid injections in patients presenting with idiopathic sudden sensorineural hearing loss following a poor response to initial oral steroid treatment.

Methods

A retrospective analysis of patient records over the course of four years was conducted, and pure tone thresholds were reviewed before treatment, after oral steroid therapy and six weeks after intratympanic steroid injection therapy.

Results

After oral steroid therapy alone, there was a mean average threshold change of 6.2 dB HL (range, −13.8–33.8 dB). This change was statistically significant for severely affected patients (those with an average presenting threshold of over 71 dB). The mean average threshold improvement following intratympanic steroid injection therapy was 2.9 dB (range, −22.5–61.3 dB); this was not statistically significant.

Conclusion

Some patients experienced moderate improvement following intratympanic steroid injection therapy; however, no specific subgroup was identified to benefit more from intratympanic steroid injection therapy.

Idiopathic sudden sensorineural hearing loss: A critique on corticosteroid therapy

Idiopathic sudden sensorineural hearing loss (ISSNHL) is a condition affecting 5-30 per 100,000 individuals with the potential to significantly reduce one's quality of life. The true incidence of this condition is not known because it often goes undiagnosed and/or recovers within a few days. ISSNHL is defined as a ≥30 dB loss of hearing over 3 consecutive audiometric octaves within 3 days with no known cause. The disorder is typically unilateral and most of the cases spontaneously recover to functional hearing within 30 days. High frequency losses, ageing, and vertigo are associated with a poorer prognosis. Multiple causes of ISSNHL have been postulated and the most common are vascular obstruction, viral infection, or labyrinthine membrane breaks. Corticosteroids are the standard treatment option but this practice is not without opposition. Post mortem analyses of temporal bones of ISSNHL cases have been inconclusive. This report analyzed ISSNHL studies administering corticosteroids that met strict inclusion criteria and identified a number of methodologic shortcomings that compromise the interpretation of results. We discuss the issues and conclude that the data do not support present treatment practices. The current status on ISSNHL calls for a multi-institutional, randomized, double-blind trial with validated outcome measures to provide science-based treatment guidance.