Idiopathic Sudden Sensorineural Hearing Loss Is Not an Otologic Emergency

Natural History of Untreated Idiopathic Sudden Sensorineural Hearing Loss

OBJECTIVE

Although corticosteroids and other treatments for idiopathic sudden sensorineural hearing loss (ISSNHL) have been described, understanding its prognosis without intervention provides valuable information for patient management. The objective of this study is to provide a comprehensive, quantitative statistical analysis of the natural history of untreated idiopathic sudden sensorineural hearing loss (ISSNHL).

STUDY TYPE AND DESIGN

A systematic review and meta-analyses.

METHODS

Two independent searches of PubMed, Scopus, Web of Science, and Cochrane Library databases up to June 30, 2022, were performed. Adults with idiopathic sudden sensorineural hearing loss who received placebo or were untreated and had audiometric outcome measures in all study types were reviewed. These data indicative of the natural history of ISSNHL were analyzed, as were study characteristics related to risk of bias. Heterogeneity as assessed via I2 and random effects analyses were performed.

RESULTS

Six studies meeting the inclusion criteria yielded 319 untreated patients whose natural history could be assessed. Heterogeneity among studies was moderate, with a variety of reported outcomes. A hearing improvement of at least 30 dB HL was observed in 36% (95% CI 0.28-0.44) of untreated patients, and of at least 10 dB HL was observed in 70% (95% CI 0.57-0.82) of untreated patients at 3 months. The mean hearing gain among untreated patients was 24.0 dB HL (95% CI 2.65-45.37) at 2-3 months.

CONCLUSIONS

The observed natural history of ISSNHL suggests that patients can regain some hearing without active treatment. In the absence of future studies collecting prospective natural history data from untreated or placebo-treated ISSNHL patients, the data presented here provide the best available historical control data for reconsideration of results in past ISSNHL studies, as well as a roadmap for design and interpretation of future ISSNHL treatment clinical trials. Furthermore, knowing there is a statistically significant mean hearing gain of 24.0 dB HL in the untreated/placebo group provides an ethical basis for future placebo study of ISSNHL. The current status on ISSNHL management calls for a multi-institutional, randomized, double-blind placebo-controlled trial with validated outcome measures to provide science-based treatment guidance. Laryngoscope, 134:S1-S15, 2024.

Sudden Sensorineural Hearing Loss after COVID-19 Vaccination: A Review of the Available Evidence through the Prism of Causality Assessment

Sudden sensorineural hearing loss (SSNHL), a rare audiological condition that accounts for 1% of all cases of sensorineural hearing loss, can cause permanent hearing damage. Soon after the launch of global COVID-19 vaccination campaigns, the World Health Organization released a signal detection about SSNHL cases following administration of various COVID-19 vaccines. Post-marketing studies have been conducted in different countries using either pharmacovigilance or medico-administrative databases to investigate SSNHL as a potential adverse effect of COVID-19 vaccines. Here, we examine the advantages and limitations of each type of post-marketing study available. While pharmacoepidemiological studies highlight the potential association between drug exposure and the event, pharmacovigilance approaches enable causality assessment. The latter objective can only be achieved if an expert evaluation is provided using internationally validated diagnostic criteria. For a rare adverse event such as SSNHL, case information and quantification of hearing loss are mandatory for assessing seriousness, severity, delay onset, differential diagnoses, corrective treatment, recovery, as well as functional sequelae. Appropriate methodology should be adopted depending on whether the target objective is to assess a global or individual risk.

Efficacy of high dose systemic versus combined (systemic and intratympanic) corticosteroid therapy in idiopathic sudden sensorineural hearing loss: A prospective randomized trial and risk factor analysis

The pathophysiology and the proper treatment of idiopathic sudden sensorineural hearing loss (ISSNHL) are an ongoing subject of debate. Locally or systemic administered corticosteroids are the most accepted drugs of treatment in reference to ISSNHL (idiopathic sudden sensorineural hearing loss), however, no strong evidence nor guidelines regarding their effectiveness yet exists. In our prospective, randomized, controlled trial 78 participants were enrolled. Patients were randomly assigned based on the day of admission to two groups according to treatment: group SS (n = 43) received intravenous systemic methylprednisolone alone, and group CT (n = 35) received intratympanic dexamethasone + systemic methylprednisolone. The primary outcome was to compare the hearing outcomes between the treatment groups based on different, widely accepted categories (Siegel, Kanzaki, modified Siegel and PTA4 gain). In consideration of the secondary outcome, we examined the effect of the various risk factors on the hearing improvement. No differences were detected regarding hearing improvement between the two groups, based on any criteria [Siegel's criteria (p = 0.604); Kanzaki's criteria (p = 0.720); modified Siegel's criteria (p = 0.524) and PTA 4 gain (p = 0.569)]. However, several clinical factors such as vertigo (p = 0.039), or cardiovascular comorbidity (p = 0.02) and the severity of initial hearing loss (p = 0.033) were found to bear a significant impact upon the hearing outcome. To the best of our knowledge, this is the first randomized controlled trial comparing high dose systemic and combination corticosteroid therapy in ISSNHL patients. Our findings suggest coexisting cardiovascular comorbidity, vertigo and severity of the initial hearing loss may bear a significantly higher impact upon hearing improvement, than the additional intratympanic steroid administration. The presented trial was registered in the European Union Drug Regulating Authorities Clinical Trials Database (name: Combinated systemic and intratympanic steroid therapy in idiopathic sudden sensorineural hearing loss, No.: 2017-000658-20) and with the ethical approval of The National Institute of Pharmacy and Nutrition (OGYÉI) (protocol No.: 7621, on 2017.02.16.).

Cochlear Implantation in Patients with Bilateral Sudden Sensorineural Hearing Loss after COVID-19 Infection

COVID-19 infection is associated with a variety of neurological manifestations. Since the inner ear is vulnerable to viruses, sensorineural hearing loss (SNHL) has been reported to occur following SARS-CoV-2 infection. We present here two cases of profound SNHL following SARS-CoV-2 infection. Pure-tone audiograms confirmed profound SNHL. The tympanogram and Auditory Brainstem Responses showed no abnormal symptoms. MRIs and CTs identified some changes but no significant anatomical nor physiological manifestations explaining the obvious cause for hearing loss. High doses of oral corticosteroids with additional conservative therapy were given with no therapeutic response, and therefore, cochlear implant surgery was performed. One case was bilaterally treated, and the other one received an implantation on one side. Both surgeries were carried out without intra- nor postoperative complications. Interestingly, in both cases, advanced fibrotic tissue was found during surgery. Both cases reported successful rehabilitation and are satisfied with their new sound perception following cochlear implantation.

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.

Prognosis of Acute Low-Tone Hearing Loss Without Vertigo: A Scoping Review

OBJECTIVE

Despite its relatively high prevalence, our understanding of the natural clinical course of acute low-tone hearing loss (ALHL) without vertigo remains incomplete. The purpose of this study is to summarize the findings of studies that evaluated recovery from hearing loss (HL), recurrence and/or fluctuation of HL, and progression to Meniere's Disease (MD) of patients presenting with ALHL without vertigo.

METHODS

A scoping review of the English literature was performed. On May 14, 2020 and July 6, 2022, MEDLINE, Embase, and Scopus were searched to identify articles related to the prognosis of ALHL. To be included, articles had to present outcomes that were clearly distinguishable for patients with ALHL without vertigo. Two reviewers evaluated articles for inclusion and extracted data. Disagreements were adjudicated by a third reviewer.

RESULTS

Forty-one studies were included. There was extensive heterogeneity between studies in regard to defining ALHL, treatment methods, and time of follow-up. Most of the cohorts (39 out of 40) reported partial or complete recovery of hearing in the majority (>50%) of patients, although reports of recurrence were relatively common. Progression to MD was infrequently reported. Shorter time from onset of symptoms to treatment predicted better hearing outcomes in 6 of 8 studies.

CONCLUSION

The literature suggests that although the majority of patients with ALHL experience hearing improvement, recurrence and/or fluctuation are common, and progression to MD occurs in a minority of patients. Additional trials utilizing standardized inclusion and outcome criteria are needed to determine the ideal treatment for ALHL.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:2457-2469, 2023.

Analysis of hearing prognosis risk factors in pediatric unilateral sudden sensorineural hearing loss

OBJECTIVES

Pediatric idiopathic sudden hearing loss (PISSNHL) is a rare disease with no established factor affecting its prognosis. In this study, we investigate the risk factors affecting the prognosis of PISSNHL.

MATERIAL AND METHODS

Among the patients who visited our hospital from January 2010 to December 2021, the characteristics associated prognosis of 54 patients with unilateral PISSNHL were retrospectively confirmed.

RESULTS

Patients' recovery was determined by applying Siegel's criteria (SC) and AAO-HNS criteria (AC). Twenty-seven (50 %) and 29 patients (54.3 %) recovered for SC and AC, respectively. Age, sex, side, duration between onset and treatment, administration of intra-tympanic steroid injection, accompanying symptoms (tinnitus and dizziness), BMI, serum creatinine level, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte count (PLR), lymphocyte count, and platelet count were not significantly different between the recovery group and the poor recovery group (P > 0.05). The patients were divided into five groups according to the initial hearing of the affected ear and again according to their audiogram type. The initial hearing levels, hearing level severity, and the audiogram type were significantly different between the deaf group (>100 dB HL) and the non-deaf group (P < 0.05).

CONCLUSION

The prognosis of PISSNHL is closely related to the initial hearing at the onset. If the initial hearing level is <100 dB, the recovery rate is approximately 50 %, therefore requiring active treatment and emotional support. It may also be related to the type of audiometric curve.

Clinical features and prognosis of pediatric idiopathic sudden sensorineural hearing loss: A bi-center retrospective study

Objective

Limited research has focused on the clinical features of sudden sensorineural hearing loss (SSNHL) in pediatric patients. This study is aimed to investigate the relationship between clinical features and the baseline hearing severity and outcomes of SSNHL in the pediatric population.

Method

We conducted a bi-center retrospective observational study in 145 SSNHL patients aged no more than 18 years who were recruited between November 2013 and October 2022. Data extracted from medical records, audiograms, complete blood count (CBC) and coagulation tests have been assessed for the relationship with the severity (the thresholds of the initial hearing) and outcomes (recovery rate, hearing gain and the thresholds of the final hearing).

Results

A lower lymphocyte count (P = 0.004) and a higher platelet-to-lymphocyte ratio (PLR) (P = 0.041) were found in the patient group with profound initial hearing than in the less severe group. Vertigo (β = 13.932, 95%CI: 4.082–23.782, P = 0.007) and lymphocyte count (β = −6.686, 95%CI: −10.919 to −2.454, P = 0.003) showed significant associations with the threshold of the initial hearing. In the multivariate logistic model, the probability of recovery was higher for patients with ascending and flat audiograms compared to those with descending audiograms (ascending: OR 8.168, 95% CI 1.450–70.143, P = 0.029; flat: OR 3.966, 95% CI 1.341–12.651, P = 0.015). Patients with tinnitus had a 3.2-fold increase in the probability of recovery (OR 3.222, 95% CI 1.241–8.907, P = 0.019), while the baseline hearing threshold (OR 0.968, 95% CI 0.936–0.998, P = 0.047) and duration to the onset of therapy (OR 0.942, 95% CI 0.890–0.977, P = 0.010) were negatively associated with the odds of recovery.

Conclusions

The present study showed that accompanying tinnitus, the severity of initial hearing loss, the time elapse and the audiogram configuration might be related to the prognosis of pediatric SSNHL. Meanwhile, the presence of vertigo, lower lymphocytes and higher PLR were associated with worse severity.

Is Sudden Sensorineural Hearing Loss an Otologic Emergency? Evidence-Based Cutoff for Optimal Treatment Initiation for Sudden Unilateral Sensorineural Hearing Loss: A Case Series and Meta-Analyses

OBJECTIVES

To study the need for defining unilateral idiopathic sudden sensorineural hearing loss (ISSNHL) as an otologic emergency and establish an evidence-based cutoff for treatment initiation for optimal outcome.

METHODS

A systematic literature search of "MEDLINE" via "PubMed," "Embase," and "Web of Science" and original case series comparing the outcome of steroidal treatment for ISSNHL as a function of delays of patient presentation, of diagnosis, and of treatment initiation. Total delay was defined as days from ISSNHL onset to first steroidal dose and divided into up to 3 days, up to 7 days, up to 14 days, and >14 days.

RESULTS

The literature search identified 1,469 ears and our original case series contributed 154 ears suitable for study inclusion, resulting in 1,623 ears for statistical analysis. An odds ratio (OR) of 0.42 (95% confidence interval [CI], 0.25-0.71) was calculated for recovery if treatment had been initiated within the third day since the sudden occurrence of a unilateral hearing loss compared with treatment initiation on or after the fourth day (I 2 = 40.1%). The calculated OR for recovery was 0.35 (95% CI, 0.26-0.47) when treatment was initiated during the first 7 days after the sudden hearing loss onset compared with a delay of 8 days or more (I 2 = 52.1%). The OR was 0.31 (95% CI, 0.21-0.46) when treatment was initiated during the first 14 days after the event compared with a longer delay (I 2 = 0.0%).

CONCLUSION

Unilateral ISSNHL should be considered a medical emergency. Initiating treatment before 3 days have elapsed since the event portends the best outcome.

LEVEL OF EVIDENCE

Level I.

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.

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.

Short-term effects of intravenous batroxobin in treatment of sudden sensorineural hearing loss: a propensity score-matched study

Background

Sudden sensorineural hearing loss (SSNHL) can cause great panic in patients. Whether it is advantageous to add intravenous batroxobin in the treatment of SSNHL remains to be determined. This study aimed to compare the short-term efficacy of therapy combined with intravenous batroxobin and that without intravenous batroxobin in SSNHL patients.

Methods

This retrospective study harvested the data of SSNHL patients hospitalized in our department from January 2008 to April 2021. The hearing levels on the admitted day (before treatment) and the discharge day were considered pre-treatment hearing and post-treatment hearing, respectively. The hearing gain was the difference value of pre-treatment hearing and post-treatment hearing. We used Siegel's criteria and the Chinese Medical Association of Otolaryngology (CMAO) criteria to evaluate hearing recovery. The complete recovery rate, overall effective rate, and hearing gain at each frequency were considered outcomes. Propensity score matching (PSM) was conducted to balance the baseline characteristics between the batroxobin group and the non-batroxobin group. Sensitivity analysis was carried out in flat-type and total-deafness SSNHL patients.

Results

During the study period, 657 patients with SSNHL were admitted to our department. Among them, a total of 274 patients met the enrolled criteria of our study. After PSM, 162 patients (81 in each group) were included in the analysis. Once the hospitalized treatment was completed, the patients would be discharged the next day. Logistic regression analysis of the propensity score-matched cohort indicated that both the complete recovery rates [Siegel's criteria, OR: 0.734, 95% CI: 0.368-1.466, p = 0.381; CMAO criteria, OR: 0.879, 95% CI: 0.435-1.777, p = 0.720] and the overall effective rates [Siegel's criteria and CMAO criteria, OR: 0.741, 95% CI: 0.399-1.378, p = 0.344] were not significantly different between the two treatment groups. Sensitivity analysis has shown similar results. For flat-type and total-deafness SSNHL patients, no significant difference was found in post-treatment hearing gain at each frequency between the two groups after PSM.

Conclusion

There was no significant difference in short-term hearing outcomes between treatment with batroxobin and treatment without batroxobin in SSNHL patients by Siegel's and CMAO criteria after PSM. Future studies for better therapy regimens of SSNHL are still needed.

Examination of the Relation Between Audiometric Configuration and Hematological Parameters in Idiopathic Sudden Sensorineural Hearing Loss

Among the hematological parameters, neutrophil/lymphocyte ratio (NLR) and platelet/ lymphocyte ratio (PLR) have been associated with inflammatory state, microvascular damage and ischemia. It is well-known that these ratios increase in idiopathic sudden sensorineural hearing loss (ISSHL). In ISSHL, different audiographic features may reflect different disease mechanisms. This study aimed to investigate whether there were differences in NLR and PLR among patient groups with different audiometric configurations. Patients meeting the study inclusion criteria were divided into four groups according to their audiogram configurations. Mean NLR and PLR values of the patient groups were compared among themselves and versus control group. The study was conducted with 166 participants. Mean NLR values were 3.07 ± 2.48, 3.30 ± 2.70, 5.24 ± 3.71, 3.57 ± 3.19 and 1.51 ± 0.68 for ascending, flat, descending and total/subtotal audiometric configuration groups and control group, respectively. Mean PLR values were 145.2 ± 126.7, 130.9 ± 57.8, 192.2 ± 94.4, 143.7 ± 70.8 and 94.1 ± 24.7 for ascending, flat, descending, total/subtotal audiometric configuration groups and control group, respectively. Both NLR and PLR were significantly greater in patients from all configuration groups than in control group (p < 0.05). In addition, the group with descending audiometric configuration showed significantly higher mean NLR and PLR compared to other audiometric configuration groups (p < 0.05). The highest level of inflammation was detected in the ISSHL patient group with high frequency hearing loss and descending audiographic configuration.

Vestibular evoked myogenic potential may predict the hearing recovery in patients with unilateral idiopathic sudden sensorineural hearing loss

OBJECTIVE

This study investigates the association between vestibular function and prognosis in patients with unilateral idiopathic sudden sensorineural hearing loss (UISSNHL).

DESIGN

A retrospective analysis of 64 patients with UISSNHL was performed. Pure tone audiometry and vestibular function tests for otoliths and semicircular canals were performed to assess the influence of vestibular functional status on the outcome of patients with UISSNHL.

RESULTS

Patients with abnormal cervical vestibular evoked myogenic potential (cVEMP) or ocular vestibular evoked myogenic potential (oVEMP) responded less favorably to treatment. In the ineffective group, cVEMP was normal in four patients (6.3%) and oVEMPs in three (4.7%). Meanwhile, cVEMP was abnormal in 32 patients (50.0%) and oVEMP in 33 (51.6%). Better hearing recovery occurred in those with normal cVEMP (33.76 ± 15.07 dB HL improvement) or oVEMP (32.55 ± 19.56 dB HL improvement), but this was not the case in those with normal caloric tests. Patients with abnormalities in both cVEMP and oVEMP were less responsive to treatment and had worse hearing recovery than those with normal results in only one of the two tests.

CONCLUSION

Abnormal oVEMP and/or cVEMP results indicate poor auditory outcomes in patients with UISSNHL. Patients with impaired otolith organ function are likely to have a larger and more severe pathological change in their inner ear.

Correlation of Neutrophil-to-Lymphocyte Ratio and the Dilation of the Basilar Artery with the Potential Role of Vascular Compromise in the Pathophysiology of Idiopathic Sudden Sensorineural Hearing Loss

Idiopathic sudden sensorineural hearing loss (SSNHL) currently lacks a clear etiology, as well as an effective treatment. One of the most probable explanations for SSNHL is impairment of the cochlear blood flow. However, dissimilar to a fundoscopic examination, direct observation of cochlear blood vessels is not possible. To indirectly support an ischemic etiology of SSNHL, we investigated whether the degree of initial hearing loss is associated with two atherosclerotic risk factors: dilatation of the basilar artery (BA) and a chronic subclinical inflammatory status measured by the neutrophil-to-lymphocyte ratio (NLR). This retrospective study collected data from 105 consecutive patients diagnosed with idiopathic SSNHL. Then, the patients were divided into two groups according to their NLR as “abnormally high NLR (>3.53, n = 22)” and “NLR within the normal range (0.78−3.53, n = 83)”. The BA diameter and severity of initial hearing loss were significantly correlated with each other in the abnormally high NLR group (p < 0.001). However, there was no significant correlation between initial hearing loss and the BA diameter in the normal NLR group (p = 0.299). Therefore, the NLR may serve as a marker for SSNHL of vascular etiology and a rationale for magnetic resonance imaging examinations based on the pathophysiology.

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.

Intratympanic corticosteroids for sudden sensorineural hearing loss

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Rare case of sudden onset sensorineural hearing loss in a patient diagnosed with sarcoidosis

We report the case of a woman in her 30s who was referred to the ear, nose and throat department with sudden onset left-sided sensorineural hearing loss (SNHL), left anterior uveitis and erythematous lower limb lesions with bilateral pitting oedema. Based on her symptoms, an underlying inflammatory systemic disease was suspected. Autoantibodies were negative but an X-ray and high-resolution CT scan of the chest were suggestive of sarcoidosis, which was confirmed on endoscopic bronchial biopsy. Following treatment with a course of oral steroids, the patient's hearing has improved but she still suffers from episodes of uveitis. While immune-mediated inner ear disorders are a recognised cause of SNHL, sarcoidosis is a very rare cause. This case demonstrates the importance of screening for systemic autoimmune aetiology in SNHL and highlights the importance of an effective multidisciplinary team in the diagnosis and management of these patients.

Otoacoustic emissions value in patients with idiopathic sudden sensorineural hearing loss

Objectives

This study aimed to determine the prognostic value of otoacoustic emissions (OAEs) in idiopathic sudden sensorineural hearing loss patients.

Methods

The study included 30 subjects with unilateral idiopathic sudden sensorineural hearing loss (ISSNHL). Each patient was evaluated four times: at baseline and after one week, one month, and three months of treatment. During each visit, each patient was subjected to full audiological history, otoscopic examination, basic audiological evaluations, and transiently evoked and distortion product otoacoustic emission (TEOAEs & DEOAEs).

Results

The hearing thresholds (frequency range 250–8000 Hz) and word recognition scores of patients with detectable TEOAEs and DPOAEs improved significantly, whereas no significant improvements were observed in those with no response.

Conclusion

Hearing improvement is better in patients with detectable TEOAEs and DPOAEs. As a result, TEOAEs and DPOAEs are recommended as routine tests in all SSNHL patients to predict outcomes and monitor treatment as TEOAEs and DPOAEs reflect the cochlear OHCs activity.

Bilateral Sudden Sensorineural Hearing Loss: A Distinct Phenotype Entity

OBJECTIVE

To investigate the clinical phenotype and hearing prognosis of patients with unilateral and bilateral (simultaneous and nonsimultaneous) sudden sensorineural hearing loss (SSNHL).

STUDY DESIGN

Retrospective cohort.

SETTING

Otology outpatient clinic of a tertiary university hospital.

PATIENTS

Three hundred eighty-five medical records from patients with SSNHL.

MAIN OUTCOME MEASURES

Comparison of demographic, clinical, and audiometric (pretreatment and posttreatment) data of patients with unilateral and bilateral SSNHL.

RESULTS

Our final analysis comprised of 239 medical records of patients with SSNHL. Most patients had unilateral SSNHL (186, 77.82%). We identified a potential underlying cause for the SSNHL in 105 (43.9%) of the cases, being more frequent in cases of bilateral simultaneous SSNHL (100%) as compared with unilateral (45.6%) and nonsimultaneous bilateral SSNHL (22.7%). Cases of simultaneous bilateral SSNHL presented more frequently with severe or profound hearing loss (89%; unilateral SSNHL 50.5%; nonsimultaneous bilateral SSNL, 59.1%) and had a significantly worse hearing recovery prognosis as compared with unilateral or nonsimultaneous bilateral SSNHL (p = 0.002).

CONCLUSION

We observed a high heterogeneity of clinical presentations of SSNHL, the most common being unilateral SSNHL. Our results demonstrate that the clinical and audiological prognosis of simultaneous bilateral SSNHL differed significantly from unilateral and nonsimultaneous bilateral SSNHL, suggesting that simultaneous cases of bilateral SSNHL may be a part of a different disease process. The presence of a simultaneous, bilateral SSNHL indicates the need to investigate the presence of an underlying systemic disease.

Effectiveness of oral corticosteroids (prednisolone) in sensorineural hearing loss post COVID-19

Background

Numerous infections can result in neurological symptoms, including anosmia, facial paralysis, and abrupt sensorineural hearing loss (SSNHL). During the earlier SARS pandemic, coronaviruses were linked to a loss of smell and taste due to brain damage.

Purpose

To clinically detect corticosteroid treatment effectiveness in SSNHL post-COVID-19 infection and to detect the factors that affect the prognosis for these patients for better diagnosis and earlier management.

Subjects and method

Subjects included 20 subjects diagnosed by PCR as COVID-19 virus positive, complaining of sudden onset hearing loss post viral infection in different durations. All subjects had basic audiological evaluation done pre-treatment and repeated after 1 week, 2 weeks, and 1 month after treatment with methylprednisolone 21-acetate tablets.

Results

Onset of hearing loss post-COVID infection ranged from 1 to 3 months. As regards the improvement recognized with treatment course, thirteen patients (65%) of all twenty patients showed complete improvement at 1 month after starting treatment, and seven patients (35%) showed no improvement even after 1 month.

Conclusion

SSNHL has been widely recognized in the context of COVID-19 to date. Early corticosteroid therapy could help in the recovery of hearing, especially if the beginning of therapy was early in the first 2 weeks.

Association Between the Number of Intratympanic Steroid Injections and Hearing Recovery in Sudden Sensorineural Hearing Loss

The frequency of intratympanic (IT) steroid injection varies from once daily to once weekly or less among studies and does not reach a uniform standard. This study investigated the potential association between the number of IT steroid injections and hearing recovery to determine the optimal number in sudden sensorineural hearing loss (SSNHL) patients. A retrospective study involving 233 SSNHL patients receiving IT steroids plus batroxobin within 7 days of onset was performed. Patients were followed up for 3 months. More than 15 dB of HL improvement in the pretreatment pure tone average (PTA) was defined as effective. The effective group had a higher IT injection numbers than the ineffective group (≥ 6 times: 84.6 vs. 61.1, p < 0.001). Regardless of the unadjusted model or adjusted model, patients who received more frequent IT steroid injections seemed more likely to recover hearing (unadjusted model, OR, 95% CI: 1.25, 1.06-1.48; p = 0.007; adjusted model, OR, 95% CI: 1.21, 1.01-1.45; p = 0.044). Six IT injections had the highest rate of hearing recovery (79.1%). In conclusion, IT injection number was an independent factor that was positively associated with hearing recovery, and the optimal number of IT steroid injections was 6. Batroxobin plus higher number of IT steroid injections showed more effective for treating SSNHL.

Idiopathic Sudden Sensorineural Hearing Loss: Speech Intelligibility Deficits Following Threshold Recovery

OBJECTIVES

This retrospective study tests the hypothesis that patients who have recovered from idiopathic sudden sensorineural hearing loss (SSNHL) show deficits in word recognition tasks that cannot be entirely explained by a loss in audibility.

DESIGN

We reviewed the audiologic profile of 166 patients presenting with a unilateral SSNHL. Hearing loss severity, degree of threshold recovery, residual hearing loss, and word recognition performance were considered as outcome variables. Age, route of treatment, delay between SSNHL onset and treatment, and audiogram configuration were considered as predictor variables.

RESULTS

Severity, residual hearing loss, and recovery were highly variable across patients. While age and onset-treatment delay could not account for the severity, residual hearing loss and recovery in thresholds, configuration of the SSNHL and overall inner ear status as measured by thresholds on the contralateral ear were predictive of threshold recovery. Speech recognition performance was significantly poorer than predicted by the speech intelligibility curve derived from the patient's audiogram.

CONCLUSIONS

SSNHL is associated with (1) changes in thresholds that are consistent with ischemia and (2) speech intelligibility deficits that cannot be entirely explained by a change in hearing sensitivity.

Usefulness of stress-related hormones as predictors and prognostic factors for idiopathic sudden sensorineural hearing loss

BACKGROUND

The pathogenesis of Idiopathic sudden sensorineural hearing loss (ISSNHL) is ambiguous. Stress is commonly defined as a cause of the disease. Serum levels of stress-related hormone (cortisol, growth hormone, aldosterone, ADH, ACTH) may be elevated in patients with ISSNHL patients.

OBJECTIVES

We aimed to determine whether psychological factors and stress hormones in patients are associated with the severity of hearing loss and therapeutic outcomes. We hypothesized that the stress hormone level in the disease sequence is a strong prognostic factor of ISSNHL. Additionally, we investigated whether the subjective degree of psychological stress is likely to contribute to the therapeutic prognosis of ISSNHL, as determined using questionnaires.

METHODS

We conducted a prospective study of patients aged between 19 and 65 years admitted for the treatment of ISSNHL at our hospital. All patients underwent pure tone audiometry (PTA) on day 0, day 5 and 2 weeks after discharge. As an objective indicator of stress, we measured the level of HPA axis-related hormones. So, we measured serum cortisol, adrenocorticotropic hormone (ACTH), aldosterone and dehydroepiandrosterone sulfate (DHEAS) levels in the venous blood sample of patients on day 1 and day 5 after admission. In addition, for subjective stress measurements, depression and anxiety levels were assessed using self-reported questionnaires, Beck Depression Inventory (BDI), and Perceived Stress Scale (PSS) in the revised to Korean versions.

RESULTS

Eighteen patients diagnosed with ISSNHL at the Department of Otorhino-laryngology were enrolled. Serum DHEAS level measured on day 1 showed a statistically significant correlation with the hearing threshold in the hearing test performed at the time of diagnosis (p = .037, correlation coefficients(r) = 0.541). Serum ACTH level was measured on day 1, and patients were classified into normal and elevated groups based on a threshold of 1.5 pg/mL; the normal group had better hearing thresholds in the first and second hearing test than the elevated group (p = .040, 0.015, respectively). In the stress-related questionnaires, the BDI score showed a statistically significant correlation with the last hearing test (p = .015, correlation coefficients(r) = 0.613).

CONCLUSION

We demonstrated the possible role of stress-related hormones in the pathogenesis of ISSNHL and suggest that depressive stress response can be a strong predictor of treatment response in patients with ISSNHL. However, the impact of response to stress on the inner ear and endolymph homeostasis remains unknown. Since this is a cross-sectional study, we can only comment on the relationship between stress and ISSNHL, not a causal relationship. Further investigation is necessary to identify the mechanism of interaction between stress and hearing ability in the inner ear.

Quality Indicators for the Diagnosis and Management of Sudden Sensorineural Hearing Loss

OBJECTIVE

Sudden sensorineural hearing loss (SSNHL) is an ideal entity for quality indicator (QI) development, providing treatment challenges resulting in variable or substandard care. The American Academy of Otolaryngology-Head and Neck Surgery recently updated their SSNHL guidelines. With SSNHL demonstrating a large burden of illness, this study sought to leverage the updated guidelines and develop QIs that support quality improvement initiatives at an individual, institutional, and systems level.

METHODS

Candidate indicators (CIs) were extracted from high-quality SSNHL guidelines that were evaluated using the Appraisal of Guidelines for Research and Evaluation II tool. Each CI and its supporting evidence were summarized and reviewed by a nine-member expert panel based on validity, reliability, and feasibility of measurement. Final QIs were selected from CIs using the modified RAND Corporation-University of California, Los Angeles appropriateness methodology.

RESULTS

Fifteen CIs were identified after literature review. After the first round of evaluations, the panel agreed on 11 candidate indicators as appropriate QIs with 2 additional CIs suggested for consideration. An expert panel meeting provided a platform to discuss areas of disagreement before final evaluations. The expert panel subsequently agreed upon 11 final QIs as appropriate measures of high-quality care for SSNHL.

CONCLUSION

The 11 proposed QIs from this study are supported by evidence and expert consensus, facilitating measurement across a wide breadth of quality domains. With the recently updated SSNHL guidelines, and a greater focus on quality improvement opportunities, these QIs may be used by healthcare providers for targeted quality improvement initiatives.

Management of sudden sensorineural hearing loss among primary care physicians in Canada: a survey study

BACKGROUND

Sudden Sensorineural Hearing Loss (SSNHL) is a medical emergency requiring immediate attention as delayed treatment can lead to permanent and devastating consequences. Primary care physicians are likely the first to be presented with SSNHL and therefore have the crucial role of recognizing it and initiating timely and appropriate management. The aim of this study was to gain insight into the current knowledge and practice trends pertaining to the diagnosis and management of SSNHL among family physicians in Canada.

METHODS

An 18-question survey targeting Canadian family physicians was marketed through two, physician-only discussion groups on the social media platform Facebook. Responses were collected between August 1st and December 22nd 2019 then aggregated and quantified.

RESULTS

52 family physicians submitted responses. 94.2% (n = 49) reported that in their practice, unilateral SSNHL warrants urgent referral to otolaryngology and 84.6% (n = 44) reported that unilateral sudden-onset hearing loss warrants urgent referral for audiological testing. 73.1% of participants (n = 38) reported that they would attempt to differentiate between conductive and sensorineural hearing loss if presented with unilateral, acute or sudden-onset hearing loss. 61.5% (n = 32) would rely on tuning fork tests to inform management decisions, as compared to 94.2% (n = 49) relying on case history and 88.5% (n = 46) on otoscopy. 76.9% (n = 40) would prescribe corticosteroids if presented with confirmed, unilateral SSNHL.

CONCLUSION

The majority of family physicians in the study would make appropriate referral and treatment decisions in the management of SSNHL, understanding it is a medical emergency. Tuning fork tests are under-utilized for informing management decisions compared to other means of differentiating conductive and sensorineural hearing loss. Further research is needed to understand why some family physicians do not prescribe corticosteroids for treatment of SSNHL, which may then identify any gaps in knowledge or inform improvements in clinical protocol.

The Effectiveness of Hyperbaric Oxygen Therapy as Salvage Treatment for Sudden Sensorineural Hearing Loss: A Retrospective Study

Background

Sudden sensorineural hearing loss (SSNHL) is a medical emergency; its etiology is unknown in most cases, The treatment, in turn, is empiric and usually consists of various pharmacological agents, mainly steroids. Hyperbaric oxygen (HBO) therapy is used routinely as salvage therapy for refractory SSNHL. While several studies have demonstrated the effectiveness of HBO therapy as salvage treatment for refractory SSNHL, its results have varied among studies, and its efficacy is still unclear.

Aim

We aimed to stratify the effect of HBO therapy as salvage treatment after the failure of steroid therapy for SSNHL.

Method

This is a retrospective case series that involved eight SSNHL patients in the past three years at King Faisal Specialist Hospital & Research Centre (KFSHRC) in Riyadh, Saudi Arabia. Patients' records were reviewed and statistical analysis was performed.

Results

Eight patients were included in this case series; six of them were males, and the mean age of all patients was 46.88 ±20.9 years. One patient had herpes zoster as the cause of SSNHL and seven patients' disease was of unknown etiology. The mean period for the onset of disease was 4.12 ±2.17 days. One patient was managed with intravenous dexamethasone and the other patients were managed with oral steroids, and all patients were then treated by HBO therapy. Of the patients, two showed significant improvement but the others did not. The cause of SSNHL, age of patients, HBO start and cessation, comorbidities, and disease onset did not affect the improvement in disease in patients (p: ˃0.05).

Conclusion

Moderate-to-severe cases of SSNHL can be improved by HBO treatment along with oral steroids, while this therapy was ineffective in severe and profound cases. No factors could be found to predict improvement in patients.

Sudden Sensorineural Hearing Loss in Children-Management and Outcomes: A Meta-analysis

OBJECTIVE

To identify which patient characteristics and treatments are associated with hearing improvement in patients with pediatric sudden sensorineural hearing loss (SSNHL).

METHODS

PubMed, Web of Science, Cochrane Library, PsycINFO, and Cumulative Index to Nursing and Allied Health Literature were systematically searched for articles published before February 5, 2019, and references of relevant articles were screened. Original English-language case series and cohort studies were included if they addressed SSNHL in patients <20 years of age. Study characteristics, patient demographics, symptoms, treatments, and hearing outcomes were extracted. The primary outcome was hearing improvement.

RESULTS

Thirteen studies were included, totaling 605 patients (670 ears). Hearing did not improve in 46.7% of ears (95% confidence interval [CI]: 34.4% to 59.0%). Imaging (computed tomography and/or magnetic resonance imaging) results were described in three studies, and 24.2% of ears (95% CI: 7.7% to 40.6%) had abnormal findings. The most common serological finding was cytomegalovirus immunoglobulin (Ig)G or IgM (34.3% of ears tested, 95% CI: -2.9% to 71.6%). Unilateral hearing loss (odds ratio [OR]:3.85, P < .001), tinnitus (OR: 2.20, P = .003), age >12 years (OR: 2.11, P = .002), and ascending audiogram (OR: 3.66, P = .005), but not systemic or intratympanic steroids, were associated with increased odds of partial or complete improvement. In contrast, profound hearing loss (OR: 0.29, P < .001) and treatment delay of >6 days (OR: 0.27, P < .001) were associated with decreased odds of improvement.

CONCLUSIONS

Despite treatment, half of patients had no improvement in hearing. Prognostic factors associated with hearing improvement were generally consistent with those established in the adult population. Further research with consistent definitions for hearing improvement is needed to improve the understanding and treatment of pediatric SSNHL.

LEVEL OF EVIDENCE

Laryngoscope, 131:425-434, 2021.

Sudden sensorineural hearing loss - A contemporary review of management issues

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

Framingham risk score is associated with hearing outcomes in patients with idiopathic sudden sensorineural hearing loss

Objective

To assess the Framingham risk score as a prognostic tool for idiopathic sudden sensorineural hearing loss patients.

Methods

Medical records were reviewed for unilateral idiopathic sudden sensorineural hearing loss patients between January 2010 and October 2017. The 10-year risk of developing cardiovascular disease was calculated. Patients were subdivided into groups: group 1 – Framingham risk score of less than 10 per cent (n = 28); group 2 – score of 10 to less than 20 per cent (n = 6); and group 3 – score of 20 per cent or higher (n = 5).

Results

Initial pure tone average and Framingham risk score were not significantly associated (p = 0.32). Thirteen patients in group 1 recovered completely (46.4 per cent), but none in groups 2 and 3 showed complete recovery. Initial pure tone average and Framingham risk score were significantly associated in multivariable linear regression analysis (R2 = 0.36). The regression coefficient was 0.33 (p = 0.003) for initial pure tone average and −0.67 (p = 0.005) for Framingham risk score.

Conclusion

Framingham risk score may be useful in predicting outcomes for idiopathic sudden sensorineural hearing loss patients, as those with a higher score showed poorer hearing recovery.

Analysis of thyroid dysfunction in patients with sudden sensorineural hearing loss

Background

Sudden sensorineural hearing loss (SSHL) refers to the sudden occurrence of unexplained sensorineural hearing loss. The present study showed that different systemic diseases had different influence on the occurrence and hearing outcome of SSHL. Thyroid hormone is one of the important factors for the development of fetal ear and auditory function. However, the distribution of thyroid dysfunction in SSHL patients and the effect of thyroid dysfunction on the occurrence and hearing outcome of SSHL has not been studied.

Methods

In this study, a retrospective analysis had been done in 676 patients with SSHL. We had described the distribution of thyroid function in patients with SSHL in detail, and by the statistical method, analyzed the relationship between the hearing outcome and thyroid dysfunction, respectively.

Results

In all patients, 24.41% (165/676) had abnormal thyroid function testing results. The onset age of SSHL in FT3 abnormal group (including low and high group) was younger than that in normal FT3 group. Recovery group had more patients with lower-than-normal T3 level as compared to non-recovery patients. Significant associations between T3 levels and hearing outcome were observed in the subgroup with longer time elapse between symptom onset and treatment (≥14 d).

Conclusion

The incidence of thyroid dysfunction in SSHL is significantly higher than in the general population. There was obvious relationship between T3 and FT3 item of thyroid dysfunction and the onset time and hearing outcome of SSHL, which indicated that T3 or FT3 indicator may be one of the affecting factors for the SSHL. Early screening and diagnosis of thyroid dysfunction, especial T3 level, may help to evaluate the prognosis in SSHL patients.

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

Objective:

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

Study design:

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

Setting:

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

Patients:

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

Interventions:

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

Main outcome measures:

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

Results:

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

Conclusions:

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

Relationship between the drainage pattern of the dural venous sinuses and hearing recovery in patients with sudden sensorineural hearing loss

Although cochlear venous insufficiency has been considered to cause sudden sensorineural hearing loss (SSHL), there is insufficient clinical evidence to support this hypothesis. We sought to determine whether there is a correlation between draining patterns of the dural venous sinuses and the side of the affected ear in SSHL, as well as hearing recovery. The medical records of 109 patients diagnosed with unilateral SSHL were retrospectively reviewed. Magnetic resonance images and pure tone audiometry were performed in all patients. We measured the dominance of the inferior petrosal sinus (IPS) and transverse-sigmoid sinus (TS/SS) ipsilateral to the affected ear. Most patients were characterized by asymmetric venous drainage (IPS, 53.2%; TS/SS, 81.7%). The dominant side of the IPS or TS/SS was independent of the side of the affected ear for all patients in this study. However, in 35 patients with early recovery within 2 weeks, the dominant side of TS/SS was significantly associated with the side of the affected ear (p = 0.011). Moreover, the dominance of both the IPS and TS/SS influenced hearing outcomes at 3 months. Dominant TS/SS ipsilateral to the affected ear, particularly in the presence of ipsilateral hypoplastic IPS, is associated with a favorable hearing prognosis of SSHL.

MR evaluation of encephalic leukoaraiosis in sudden sensorineural hearing loss (SSNHL) patients

Epidemiological evidence suggests a strict correlation between sudden sensorineural hearing loss (SSNHL) and cerebrovascular disorders. Leukoaraiosis represents a diffuse alteration of the periventricular and subcortical white matter. The aim of our study was to verify if the presence of white matter hyperintensity (WMH) was higher in patients affected by SSNHL compared to controls and evaluate the correlation between WMH and the cardiovascular risk factors, hearing level, and the response to therapy in SSNHL patients. The study group included 36 subjects affected by unilateral SSNHL. Thirty-six age- and sex-matched normal subjects with a negative history of SSNHL were used as controls. All patients underwent magnetic resonance imaging (MRI) (1.5 Tesla GE Signa) and the extent of leukoaraiosis was assessed with the Fazekas scale. The results of the present study demonstrate a high prevalence of WMH in SSNHL patients compared to controls confirming the hypothesis of a vascular impairment in SSNHL patients. The higher recovery rate in patients with greater periventricular white matter hyperintensity (PWMH) may suggest a vascular etiology that is still responsive to medical treatment. We aim to expand both the number of patients and the controls to avoid the limitation of the still small number to warrant solid scientific conclusions.

Update on consensus on diagnosis and treatment of idiopathic sudden sensorineural hearing loss

INTRODUCTION

Idiopathic sudden sensorineural hearing loss (ISSNHL) is a sudden, unexplained unilateral hearing loss.

OBJECTIVES

To update the Spanish Consensus on the diagnosis, treatment and follow-up of ISSNHL.

MATERIAL AND METHODS

After a systematic review of the literature from 1966 to March 2018, on MESH terms «(acute or sudden) hearing loss or deafness», a third update was performed, including 1508 relevant papers.

RESULTS

Regarding diagnosis, 11ISSNHL is clinically suspected, the following diagnostic tests are mandatory: otoscopy, acumetry, tonal audiometry, speech audiometry, and tympanometry, to discount conductive causes. After clinical diagnosis has been established, and before treatment is started, a full analysis should be performed. An MRI should then be requested, ideally performed during the first 15 days after diagnosis, to discount specific causes and to help to understand the physiopathological mechanisms in each case. Although treatment is very controversial, due to its effect on quality of life after ISSNHL and the few rare adverse effects associated with short-term steroid treatment, this consensus recommends that all patients should be treated with steroids, orally and/or intratympanically, depending on each patient. In the event of failure of systemic steroids, intratympanic rescue is also recommended. Follow-up should be at day 7, and after 12 months.

CONCLUSION

By consensus, results after treatment should be reported as absolute decibels recovered in pure tonal audiometry and as improvement in speech audiometry.

Efficacy of systemic and intratympanic corticosteroid combination therapy versus intratympanic or systemic therapy in patients with idiopathic sudden sensorineural hearing loss: a randomized controlled trial

OBJECTIVE

The present study was conducted to compare the rates of recovery from idiopathic sudden deafness after the treatment with oral and intratympanic corticosteroids in both mono and combination therapies.

STUDY DESIGN

Triple-blind randomized clinical trial.

SETTINGS

Tertiary referral hospital.

SUBJECTS AND METHODS

A total of 112 patients who were admitted to the ENT emergency department randomly divided into three groups: an oral corticosteroid plus intratympanic placebo (systemic corticosteroid monotherapy group); an intratympanic corticosteroid plus oral placebo group (IT monotherapy group); and a combination therapy group (IT plus systemic combination group). All patients were treated additionally with antiviral and proton pomp inhibitor. An audiometry was performed once before beginning the therapies and again at the end of the therapy.

RESULTS

Of the total of 112 patients, 32 received intratympanic (IT) corticosteroids, 45 were receiving systemic corticosteroids, and 35 were receiving a combination of the two. A total of 74 patients (66.1%) responded positively [response to treatment was calculated as gain of at least 10 dB in 10 dB in average threshold or with the minimum improvement of 15% in speech discrimination scores (SDS)] to corticosteroid therapy. No significant differences were observed between the three groups (IT, systemic group, and combination therapy group) in their overall response to treatment (p = 0.5). Patients who suffered from concomitant tinnitus and dizziness responded less positively to the treatment (p < 0.002). Positive family history of SSNHL seems to be negative prognostic factors in the response to treatment (p < 0.001). The response to treatment was not related to the pattern (p = 0.04) and initial severity of hearing loss (p = 0.9).

CONCLUSION

This study did not find any difference in the rate of hearing improvement between systemic, intratympanic, and combined corticosteroid therapy for sudden hearing loss.

LEVEL OF EVIDENCE

1b.

Evaluation of cardiovascular risks and recovery of idiopathic sudden sensorineural hearing loss in hospitalised patients: comparison between complete and partial sudden sensorineural hearing loss

Objective:

To evaluate the presence of cardiovascular risk factors and recovery of idiopathic sudden sensorineural hearing loss in hospitalised patients.

Methods:

A single-centre retrospective study of 80 patients hospitalised for idiopathic sudden sensorineural hearing loss was conducted over a 6-year period. Mean pure tone hearing thresholds were assessed by pure tone audiometry.

Results:

Twenty-three of 80 patients (28.75 per cent) initially had no cardiovascular risk factors. Forty-five patients had hyperlipidaemia, 22 patients had hypertension, 7 patients had diabetes mellitus and 7 patients were obese. No statistically significant difference was observed between patients with complete versus partial sudden sensorineural hearing loss (p = 0.0708) concerning the cardiovascular risk factors. At long-term follow up, the hearing recovery rate was not significantly different between the two groups of patients (p = 0.7541).

Conclusion:

The lack of a clear relationship between idiopathic sudden sensorineural hearing loss and cardiovascular risk factors suggests that sudden sensorineural hearing loss has a predominantly multifactorial disease profile regardless of hearing impairment severity.

Characteristics and Spontaneous Recovery of Tinnitus Related to Idiopathic Sudden Sensorineural Hearing Loss

Objective:

To evaluate the characteristics and spontaneous recovery of tinnitus related to idiopathic sudden sensorineural hearing loss (ISSNHL).

Study Design:

Retrospective analysis from two randomized placebo-controlled clinical trials for treatment of ISSNHL within 48 hours from onset (Study A), or of tinnitus related to ISSNHL within 3 months from onset (Study B).

Setting:

Forty-eight European sites (academic tertiary referral centers, private ENT practices).

Patients:

One hundred thirteen adult patients of which 65 with hearing loss ≥30 dB (Study A) and 48 with persistent acute tinnitus (Study B) at baseline.

Interventions:

Intratympanic (i.t.) injection of placebo gel in single dose or in triple dose during 3 consecutive days.

Main Outcome Measures:

Frequency of tinnitus, subjective tinnitus loudness, rates of complete tinnitus remission, and complete hearing recovery during 3 months follow-up.

Results:

In acute ISSNHL, tinnitus loudness decreased rapidly in cases of mild-moderate hearing loss, and tinnitus had completely resolved in two-thirds of patients after 3 months. Hearing recovery preceded tinnitus resolution. When associated with severe-profound hearing loss, tinnitus improved significantly less. Complete hearing recovery and full tinnitus remission were both about three times more frequent in mild-moderate hearing loss patients than in severe-profound cases. Improvement in tinnitus loudness over time can be approximated by a negative exponential function.

Conclusions:

Prognosis for ISSNHL-related tinnitus is relatively poor in case of severe-profound hearing loss and the longer it has persisted. Alleviation or management of tinnitus should be a key therapeutic objective especially in pronounced ISSNHL cases.

Factors Prognostic of Season-Associated Sudden Sensorineural Hearing Loss: A Retrospective Observational Study

Background and Objectives

This study examined whether the prognosis of sudden deafness was dependent on the time of onset and evaluated the factors affecting prognosis during each period.

Subjects and Methods

Patients who developed sudden hearing loss from January 2005 to December 2015 were evaluated retrospectively. Meteorological data were obtained from the official website of the Korea Meteorological Administration. Factors prognostic of hearing recovery rate were analyzed.

Results

The hearing recovery rate of the 318 patients who developed sudden deafness did not differ significantly by month. Mean temperature and daily temperature range at onset of sudden deafness were not associated with recovery rate.

Conclusions

The recovery rate in patients with sudden deafness did not differ markedly by season.

Framingham Risk Score as a Prognostic Predictor of Sudden Sensorineural Hearing Loss: A Preliminary Study

Objectives/Hypothesis:

Predicting the prognosis of idiopathic sudden sensorineural hearing loss (ISSHL) remains challenging. This investigation aimed to apply Framingham Risk Scores (FRS) to assess the combination of prognostic factors following ISSHL and investigate the predictive role of FRS in patients with multiple comorbidities including hypertension, diabetes, and hyperlipidemia.

Study design:

Retrospective study.

Methods:

Twenty-one patients presenting with unilateral idiopathic sudden sensorineural hearing loss and multiple comorbidities were surveyed. Framingham Risk Score was calculated, and patients were assigned into high-risk (FRS ≥20%) and low-risk (FRS <20%) groups. Mean pure tone audiometry (PTA) threshold of both groups and hearing outcomes following established criteria were investigated. All patients were treated with the same protocol of oral methylprednisolone.

Results:

Overall successful recovery rate (complete + marked recovery) was 23.81%. The mean PTA threshold of the low-risk group showed significant improvement (mean PTA ± standard error, SE: pretreatment, 73.23 ± 11.80; posttreatment, 54.89 ± 10.25, P = .002), while the high-risk group did not show significant improvement in mean PTA threshold (mean PTA ± SE: pretreatment, 71.94 ± 11.77; posttreatment, 68.89 ± 12.81, P = .73).

Conclusion:

Framingham Risk Scores may be useful in predicting outcomes for ISSHL patients with multiple comorbidities.

Sudden sensorineural hearing loss: Is there a connection with inner ear electrolytic disorders? A literature review

Electrolytic disorders of the inner ear represent a model that could be implicated in partially explaining the pathogenesis of sudden sensorineural hearing loss (SSNHL). Different types of electrolytes and different inner-ear loci are involved in cochlear homeostasis physiologically, to ensure the maintenance of an ion-balanced cochlear environment allowing a normal hair cell function. It has been hypothesized that a sudden loss of endocochlear potential, due to a rapid disruption of the inner ear fluid osmolality, could be responsible for a deterioration of the hearing function caused by damaged hair cells. The aim of this paper was to review the current literature and identify sources which might validate/fortify the hypothesis that inner ear electrolytic disorders have a role in the etiopathogenesis of SSNHL. The data in the literature underline the importance of ionic homeostasis in the inner ear, but they do not support a direct link between SSNHL and electrolyte disorders/imbalances. There is marginal evidence from otoacoustic emissions research that an indirect link might be present.

The efficacy of combination therapy for idiopathic sudden sensorineural hearing loss

OBJECTIVES/HYPOTHESIS

The aim of this study was to compare the hearing results of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) who initially were treated with either a combination therapy of systemic steroids (SS) and intratympanic steroid injection (IT-S) or SS only.

METHODS

The study followed a retrospective case-control design. One-hundred five patients who were diagnosed with ISSNHL and required treatment via admission were enrolled in this study. The control group (n = 53) was treated with SS, and the study group (n = 52) received SS as well as IT-S. We divided the patients according to pretreatment hearing levels. The outcome measured was improvement after the treatment audiology data at pretreatment were compared with those at day 10 and > 90 days after the treatment. Outcome data were analyzed using the t test, Pearson's χ(2) test, Fisher's exact test, and multivariate analyses of covariance with adjustment for pretreatment hearing levels.

RESULTS

After more than 90 days, the average pure tone audiometry (PTA) in the control and study groups were 54.8 ± 31.4 dB and 43 ± 31.2 dB, respectively (P = 0.013). Hearing recovery rate was 57.7% in the control group and 69.8% in the study group. The hearing gain of the study group was higher than that of the control group at high frequencies within the 10 days of the treatment period. Analysis between subgroups, divided according to the severity of pretreatment hearing level, showed that the recovery rate was higher at all frequencies in the study group than in the control group in patients with mild to moderate hearing loss (pretreatment PTA < 70 dB). However, in patients with severe to profound hearing loss (pretreatment PTA ≥ 70 dB), the hearing outcomes of the study and control groups were not significantly different, except at a low frequency.

CONCLUSION

The results of this study suggest that the treatment of ISSNHL with combination therapy results in higher hearing recovery rates when compared to treatment with SS alone, even in patients with severe hearing loss.

LEVEL OF EVIDENCE

3b. Laryngoscope, 126:1871-1876, 2016.