Viral causes of hearing loss: a review for hearing health professionals

Bilateral, Sequential Sudden Hearing Loss in a Patient With Multiple COVID-19 Infections and Potential Implications on Subsequent Cochlear Implant Performance

Viruses are often implicated as a cause of sensorineural hearing loss (SNHL), particularly sudden cases, including COVID-19. Determining the viral mechanism that leads to hearing loss is necessary for its future prevention and treatment. The 47-year-old woman who is the subject of this case study presented with sudden SNHL following multiple infections of COVID-19. Following a trial of a contralateral routing of sound device, she received a right cochlear implant (CI). Following a period of high performance, additional cases of COVID-19 infection and device failure issues resulted in the explant/reimplant of 1 ear and implantation of the contralateral ear. Despite extensive rehabilitation after these events, the patient continues to experience difficulties in speech understanding, not reaching her initial high levels of right ear performance. Further research is needed to determine the implications of COVID-19 as it relates to SNHL. This case study aimed to highlight the course of treatment and provide insight into the impact of COVID-19 on sudden hearing loss and its relationship to CI performance.

Pre-registered controlled comparison of auditory function reveals no difference between hospitalised adults with and without COVID-19

OBJECTIVE

Several viruses are known to have a negative impact on hearing health. The global prevalence of COVID-19 means that it is crucial to understand whether and how SARS-CoV2 affects hearing. Evidence to date is mixed, with studies frequently exhibiting limitations in the methodological approaches used or the populations sampled, leading to a substantial risk of bias. This study addressed many of these limitations.

DESIGN

A comprehensive battery of measures was administered, including lab-based behavioural and physiological measures, as well as self-report instruments. Performance was thoroughly assessed across the auditory system, including measures of cochlear function, neural function and auditory perception. Hypotheses and analyses were pre-registered.

STUDY SAMPLES

Participants who were hospitalised as a result of COVID-19 (n = 57) were compared with a well-matched control group (n = 40) who had also been hospitalised but had never had COVID-19.

RESULTS

We find no evidence to support the hypothesis that COVID-19 is associated with deficits in auditory function on any auditory test measure. Of all the confirmatory analyses, only the self-report measure of hearing decline indicated any difference between groups.

CONCLUSION

Results do not support the hypothesis that COVID-19 infection has a significant long-term impact on the auditory system.

Establishing multifactorial risk factors for adult-onset hearing loss: A systematic review with topic modelling and synthesis of epidemiological evidence

BACKGROUND

This systematic review explores the multifaceted nature of risk factors contributing to adult-onset HL. The objective was to synthesise the most recent epidemiological evidence to generate pooled proportional incidences for the identified risk factors.

METHODS

We conducted an extensive search of electronic databases (MEDLINE, EMBASE, and psychINFO) for studies providing epidemiological evidence of risk factors associated with hearing loss. Topic modelling using Latent Dirichlet Allocation (LDA) was first conducted to determine how many risk factor themes were available from the papers. Data were analysed by calculating the pooled proportional incidence using a meta-analysis of proportions.

RESULTS

From the 72 studies reviewed, six key risk factor themes emerged through LDA topic modelling. The review identified ototoxicity, primarily caused by cancer treatments and antibiotics, infectious diseases like COVID-19, occupational noise exposure, lifestyle factors, health conditions, biological responses, and age progression as significant risk factors for HL. The highest proportional incidence was found with cancer-related ototoxicity at 55.4% (95%CI: 39.0-70.7), followed closely by ototoxicity from infectious diseases at 50.0% (95%CI: 28.5-71.5). This high proportional incidence suggests the need to explore less destructive therapies and proactively monitor hearing function during treatments.

CONCLUSIONS

The findings of this review, combined with the synthesis of epidemiological evidence, enhance our understanding of hearing loss (HL) pathogenesis and highlight potential areas for intervention, thereby paving the way for more effective prevention and management of adult-onset hearing loss in our ageing global population.

Sudden Secondary Sensorineural Hearing Loss Following Hand, Foot, and Mouth Disease in an Adult Patient: A Case Report

Introduction: Sudden sensorineural hearing loss (SSNHL) can present as sudden hearing loss within 72 hours. Studies have shown that viral infection, including direct invasion, indirect reactions, stress responses, and immune-mediated hearing loss, is the main cause of SSNHL. Viral infection may play an important role in SSNHL by causing injury to the inner ear through blood or cerebrospinal fluid. In this article, we describe an adult case of SSNHL following hand, foot, and mouth disease (HFMD). Case Report: A 34-year-old man presented with sudden hearing loss in the right ear 4 days after HFMD onset. Tinnitus, ear fullness, and a slightly heavy head appeared synchronously as accompanying symptoms. Before 6 days, he had a fever for 2 days (the highest temperature was 39.4°C), followed by vesicles in the oral mucosa and papules on the hands and feet after cohabitation with his child diagnosed with HFMD.

Impact on the first year of life of newborns with gestational infection by SARS-COV-2. Analysis of auditory effects

Introduction

One of the causes of congenital hearing loss are infections suffered by the mother during pregnancy. The objective of this study was to investigate the effects on hearing in newborns to SARS-CoV-2 seropositive mothers during pregnancy. We also studied the hearing impact in the first year of life of the newborns to investigate whether neonatal infection produced a risk of infantile sensorineural hearing loss.

Material and methods

All children born in our center whose mother had been infected with SARS-CoV-2 positive COVID were included and were audiologically studied at two and a half months and at one year of life. All infants were evaluated by brainstem evoked response audiometry (BERA) and auditory steady-state responses (ASSR).

Results

The range of the latencies for BERA founded were inside the desired ranges of normality both at two and a half months and at one year of life No significant differences by sex and ears were found in the BERA performed (p > 0,05). The mean ASSR values were found to be significantly below 30 dB in all frequencies studied both at two and a half months, and at one year of life (p < 0,05).

Conclusion

There is no association between COVID-19 infection during pregnancy and neonatal hearing loss. Further studies are needed to clarify this field since it is still unclear whether pregnant women infected with SARS-CoV-2 can produce hearing alterations in their newborns according to the current evidence in the literature.

Number of initial symptoms of SARS-CoV-2 infection is associated with the risk of otological symptoms: a retrospective study

BACKGROUND

The characteristics of otological symptoms in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are lacking. Almost no research has been conducted to explore the emergence of otological symptoms after coronavirus disease 2019 infection. The aims of this study were to investigate the prevalence and specific clinical characteristics of and risk factors for otological symptoms among patients with SARS-CoV-2 infection.

METHODS

We included two groups to investigate the prevalence and clinical characteristics of otological symptoms among patients with SARS-CoV-2 infection. The first sample (S1) was drawn retrospectively from four communities via questionnaires, and the second sample (S2) from an outpatient clinic.

RESULTS

A total of 189 participants were included in S1 (124 women [65.6%]; mean [standard deviation (SD)] age, 33.66 [13.56] years), and 47 in S2 (25 women [53.2%]; mean [SD] age, 45.28 [14.64] years). The most prevalent otological symptoms in S1 were dizziness (15.9%), tinnitus (7.9%), aural fullness (6.9%), otalgia (5.3%), hearing loss (1.6%), and otopyorrhoea (1.1%). Moreover, for each additional typical symptom of SARS-CoV-2 infection, the risk (odds ratio) of otological symptoms increased by 1.33 (95% confidence interval: 1.10-1.61, p = 0.003). The prevalence of aural fullness was higher in the unvaccinated group than that in the group receiving two or three vaccinations (p = 0.018).

CONCLUSIONS

Various otological symptoms may occur in patients with SARS-CoV-2 infection. The number of typical symptoms of SARS-CoV-2 infection is positively associated with the probability of otological symptoms. However, vaccination may reduce the probability of certain otological symptoms.

Hearing Loss and Disorders: The Repercussions of Climate Change

PURPOSE

Climate change is considered to be the greatest threat to human health in the 21st century, and its effects are accelerating. Extensive research has clearly demonstrated its increasing impact across the continuum of health conditions. Despite this, there has been limited attention to the ramifications of climate change on hearing loss and hearing disorders. This lack of consideration is somewhat surprising as the environment itself and its changing nature have a substantial effect on hearing.

METHOD

Tackling climate change could be the greatest global health opportunity of the 21st century. To address this issue, this tutorial provides a general introduction to climate change and its three major elements (pollution, infectious diseases, and extreme weather events) and their effects on health. The substantial consequences of climate change for the incidence, development, and exacerbation of hearing loss and disorders are clearly described and detailed.

CONCLUSIONS

The challenge of responding to this very real and escalating threat to hearing requires a combination of prevention, advocacy, and education. These three roles place audiologists in the perfect position to take action on the far-reaching effects of climate change on hearing loss and disorders. To respond to this challenge and to fulfill these roles, several strategies, ranging from the individual level to the global level, are delineated for audiologists to incorporate into their practice.

Association between COVID-19 and sensorineural hearing loss: Evidence from a Mendelian randomization study in European and East Asian population

BACKGROUND

Long coronavirus disease (COVID), characterized by persistent and sometimes debilitating symptoms following a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has garnered increasing attention as a potential public health crisis. Emerging evidence indicates a higher incidence of hearing loss in individuals who have had COVID 2019 (COVID-19) compared to the general population. However, the conclusions were inconsistent, and the causal relationship between COVID-19 and sensorineural hearing loss remains unknown.

METHODS

To addresses this outstanding issue, we performed Mendelian randomization analysis to detect the causal association between COVID-19 and hearing loss using the largest genome-wide association study data to date in the European population and confirmed the results in the East Asian population. Comprehensively sensitive analyses were followed, including Cochran's Q test, Mendelian randomization (MR)-Egger intercept test, MR-pleiotropy residual sum and outlier, and leave-one-out analysis, to validate the robustness of our results.

RESULTS

Our results suggested that there is no causal association between COVID-19 and the risk of hearing loss in the European population. Neither the susceptibility, hospitalization, and severity of COVID-19 on hearing loss (inverse variance weighted method: odds ratio (OR) = 1.046, 95% confidence interval (CI) = 0.907-1.205, p = .537; OR = 0.995, 95% CI = 0.956-1.036, p = .823; OR = 0.995, 95% CI = 0.967-1.025, p = .76). Replicated analyses in the East Asian population yielded consistent results. No pleiotropy and heterogeneity were found in our results.

CONCLUSION

In conclusion, our MR results do not support a genetically predicted causal relationship between COVID-19 and sensorineural hearing loss. Thus, the associations observed in prior observational studies may have been influenced by confounding factors rather than a direct cause-and-effect relationship. More clinical and mechanism research are needed to further understand this association in the future.

Sustained delivery of triamcinolone acetonide from a thermosensitive microemulsion gel system for the treatment of sensorineural hearing loss

Intratympanic administration for the delivery of steroids has been extensively studied but limited because of low permeability of the drug through the row window membrane. Here, to effectively deliver poorly soluble triamcinolone acetonide (TA), microemulsions (ME) were prepared from Capmul MCM (oil), Cremophor RH40 (surfactant), and tetraglycol (cosurfactant) based on solubility studies, emulsifying ability test, and pseudoternary phase diagrams. Microemulsion gel (MEG) was prepared by mixing TA-ME with a poloxamer hydrogel base. The physicochemical properties of ME and MEG formulations were characterized, and the toxicity and oto-protective effectiveness were evaluated in vitro and in vivo. The ME-3 formulation showed a small droplet size (16.5 ± 0.2 nm), narrow PDI (0.067 ± 0.041), and enhanced TA solubility (2619.7 ± 57.6 μg/g). The optimized MEG demonstrated temperature-dependent gelation with a gelation time of 208 ± 10 sec at 37 °C. Slow degradation of the gel matrix sustained release of TA from MEG compared to the ME formulation. Both TA-ME and TA-MEG were found to be nontoxic to NIH3T3 cells at the test concentrations (0 to 5 µg/mL), and biocompatible after intratympanic administration to mice. The incorporation of ME into thermosensitive hydrogels prolonged retention of TA at the site of administration until 6 days. As a consequence, the enhanced drug absorption into the cochlea in TA-MEG group (approximately 2 times higher than other groups) protected hair cells, spiral ganglion neurons, and stria vascular cells from cisplatin-induced damage. Therefore, this injectable TA-loaded MEG is an effective and safe vehicle for the sustained delivery of triamcinolone acetonide into the inner ear.

Acute and Longer-Term Effects of COVID-19 on Auditory and Vestibular Symptoms

OBJECTIVE

To evaluate long-term effects of COVID-19 on auditory and vestibular symptoms in a diverse cohort impacted by the initial 2020 COVID-19 infection in the pandemic's epicenter, before vaccine availability.

STUDY DESIGN

Cohort study of individuals with confirmed COVID-19 infection, diagnosed in the March-May 2020 infection wave. A randomized, retrospective chart review of 1,352 individuals was performed to identify those with documented new or worsening auditory (aural fullness, tinnitus, hyperacusis, hearing loss) or vestibular (dizziness, vertigo) symptoms. Those with documented symptoms (613 of the 1,352 initial cohort) were contacted for a follow-up telephone survey in 2021-2022 to obtain self-report of aforementioned symptoms.

SETTING

Academic tertiary hospital system in Bronx, NY.

PATIENTS

Adults 18 to 99 years old with confirmed COVID-19 infection, alive at time of review. One hundred forty-eight charts were excluded for restricted access, incomplete data, no COVID-19 swab, or deceased at time of review.

INTERVENTION

Confirmed COVID-19 infection, March to May 2020.

MAIN OUTCOMES MEASURES

Auditory and vestibular symptoms documented in 2020 medical records and by self-report on 2021 to 2022 survey.

RESULTS

Among the 74 individuals with documented symptoms during the first 2020 COVID-19 wave who participated in the 2021 to 2022 follow-up survey, 58% had documented vestibular symptoms initially in 2020, whereas 43% reported vestibular symptoms on the 2021 to 2022 survey ( p = 0.10). In contrast, 9% had documented auditory symptoms initially in 2020 and 55% reported auditory symptoms on the 2021 to 2022 survey ( p < 0.01).

CONCLUSIONS

COVID-19 may impact vestibular symptoms early and persistently, whereas auditory effects may have more pronounced long-term impact, suggesting the importance of continually assessing COVID-19 patients.

Healthy ageing: Herpes zoster infection and the role of zoster vaccination

Populations are ageing worldwide, with considerable time lived in ill-health, putting upwards pressure on healthcare budgets. Healthy ageing is defined as maintaining functional ability, including the ability to: meet basic needs; learn, grow and make decisions; be mobile; build and maintain relationships; and contribute to society. The risk and impact of infectious diseases increase with age due to immunosenescence. Vaccination can help to prevent disease in older adults, promoting healthy ageing and active lives. Herpes zoster (HZ) occurs when the varicella zoster virus is reactivated due to declining immunity. HZ is common, with a lifetime risk of one-third, and increases in incidence with age. HZ is associated with severe and intense pain, substantially affecting the functional status of patients as well as their overall health-related quality of life. HZ and its complications may result in prolonged morbidity, including persistent pain (post-herpetic neuralgia, PHN), hearing impairment, vision loss and increased risk of stroke and myocardial infarction. HZ and PHN are difficult to treat, substantiating the benefits of prevention. Vaccines to prevent HZ include a recombinant zoster vaccine (RZV). RZV has shown efficacy against the HZ burden of disease and HZ burden of interference on activities of daily living of over 90% in immunocompetent adults aged ≥50 years. Vaccine efficacy against HZ was maintained at over 70% at 10 years post-vaccination. Adult vaccination, including against HZ, has the potential to reduce burden of disease, thus helping to maintain functioning and quality of life to support healthy ageing in older adults.

Cytomegalovirus infection during pregnancy

Cytomegalovirus (CMV) infection during pregnancy is a global silent problem. Additionally, it is the leading cause of congenital infections, non-genetic sensorineural hearing loss, and neurodevelopmental delays in infants. However, this has barely been recognized globally. This condition lacks adequate attention, which is further emphasized by the lack of awareness among healthcare workers and the general population. The impact of CMV infection is often overlooked because of the asymptomatic nature of its presentation in infected pregnant women and newborns, difficulty in diagnosis, and the perception that infants born to women with pre-existing antibodies against CMV have normal neonatal outcomes. This article highlights the latest information on the epidemiology, transmission, clinical manifestations, and development of CMV infection and its management. We reviewed the pathophysiology and clinical manifestations of CMV infection in pregnant women, diagnostic methods, including screening and prognostic markers, and updates in treatment modalities. Current advancements in research on vaccination and hyperimmunoglobulins with worldwide treatment protocols are highlighted.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Clinical characteristics and prognosis of sudden sensorineural hearing loss in single-sided deafness patients

Background

Sudden sensorineural hearing loss (SSNHL) in patients with single-sided deafness (SSD) is rare. The prognosis of the sole serviceable hearing ear is very important for these patients. However, the clinical characteristics and prognosis of SSNHL in SSD patients are not well-documented.

Objective

This study aimed to investigate the clinical features and treatment outcomes of SSNHL in SSD patients.

Methods

Clinical data of 36 SSD patients and 116 non-SSD patients with unilateral SSNHL from January 2013 to December 2022 were retrospectively investigated. The clinical characteristics of the SSD patients were analyzed. All SSD patients were treated with intratympanic steroids plus intravenous steroids. Pure-tone average (PTA) and word recognition score (WRS) before and after treatment were recorded. The hearing recovery of SSNHL in SSD patients in comparison with non-SSD patients was explored. Auditory outcomes in SSD patients with different etiologies were also compared.

Results

Initial hearing threshold showed no significant differences between the SSD group and the non-SSD group (66.41 ± 24.64 dB HL vs. 69.21 ± 31.48 dB HL, p = 0.625). The SSD group had a higher post-treatment hearing threshold (median (interquartile range, IQR) 53.13(36.56) dB HL) than the non-SSD group (median 32.50(47.5) dB HL, p < 0.01). Hearing gains (median 8.75(13.00) dB) and the rate of significant recovery (13.89%) were lower in the SSD group than in the non-SSD group (median 23.75(34.69) dB, 45.69%). The etiology of SSD was classified as SSNHL, special types of infection, chronic otitis media, and unknown causes. SSNHL accounted for the maximum proportion (38.9%) of causes of SSD in the SSD group. Hearing gains were lower in the SSNHL-SSD group than in other causes of the SSD group. A binary logistic regression analysis demonstrated that SSD serves as an indicator of unfavorable hearing recovery outcomes (OR = 5.264, p < 0.01).

Conclusion

The prognosis of SSNHL in SSD patients is unsatisfactory. SSNHL accounts for the maximum proportion of causes of SSD in this group of patients. For SSD patients caused by SSNHL, less hearing improvement after treatment was expected when SSNHL occurred in the contralateral ear in comparison with SSD patients with other causes.

Prevalence of self-perceived audiovestibular symptoms in Egyptian COVID-19 patients

BACKGROUND

According to National Institute for Health and Care Excellence (NICE), UK, common audiovestibular symptoms of COVID-19 include dizziness, tinnitus, and otalgia. The pathogenesis of otologic disorders ranges from direct damage to the inner ear structures to immune-mediated damage. Since the start of the pandemic, the prevalence of audiovestibular symptoms linked to COVID-19 has not been thoroughly investigated in Egypt. Our objective is to study and analyze the prevalence of the audiovestibular symptoms in the Egyptian population with history of COVID-19 infection.

METHODS

A cross-sectional study was conducted among Egyptian adults on the presence and nature of the audiovestibular manifestations in COVID-19 patients. An online questionnaire was used. The questionnaire was developed using Google Form. It was disseminated to the target population through social platforms from October 2021 till February 2022.

RESULTS

Data from 245 respondents were collected through online assessment of a convenient sample. The following de novo audiovestibular symptoms were experienced by the participants: Vertigo 20.8%, hearing loss 13.9%, tinnitus 12.7% and ear fullness 11.4%. No correlation was found between the investigations done (D-Dimer, CT chest) and the audiovestibular symptoms.

CONCLUSION

Audiovestibular symptoms are fairly common among COVID-19 patients, with higher prevalence, particularly of vertigo, in our study sample compared to the literature. It is recommended that patients with audiovestibular symptoms undergo early testing so that prompt interventions can be taken.

Are Current Data Sufficient to Infer that Hearing Aids Contribute to Postural Control and Balance in Older Adults? A Systematic Review

INTRODUCTION

Balance and postural control are related to hearing and hearing loss, but whether they can be improved with hearing aid use in older adults is not clear. We systematically reviewed controlled studies in which balance and hearing were tested in experienced older hearing aid users to determine the potential effects of hearing aid use on balance.

METHODS

The review was pre-registered in PROSPERO and performed in accordance with PRISMA. The question, inclusion, and exclusion criteria were defined using the Population, Intervention, Control, Outcomes and Study design (PICOS) framework. Older adults with hearing loss and no experience with hearing aids, or balance tests conducted without hearing aids in hearing aid users served as controls.

RESULTS

A total of 803 studies were screened, eight of which met the inclusion and exclusion criteria and were included in the final review. Five of the eight studies found a significant correlation between the use of hearing aids and the outcomes of the balance tests. The quality of the studies was limited or moderate. Key Discussion: The role of hearing aids in balance and postural control is unclear because of the quality of the papers and the sparse reporting of hearing status and hearing aids quality of fitting and use.

Prevalence and Types of Otological Symptoms Presenting in COVID-19 Patients in Jeddah, Saudi Arabia: A Questionnaire-Based Study

Background The clinical manifestations of coronavirus disease 2019 (COVID-19) can cause sensory dysfunction of taste, smell, and hearing. Otological symptoms may exceed hearing loss to ear pressure, tinnitus, and hyperacusis. Objective The objective of this study was to identify the prevalence and types of otological symptoms among patients diagnosed with COVID-19 in Jeddah, Saudi Arabia. Methods This is a cross-sectional study that was conducted among COVID-19 patients who have been diagnosed at Dr. Soliman Fakeeh Hospital (DSFH), Jeddah KSA, aged 18 years or older. The data collection was done through phone-call interviews utilizing an online form of a pre-structured questionnaire. The form included six otological symptoms; each symptom was further detailed with regard to duration, intensity, clinical course (continuous vs intermittent), and recovery. Results A total of 406 responses from patients diagnosed with COVID-19 were analyzed. Females represented 53.7% of the sample. The highest proportion of patients (30%) was in the age group of 31-40, followed by 22.9% in the age group of 25-30. The otological symptoms' prevalence rates were as follows: dizziness, vertigo, or imbalance 34.5%, ear pain 13.1%, tinnitus 12.1%, ear pressure 10%, hearing loss 6.4%, and hyperacusis 5.4%. Males had a higher prevalence of tinnitus, while females had higher reported symptoms of ear pain, hearing loss, and hyperacusis. Conclusion The most common otological symptoms were dizziness, vertigo, and imbalance among one-third of COVID-19 patients. Females reported higher rates of symptoms with ear pressure having significantly higher odds among females. Age groups were also significantly associated with ear pain, tinnitus, and ear pressure.

Insights into perceived listening difficulties post COVID-19 infection: no measurable hearing difficulty on clinical tests despite increased self-reported listening effort

Objective

The aim was to use a battery of clinic-based auditory assessment procedures to compare participants with and without self-reported hearing difficulties following a confirmed COVID-19 infection. A further aim was to compare the groups on self-reported measures of listening effort and fatigue.

Methods

There were 25 participants in each group (age range 20-59 years, 80% females). Participants were recruited after a minimum of 4 weeks of testing positive. Hearing assessment involved tympanometry, acoustic reflex thresholds, pure-tone audiometry (PTA; 0.25-14 kHz), and distortion product otoacoustic emissions (DPOAEs; 0.5-10 kHz). Listening effort was assessed using the Arabic version of the Effort Assessment Scale (EAS-A) and fatigue was assessed using the Arabic version of the Fatigue Assessment Scale (FAS-A).

Results

There was no difference between groups on any measure except for greater self-reported listening effort in the perceived hearing difficulty group (p = 0.01).

Conclusion

The only difference between groups was self-reported listening effort. This could be due to a subclinical auditory deficit following COVID-19, increased listening effort due to the impact of COVID-19 on cognitive processes, or a psychosomatic response/health anxiety.

Hearing loss and COVID-19: an umbrella review

INTRODUCTION

COVID-19 can result in an extensive range of extrapulmonary, and neurological signs and symptoms such as olfactory and/or taste dysfunction, and otologic symptoms. The aim of this study was to investigate the hearing loss manifestation from COVID-19.

METHODS

The goal of this umbrella review was to examine hearing loss associated with COVID-19 disease. English literature published until October 15, 2022 in online databases including PubMed, Scopus, Web of Science, and Embase was considered for this purpose. Eligibility of the articles for subsequent data extraction was evaluated in a two-step selection process with consideration to an inclusion/exclusion criterion. This review followed the PRISMA protocol and the Amstar-2 checklist for quality assessment.

RESULTS

A total of four treatment strategies were used by different studies which included oral corticosteroids, intratympanic corticosteroids, combined oral and intratympanic corticosteroids, and hyperbaric oxygen therapy. Five studies investigated corticosteroid use in the forms of oral or intratympanic injection; four studies reported (complete or partial) hearing improvements after steroid treatment, while one study stated no significant improvement in hearing function. One study reported that oral corticosteroid monotherapy alone was not effective, while vestibular symptoms were ameliorated by a combination of oral prednisone, intratympanic dexamethasone injection, and hydroxychloroquine.

CONCLUSION

The findings suggest that despite being one of the rare complications of COVID-19, hearing loss can impact a patient's quality of life. The most common type reported was sensorineural hearing loss, which can be diagnosed with variable techniques.

Gestational Mild COVID-19 Infection Associated Neonatal Hearing Loss: A Case-Control Study from North India

COVID-19 infection during pregnancy is potentially dangerous to neonatal hearing, as it is the period of organogenesis, and associated hyperthermia may cause vascular damage, disruption of cell migration, and death of the dividing neuroblasts. To investigate the possible association between neonatal hearing loss and gestational mild COVID-19 infection. A prospective case-control study was conducted at a tertiary healthcare centre in North India from March 2020 to Oct 2022. Cases included the neonates born to COVID-19-positive mothers were subjected to hearing screening at 1, 3 and 6 months using otoacoustic emission (OAE) and automated auditory brainstem response (AABR). Similar protocol was applied to controls, i.e., neonates borne to mothers with no gestational history of COVID infection. Results were analyzed statistically. Our study reported that the statistical difference between groups A (n = 942) and B (n = 942) for gestational COVID-19 infection and neonatal hearing loss was insignificant at 1 month (p-value 0.272 for OAE and p-value 0.634 for AABR) and also insignificant at 3 and 6 months (p-value 0.679 for AABR, for both). The association between gestational mild COVID-19 infection during gestation and neonatal hearing loss is statistically insignificant at initial screening as well as sequential screenings.

DOES AUDIOVESTIBULAR POST-COVID SYNDROME EXIST?

The purpose of this study was to present and analyze patients with audiovestibular post COVID-19 syndrome, and highlight the most characteristic and most common findings. We analyzed 87 patients aged between 20 and 86 years who presented to the Audiology Division between February 1, 2021 and July 1, 2021 after having been isolated due to the SARS-CoV-2 infection. Study patients presented with complaints of persistent hearing loss, tinnitus, and vertigo, lasting for more than 3 months. Study results showed that there was acute sensorineural hearing loss in 4 patients during the SARS-CoV-2 infection. None of the patients experienced complete hearing recovery after 3 months. High frequency hearing loss (at 4 kHz and 6 kHz) occurred bilaterally, and was found in 52 patients. This finding of gradual hearing loss was both the most characteristic and most common in COVID patients. Extensive damage can directly occur to inner ear structures, including hair cells, the Corti organ, and the cochlear nerve because of this viral infection. A total of 73 patients had tinnitus. 68 patients had unilateral tinnitus, and only 5 patients had bilateral tinnitus. Exacerbation of tinnitus was recorded in 12 patients and new-onset tinnitus in 61 patients. Vertigo occurred in 9 patients, all of which were new-onset. A conclusion of our research is that audiovestibular post-COVID syndrome does exist. Further research with more patients and over a longer period is needed to obtain a better and longer effect on the audiovestibular system and audiovestibular complications, as well as an insight into possible recovery.

[Radiologic Imaging of Pediatric Hearing Loss]

Hearing loss in childhood has serious consequences for the entire development of the child. It is very important to make an accurate early diagnosis. The assessment usually includes physical, genetic, and radiological examination. In imaging diagnostics, CT, Cone Beam CT and or MRI of the petrous bone are the usual imaging modalities for the assessment of diseases of mastoid air cells, middle ear, external ear, the cochlea, the vestibulocochlear nerve, and the brain.

A Prospective Study on Post Covid Sudden Onset Sensory Neural Hearing Loss and Its Recovery

Sudden sensorineural hearing loss (SSNHL) is a known complication of a number of viral infections, but there is little literature to date on its association to Corona virus disease 2019(COVID-19).This study aimed to investigate the incidence and recovery from SSNHL in post COVID-19 patients. A study was conducted in 6 months of duration at our tertiary care COVID dedicated hospital. Total 280 patients with age group of 12-70 years, laboratory confirmed COVID 19 positive patients having mild to moderate COVID symptoms were included. Patients were examined clinically along with all safety measures to analyze incidence and their recoveries from SSNHL by clinical examination and using Pure Tone Audiometry (PTA). Out of 280 patients the incidence of only SSNHL is 1.07% (3 patients) and SSNHL with tinnitus is 2.14%(6 patients).Total recovery(TR) regained in 2 patients of SSNHL, Partial recovery(PR) in 4 patients, Slight improvement(SI) in 1 patient and no recovery(NR) in 2 patients. The incidence of SSNHL in time of COVID 19 pandemic appears to be higher (3.2%) than before the pandemic (0.005%-0.16%). Incidence among younger age group and patients with no comorbidities has been also increased. In diagnosed case of SSNHL, early treatment with short term course of oral steroids and neuromodulator drugs are the mainstay treatment. Awareness of such non-specific presentation of COVID 19 patients is crucial and shared decision making with the patient and providing health care personnel is necessary for decreasing the hearing loss associated morbidity.

Irreversible Sensorineural Hearing Loss in Post Covid-19 Patients-An Institutional Prospective Study

SARS-CoV-2 virus could damage the hearing by several mechanisms, it could damage the auditory centre in the temporal lobe and direct peripheral injury to the sensory cells of the cochlear due to neurotropism of the virus. A Prospective hospital-based observational study was carried out at a tertiary care centre for a period of 22 months from January 2021 to October 2022. A total of 100 patients were selected according to inclusion criteria and exclusion criteria. Pure-tone audiometry (PTA) was done as a screening test; patients were followed up till 6 months. Among those patients who had hearing loss, repeat audiological profile (PTA) was done after 1 month, 13(65%) patients were found to have normal hearing. After 3 months, repeat PTA was done, 18 patients (90%) found to have normal hearing and the remaining 2 patients followed up till 6 months and again PTA was done where only 1 patient continued to have sensorineural hearing loss.

The short-term effect of COVID-19 on the cochleovestibular system in pediatric patients

OBJECTIVES

The audio-vestibular equivalent of neurological symptoms secondary to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been discussed; however, it has not been fully clarified. Although it has been reported that the vestibulocochlear system is affected in adult coronavirus disease-2019 (COVID-19) patients, there is no study in the literature in which the pediatric patient group with COVID-19 was evaluated comprehensively with auditory and vestibular tests. In this study, the short-term damage caused by SARS-CoV-2 in the vestibulocochlear system in pediatric patients was examined.

METHODS

This study aimed to evaluate the vestibulocochlear system of pediatric patients (aged 9-15 years) with a recent history of COVID-19. The study included 35 individuals with a recent history of COVID-19 and 35 age-gender-matched healthy individuals (control group). Pure tone audiometry, suppressed otoacoustic emission (OAE), video head impulse test (VHIT), and cervical and ocular vestibular evoked myogenic potentials (c/o-VEMP) tests were administered to all participants following their otoscopic examinations, and the obtained data were compared between the two groups.

RESULTS

When the data obtained with pure tone audiometry were compared, statistically significant differences were found between the groups at four different frequencies (1000, 2000, 4000, and 8000 Hz) in favor of the control group. There was a statistically significant difference between the groups in the signal-to-noise ratio (SNR) values obtained before noise at 2800 Hz and before and after noise at 4000 Hz. VHIT lateral gain, LARP gain, and RALP gain were statistically significantly lower in the COVID-19 group than in the control group (p < 0.05). VHIT lateral asymmetry parameter was measured higher in the COVID-19 group than in the control group, and this difference was statistically significant (p < 0.05). In the VHIT test, the asymmetry parameter was significantly higher in the COVID-19 group (p < 0.05). In the o-VEMP test, n10 latency, p15 latency, n10-p15 interlatency, n10-p15 interpeak amplitude, and asymmetry parameters were measured, and no statistically significant difference was found between the COVID-19 group and the control group (p > 0.05).

CONCLUSION

Evidence was obtained that the cochleovestibular system was damaged in pediatric patients in the early post-COVID-19 period.

The Incidence of Sudden Sensorineural Hearing Loss (SSNHL) in COVID-19 Patients in Tertiary Care Referral Units

COVID-19 is a new pandemic infectious disease that emerged in Wuhan, China, at the end of 2019. We aimed to evaluate the sudden sensorineural hearing loss (SSNHL) prevalence after COVID-19 infection or even vaccination. This is a two-center retrospective, observational cross-sectional study performed at tertiary care referral Audiovestibular Medicine Units at the period between August 1, 2020, and October 31, 2021. All SSNHL patients diagnosed in a period of a month with COVID-19 or vaccinated with a COVID-19 vaccine were included in this study. Fifty-three cases with confirmed COVID-19 and one patient vaccinated with a COVID-19 vaccine 1 week before, who reported sudden sensory neural hearing loss, were included in this study. Forty-eight patients had unilateral hearing loss and 6 patients had bilateral hearing loss. Forty-nine patients had typical COVID-19 symptoms; one patient discovered them after complaining of anosmia and ageusia and one patient after COVID-19 vaccination; and three patients were complaining only from hearing loss and had a PCR test for nasopharyngeal swabs to prove infection. Different degrees of SSNHL ranged from mild to severe and most of the patients had severe hearing loss. With more patients, COVID-19 may be a potential factor in sudden sensorineural hearing loss. It should be kept in mind that SSNHL may be the only indicator used to identify COVID-19 cases.

Health progression for Covid-19 survivors hospitalized in geriatric clinics in Sweden

OBJECTIVE

To analyse if the health progression of geriatric Covid-19 survivors three months after an acute Covid-19 infection was worse than in other geriatric patients. Specifically, we wanted to see if we could see distinct health profiles in the flow of re-admitted Covid-19 patients compared to re-admitted non-Covid-19 controls.

DESIGN

Matched cohort study.

SETTING AND PARTICIPANTS

Electronic medical records of geriatric patients hospitalised in geriatric clinics in Stockholm, Sweden, between March 2020 and January 2022. Patients readmitted three months after initial admission were selected for the analysis and Covid-19 survivors (n = 895) were compared to age-sex-Charlson comorbidity index (CCI)-matched non-Covid-19 controls (n = 2685).

METHODS

We assessed using binary logistic and Cox regression if a previous Covid-19 infection could be a risk factor for worse health progression indicated by the CCI, hospital frailty risk score (HFRS), mortality and specific comorbidities.

RESULTS

The patients were mostly older than 75 years and, already at baseline, had typically multiple comorbidities. The Covid-19 patients with readmission had mostly had their acute-phase infection in the 1st or 2nd pandemic waves before the vaccinations. The Covid-19 patients did not have worse health after three months compared to the matched controls according to the CCI (odds ratio, OR[95% confidence interval, CI] = 1.12[0.94-1.34]), HFRS (OR[95%CI] = 1.05[0.87-1.26]), 6-months (hazard ratio, HR[95%CI] = 1.04[0.70-1.52]) and 1-year-mortality risk (HR[95%CI] = 0.89[0.71-1.10]), adjusted for age, sex and health at baseline (the CCI and HFRS).

CONCLUSIONS AND IMPLICATIONS

The overall health progression of re-hospitalized geriatric Covid-19 survivors did not differ dramatically from other re-hospitalized geriatric patients with similar age, sex and health at baseline. Our results emphasize that Covid-19 was especially detrimental for geriatric patients in the acute-phase, but not in the later phase. Further studies including post-vaccination samples are needed.

Efficacy and safety of antivirals in treating hearing loss: A systematic review and network meta-analysis

Objectives

This study aimed to compare and rank the therapeutic effects of antivirals in treating hearing loss using a network meta-analysis approach.

Methods

We searched the PubMed, Embase, and Cochrane Library databases to identify eligible randomized controlled trials (RCTs) through April 2022. Placebo-controlled or head-to-head RCTs of three categories of antivirals for hearing loss were included, and pooled relative risks (RRs) with 95% confidence interval (CI) were calculated using pairwise and network meta-analyses.

Results

Six RCTs with 405 patients were included in the final analysis. The results showed that ganciclovir had relatively better effects on the incidence of hearing recovery (surface under the cumulative ranking: 88.8%) compared with other antivirals. However, pairwise comparison analyses found that the use of antivirals significantly increased the incidence of hearing recovery compared with the use of a placebo (RR: 1.27; 95% CI: 1.04-1.54; P = 0.017), while no significant difference was observed between any two categories of antivirals. Finally, the use of antivirals did not increase the risk of adverse events compared with the use of a placebo (RR: 1.27; 95% CI: 0.82-1.98; P = 0.285).

Conclusion

Antivirals are more efficacious than placebos for hearing recovery in patients with hearing loss, and ganciclovir is the most likely to increase the incidence of hearing recovery.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hearing loss in outbred Hartley guinea pigs experimentally infected with Pichinde virus as a surrogate model of human mammarenaviral hemorrhagic fevers

Lassa fever (LF) is a neglected tropical disease that is caused by Lassa virus (LASV), a human hemorrhagic fever-causing mammarenavirus. A notable sequela of LF is sensorineural hearing loss (SNHL) that can develop in about 33% of the patients. Animal models of LF-associated SNHL have been limited in size and scope because LASV is a biosafety level 4 (BSL4) pathogen that requires its handling in a high biocontainment laboratory. In this report, we describe the development of an alternative arenavirus hearing loss model by infecting outbred Hartley guinea pigs with a virulent strain (rP18) of the Pichinde virus (PICV), which is a guinea pig-adapted mammarenavirus that has been used as a surrogate model of mammarenaviral hemorrhagic fevers in a conventional (BSL2) laboratory. By measuring auditory brainstem response (ABR) throughout the course of the virulent rP18 PICV infection, we noticed that some of the animals experienced an acute but transient level of hearing loss. Cochleae of hearing-impaired animals, but not of controls, had demonstrable viral RNA by quantitative RT-PCR, indicating the presence of virus in the affected inner ear with no overt histopathological changes. In contrast, neither the outbred Hartley guinea pigs infected with a known avirulent strain (rP2) of PICV nor those that were mock-infected showed any evidence of hearing loss or viral infection of the inner ear. This is the first report of an immunocompetent small animal model of mammarenavirus-induced hearing loss that can be used to evaluate potential therapeutics against virus-induced hearing impairment under a conventional laboratory setting.

Importance of TORCH Profile in Hearing Impaired Paediatric Population Planned for Cochlear Implant: A Study From an Eastern India Tertiary Care Centre

TORCH group of infections are one of the most common causes of bilateral profound hearing loss in a developing country like ours. Seroprevalance is quite high in eastern part of our country. Screening for TORCH infections in children's with profound hearing loss has significant prognostic, planning and policy forming implications. To evaluate the seroprevalance of TORCH infections in prospective cochlear implant children and its significance. Ours is a retrospective study conducted from 2017 to 2018 on 50 children with bilateral profound hearing loss attending the Department of ENT at AIIMS, Patna. Thorough clinical and audiological assessment of the patients was done using objective tests like OAE (otoacoustic emission), ABR (auditory brainstem response) and subjective tests like BOA(behavioural audiometry) and PTA (puretone audiometry) wherever feasible. Blood samples were collected and serotesting was done using ELISA for Toxoplasma, Rubella, Cytomegalovirus (CMV) and Herpes Simplex Virus (HSV) (TORCH). We found that IgM was negative for all patients. Seroprevalance for IgG was 16.3% for toxoplasma, 74.4% for rubella, 69.8% for CMV and 20.9% for HSV. All the children had bilateral severe to profound loss on ABR and bilateral REFER on OAE. As prevalence of TORCH infection is quite common in India and is an established risk factor for sensorineural hearing loss with multisystem involvement screening for the same will help in early identification and in decision making for cochlear implantation thus improving the prognosis and also aid in policy making.

Common and uncommon audio-vestibular findings in COVID-19 patients

Background

COVID-19 is the new version of the old coronavirus known since 1960, which caused the Middle East respiratory syndrome (MERS-CoV) in 2012 and the severe acute respiratory syndrome (SARS) in 2003.

Symptoms included fever and cough, diarrhea and vomiting, and neurological symptoms like anosmia.

Methods

One hundred twenty-eight patients diagnosed as COVID-19 with audio-vestibular complaints were subjected to audio-vestibular assessment and were included in the study.

Results

In our study on COVID-19 patients who reported audio-vestibular complaints, hearing loss was found in 43.8% of patients in comparison to vertigo that represented 40.6% of cases. The most common type was sensorineural hearing loss representing 29.7% of patients and which was unilateral and sudden in 35.7% of them. Less commonly conductive hearing loss (CHL) was found in 14.1% of cases the most common form was bilateral mild to moderate CHL (83.3%) due to bilateral middle ear effusion.

Among cases with vertigo, the most common etiology was benign paroxysmal positional vertigo (BPPV) (42.5%) then uncompensated vestibular neuritis (VN) (31.5%), and lastly, combined BPPV with VN (25%) of cases. Less frequently we found tinnitus in (13.3%) which was bilateral in (64.7%), labyrinthitis (5.5%), and acute VN 5.5%).

The significant increase in the number of audiovestibular complaining cases that were observed in the course of the recurrent waves’ peaks pushed us to study the relationship between the pandemic and the audiovestibular system. The effect of COVID on AV systems is well noticed and management would be mandatory.

An emerging role for stress granules in neurodegenerative disease and hearing loss

Stress granules (SGs) are membrane-less cytosolic assemblies that form in response to stress (e.g., heat, oxidative stress, hypoxia, viral infection and UV). Composed of mRNA, RNA binding proteins and signalling proteins, SGs minimise stress-related damage and promote cell survival. Recent research has shown that the stress granule response is vital to the cochlea's response to stress. However, emerging evidence suggests stress granule dysfunction plays a key role in the pathophysiology of multiple neurodegenerative diseases, several of which present with hearing loss as a symptom. Hearing loss has been identified as the largest potentially modifiable risk factor for dementia. The underlying reason for the link between hearing loss and dementia remains to be established. However, several possible mechanisms have been proposed including a common pathological mechanism. Here we will review the role of SGs in the pathophysiology of neurodegenerative diseases and explore possible links and emerging evidence that they may play an important role in maintenance of hearing and may be a common mechanism underlying age-related hearing loss and dementia.

A Drosophila model for Meniere's disease: Dystrobrevin is required for support cell function in hearing and proprioception

Meniere's disease (MD) is an inner ear disorder characterised by recurrent vertigo attacks associated with sensorineural hearing loss and tinnitus. Evidence from epidemiology and Whole Exome Sequencing (WES) suggests a genetic susceptibility involving multiple genes, including α-Dystrobrevin (DTNA). Here we investigate a Drosophila model. We show that mutation, or knockdown, of the DTNA orthologue in Drosophila, Dystrobrevin (Dyb), results in defective proprioception and impaired function of Johnston's Organ (JO), the fly's equivalent of the inner ear. Dyb and another component of the dystrophin-glycoprotein complex (DGC), Dystrophin (Dys), are expressed in support cells within JO. Their specific locations suggest that they form part of support cell contacts, thereby helping to maintain the integrity of the hemolymph-neuron diffusion barrier, which is equivalent to a blood-brain barrier. These results have important implications for the human condition, and notably, we note that DTNA is expressed in equivalent cells of the mammalian inner ear.

The Absence of Permanent Sensorineural Hearing Loss in a Cohort of Children with SARS-CoV-2 Infection and the Importance of Performing the Audiological “Work-Up”

Background: Currently, the novel coronavirus (SARS-CoV-2) causes an acute respiratory illness named COVID-19 and is a controversial risk factor for hearing loss (HL). Herein, we aim to describe the associated symptoms and to evaluate hearing function in the COVID-19 pediatric population. Methods: A retrospective cross-sectional observational study was carried out on 37 children who contracted COVID-19 infection with no previous audio-vestibular disorders. Clinical data on the infections were collected, and an audiological assessment of all affected children was performed by using different diagnostic protocols according to their age. Results: Fever, upper respiratory and gastrointestinal manifestations were common presentations of infection. Audiological function was normal in 30 (81.08%) children, while 7 children showed an increased hearing threshold: 6 (16.21%) had transient conductive hearing loss (CHL) due to middle ear effusion and normalized at the follow-up and 1 had sensorineural hearing loss (SNHL). A single child was affected by bilateral SNHL (2.7%); however, he underwent a complete audiological work-up leading to a diagnosis of genetic HL due to a MYO6 gene mutation which is causative of progressive or late onset SNHL. Conclusions: HL needs to be considered among the manifestations of COVID-19 in children, nevertheless, we found cases of transient CHL. The onset of HL during or following COVID-19 infection does not eliminate the indication for maintaining audiological surveillance and audiological work-ups, including genetic diagnosis, to avoid the risk of mistaking other causes of HL.

Update on Findings about Sudden Sensorineural Hearing Loss and Insight into Its Pathogenesis

Sudden sensorineural hearing loss (SSNHL) is routinely encountered and is one of the most common emergent diseases in otolaryngology clinics. However, the etiology of SSNHL remains unclear. Due to the inaccessibility of the living human inner ear for biopsy, studies investigating the etiology of SSNHL have been performed by analyzing data obtained from examinations using peripheral blood or imaging. We updated the findings obtained from serological, magnetic resonance imaging, genetic, and viral examinations to reveal the etiology of SSNHL. Regarding viral examination, we focused on sensorineural hearing loss associated with coronavirus disease (COVID-19) because the number of correlated reports has been increasing after the outbreak. The updated findings revealed the following three possible mechanisms underlying the development of SSNHL: thrombosis and resulting vascular obstruction in the cochlea, asymptomatic viral infection and resulting damage to the cochlea, and cochlear inflammation and resulting damage to the cochlea. Thrombosis and viral infection are predominant, and cochlear inflammation can be secondarily induced through viral infection or even thrombosis. The findings about sensorineural hearing loss associated with COVID-19 supported the possibility that asymptomatic viral infection is one of the etiologies of SSNHL, and the virus can infect inner ear tissues and directly damage them.

Is COVID-19 to Blame for Sensorineural Hearing Deterioration? A Pre/Post COVID-19 Hearing Evaluation Study

OBJECTIVES

Here, we aimed to (a) determine whether a clinically significant sensorineural hearing loss (SNHL) change could be detected in post-coronavirus disease (COVID-19) hearing levels on comparing them with pre-infection hearing levels after controlling for the effect of age and (b) to identify risk factors, such as hypertension, diabetes, and smoking, which increase the likelihood of hearing loss in COVID-19 patients.

METHODS

We retrospectively analyzed hearing thresholds in unvaccinated patient's pre- and post-COVID-19 infection. Thresholds were controlled for age and the duration between the pre- and post-COVID-19 hearing evaluations. Correlations between additional COVID-19-related symptoms, hypertension, diabetes, and smoking and hearing threshold changes were analyzed.

RESULTS

A significant (but not clinical) threshold elevation was found post-COVID-19 infection. However, on controlling for age and the duration between the pre- and post-COVID-19 hearing evaluations, no significant threshold elevation was found. No significant correlation was found between hearing threshold changes and additional COVID-19-related symptoms, hypertension, diabetes, or smoking.

CONCLUSION

COVID-19 did not lead to a significant hearing threshold elevation in our cohort, even among patients with additional COVID-19 symptoms, hypertension, or diabetes mellitus or among those who smoked.

LEVEL OF EVIDENCE: 3

nonrandomized controlled cohort, follow-up study Laryngoscope, 2022.

Depletion of CD4 and CD8 T Cells Reduces Acute Disease and Is Not Associated with Hearing Loss in ML29-Infected STAT1-/- Mice

Lassa virus (LASV) is a zoonotic virus endemic to western Africa that can cause a potentially lethal and hemorrhagic disease, Lassa fever (LF). Survivors suffer a myriad of sequelae, most notably sudden onset sensorineural hearing loss (SNHL), the mechanism of which remains unclear. Unfortunately, studies aiming to identify the mechanism of these sequelae are limited due to the biosafety level 4 (BSL4) requirements of LASV itself. ML29, a reassortant virus proposed as an experimental vaccine candidate against LASV, is potentially an ideal surrogate model of LF in STAT1-/- mice due to similar phenotype in these animals. We intended to better characterize ML29 pathogenesis and potential sequelae in this animal model. Our results indicate that while both CD4 and CD8 T cells are responsible for acute disease in ML29 infection, ML29 induces significant hearing loss in a mechanism independent of either CD4 or CD8 T cells. We believe that this model could provide valuable information for viral-associated hearing loss in general.

Tinnitus emerging in the context of a COVID-19 infection seems not to differ in its characteristics from tinnitus unrelated to COVID-19

Background and aim

COVID-19 is a respiratory disease caused by the new coronavirus SARS-CoV-2, for which the first cases were reported in China, by December 2019. The spectrum of clinical presentations is wide, ranging from asymptomatic cases to a severe acute respiratory syndrome, sometimes with multiple systems involvement. Viral infections, including those related to respiratory virus, may cause hearing loss and, by extent, considering its pathophysiology, tinnitus. A systematic review on inner ear related symptoms in patients with COVID-19 reported 4.5% occurrence rate of tinnitus, with high variance of prevalence between the studies. Our aim is to further explore the relationship between COVID-19 and tinnitus. For this purpose we analyzed a sample of people who had suffered from a COVID-19 infection in the city of Volta Redonda, Brazil. In detail, we compared those with new onset tinnitus during or after the COVID-19 infection with those without tinnitus and those with tinnitus onset before the COVID-19 infection.

Methods

Fifty-seven patients over 18 years old and previously diagnosed with COVID-19 confirmed by a RT-PCR test were included. Patients were subdivided in three groups: no tinnitus (NT), tinnitus that already existed before COVID-19 (chronic tinnitus, CT) and tinnitus that arose during or after COVID-19 (post-COVID-19 tinnitus, PCT). Data concerning COVID-19 symptoms, drugs prescribed for COVID-19, tinnitus characteristics, comorbidities and other otological symptoms were collected. For all the patients, tonal audiometry and otoacoustic emissions were performed. Tinnitus patients fulfilled the Tinnitus Handicap Inventory (THI) and visual-analog scales (VAS) for loudness and distress. Patients with CT answered a simple question about the worsening of their tinnitus after COVID-19.

Results

PCT was reported by 19.3% of the patients, while 22.8% reported CT. No statistical difference was found between CT and PCT concerning hearing function, tinnitus characteristics and tinnitus distress. There was also no statistically significant difference between PCT and NT with respect to COVID-19 symptoms and pharmacological COVID-19 treatment. Patients with CT reported worsening of their tinnitus after COVID-19.

Conclusion

As with other viral infections, inner ear symptoms may be associated with COVID-19. In our sample patients with tinnitus onset before COVID-19 and those with tinnitus onset during or after COVID-19 did not differ significantly in their clinical characteristics and their hearing function, suggesting that tinnitus occurring in the context of a COVID-19 infection is not related to a unique pathophysiological mechanism. The comparison of COVID-19 patients, who developed tinnitus with those who did not develop tinnitus did not reveal any differences in COVID-19 symptoms or COVID-19 treatment. Thus, there was no hint, that a specific expression of COVID-19 is closely related to post COVID-19 tinnitus onset. Although some drugs used to treat tinnitus are known to damage the inner ear cells (especially hydroxychloroquine), we did not see any relationship between the intake of these drugs and tinnitus onset, eventually due to the short prescription time and low doses. Among those patients who had tinnitus before COVID-19 30,8% reported worsening after COVID-19. Overall, tinnitus emerging in the context of a COVID-19 infection seems not to differ from tinnitus unrelated to COVID-19. For further exploring the relationship of tinnitus and COVID-19, large population based studies are warranted.

Lymphocytic choriomeningitis virus: An under-recognized congenital teratogen

BACKGROUND

Lymphocytic choriomeningitis virus (LCMV) is a neglected rodent-borne arenavirus associated with transplacental transmission and fetal infection.

AIM

To summarize the epidemiological, clinical, and diagnostic features of reported patients with congenital LCMV infection.

METHODS

A literature search was conducted in PubMed, Medline, Google Scholar, and ResearchGate. The keywords used were ‘congenital lymphocytic choriomeningitis virus,’ and 48 studies were included. In addition, we conducted a relevant search by Reference Citation Analysis (RCA) (https://www.referencecitationanalysis.com).

RESULTS

The results have shown 27 reports of congenital LCMV infection in 86 patients, with 52.73% of them being males. Patients presented with chorioretinitis (83.53%), hydrocephalus (54.12%), and psychomotor retardation or developmental delay (54.12%). Computed tomography and/or magnetic resonance imaging most often demonstrated ventriculomegaly (74.07%), periventricular calcifications (66.67%), and microcephaly (40%). Most mothers of congenitally infected infants were exposed to rodents during pregnancy, predominantly mice, with flu-like symptoms mainly occurring during the first two trimesters of gestation. Mortality in congenitally infected children was 16.47%. The diagnosis of congenital LCMV infection was confirmed serologically in most patients (86.67%).

CONCLUSION

LCMV is still an insufficiently recognized fetal teratogen that often leads to long-term neurologic sequelae. Clinicians need to be familiar with LCMV and its potential teratogenic effect and as well as to effectively differentiate LCMV from other TORCH (T: Toxoplasma gondii, O: Other pathogens, R: Rubella virus, C: Cytomegalovirus, H: Herpes simplex virus) pathogens.

Unilateral, permanent hearing loss following severe COVID-19 infection

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

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

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

Cochleovestibular findings linked to COVID-19: A scoping review for clinical care planning in South Africa

Background

On 30 January 2020, the World Health Organization (WHO) officially declared an outbreak of the coronavirus disease 2019 (COVID-19) to be a global health emergency. Research has focused on the impact and response to life-threatening symptoms of COVID-19 across the lifespan; however, there is a need to investigate the effects of COVID-19 on the cochleovestibular system, as viral infections are known to impact this system. This is particularly important for contexts where resources are limited and prioritisation of resources requires strong risk versus benefit evaluations.

Objective

Therefore, the purpose of this scoping review was to investigate published evidence on the impact of COVID-19 on the cochleovestibular system across the lifespan in order to allow for strategic clinical care planning in South Africa, where capacity versus demand challenges exist.

Methods

Electronic bibliographic databases such as CINAHL, EBSCOHost, MEDLINE, ProQuest, PubMed, Scopus and ScienceDirect were searched for peer-reviewed publications between January 2020 and January 2022. These had to be published in English and related to the impact of COVID-19 on the cochleovestibular system, where the question was: ‘what evidence has been published on the impact of COVID-19 on the cochleovestibular system?’ Review selection and characterisation was performed by the researcher with an independent review by a colleague using pretested forms.

Results

Of a total of 24 studies that met the inclusion criteria, the current scoping review revealed limited conclusive published evidence linking COVID-19 to permanent hearing function symptoms. Current evidence supports the possibility of COVID-19, similar to other viral infections in adults, impacting the cochleovestibular system and causing tinnitus, vertigo and sudden sensorineural hearing loss (SSNHL), with the symptoms being generally temporary and resolving either partially or completely following therapy with steroids, with very inconclusive findings in the paediatric population.

Conclusion

These findings raise global implications for properly designed studies, which include longitudinal follow-up of cases across the lifespan, examining this link with some focus on establishing the pathophysiologic mechanisms at play as well. In the meanwhile, current findings raise the value of polymerase chain reaction (PCR) testing for all patients presenting with unexplained cochleovestibular symptoms during the pandemic, as these may be the only presenting symptoms indicating COVID-19, thus requiring careful treatment and management.

The prevalence of Post-Ebola Syndrome hearing loss, Sierra Leone

BACKGROUND

Globally, hearing loss is the second leading cause of disability, affecting approximately 18.7% of the world's population. However, the burden of hearing loss is unequally distributed, with the majority of affected individuals located in Asia or Sub-Saharan Africa. Following the 2014 West African Ebola Outbreak, disease survivors began to describe hearing loss as part of the constellation of symptoms known as Post-Ebola Syndrome. The goal of this study was to more fully characterize hearing loss among Ebola Virus Disease (EVD) survivors.

METHODOLOGY AND PRINCIPAL FINDINGS

EVD survivors and their household contacts were recruited (n = 1,12) from Eastern Sierra Leone. Each individual completed a symptom questionnaire, physical exam, and a two-step audiometry process measuring both air and bone conduction thresholds. In comparison to contacts, EVD survivors were more likely to have complaints or abnormal findings affecting every organ system. A significantly greater percentage of EVD survivors were found to have hearing loss in comparison to contacts (23% vs. 9%, p < 0.001). Additionally, survivors were more likely to have bilateral hearing loss of a mixed etiology. Logistic regression revealed that the presence of any symptoms of middle or inner ear (p < 0.001), eye (p = 0.005), psychiatric (p = 0.019), and nervous system (p = 0.037) increased the odds of developing hearing loss.

CONCLUSIONS AND SIGNIFICANCE

This study is the first to use an objective and standardized measurement to report hearing loss among EVD survivors in a clinically meaningful manner. In this study it was found that greater than 1/5th of EVD survivors develop hearing loss. The association between hearing impairment and symptoms affecting the eye and nervous system may indicate a similar mechanism of pathogenesis, which should be investigated further. Due to the quality of life and socioeconomic detriments associated with untreated hearing loss, a greater emphasis must be placed on understanding and mitigating hearing loss following survival to aid in economic recovery following infectious disease epidemics.

Thromboelastography Predicting the Prognosis of Sudden Sensorineural Hearing Loss

OBJECTIVES

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

DESIGN

Single-centre, retrospective study.

SETTING

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSION

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

An Evaluation of Maximum Safe Practice Time of Iranian Musical Instruments to Protect Noise-Induced Hearing Loss in Professionals

Background: Noise-induced hearing loss (NIHL) is one of the most common causes of sensorineural hearing loss. The prevention of NIHL in musicians requires a better understanding of its contributing exposure factors. We aimed to determine typical sound exposure levels received by professional musicians during solitary practice and calculate the maximum safe practice time (MSPT) for the main Iranian musical instruments.

Methods: We conducted a cross-sectional study on 185 professional musicians (147 men and 38 women) between April 2018 and April 2019. The MSPT was calculated for each instrument if the mean sound level was below 85 dB in all musicians, and the music was considered a safe instrument; if it was >85 dB, it was considered a high-risk instruments and some other instruments had different mean sound level (in some participants <85 dB and some other players >85 dB), so these instruments were considered as borderline instruments.

Results: The mean age of the participants was 36.66 ± 0.85 years and their mean daily practice time was 2.89 ± 0.13 hours. The daily practice was significantly higher in plucked string instruments as compared to other instruments (p<0.001). The mean sound level of every instrument varied from 67.77 to 100.77 dB in the right ear and 67.20 to 100.12 dB in the left ear. The highest sound level was in sorna and the lowest one in zanburak.

Conclusion: It seems musicians observe the MSPT of each instrument as much as possible. It is recommended to determine the comprehensive protocol for each instrument to prevent hearing loss in musicians.

Audio-Vestibular Profile of COVID-19; Systematic Review and Meta-analysis

Introduction

After more than a year of the COVID-19 pandemic, audio-vestibular problems have been reported as consequences. Several limited case report studies with different methodologies were published. This study aimed to describe the impact of COVID-19 on the auditory-vestibular system and communication problems in subjects with hearing impairment.

Materials and Methods

The current systematic review was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guideline. PubMed, Web of Science, and Google Scholar were searched to find relevant articles using combined keywords.

Results

Out of 26 final studies, 20 studies dealt with the effects of COVID-19 on the auditory and vestibular system, and six articles examined the COVID-19 effects on hearing-impaired people and patients. In these studies, dizziness (17.8%), tinnitus (8.1%), and vertigo (2.8%) were common symptoms. Most studies were case reports (42.30%), and in terms of quality, nine studies (34.61%) were in the suitable quality group.

Conclusions

COVID-19 might cause auditory-vestibular system problems by directly affecting the structures or functions of the inner ear or by weakening the immune system. The need for taking preventive measures during the COVID-19 pandemic has caused communication and social challenges, particularly for people with hearing loss.

Isolation and Identification of Pathogenic Bacteria Causing Otitis Media in Misan Governorate

This study examined 150 ear swab samples from patients with otitis media who consulted at Al-Sadr Teaching Hospital from January to April 2021 in Misan, Iraq. The participants were aged 14–50 years, among which the infection rate was highest in participants aged 14–22 years and lowest in those aged 40–50 years. Subsequently, bacterial isolates were identified based on their morphology in various culture media and using biochemical tests. Six bacterial species were identified, namely Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Streptococcus pneumoniae, Klebsiella pneumoniae, and Staphylococcus epidermidis. Staphylococcus aureus had the highest infection rate (30%), whereas Staphylococcus epidermidis had the lowest infection rate (8.55%). When the sensitivity of each isolate to antibiotics was determined, Escherichia coli was the most sensitive to trimethoprim (TMP), whereas Pseudomonas aeruginosa was the most resistant to 75% of the tested antibiotics.

Evaluation of the efferent auditory system in COVID-19 adult patients

BACKGROUND

The short- and long-term effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the medial olivocochlear reflex and outer hair cells in the cochlea remain largely unclear.

AIMS

The aim of this study was to investigate the efferent auditory system effects in adult patients with COVID-19.

MATERIALS AND METHODS

The study included 18-50 years old 44 volunteers: 26 individuals (52 ears) with COVID-19 in the study group and 18 healthy individuals (36 ears) in the control group. Otolaryngological examination, immitancemetric evaluation, distortion product otoacoustic emission (DPOAE), contralateral acoustic stimulation with DPOAE, audiometric evaluation, and high frequency audiometric evaluation were performed in all individuals participating in the study.

RESULTS

In our study, patients with COVID-19 had significantly lower DPOAE results with or without broadband noise at only 6 kHz frequency and contralateral suppression results at all frequencies compared to healthy individuals. A statistically significant difference was found between the study and control groups according to whether the participants had a response in the high frequency audiometry at 12 and 16 kHz frequencies.

CONCLUSIONS

COVID-19 affects many systems in the body. As a result of the findings obtained in the present study, it is shown that the auditory efferent system may also be affected.

Relationship between SARS-CoV-2 and hearing loss: A mini-review

The most reported symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were initially fever, dry cough, and sore throat. However, as we continue to review the literature, the loss of taste and smell were also added as clinical symptoms of the novel SARS-CoV-2. At present, the effects of SARS-CoV-2 on the auditory system is still not well-understood. This study is mini-review and aims to find out more about the relationship between SARS-CoV-2 and hearing loss through review of the literature. From our findings, hearing loss is the primary otological symptom of SARS-CoV-2, followed by tinnitus and dizziness. In conclusion, SARS-CoV-2 may have an effect on our auditory system, but due to the small sample sizes in the existing literature, further prospective studies are warranted to determine the relationship between the virus and hearing loss.