Early identification of idiopathic sudden sensorineural hearing loss

The role of hyperbaric oxygen in idiopathic sudden sensorineural hearing loss

Idiopathic sudden sensorineural hearing loss is an unexplained sudden loss of sensorineural hearing, with no specific pathogenesis, and is difficult to treat. The most common therapeutic strategy for idiopathic sudden sensorineural hearing loss is the use of steroids combined with neurotrophic drugs, as other treatments have shown limited efficacy. However, in recent years, hyperbaric oxygen therapy has emerged as a promising treatment option. Studies have shown that hyperbaric oxygen therapy, in combination with conventional treatments, can effectively alleviate inner ear edema, improve blood circulation, and suppress inflammation. Therefore, hyperbaric oxygen therapy plays an important role in the treatment of idiopathic sudden sensorineural hearing loss. In this review, we aim to assess existing studies and summarize the clinical effects and mechanisms of hyperbaric oxygen therapy in idiopathic sudden sensorineural hearing loss, providing a basis for further research on the clinical treatment of this disorder.

Monoallelic loss of the F-actin-binding protein radixin facilitates startle reactivity and pre-pulse inhibition in mice

Hearing impairment is one of the most common disorders with a global burden and increasing prevalence in an ever-aging population. Previous research has largely focused on peripheral sensory perception, while the brain circuits of auditory processing and integration remain poorly understood. Mutations in the rdx gene, encoding the F-actin binding protein radixin (Rdx), can induce hearing loss in human patients and homozygous depletion of Rdx causes deafness in mice. However, the precise physiological function of Rdx in hearing and auditory information processing is still ill-defined. Here, we investigated consequences of rdx monoallelic loss in the mouse. Unlike the homozygous (−/−) rdx knockout, which is characterized by the degeneration of actin-based stereocilia and subsequent hearing loss, our analysis of heterozygous (+/−) mutants has revealed a different phenotype. Specifically, monoallelic loss of rdx potentiated the startle reflex in response to acoustic stimulation of increasing intensities, suggesting a gain of function relative to wildtype littermates. The monoallelic loss of the rdx gene also facilitated pre-pulse inhibition of the acoustic startle reflex induced by weak auditory pre-pulse stimuli, indicating a modification to the circuit underlying sensorimotor gating of auditory input. However, the auditory brainstem response (ABR)-based hearing thresholds revealed a mild impairment in peripheral sound perception in rdx (+/-) mice, suggesting minor aberration of stereocilia structural integrity. Taken together, our data suggest a critical role of Rdx in the top-down processing and/or integration of auditory signals, and therefore a novel perspective to uncover further Rdx-mediated mechanisms in central auditory information processing.

Hearing loss and brain disorders: A review of multiple pathologies

Several causative factors are associated with hearing loss (HL) and brain disorders. However, there are many unidentified disease modifiers in these conditions. Our study summarised the most common brain disorders associated with HL and highlighted mechanisms of pathologies. We searched the literature for published articles on HL and brain disorders. Alzheimer's disease/dementia, Parkinson's disease, cognitive impairment, autism spectrum disorder, ataxia, epilepsy, stroke, and hypoxic-ischaemic encephalopathy majorly co-interact with HL. The estimated incidence rate was 113 per 10,000 person-years. Genetic, epigenetic, early life/neonatal stress, hypoxia, inflammation, nitric oxide infiltration, endoplasmic reticulum stress, and excess glutamate were the distinguished modifiers identified. Various mechanisms like adhesion molecules, transport proteins, hair cell apoptosis, and neurodegeneration have been implicated in these conditions and are serving as potential targets for therapies. To improve the quality of life of patients, these understandings will improve clinical diagnoses and management of HL and brain disorders.

What did you say? A review of the management of sudden sensorineural hearing loss

ABSTRACT

Ambulatory care providers are likely to encounter patients who complain of sudden hearing loss and may be challenged to provide the most appropriate treatments. Using a vignette, this article provides an overview of recently updated guidelines that can help with rapid identification and management, to increase the likelihood of hearing improvement.

Antidepressants and risk of sudden sensorineural hearing loss: a population-based cohort study

BACKGROUND

Increasing numbers of animal studies have found that sudden sensorineural hearing loss (SSNHL) is related to the mechanism of serotonergic modulation. However, the relationship between antidepressants and SSNHL is unclear in humans. Therefore, this study aimed to evaluate the association between antidepressant use and risk of SSNHL.

METHODS

Data from 218 466 antidepressant users and 1 116 518 nonusers were obtained from the Taiwan Longitudinal Health Insurance Database. We used propensity-score matching (PSM) and inverse-probability treatment weighting (IPTW) to eliminate any bias. Each patient was tracked for 5 years to ascertain whether or not they were diagnosed with SSNHL. Cox proportional-hazard regression analyses were performed to calculate the SSNHL risk.

RESULTS

The adjusted hazard ratio (aHR) of SSNHL for antidepressant users was 1.36 compared with nonusers in the full cohort study. The aHR for antidepressant users was 1.44 and 1.49 compared with the nonusers in the IPTW and PSM cohorts, respectively. All classes of antidepressants consistently increased the SSNHL risk. Additionally, patients receiving four classes of antidepressants were associated with a much higher SSNHL risk (aHR, 2.05) and those receiving one or two classes of antidepressants had a relatively lower SSNHL risk.

CONCLUSION

Antidepressants increased SSNHL risk, regardless of their class. Furthermore, patients who took a higher number of antidepressant classes showed an increased risk of developing SSNHL than those who took a lower number of antidepressant classes. Therefore, physicians should estimate the risks and benefits of antidepressant use and avoid prescribing antidepressants concurrently.

A Smartphone-Based Approach to Screening for Sudden Sensorineural Hearing Loss: Cross-Sectional Validity Study

Background

Sudden sensorineural hearing loss (SSNHL) is an otologic emergency that warrants urgent management. Pure-tone audiometry remains the gold standard for definitively diagnosing SSNHL. However, in clinical settings such as primary care practices and urgent care facilities, conventional pure-tone audiometry is often unavailable.

Objective

This study aimed to determine the correlation between hearing outcomes measured by conventional pure-tone audiometry and those measured by the proposed smartphone-based Ear Scale app and determine the diagnostic validity of the hearing scale differences between the two ears as obtained by the Ear Scale app for SSNHL.

Methods

This cross-sectional study included a cohort of 88 participants with possible SSNHL who were referred to an otolaryngology clinic or emergency department at a tertiary medical center in Taipei, Taiwan, between January 2018 and June 2019. All participants underwent hearing assessments with conventional pure-tone audiometry and the proposed smartphone-based Ear Scale app consecutively. The gold standard for diagnosing SSNHL was defined as the pure-tone average (PTA) difference between the two ears being ≥30 dB HL. The hearing results measured by the Ear Scale app were presented as 20 stratified hearing scales. The hearing scale difference between the two ears was estimated to detect SSNHL.

Results

The study sample comprised 88 adults with a mean age of 46 years, and 50% (44/88) were females. PTA measured by conventional pure-tone audiometry was strongly correlated with the hearing scale assessed by the Ear Scale app, with a Pearson correlation coefficient of .88 (95% CI .82-.92). The sensitivity of the 5–hearing scale difference (25 dB HL difference) between the impaired ear and the contralateral ear in diagnosing SSNHL was 95.5% (95% CI 87.5%-99.1%), with a specificity of 66.7% (95% CI 43.0%-85.4%).

Conclusions

Our findings suggest that the proposed smartphone-based Ear Scale app can be useful in the evaluation of SSNHL in clinical settings where conventional pure-tone audiometry is not available.