Concurrent hyperbaric oxygen therapy and intratympanic steroid application as salvage therapy after severe sudden sensorineural hearing loss

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

Introduction

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

Methods

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

Results

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

Discussion

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

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.

The use of hyperbaric oxygen therapy in acute hearing loss: a narrative review

INTRODUCTION

Acute hearing loss can have a major impact on a patient's life. This holds true for both acute acoustic trauma (AAT) and idiopathic sudden sensorineural hearing loss (ISSHL), two devastating conditions for which no highly effective treatment options exist. This narrative review provides the rationale and evidence for HBOT in AAT and ISSHL.

METHODS

Narrative review of all the literature available on HBOT in acute hearing loss, studies were retrieved from systematic searches on PubMed and by cross referencing.

DISCUSSION

First, the etiological mechanisms of acute hearing loss and the mechanism of action of HBOT were discussed. Furthermore, we have provided an overview of 68 studies that clinically investigated the effect of HBOT in the last couple of decades. For future studies, it is recommend to start as early as possible with therapy, preferably within 48 h and to use combination therapy consisting of HBOT and corticosteroids.

IMPLICATIONS FOR PRACTICE

HBOT has been used quite extensively for acute hearing loss in the last couple of decades. Based on the amount of studies showing a positive effect, HBOT should be discussed with patients (shared decision making) as optional therapy in case of AAT and ISSHL.

Diagnostics and therapy of sudden hearing loss

This article reviews recent aspects of diagnostics, differential diagnostics, and evidence in systemic and local therapy of idiopathic sudden sensorineural hearing loss (ISSHL). Since a number of disorders can be accompanied by sudden hearing loss, a meaningful and targeted diagnostic strategy is of utmost importance. An important differential diagnosis of sudden hearing loss are intralabyrinthine schwannomas (ILS). The incidence of ILS is probably significantly underestimated. This may be due to the lack of awareness or lack of explicit search for an intralabyrinthine tumor on MRI or an inappropriate MRI technique for the evaluation of sudden hearing loss ("head MRI" instead of "temporal bone MRI" with too high slice thicknesses). Therefore, the request to the radiologist should specifically include the question for (or exclusion of) an ILS. With special MRI techniques, it is possibly today to visualize an endolymphatic hydrops. The evidence in the therapy of ISSHL is - with respect to the quality and not quantity of studies - unsatisfying. The value of systemically (low dose) or intratympanically applied corticosteroids in the primary treatment of ISSHL is still unclear. In order to investigate the efficacy and safety of high dose corticosteroids as primary therapy for ISSHL, a national, multicenter, three-armed, randomized, triple-blind controlled clinical trial is currently performed in Germany (http://hodokort-studie.hno.org/). After insufficient recovery of the threshold with systemic therapy of ISSHL, intratympanic corticosteroid therapy appears to be associated with a significantly higher chance of an improved hearing threshold than no therapy or placebo. Both, hearing gain and final hearing threshold, however, appear to be independent from the onset of secondary therapy. Based on currently available data from clinical studies, no recommendation can be made with respect to the type of corticosteroid and specifics of the intratympanic application protocol.

Concurrent hyperbaric oxygen therapy and intratympanic steroid application as salvage therapy after severe sudden sensorineural hearing loss

Concurrent hyperbaric oxygen therapy (HBOT) and intratympanic steroid application (ITS) are beneficial as salvage therapy for therapy‐refractory sudden sensorineural hearing loss (SSNHL). The findings encourage further research on the treatment of noise‐induced and idiopathic SSNHL with concurrent use of HBOT and ITS respecting also patients with long‐term or therapy‐refractory SSNHL.