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

Background and purpose

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

Materials and methods

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

Results

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

Conclusion

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

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

Background

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

Materials and methods

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

Results

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

Conclusion

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

Hyperbaric Oxygen Therapy in the Treatment of Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSHL) is a frustrating and frightening experience for a patient [...].

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVES

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Avoiding Definitive Conclusions in Meta-analysis of Heterogeneous Studies With Small Sample Sizes

This Viewpoint argues for caution when interpreting the findings of meta-analyses of heterogenous studies with small samples.

Intratympanic corticosteroids for sudden sensorineural hearing loss

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Clinical features and prognosis of severe-to-profound sudden sensorineural hearing loss

PURPOSE

Sudden sensorineural hearing loss (SSNHL) is an otologic emergency. Despite multiple efforts to clarify the factors affecting the prognosis of severe-to-profound SSNHL, various studies showed inconsistent results and lack of clinical significance. Therefore, we examined the clinical features and outcomes of severe-to-profound SSNHL.

MATERIALS AND METHODS

We included patients who experienced SSNHL between 2018 and 2021 and were diagnosed according to the American Academy of Otolaryngology-Head and Neck Surgery criteria; hearing loss over 70 dB on initial pure tone audiometry (PTA) was used to define severe-to-profound SSNHL. We retrospectively examine the demographic, laboratory, radiologic, and audiometric data of SSNHL patients. We also evaluated the final hearing gain of these patients by assessing their PTA findings and word-recognition scores.

RESULTS

Of the 178 patients, 94 (52.81%) and 84 (47.19%) showed profound (>90 dB) and severe (>70 to 90 dB) hearing loss, respectively. The presence of vertigo and hypertension differed significantly between the severe and profound groups (p < 0.001 and p = 0.012, respectively), as did the initial serum creatinine level (p = 0.043). Recovery in PTA showed a reliable correlation with the interval between onset and treatment in the severe group and periventricular white-matter findings in the profound group (p < 0.001 and p = 0.011, respectively). The presence of hypertension was related to recovery of low tone (p = 0.023 for 250 Hz; p = 0.034 for 500 Hz), while glycated hemoglobin level was related to recovery of high tone in the severe group (p = 0.049 for 4000 Hz; p = 0.047 for 8000 Hz).

CONCLUSIONS

Severe-to-profound SSNHL showed poor prognosis for hearing gain. The interval from onset to treatment was a significant prognostic factor for severe SSNHL, while the presence of vertigo, estimated glomerular filtration rate, and periventricular white-matter findings were significant prognostic factors for profound SSNHL.

The value of having an initial word recognition score for a precise prognosis of idiopathic sudden sensorineural hearing loss

OBJECTIVE

Although the hearing thresholds of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) closely relate to the prognosis that results in progressive floor effects, many studies have usually used hearing thresholds as the main outcome of the measurement of prognostic factors. The present study aimed to identify the prognostic factors related to initial hearing tests and speculates the effects of word recognition score (WRS) on the prognoses for patients with ISSNHL.

METHODS

Between March 2011 and November 2020, we retrospectively reviewed chart profiles of 2,636 ISSNHL patients. The 180 patients who met the inclusion criteria were asked to participate in the present study. Based on their initial WRS, all these patients were divided into good WRS (GW) and poor WRS (PW) groups with 52% as the cut-off points. Demographic, clinical, and audiological variables, such as age, onset time, duration of treatment, gender, ear side, comorbidities (i.e., hypertension, diabetes mellitus, tinnitus, dizziness), hearing configuration (i.e., ascending, descending, flat, irregular, and profound), treatment options (i.e., systemic corticosteroid therapy per oral, intratympanic steroid injection, and hyperbaric oxygen therapy), and WRS were analyzed as being underlying prognostic factors.

RESULTS

Both groups showed significantly different distributions for hearing thresholds and hyperbaric oxygen therapy (HBOT) as general characteristics. The results of a multivariate logistic regression analysis showed that the odds ratio (OR) of age (OR: 0.96, 95% CI: 0.59 - 24.25), duration of treatment (OR: 0.98, 95% CI: 0.96 - 1.00), ascending configuration (OR: 4.97, 95% CI: 1.64 - 16.62), irregular configuration (OR: 4.58, 95% CI: 1.62 - 13.79), and WRS (OR: 1.01, 95% CI: 1.00 - 1.02) were the significant prognostic factors for all the patients. Further analysis of those patients with WRS under 52% cut-off points showed that an ascending configuration (OR: 5.87, 95% CI: 1.18 - 35.99), irregular configuration (OR: 8.03, 95% CI: 1.69 - 46.30), and WRS (OR: 1.05, 95% CI: 1.01 - 1.10) significantly affected the prognosis. As the initial WRS of ISSNHL patients decreased, the OR of the WRS itself increased. These results suggested that the importance of WRS as the prognostic factor was stressed for PW patients.

CONCLUSION

The age, duration of treatment, initial hearing configuration (ascending and irregular types), and WRS were the significant prognostic factors for patients with ISSNHL. It was learned that WRS could be a remarkable prognostic factor to consider, especially for ISSNHL patients with poor WRS.

Hyperbaric Oxygen Therapy for Patients With Sudden Sensorineural Hearing Loss: A Systematic Review and Meta-analysis

Importance

Sudden sensorineural hearing loss (SSNHL) is an acute, usually unilateral deficit. Systemic and intratympanic steroids are accepted treatments. Although evidence suggests that hyperbaric oxygen therapy (HBOT) may be beneficial, it is not widely offered.

Objectives

To review and evaluate recent evidence of the association of HBOT with hearing outcomes in SSNHL and to determine if HBOT should be a single or part of a combination treatment regimen.

Data Sources

Cochrane Central Register of Controlled Trials, PubMed, EMBASE, CINAHL, Web of Science, CAB, ICTRP, Google Scholar, Clinicaltrials.gov, and ISRCTN databases were searched for randomized controlled trials (RCTs) published in English from January 1, 2000, and April 30, 2020.

Study Selection

Prospective RCTs involving only adult participants (≥18 years) with SSNHL and comparing HBOT, as a single or combination therapy, with control therapies, such as steroids and/or placebo. Only RCTs that used the American Academy of Otolaryngology-Head and Neck Surgery's diagnostic criteria for SSNHL were included.

Data Extraction and Synthesis

Data were extracted independently by 2 researchers. A fixed-effects model was used for analysis and performed from November 30, 2020, to May 20, 2021.

Main Outcomes and Measures

The mean difference in absolute hearing gain recorded by pure-tone audiometric (PTA) thresholds averaged across 4 low (0.5, 1, 2, and 3 or 4 kHz) or 3 high (3 or 4, 6, and 8 kHz) frequencies was the primary outcome. The secondary outcomes were the odds ratio of hearing recovery defined as a hearing gain of ≥10 decibels (dB) in PTA average and treatment-related adverse effects.

Results

Of the 826 records initially identified, 358 duplicates and 451 articles were excluded based on article type, title, and abstract. The full texts of 17 articles were reviewed, of which 14 were excluded because they were either not prospective RCTs (11 articles), the participants were less than 18 years old (2 articles), or the PTA was not reported at frequencies of interest (1 article). Three prospective RCTs with a total of 88 participants who received HBOT in the intervention groups and 62 participants who received only medical therapy in the control groups were studied. The intergroup difference in mean absolute hearing gain (mean difference, 10.3 dB; 95% CI, 6.5-14.1 dB; I2 = 0%) and the odds ratio of hearing recovery (4.3; 95% CI, 1.6-11.7; I2 = 0%) favored HBOT over the control therapy.

Conclusions and Relevance

In this systematic review and meta-analysis, HBOT as part of a combination treatment was significantly associated with improved hearing outcomes in patients with SSNHL over control treatments.

Trial Registration

PROSPERO Identifier: CRD42020193191.

Tympanic Membrane Perforation After Intratympanic Steroid Injection: A Systematic Review and Meta-analysis

OBJECTIVE

We investigated the incidence of tympanic membrane (TM) perforations induced after intratympanic steroid injection (ITSI) in patients with sudden sensorineural hearing loss (SSNHL) through a systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, and MEDLINE.

REVIEW METHODS

Primary database searches were performed, and 1901 records were identified. After removal of 1802 articles through abstract screening, the remaining 99 full-text journals were assessed for eligibility to be included in the study. Fifty-eight studies that used either ventilation tubing (VT) or tympanocentesis (TC) for ITSI were selected for analysis. The subjects were divided into VT and TC groups. The rate of TM perforation after ITSI in 2 groups, sites of ITSI, needle gauge, and influence on residual hearing were investigated.

RESULTS

The cohorts comprised patients who underwent VT (n = 257, 9.6%) and TC (n = 2415, 90.4%). The proportion of TM perforation after ITSI in each group was 0.073 (95% CI, 0.0469-0.1113) and 0.010 (95% CI, 0.0045-0.0215), respectively, which suggested that the VT group showed a significantly higher TM perforation rate than the TC group (P < .001). In the subgroup analyses, there was no significant difference in the odds ratio for the rate of TM perforation according to the injection site and needle gauge for TC. The proportion of surgical repair showed no significant difference between the 2 groups.

CONCLUSION

ITSI via VT may have a significantly higher risk of TM perforation than ITSI via TC, although those are relatively small overall. ITSI should be performed in the direction to minimize possible adverse effects.

The Clinical Value of Periventricular White Matter Hyperintensity on MRI in Sudden Sensorineural Hearing Loss

OBJECTIVES

To assess the clinical value of periventricular white matter hyperintensity (PWMH) found on brain magnetic resonance imaging (MRI) in patients with sudden sensorineural hearing loss (SSNHL).

METHODS

In this prospective study, 115 patients who were diagnosed with SSNHL aged between 55 and 75 years were analyzed. All subjects underwent brain MRI and were divided into a PWMH and control groups, depending on the presence of PWMH on MRI. PWMH was subdivided into 3 groups according to severity. Pure-tone average results and hearing gain were compared between the 2 groups before treatment and 2 months after treatment. Hearing improvement was assessed using Sigel's criteria.

RESULTS

A total of 106 patients (43 in the PWMH group and 63 in the control group) finally completed the 2-month follow-up. Average hearing gain in the PWMH group was significantly higher than in the control group (34.8 ± 20.3 and 25.9 ± 20.3, respectively, P = .029). PWMH score 1 showed significantly better hearing levels and hearing gain compared to PWMH score 3 and the control group. Multivariate analysis revealed that younger age, better initial hearing level, and the presence of PVWM score 1 were associated with good recovery.

CONCLUSIONS

The presence of PWMH score 1 on brain MRI in patients with SSNHL was associated with better treatment response and was a good prognostic factor in a multivariate analysis while the hearing recovery in more severe PWMH (scores 2, 3) was not different from the control group.

Steroid Administration Approach for Idiopathic Sudden Sensorineural Hearing Loss: A National Survey in China

OBJECTIVE

To optimize a protocol for the steroid administration approach for idiopathic sudden sensorineural hearing loss (ISSNHL) in China.

METHODS

A questionnaire was distributed to otolaryngologists. The data on demographics, indications for first-line and salvage treatment, such as intratympanic administration of steroids (ITS) and postauricular steroids (PAS), and procedures were analyzed.

RESULTS

74 respondents used oral steroids, 112 used intravenous injections, 10 used ITS and 6 used PAS as a monotherapy for first-line treatment, and 135 used ITS or PAS in conjunction with oral or intravenous injection as a first-line treatment. Of the 249 respondents who used ITS, 97.19% adopted it as salvage therapy. The most commonly used steroid was 0.5 ml dexamethasone at 5 mg/ml and the most common side effect was pain. Of the 174 respondents who used PAS, 94.25% used it as salvage therapy. The most commonly used steroid was 0.5 ml methylprednisolone mixed with 0.5 ml lidocaine.

CONCLUSIONS

The obtained data suggested that intravenous injection of steroids was the most popular treatment for ISSNHL and that ITS or PAS were used as a salvage treatment in China.

Hyperbaric Oxygenation as Adjunctive Therapy in the Treatment of Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss seems to become a serious social health problem in modern societies. According to the World Health Organization (WHO) reports, adult-onset sensorineural hearing loss is found to be one of the leading diseases at the global level, especially in high-income countries, and is foreseen to move up from the 14th to 7th leading cause of the global burden of diseases by the year 2030. Although the direct mortality rate of this disease is very low, its influence on quality of life is huge; that is the reason why the implementation of the most effective and the safest therapies for the patient is crucial for minimizing the risk of complications and adverse reactions to treatment. The aim of this paper is to present hyperbaric oxygen therapy (HBOT) as a medical procedure useful in the treatment of sudden sensorineural hearing loss as adjunctive therapy of high efficacy. This paper focuses on the molecular mechanisms of action and clinical effectiveness of HBOT in the treatment of idiopathic sudden deafness, taking into consideration both the benefits and potential risks of its implementation.

Comparison of Steroid Treatment with and without Hyperbaric Oxygen Therapy for Idiopathic Sudden Sensorineural Hearing Loss

Background and Objectives

In this study, we compared the outcomes of patients with idiopathic sudden sensorineural hearing loss who underwent steroid treatment with or without hyperbaric oxygen (HBO) therapy and were followed-up in our clinic.

Subjects and Methods

Patients were divided into two groups according to their treatment regimen. Steroid group received intravenous 1 mg/kg methylprednisolone which was due to be completed in 2-3 weeks with decreasing doses, and five doses of 0.5 mL intratympanic dexamethasone. Steroid+HBO group received the same steroid treatment with the addition of HBO therapy. The audiologic results of both treatment groups were compared after considering the patients’ risk factors.

Results

There was no significant difference between the steroid and Steroid+HBO groups in terms of hearing gain and degree of recovery, both at all degrees of hearing loss, and in severe and profound hearing loss. Hearing gain was similar when evaluated by audiogram type and admission time in both treatment groups.

Conclusions

We found that the addition of HBO therapy to systemic plus intratympanic steroid treatment did not affect hearing gain at all degrees of hearing loss in this study. Furthermore, audiogram type and admission time did not affect hearing gain between the two groups.

Efficacy of the additional effect of hyperbaric oxygen therapy in combination of systemic steroid and prostaglandin E1 for idiopathic sudden sensorineural hearing loss

PURPOSE

The efficacies of hyperbaric oxygen therapy (HBO), systemic steroid, prostaglandin E₁, or the combination of any two modalities have been reported in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). However, little is known about the combined efficacy of HBO, systemic steroid, and prostaglandin E₁ for this disorder. We aimed to investigate the efficacy of HBO combined with systemic steroids and prostaglandin E₁ as triple therapy in patients with ISSNHL.

MATERIALS AND METHODS

We retrospectively evaluated the records of 67 patients with ISSNHL who were treated with systemic steroid and prostaglandin E₁, with (n = 38) or without (n = 29) HBO. The inclusion criteria included a diagnosis of ISSNHL within 14 days of symptom onset, age ≥15 years, treatment according to the protocol, and clinical follow-up of at least 1 month. The patients' hearing levels were evaluated 1 month after hearing loss onset. The primary outcome was hearing improvement on pure tone audiometry. We also evaluated the demographic profiles of patients.

RESULTS

Patients treated with triple therapy showed significantly greater hearing improvement (p < 0.01) than those treated without HBO, despite some differences between the two treatment groups. Multivariate logistic regression analysis revealed a significant positive correlation between pure tone audiometry improvement and hyperbaric oxygen therapy, after adjustment for confounding factors (odds ratio = 7.42; 95% and confidence interval = 2.37-23.3; p = 0.001).

CONCLUSION

HBO with systemic steroid and prostaglandin E₁ administration conferred significant therapeutic benefits for ISSNHL. Therefore, routine use of triple therapy is recommended for patients with ISSNHL.

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.

Use of Gases to Treat Cochlear Conditions

Although the cochlear vascular supply (stria vascularis) is designed to block to certain compounds and molecules, it must enable gas exchange to survive. The inner ear capillaries must deliver oxygen and remove carbon dioxide for the cochlea to function. These gases diffuse through tissues across a concentration gradient to reach the desired target. Tight junctions or the endothelial basement membrane do not impede them. Therefore, gases that can diffuse into the inner ear are attractive as therapeutic agents. The two gases most often used in this way are oxygen and hydrogen, although carbon dioxide, ozone, and argon have also been investigated. Typically, oxygen is delivered as hyperbaric oxygen (HBO) (oxygen at pressure higher than atmospheric) to provide increased oxygen levels to the inner ear. This not only relieves hypoxia, but also has anti-inflammatory and other biochemical effects. HBO is used clinically to treat idiopathic sudden sensorineural hearing loss, and both animal and human studies suggest it may also assist recovery after acute acoustic trauma. Laboratory studies suggest hydrogen works as a free radical scavenger and reduces the strong oxidants hydroxyl radicals and peroxynitrite. It also has anti-apoptotic effects. Because of its anti-oxidant and anti-inflammatory effects, it has been studied as a treatment for ototoxicity and shows benefit in an animal model of cisplatinum toxicity. Gas diffusion offers an effective way to provide therapy to the inner ear, particularly since some gases (oxygen, hydrogen, carbon dioxide, ozone, argon) have important therapeutic effects for minimizing cochlear damage.