[Local drug therapy for inner ear hearing loss]

[Role of intratympanic glucocorticoid treatment in sudden hearing loss]

Idiopathic sudden sensorineural hearing loss (ISSNHL) is one of the most common diseases in otolaryngology. Its etiology remains unknown. Furthermore, there is only a low level of evidence for the efficacy of established treatment modalities. In addition to systemic glucocorticoids, intratympanic corticosteroid treatment (ICT) has become increasingly important for treatment of ISSNHL. Different application strategies and treatment regimens have been described; however, uniform standards do not yet exist. ICT may be used for primary treatment as well as salvage therapy. Current data from meta-analyses show no benefit of intratympanic versus systemic primary therapy for sudden hearing loss (moderate evidence) but suggest a benefit of intratympanic secondary treatment over no treatment or placebo (high effect size, low evidence). Regarding combination of systemic and local glucocorticoid therapy in primary treatment of hearing loss, there may be a small benefit over systemic treatment alone (low effect size, low evidence).

Post-operative hearing among patients with labyrinthine fistula as a complication of cholesteatoma using "under water technique"

Introduction

During surgery in patients with labyrinthine fistula the mandatory complete removal of the cholesteatoma while preserving inner ear and vestibular function is a challenge. Options so far have been either the complete removal of the cholesteatoma or leaving the matrix on the fistula. We evaluated an alternative “under water” surgical technique for complete cholesteatoma resection, in terms of preservation of postoperative inner ear and vestibular function.

Methods

From 2013 to 2019, 20 patients with labyrinthine fistula due to cholesteatoma were operated. We used the canal wall down approach and removal of matrix on the fistula was done as the last step during surgery using the “under water technique”. The pre and postoperative hearing tests and the vestibular function were retrospectively examined.

Results

There was no significant difference between pre and post-operative bone conduction thresholds; 20% experienced an improvement of more than 10 dB, with none experiencing a postoperative worsening of sensorineural hearing loss. Among seven patients who presented with vertigo, two had transient vertigo postoperatively but eventually recovered.

Conclusion

Our data show that the “under water technique” for cholesteatoma removal at the labyrinthine fistula is a viable option in the preservation of inner ear function and facilitating complete cholesteatoma removal.

The Clinical Effects of Steroids Therapy in the Preserving Residual Hearing after Cochlear Implantation with the OTICON Neuro Zti EVO

Background: A prospective clinical study was conducted to investigate whether two different pharmacotherapy strategies of steroid administration impact hearing preservation in adult patients who underwent cochlear implantation with the Oticon Medical Neuro cochlear implant system. Methods: Twenty nine adult participants were included. Pure tone audiometry was performed before implantation, during processor activation and 12 months after activation. There were three treatment groups: (1) intravenous steroid therapy (standard steroid therapy with dexamethasone administrated intravenously at the dose 0.1 mg/kg body mass twice a day); (2) combined oral and intravenous steroid therapy (extended steroid therapy with dexamethasone administrated intravenously at the dose 0.1 mg/kg b.m. twice a day and prednisone (orally) at the dose 1 mg/kg body mass/24 h), and (3) no steroid therapy (a control group). Patients’ hearing thresholds before implantation were on average 103 dB HL, 89 dB HL, and 93 dB HL, respectively. Results: Deterioration of hearing thresholds was observed in all three patients’ groups. Twelve months after surgery the patients with and without steroid therapy had similar hearing thresholds. Conclusions: The steroid regimen used in this study did not play a significant role in patients with non-functional residual hearing, who underwent cochlear implantation with the Oticon Medical Neuro cochlear implant system.

[Hormonal influence on hearing]

BACKGROUND

Hearing loss leads to impairments in communication, social interactions, and cognitive functions. This renders early treatment particularly important. A causal therapy is not yet available. Human and animal studies have shown that certain hormones can have a positive effect on hearing.

OBJECTIVE

This review provides an overview of the effects of various hormones on hearing and describes the potential benefit for future therapeutic approaches.

MATERIALS AND METHODS

A systematic literature review of reviews dealing with the effects of various hormones on hearing in humans and animals published in PubMed between 2015 and 2020 was conducted.

RESULTS

Hormones may mediate antiapoptotic effects on structure-relevant cells of the cochlea and auditory pathway, and may influence hair cell functionality or the electrolyte balance of the endo- and perilymph. Current research focuses on glucocorticoids; the mineral corticoid aldosterone; the sex hormones estrogen, progesterone, and testosterone; the growth hormones GH (growth hormone) and IGF‑1 (insulin-like growth factor 1); thyroid hormones; and insulin. Study results are still inconsistent at this time, but various hormones appear to represent a possible future treatment option for acute hearing loss. Long-term hormone treatment, which would be necessary particularly in the case of age-related hearing loss, does not currently represent a sensible course of action due to the side effect profile of the systemic treatment/lack of practicable topical application options.

CONCLUSION

The mode of action of hormones is complex. Whether they can be used in the future for individualized treatment of patients with acute hearing impairment requires further investigation.

Postauricular injection in the treatment of all-frequency and high frequency descending sudden hearing loss: A protocol for systematic review and meta-analysis

BACKGROUND

Sudden hearing loss (SHL) is a disease, at the same time a symptom, which needs to be treated in a timely manner and counts as an emergency health problem in the Department of Otolaryngology. There are many types of sudden hearing loss and among them, the occurrence of all-frequency descending sudden hearing loss and high frequency sudden hearing loss are high. The conventional treatment for these 2 types of sudden hearing loss sometimes is not as effective as expected. Postauricular injection of glucocorticoids could be the most effective treatment method. However, the effectiveness and safety of postauricular injection of glucocorticoid needs to be assessed systematically.

METHODS

The protocol for the meta-analysis was conducted under the guidance of Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). The aim is to undertake a systematic review and meta-analysis on the effectiveness and safety of postauricular injection of glucocorticoid to treat patient diagnosed with all-frequency and high frequency descending sudden hearing loss. We searched through the following databases: English databases (PubMed, EMBASE, Web of Science) and Chinese databases (CNKI, Wanfang databases, CBM, VIP). The final selected articles will be evaluated using Cochrane RCT evaluation criteria. Revman 5.0 will be used for data analysis. Subgroup analysis, sensitivity analysis, and meta regression will detect sources of heterogeneity. Ethics approval was not required for this protocol. The findings will be disseminated through journal articles or conference presentations.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/5Q9NA.

RESULTS

Objectively, evaluate the efficacy and safety of postauricular injection of glucocorticoid in treating all-frequency descending sudden hearing loss and high frequency sudden hearing loss.

CONCLUSION

To provide evidence-based medicine for glucocorticoid treatment methods in patients with all-frequency descending sudden hearing loss and high frequency descending hearing loss.

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.

Reduction of permanent hearing loss by local glucocorticoid application : Guinea pigs with acute acoustic trauma

BACKGROUND

High-intensity noise exposure from impulse and blast noise events often leads to acute hearing loss and may cause irreversible permanent hearing loss as a long-term consequence. Here, a treatment regime was developed to limit permanent damage based on a preclinical animal model of acute noise trauma.

AIM

To develop clinical trials for the treatment of acute noise traumas using approved drugs. The otoprotective potential of glucocorticoids applied locally to the inner ear was examined.

MATERIALS AND METHODS

A series of experiments with different impulse noise exposures were performed. Permanent hearing loss and hair cell density were assessed 14 days after exposure. Hearing and hair cell preservation were investigated as a function of the glucocorticoid dose.

RESULTS

After impulse noise exposure, local application to the round window of the cochlea of high-dose prednisolone (25 mg/ml) or methylprednisolone (12.5 mg/ml) resulted in a statistically significant reduction in hearing loss compared with the control group.

CONCLUSION

The local application of high doses of the drugs to the round window of the cochlea appears to be an effective treatment for acute noise trauma.

Intracochlear drug delivery in combination with cochlear implants : Current aspects

Local drug application to the inner ear offers a number of advantages over systemic delivery. Local drug therapy currently encompasses extracochlear administration (i. e., through intratympanic injection), intracochlear administration (particularly for gene and stem cell therapy), as well as various combinations with auditory neurosensory prostheses, either evaluated in preclinical or clinical studies, or off-label. To improve rehabilitation with cochlear implants (CI), one focus is the development of drug-releasing electrode carriers, e. g., for delivery of glucocorticosteroids, antiapoptotic substances, or neurotrophins to the inner ear. The performance of cochlear implants may thus be improved by protecting neuronal structures from insertion trauma, reducing fibrosis in the inner ear, and by stimulating growth of neuronal structures in the direction of the electrodes. Controlled drug release after extracochlear or intracochlear application in conjunction with a CI can also be achieved by use of a biocompatible, resorbable controlled-release drug-delivery system. Two case reports for intracochlear controlled release drug delivery in combination with cochlear implants are presented. In order to treat progressive reduction in speech discrimination and increased impedance, two cochlear implant patients successfully underwent intracochlear placement of a biocompatible, resorbable drug-delivery system for controlled release of dexamethasone. The drug levels reached in inner ear fluids after different types of local drug application strategies can be calculated using a computer model. The intracochlear drug concentrations calculated in this way were compared for different dexamethasone application strategies.

[Intratympanic injection therapy for therapy refractory acute hearing loss: A safe option for secondary treatment]

BACKGROUND

High-dose corticosteroids are currently recommended for idiopathic sudden sensorineural hearing loss (ISSNHL) treatment. Intratympanic injections (ITI) are of growing importance, especially in cases of therapy resistance. The selection of patients for this procedure in SSNHL has not been adequately examined so far.

STUDY DESIGN

A total of 77 patients with ISSNHL after ineffective systemic pretreatment underwent intratympanic administration of dexamethasone and hyaluronic acid. Improvement after treatment was determined by pure tone audiometry for both ears before and of the treated ear after ITI.

RESULTS

In this study 34 female and 43 male patients with mean age of 57 years showed a pre-ITI hearing loss of 35 dB in the lower frequencies and 69 dB in the higher frequencies. The mean hearing gain was 10 dB and the response rate was 62%. Absolute hearing gain revealed significant improvements at 500 Hz, 1 kHz and 2 kHz. Under inclusion of contralateral thresholds there were hardly any differences up to 4 kHz. In a detailed analysis of responders moderate improvements could be observed even in higher frequencies. Overall, no relevant adverse events occurred.

CONCLUSION

Treatment of ISSNHL resistant to systemic regimens by ITI of steroids provides an option that offers additional prospects of auditory improvement for affected patients. The presented results indicate that these modalities are also valid for patients with pancochlear ISSNHL.