Intratympanic steroids for sensorineural hearing loss

Therapeutic efficacy of methylprednisolone sodium succinate via diverse administration routes for mid- to high-frequency sudden sensorineural hearing loss

BACKGROUND

Sudden sensorineural hearing loss (SSNHL), characterized by a rapid and unexplained loss of hearing, particularly at moderate to high frequencies, presents a significant clinical challenge. The therapeutic use of methylprednisolone sodium succinate (MPSS) via different administration routes, in combination with conventional medications, remains a topic of interest.

AIM

To compare the therapeutic efficacy of MPSS administered via different routes in combination with conventional drugs for the treatment of mid- to high-frequency SSNHL.

METHODS

The medical records of 109 patients with mid- to high-frequency SSNHL were analyzed. The patients were divided into three groups based on the route of administration: Group A [intratympanic (IT) injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection], Group B (intravenous injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection), and Group C (single IT injection of MPSS). The intervention effects were compared and analyzed.

RESULTS

The posttreatment auditory thresholds in Group A (21.23 ± 3 .34) were significantly lower than those in Groups B (28.52 ± 3.36) and C (30.23 ± 4.21; P < 0.05). Group A also exhibited a significantly greater speech recognition rate (92.23 ± 5.34) than Groups B and C. The disappearance time of tinnitus, time to hearing recovery, and disappearance time of vertigo in Group A were significantly shorter than those in Groups B and C (P < 0.05). The total effective rate in Group A (97.56%) was significantly greater than that in Groups B and C (77.14% and 78.79%, χ 2 = 7.898, P = 0.019). Moreover, the incidence of adverse reactions in Groups A and C was significantly lower than that in Group B (4.88%, 3.03% vs 2.57%, χ 2 = 11.443, P = 0.003), and the recurrence rate in Group A was significantly lower than that in Groups B and C (2.44% vs 20.00% vs 21.21%, χ 2 = 7.120, P = 0.028).

CONCLUSION

IT injection of MPSS combined with conventional treatment demonstrates superior efficacy and safety compared to systemic administration via intravenous infusion and a single IT injection of MPSS. This approach effectively improves patients' hearing and reduces the risk of disease recurrence.

Long-term efficacy of dexamethasone treatment via tympanic antrum catheterization for intractable Meniere's disease

Objective

To explore the long-term efficacy and safety of dexamethasone treatment via tympanic antrum catheterization (TAC) in intractable Meniere's disease (MD).

Methods

In this retrospective analysis, 60 unilateral intractable MD patients treated with TAC in our hospital from January 2020 to August 2020 were followed for 2 years. Fifty patients who underwent endolymphatic sac decompression (ESD) and 50 patients who accepted intratympanic steroids (ITS) were established as the control groups. Vertigo control, hearing level, tinnitus, aural fullness and functional level were assessed during the study.

Results

The effective vertigo control rate of intractable MD patients with TAC treatment was 76.7% (46/60) after 2 years follow-up, with a complete control rate of 58.3% (35/60) and a substantial control rate of 18.3% (11/60). The vertigo control rate of TAC was comparable to that of ESD (χ2 = 0.313, p &gt; 0.05), and significantly higher than that of ITS (χ2 = 4.380, p &lt; 0.05). The hearing loss rate of these patients was 10.8% (4/37), which was not significantly different from the control groups (χ2 = 2.452, p &gt; 0.05). The tinnitus improvement rate of patients with TAC was 56.7% (34/60), which was significantly higher than that of patients with ESD (χ2 =11.962, p &lt; 0.001) and ITS (χ2 =15.278, p &lt; 0.001). The aural fullness improvement rate in the TAC group was 56.7% (34/60), which was significantly higher than that in the ESD (χ2 = 11.962, p &lt; 0.001) and ITS groups (χ2 = 5.635, p &lt; 0.05). The functional level improvement rate in the TAC group was 71.7% (43/60), which was much higher than that in the ITS group (χ2 = 17.256, p &lt; 0.001), but there was no significant difference between TAC and ESD (χ2 = 0.410, p &gt; 0.05). No patients had complications or adverse reactions following TAC treatment.

Conclusion

Dexamethasone treatment via TAC can effectively control vertigo attacks and improve related symptoms of intractable MD patients, providing valuable new insights into the treatment of MD.

Efficacy and safety of standardized Ginkgo biloba L. leaves extract as an adjuvant therapy for sudden sensorineural hearing loss: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Ginkgo biloba L. has been used for medical purposes in China for centuries. Standardized Ginkgo biloba L. leaves extract (GBE) is a widely used botanical drug which displays a variety of pharmacological effects against sudden sensorineural hearing loss (SSNHL).

AIM OF THE STUDY

To evaluate the efficacy and safety of GBE as an adjuvant therapy, administered with corticosteroids, for the initial management of patients with SSNHL.

MATERIALS AND METHODS

We searched seven databases for randomized clinical trials (RCTs) comparing GBE plus corticosteroids with corticosteroids alone for SSNHL treatment. Data analysis was carried out by Review Manager 5.4 and Stata 16.0 software. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. We subsequently evaluated the certainty of evidence using the GRADE (Grading of Recommendation Assessment, Development and Evaluation) approach.

RESULTS

A total of 11 RCTs involving 1069 patients were included. Meta-analysis indicated that the clinical cure rate (RR = 1.33, 95% CI = 1.12 to 1.58, P = 0.001) and total effective rate (RR = 1.24, 95%CI = 1.17 to 1.31, P < 0.001) in SSNHL patients receiving GBE plus corticosteroids was superior to patients receiving corticosteroids alone. After treatment, pure tone average (PTA) improvement of observation group was better than that in the control group (WMD = 10.33, 95%CI = 6.46 to 14.21, P < 0.001). The levels of whole blood high shear viscosity (WMD = 0.93, 95%CI = 0.28 to 1.59, P = 0.005), whole blood medium shear viscosity (WMD = 0.53, 95%CI = 0.11 to 0.95, P = 0.01), whole blood low shear viscosity (WMD = 1.26, 95%CI = 0.80 to 1.72, P < 0.001), plasma viscosity (WMD = 0.19, 95%CI = 0.09 to 0.30, P < 0.001) and fibrinogen (WMD = 0.80, 95%CI = 0.25 to 1.35, P = 0.004) were lower than those in the control group. There was no significant difference in the change of hematokrit between two groups (WMD = 4.23, 95%CI = -0.54 to 8.99, P = 0.08). GBE was generally well tolerated, and there was no significant difference in the incidence of adverse reactions between two groups (RR = 1.01, 95%CI = 0.57 to 1.79, P = 0.97).

CONCLUSION

The results of the current study suggested that GBE might be effective and promising as an adjuvant to corticosteroids in the initial treatment of moderate to profound SSNHL. However, the GRADE assessment indicated that the overall strength of evidence was not high. Further studies with high methodological quality and low risk of bias are needed to confirm the positive results. PROSPERO registration No. CRD 42020190113.

Postauricular injection of methylprednisolone sodium succinate as a salvage treatment for refractory sudden sensorineural hearing loss

BACKGROUND

Postauricular steroid administration has been popular for treating sudden sensorineural hearing loss. However, there are few reports on its use in patients with refractory sudden sensorineural hearing loss (RSSNHL).

AIMS

The objective of this study was to investigate the therapeutic efficacy of postauricular steroid injection as a salvage treatment for RSSNHL patients.

METHODS

This retrospective study enrolled 63 RSSNHL patients between January 2016 and January 2019. Thirty-three patients of them who have been divided into the treatment group received postauricular methylprednisolone sodium succinate injection. The remaining 30 patients who formed the control group did not receive any steroid as a salvage therapy. Improvements in hearing were evaluated between pre-salvage therapy and 3 months follow-up after salvage therapy.

RESULTS

The median hearing gain in PTA was 9.88 dB HL (quartile range 7.58, 18.65) in the treatment group and 0.90 dB HL (quartile range 0.00, 4.90) in the control group (P<0.01). According to the criteria of Furuhashi, the total percentage for effective prognosis was 48.48% (16/33) in the treatment group and 10.00% (3/30) in the control group (P<0.01). The time interval from onset to study entry was significantly and independently associated with the prognosis for RSSNHL patients (P< 0.01).

CONCLUSIONS

The present findings suggest that postauricular corticosteroid administration as a salvage treatment demonstrated better results than no treatment for RSSNHL patients. The time interval from onset to study entry was mainly the prognostic factor for RSSNHL patients. It is therefore considered that postauricular corticosteroid administration may be used as a salvage therapy for RSSNHL patients.

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.

Predictor parameters for poor prognosis in patients with sudden sensorineural hearing loss: fibrinogen to albumin ratio vs C-reactive protein to albumin ratio

Introduction

Prognosis of sudden sensorineural hearing loss may be predicted using several parameters of laboratory blood analysis.

Objective

To identify and investigate the most significant indicator parameters related to the poor prognosis of sudden sensorineural hearing loss.

Methods

Eighty-eight patients were included, and three groups were constituted: non-recovery group with14 patients, recovery group with 33 patients and control group with 41 individuals. We compared fibrinogen-to-albumin ratio, C-reactive protein-to-albumin ratio, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, white blood cell and hemoglobin of the groups. Then, we investigated the most significant indicator parameters related to the poor prognosis of sudden hearing loss.

Results

The mean hemoglobin, mean platelet-lymphocyte ratio and median white blood cell values did not significantly differ among three groups (p = 0.36, p = 0.86 and p = 0.79, respectively). A significant difference of median fibrinogen-albumin ratio, C-reactive protein-albumin ratio, neutrophil-to-lymphocyte ratio was evident among three groups (p < 0.001, p = 0.003 and p = 0.002, respectively). Median fibrinogen-albumin ratio, C-reactive protein-albumin ratio and neutrophil-to-lymphocyte ratio values were significantly greater in the non-recovery group, compared with the controls (p < 0.001, p = 0.003 and p = 0.005, respectively). Median fibrinogen-to-albumin ratio, C-reactive protein-to-albumin ratio and neutrophil-to-lymphocyte ratio were significantly greater in the recovery group, compared with the controls (p < 0.001, p = 0.013 and p = 0.005, respectively). Moreover, the median fibrinogen-albumin ratio was significantly greater in the non-recovery group compared with the recovery group (p = 0.017). However, no statistically significant difference of median C-reactive protein-albumin ratio, neutrophil-to-lymphocyte was evident between the non-recovery and recovery groups (p = 0.15).

Conclusion

Increased levels of fibrinogen-albumin ratio may be predictive for poor prognosis in patients with sudden sensorineural hearing loss.

Dexamethasone eardrop with grommet placement vs intratympanic steroid injection for sudden sensorineural hearing loss: A randomized prospective clinical trial

OBJECTIVES

The purpose of this study was to compare different means of intratympanic steroid delivery in the treatment of idiopathic sudden sensorineural hearing loss.

DESIGN

Prospective, multicentered, randomized controlled trial.

SETTING AND PARTICIPANTS

Fifty-six patients who fulfilled the inclusion criteria for idiopathic sudden sensorineural hearing loss who failed or were contraindicated for oral steroids were included in this study. Patients were randomly divided into 2 groups according to delivery methods: group A received 4 sections of intratympanic dexamethasone injection and group B received grommet placement with dexamethasone delivery followed by 3 sections of dexamethasone ear drop application. Self-administered paper-based questionnaires were filled out to measure subjective pain scores, vertigo, anxiety, and overall satisfaction immediately after each procedure. Hearing threshold was measured with pure tone audiogram in the follow-up.

RESULTS

There was no statistical significance detected in hearing threshold improvement between both groups (P = 0.30). Grommet placement followed by dexamethasone eardrop application demonstrated a significant difference in shorter waiting time (24 min in grommet group vs 52 min in injection group; P < 0.01); and better overall satisfaction (1.6 in grommet group vs 2.5 in injection group; P < 0.05).

CONCLUSIONS

Grommet placement followed by dexamethasone eardrop application is a good alternative for a patient indicated for intratympanic steroid, with less administrative cost, shorter waiting time, and more satisfaction.

[Effect of tympanic dexamethasone injection in the treatment of different types of sudden deafness]

Objective:The aim of this study is to explore the best administration, timing and efficacy of dexamethasone and Mison in the treatment of different types of sudden deafness. Method:242 cases of sudden deafness first diagnosed in our department were selected. According to the guidelines（2015）, the patients were divided into low frequency descending type （49 cases）, high frequency descending type （66 cases）, flat descending type （71 cases） and total deafness （56 cases）. Different types of patients were randomly divided into tympanic injection group and systemic administration group on the basis of routine treatment. Tympanic injection group was further divided into initial injection group and delayed injection group. Tympanic injection was performed under ear endoscope, once every other day, three times for low frequency descending deafness, and five times for other types of deafness. Result:In comparison of total effective rate, there were significant differences among the three treatments in 49 cases of low frequency descending type, 71 cases of flat descending type and 56 cases of total deafness type （P<0.05）. In 66 cases of high frequency descending type, there was no significant difference among the three treatments （P>0.05）. In the comparison of cure rate, the difference of cure rate among the three treatment methods was also significant in low frequency descending type （P<0.05）. In the other three types of deafness, there was no significant difference among the three treatment methods （P>0.05）. There was no significant difference in the effective rate between men and women （P>0.05） in all patients treated by tympanic injection. There was significant difference in the effective rate of tympanic injection within 7 days of onset and 7 days after onset （P<0.05）. Conclusion:Intratympanic injection of dexamethasone is safe, effective, and easy to use as an initial treatment for low frequency descent, flat, and full deafness, and the sooner the better.

Cochlear Glucocorticoid Receptor and Serum Corticosterone Expression in a Rodent Model of Noise-induced Hearing Loss: Comparison of Timing of Dexamethasone Administration

Glucocorticoid (GC) is a steroid hormone secreted from the adrenal cortex in response to stress, which acts by binding to cytoplasmic glucocorticoid receptors (GRs). Dexamethasone (DEX) is a synthetic GC exhibiting immunosuppressive effects in both human and rodent models of hearing loss. While clinical evidence has shown the effectiveness of DEX for treatment of various inner ear diseases, its mechanisms of action and the optimal timing of treatment are not well understood. In the present study, intergroup comparisons were conducted based on the time point of treatment with DEX: (1) pretreatment; (2) posttreatment; and (3) pre&post-noise. The pre&post DEX treatment group showed a significant improvement in threshold shift at 1 day post-noise exposure as compared to the TTS (transient threshold shift)-only group at 8 and 16 kHz. Both TTS and PTS (permanent threshold shift) significantly reduced cochlear GR mRNA expression and increased serum corticosterone and cochlear inflammatory cytokines. The pre&post DEX treatment group showed a significant decrease in serum corticosterone level as compared to other DEX treatment groups and TTS-treated group at 3 days after acoustic trauma. Our results suggest that the timing of DEX administration differentially modulates systemic steroid levels, GR expression and cochlear cytokine expression.

Intratympanic steroids for combined treatment of idiopathic sudden hearing loss: when is it too late?

Background: Idiopathic sudden sensorineural hearing loss (ISSNHL) requires early treatment. Objective: To describe our experience on intratympanic steroid treatment (ITS) of ISSNHL analyzing the delay to start therapy as prognostic factor. Material and methods: We perform a retrospective study on ISSNHL treated with systemic steroids without full recovery on PTA (pure tone average) according to Siegel criteria. They were divided into two different groups: one group that additionally received ITS as combined therapy (treatment group), and another without it (control group). We analyzed the hearing recovery at 6 months and 2 years, and the influence of the delay to start ITS in the recovery. Results: After ITS was added, further complete recovery was achieved in 10 patients of the treatment group. After 6 months, PTA improvement in the treatment group was 10.84 dB, compared to 1.13 dB in the control group (p<.0001). Nevertheless, patients starting such combination of oral steroids and ITS within 8 days of diagnosis had an additional gain of 15 dB in the first 6 months, that increased to 19.17 dB after 24 months (p<.022). Conclusions: When ITS was added within the first 8 days, a significantly better and more stable response was obtained.

Immune cells and non-immune cells with immune function in mammalian cochleae

The cochlea has an immune environment dominated by macrophages under resting conditions. When stressed, circulating monocytes enter the cochlea. These immune mediators, along with cochlear resident cells, organize a complex defense response against pathological challenges. Since the cochlea has minimal exposure to pathogens, most inflammatory conditions in the cochlea are sterile. Although the immune response is initiated for the protection of the cochlea, off-target effects can cause collateral damage to cochlear cells. A better understanding of cochlear immune capacity and regulation would therefore lead to development of new therapeutic treatments. Over the past decade, there have been many advances in our understanding of cochlear immune capacity. In this review, we provide an update and overview of the cellular components of cochlear immune capacity with a focus on macrophages in mammalian cochleae. We describe the composition and distribution of immune cells in the cochlea and suggest that phenotypic and functional characteristics of macrophages have site-specific diversity. We also highlight the response of immune cells to acute and chronic stresses and comment on the potential function of immune cells in cochlear homeostasis and disease development. Finally, we briefly review potential roles for cochlear resident cells in immune activities of the cochlea.

Hearing Changes After Intratympanically Applied Steroids for Primary Therapy of Sudden Hearing Loss: A Meta-analysis Using Mathematical Simulations of Drug Delivery Protocols

OBJECTIVE

Controlled and uncontrolled studies with primary intratympanic or combined intratympanic and systemic application of glucocorticosteroids for idiopathic sudden hearing loss were analyzed by means of a meta-analysis in an attempt to establish optimal local drug delivery protocols.

STUDY DESIGN

A total of 25 studies with 28 treatment groups between January 2000 and June 2014 were selected that adequately described drug delivery protocols. Cochlear drug levels were calculated by a validated computer model of drug dispersion in the inner ear fluids based on the concentration and volume of glucocorticoids applied, the time the drug remained in the middle ear, and the specific timing of injections. Various factors were compared with hearing outcome, including baseline data, individual parameters of the application protocols, calculated peak concentration (Cmax), and total dose (area under the curve).

RESULTS

There was no dependence of hearing outcome on individual parameters of the application protocol, Cmax, or area under the curve. Final hearing threshold was notably independent of delay of treatment.

CONCLUSION

During primary intratympanic or combined steroid therapy of idiopathic sudden hearing loss, the tendency toward early treatment having a positive effect on hearing improvement is thought to be a "sham effect," likely related to spontaneous recovery. Change in pure-tone average may not be an adequate outcome parameter to assess effectiveness of the intervention, as it depends on the degree of initial hearing loss. Final pure-tone average provides a better alternative.

A comparison between systemic and intratympanic steroid therapies as initial therapy for idiopathic sudden sensorineural hearing loss: a meta-analysis

CONCLUSIONS

Intratympanic steroid (ITS) treatment groups exhibited better outcomes in PTA improvement and recovery rate than systemic steroid therapy (SST) groups. Whether initial hearing loss severity would influence the PTA improvement and recovery rate still requires further research.

OBJECTIVE

This article was aimed at evaluating whether intratympanic steroid (ITS) treatment would provide benefits over systemic steroid therapy (SST) as initial therapy in patients with idiopathic sudden sensorineural hearing loss (ISSHL). A meta-analysis was carried out based on published RCTs that included the hearing outcomes of ITS treatment and SST in ISSHL as initial therapy. Both PTA differences and recovery rate were analyzed.

METHODS

The literature search was based on the online database including Pubmed, Embase, and Cochrane trails, which completed in July 2016. This study extracted the relevant data following the selection criteria. Mean difference (MD) of PTA differences and Odds ratio (OR) of recovery rate were calculated within 95% confidence intervals.

RESULTS

Six eligible articles were reviewed. The pooled MDs of PTA differences was 3.42 (95% CI = 0.17-6.67, p = .04) and the pooled ORs of recovery rate was 2.05 (95% CI = 1.38-3.03, p = .0003), which indicated that ITS treatment yielded better PTA improvement than SST. Sub-group analyses based on the initial hearing loss were also conducted; however, the difference was insignificant according to our analysis results (p = .82 for PTA improvement and p = .26 for recovery rate).

The Effects of Prognostic Factors in Idiopathic Sudden Hearing Loss

Introduction  Sudden hearing loss is one of the otologic emergencies. The treatment of this disease is affected negatively by some prognostic factors. Objective  In this study, the effects of early treatment initiation in patients with idiopathic sudden hearing loss and of prognostic factors in early treated patients were investigated. Methods  Out of the 216 patients admitted between September 2007 and September 2015, 154 were identified as having idiopathic sudden hearing loss; they were followed-up for a mean time of 7.4 months, and evaluated retrospectively. The effects of several parameters on the success of the treatment were statistically evaluated, such as the time the treatment was initiated, being of the female gender, the severity of the hearing loss, having descending type audiogram patterns, being older than 60 years old, and the co-presence of vertigo. Results  Success rates were found to be significantly higher in idiopathic hearing loss patients that were admitted within the first week ( p  < 0.05) of the onset of the hearing loss. However, the outcomes were found to be similar when patients admitted within the first 3 days and 4-7 days after the occurrence of the hearing loss were compared ( p  > 0.05). Parameters such as female gender, severe hearing loss, descending type audiogram, being older than 60 years old, and co-presence of vertigo didn't reveal statistically significant effects on the outcome ( p >0.05). Conclusion  The aforementioned prognostic factors, which are well-known in the literature, did not have significant effects when the idiopathic sudden hearing loss treatment was initiated within the first 7 days of the onset of the hearing loss.

Intratympanic methylprednisolone perfusion as a salvage treatment for profound idiopathic sudden sensorineural hearing loss

Objective:

This study aimed to examine the effectiveness of intratympanic methylprednisolone perfusion as salvage treatment for profound idiopathic sudden sensorineural hearing loss.

Methods:

A retrospective clinical study of 97 patients with unilateral profound idiopathic sudden sensorineural hearing loss was performed. In all, 83 patients who received salvage intratympanic methylprednisolone perfusion plus conventional treatment (except for steroids) as the second-line therapy were assigned to the study group, while 14 patients who received conventional treatment alone were assigned to the comparison group.

Results:

In the study group, treatments in patients with a shorter interval from disease onset to intratympanic methylprednisolone perfusion (up to 15 days) had significantly greater improvements in the overall effective rate and pure tone average compared with patients with a longer interval (over 15 days). For patients with a short interval from disease onset to intratympanic methylprednisolone perfusion, those in the study group had significantly greater improvements in the overall effective rate and pure tone average compared with those in the comparison group. In both the study and comparison groups, hearing improvements were greater at low frequencies than at medium and high frequencies.

Conclusion:

The interval from disease onset to intratympanic methylprednisolone perfusion was the major factor affecting hearing recovery. Early second-line salvage intratympanic methylprednisolone perfusion significantly improved the degree of hearing recovery in profound idiopathic sudden sensorineural hearing loss patients after failure of systemic steroid treatment.

Clinical Implication of the Threshold Equalizing Noise Test in Patients With Sudden Sensorineural Hearing Loss

OBJECTIVE

The aims of the present study were to investigate the prevalence of cochlear dead regions (DRs) in patients with sudden sensorineural hearing loss (SSNHL) and compare the hearing outcome according to the presence of DRs.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS AND METHODS

The threshold-equalizing noise (HL) test was performed on a total of 112 ears diagnosed with SSNHL. Ears were divided into two groups based on the presence of DRs. Eighty-two ears belonged to the group without DRs and 30 ears belonged to the group with DRs. There was no difference between the two groups with respect to age, sex, side of affected ear, presence of bilateral SSNHL, presence of vertigo, history of treatment, and initial pure-tone thresholds. Pure-tone audiograms were gathered at the time of initial presentation and at 1, 3, and 6 months after onset of symptoms.

RESULTS

The prevalence of DRs was observed to be 29% and was found to be prevalent at 1k and 1.5k Hz in patients with SSNHL. When the hearing thresholds over times were compared between the two groups, subjects with DRs showed significantly poorer hearing outcome compared with those without DRs. The improvements in word recognition scores over times were also less in subject with DRs than those without DRs.

CONCLUSION

DRs are associated with worse hearing thresholds at follow-up audiogram and might be associated with unfavorable hearing outcome in patients with SSNHL.

Intratympanic dexamethasone injection vs methylprednisolone for the treatment of refractory sudden sensorineural hearing loss

Background:

During the past years various drugs have been used for sudden sensorineural hearing loss (SSNHL) treatment including steroids that are shown to be beneficial. Directed delivery of high doses of steroids into the inner ear is suggested for its potential and known as intratympanic steroids therapy (IST). Despite the use of dexamethasone and methylprednisolone as the traditional treatments, there are still debates about the optimal dosage, preferred drug, and the route of administration.

Materials and Methods:

We performed a randomized clinical trial study in which 50 patients suffering from SSNHL and resistant to standard therapy were employed. Each patient took 0.5 ml methylprednisolone (40 mg/mg) along with bicarbonate or dexamethasone (4 mg/mL) through direct intratympanic injection. This method was performed and scheduled once every 2 days for three times only for the dexamethasone receiving group. Hearing test was carried out and the results were analyzed according to a four-frequency (0.5, 1.0, 2.0, 3.0 kHz) pure tone average (PTA) and Siegel's criteria.

Results:

According to Siegel's criteria, three out of 25 (12%) dexamethasone receiving patients were healed in 1 and 4 (16%), 9 (32%) were respectively recovered in Siegel's criteria 2, 3, and 9 (32%) showed no recovery. In the group receiving methylprednisolone, recovery was found in 6 (24%), 8 (32%), 7 (28%) patients in the Siegel's criteria 1, 2, 3, respectively, and in 4 (16%) patients no recovery was recorded. In methylprednisolone group, hearing was significantly improved compared to the dexamethasone group (P < 0.05). The general hearing improvement rate was 84% in methylprednisolone receiving patients showing a significantly higher improvement than 64% in the dexamethasone group.

Conclusions:

Topical intratympanic treatment with methylprednisolone is safe and an effective treatment approach for those SSNHL cases that are refractory to the common therapies by Dexamethasone.

Intratympanic Steroids for Treatment of Sudden Hearing Loss after Failure of Intravenous Therapy

OBJECTIVE: We sought to describe our experience with intratympanic steroid treatment of sudden sensorineural hearing loss after failure of intravenous steroid treatment.

STUDY DESIGN AND SETTING: We conducted a nonrandomized prospective clinical trial. Fifty patients presenting with sudden onset idiopathic hearing loss were treated intravenously over five days. After this period, patients with treatment failure (18 cases) were offered intratympanic steroid treatment. Nine patients refused, whereas the other nine patients received three weekly injections of methylprednisolone. Recovery of hearing was reported as improvement of more than 15 dB in pure tone average.

RESULTS: Intratympanic steroid treatment improved hearing loss in five patients (55%). This is significant compared with those patients who refused intratympanic treatment, who showed no further improvement ( P < 0.05). No serious adverse effects were observed.

CONCLUSION: Intratympanic steroids significantly improve the recovery outcome of sudden hearing loss that had not recovered after intravenous steroid treatment.

SIGNIFICANCE: Intratympanic steroids are an effective and safe therapy in sudden sensorineural hearing loss cases that are refractory to standard treatment.

Is Intratympanic Dexamathasone Injection Effective for the Treatment of Idiopathic Sudden Sensorineural Hearing Loss?

BACKGROUND AND OBJECTIVES

The purpose of this study is to identify the effectiveness of intratympanic (IT) steroids when used as an initial therapy in sudden sensorineural hearing loss (SSNHL), and when it is used as a salvage therapy in a refractory SSNHL.

SUBJECTS AND METHODS

This retrospective study included 122 patients with SSNHL. First, patients were divided into three groups according to the initial treatment; IT steroid, systemic steroid and combined (systemic and IT steroid) groups. Second, patients were divided into two groups according to the salvage treatment in a refractory SSNHL; IT steroid and the control (non IT group). Fifty eight patients who did not respond to initial therapy were included in the second analysis. Hearing was assessed immediately before the treatment and 2 weeks, 4 weeks and 3 months after the treatments. Hearing recovery was defined as an improvement of >15 dB and the final hearing of 25-45 dB in the audiogram.

RESULTS

When we analyzed the hearing recovery in initial treatment, the comparison of audiogram among three groups did not result in significantly different outcomes. There were no differences in the recovery rate in 2 and 4 weeks throughout all the frequencies. Also, the analysis of the salvage treatment demonstrated that neither IT steroid group nor control group was significantly effective in treating the refractory SSNHL.

CONCLUSIONS

The results suggest that initial treatment of SSNHL with IT steroid alone is as effective as systemic steroid alone or a combination therapy. Also, salvage IT steroids for refractory SSNHL did not have any additional beneficial effects.

Histone Deacetylase 2 in Sudden Sensorineural Hearing Loss Patients in Response to Intratympanic Methylprednisolone Perfusion

OBJECTIVE

To evaluate the expression of histone deacetylase 2 (HDAC2) in peripheral blood mononuclear cells (PBMCs) from patients with sudden sensorineural hearing loss (SSNHL) who were refractory to systemic glucocorticoid treatment and to identify the relationship between the level of HDAC2 and glucocorticoid insensitivity.

STUDY DESIGN

Prospective clinical study.

SETTING

This study was conducted in Nanjing Drum Tower Hospital, Nanjing University Medical School.

SUBJECTS AND METHODS

PBMCs were collected from 42 refractory SSNHL patients. After a 10-day intratympanic methylprednisolone perfusion (IMP) and systemic Ginkgo biloba extract treatment, the SSNHL patients were divided into 2 groups according to their hearing recovery after IMP (IMP sensitive and insensitive). Real-time polymerase chain reaction and HDAC2 protein assays were used to detect the relative expression levels of HDAC2 in PBMCs. The HDAC2 mRNA expression and protein levels in PBMCs collected from 17 volunteers were used as normal HDAC2 reference levels.

RESULTS

Compared with normal reference levels, HDAC2 protein levels were significantly reduced, while the HDAC2 mRNA expression was much higher in all refractory SSNHL patients before IMP. HDAC2 mRNA expression and HDAC2 protein levels were significantly elevated in the IMP-sensitive group, while no change was observed in the IMP-insensitive group after IMP plus systemic antioxidant treatment.

CONCLUSIONS

Reduced HDAC2 protein levels may be 1 of the mechanistic underpinnings of corticosteroid insensitivity in refractory SSNHL patients. IMP can increase HDAC2 protein levels and the expression of HDAC2 mRNA in IMP-sensitive patients. HDAC2 protein levels might be regulated through posttranslational modifications.

Microperforations significantly enhance diffusion across round window membrane

HYPOTHESIS

Introduction of microperforations in round window membrane (RWM) will allow reliable and predictable intracochlear delivery of pharmaceutical, molecular, or cellular therapeutic agents.

BACKGROUND

Reliable delivery of medications into the inner ear remains a formidable challenge. The RWM is an attractive target for intracochlear delivery. However, simple diffusion across intact RWM is limited by what material can be delivered, size of material to be delivered, difficulty with precise dosing, timing, and precision of delivery over time. Further, absence of reliable methods for measuring diffusion across RWM in vitro is a significant experimental impediment.

METHODS

A novel model for measuring diffusion across guinea pig RWM, with and without microperforation, was developed and tested: cochleae, sparing the RWM, were embedded in 3D-printed acrylic holders using hybrid dental composite and light cured to adapt the round window niche to 3 ml Franz diffusion cells. Perforations were created with 12.5-μm-diameter needles and examined with light microscopy. Diffusion of 1 mM Rhodamine B across RWM in static diffusion cells was measured via fluorescence microscopy.

RESULTS

The diffusion cell apparatus provided reliable and replicable measurements of diffusion across RWM. The permeability of Rhodamine B across intact RWM was 5.1 × 10(9-) m/s. Manual application of microperforation with a 12.5-μm-diameter tip produced an elliptical tear removing 0.22 ± 0.07% of the membrane and was associated with a 35× enhancement in diffusion (P < 0.05).

CONCLUSION

Diffusion cells can be applied to the study of RWM permeability in vitro. Microperforation in RWM is an effective means of increasing diffusion across the RWM.

Does age influence the success of intra-tympanic steroid treatment in idiopathic sudden deafness?

CONCLUSIONS

The present study shows that AGE, DELAY, and PTA_PRE may be considered factors influencing therapeutic success in intra-tympanic steroid therapy.

OBJECTIVE

The aim of the study is to evaluate the relationship between the therapeutic success of intra-tympanic prednisolone therapy and age, in patients affected by idiopathic sudden sensorineural hearing loss (ISSNHL), considering the influence of factors such as delay, gender, and pure tone average (PTA) pre-therapy.

METHOD

This retrospective study involved 402 consecutive patients, affected by unilateral ISSNHL between January 2009 and January 2014. Patients were divided into two groups based on age: group one with 94 patients aged over 65 years and group two with all 402 patients enrolled in the study, including those over 65.

RESULTS

PTA recorded before the beginning of the therapy (PTA_PRE) in group one was worse than for group two. In both groups the therapy was significantly effective in improving hearing thresholds, even if PTA_PRE was significant and negatively correlated with success rate. This effect disappeared within the population over 65. On average, each day of DELAY from the onset of hearing loss to the beginning of therapy cuts almost 2% of the possibility to recover. AGE was negative and significant when specified continuously for group two.

Sudden sensorineural hearing loss: Is antiviral treatment really necessary?

OBJECTIVES

It was aimed to investigate the necessity of antiviral agents in the ISSHL treatment.

METHODS

In this study, the patients, diagnosed with sudden hearing loss and admitted in the first 7 days of hearing loss were divided into two groups; a combination therapy was administered to one of the groups, and famciclovir was administered to the other group as an antiviral treatment in addition to the combined therapy. Both groups were compared in terms of levels of recovery.

RESULTS

No statistically significant difference was found in the recovery rates between the two groups (p=0.7).

CONCLUSION

In this study, the additional antiviral treatment was found to have no effect on the remission rates in patients with ISSHL treated with combined therapy.

Intratympanic steroid injection as a salvage treatment for sudden sensorineural hearing loss

OBJECTIVE

To determine the efficacy of intratympanic methylprednisolone injections for treating sudden sensorineural hearing loss.

METHOD

A retrospective chart review was performed to identify patients suffering from sudden sensorineural hearing loss with no recovery after oral steroids. Patients were given up to three intratympanic methylprednisolone injections at one-week intervals. They were classified according to their functional hearing class, remission was monitored and potential factors affecting prognosis were analysed.

RESULTS

Intratympanic injections provide effective salvage therapy for sudden sensorineural hearing loss (p = 0.039). Changes in pure tone average and speech discrimination score were analysed following intratympanic methylprednisolone injections. The pure tone average reached a plateau after the second injection; however, the speech discrimination score improved until after the third injection. Hearing improvement after intratympanic injections mainly occurred at low frequencies. The interval between symptoms appearing and intratympanic injections starting was not significantly associated with remission (p = 0.680).

CONCLUSION

A delay between symptom onset and the first intratympanic methylprednisolone injection does not seem to affect prognosis.

Evaluation of intratympanic formulations for inner ear delivery: methodology and sustained release formulation testing

A convenient and efficient in vitro diffusion cell method to evaluate formulations for inner ear delivery via the intratympanic route is currently not available. The existing in vitro diffusion cell systems commonly used to evaluate drug formulations do not resemble the physical dimensions of the middle ear and round window membrane. The objectives of this study were to examine a modified in vitro diffusion cell system of a small diffusion area for studying sustained release formulations in inner ear drug delivery and to identify a formulation for sustained drug delivery to the inner ear. Four formulations and a control were examined in this study using cidofovir as the model drug. Drug release from the formulations in the modified diffusion cell system was slower than that in the conventional diffusion cell system due to the decrease in the diffusion surface area of the modified diffusion cell system. The modified diffusion cell system was able to show different drug release behaviors among the formulations and allowed formulation evaluation better than the conventional diffusion cell system. Among the formulations investigated, poly(lactic-co-glycolic acid)-poly(ethylene glycol)-poly(lactic-co-glycolic acid) triblock copolymer systems provided the longest sustained drug delivery, probably due to their rigid gel structures and/or polymer-to-cidofovir interactions.

Relationship of glucocorticoid receptor expression in peripheral blood mononuclear cells and the cochlea of guinea pigs and effects of dexamethasone administration

Background

Glucocorticoids (GCs) are widely used to treat sudden sensorineural hearing loss (SSNHL) and significantly improve hearing. However, GC insensitivity has been observed in some patients of SSNHL.

Objective

To study the correlation between GR expression in peripheral blood mononuclear cells (PBMCs) and in the cochlea of guinea pigs at mRNA and protein levels.

Methods

One group of guinea pigs received dexamethasone (10 mg/kg/day) intraperitoneally for 7 consecutive days (dexamethasone group), and another group of guinea pigs received normal saline (control group). Real time PCR and Western blotting were used to detect the expression of GR mRNA and GR protein in PBMCs and the cochleae.

Results

The GR mRNA and GR protein were detected in both PBMCs and the cochlear tissue of guinea pigs. GR mRNA and GR protein levels in PBMCs were positively correlated with those in the cochlea. The expression of GR mRNA and GR protein was significantly increased in the dexamethasone group compared to the control group.

Conclusions

Levels of GR mRNA and GR protein in the PBMCs were positively correlated with those in the cochlea of guinea pigs. Systemic dexamethasone treatment can significantly up-regulate GR expression in PBMCs and in the cochlea. Measurement of the GR level in PBMCs could be used as an indicator of GR level in the cochlea.

Proinflammatory cytokine IL-1 β polymorphisms in sudden sensorineural hearing loss

The cause and pathogenesis of sudden sensorineural hearing loss (SSNHL) remain unknown. IL-1β is one of the most powerful inflammatory cytokines. The aim of this study was to evaluate the relationships between interleukin-1 β (IL-1β) gene polymorphisms (-511 C/T and +3953 C/T) in patients with SSNHL. One hundred two patients affected by SSNHL and 595 controls were genotyped for IL-1β gene polymorphisms. The polymorphisms were analyzed by polymerase chain reaction amplification and DNA fragment separation via electrophoresis. Compared to controls, the IL-1β (+3953) T allele increased the relative risk of SSNHL in subjects with IL-1β (-511) TT genotype (p = 0.022, OR = 9.111, 95% CI = 1.441-57.618). In this study, polymorphisms in the IL-1β -511 and IL-1β +3953 loci were assessed for evidence of association with SSNHL. From this assessment, a significant difference in carriage of both the IL-1β -511 T allele and the IL-1β +3953 T allele was observed between SSNHL and controls. This suggests that the IL-1β -511 and +3953 loci may play an important role in the etiopathogenesis of SSNHL.

Evaluation of intratympanic dexamethasone for treatment of refractory sudden sensorineural hearing loss

OBJECTIVE

To observe and compare the efficacy of intratympanic application of dexamethasone (DXM) for the treatment of refractory sudden sensorineural hearing loss (SSNHL), the DXM was given in three different ways: by tympanic membrane injection, by drip through a ventilation tube, and by perfusion through a round window catheter.

METHODS

We conducted a nonrandomized retrospective clinical trial involving 55 patients with refractory SSNHL. For 21 patients (the perfusion group), DXM (2.5 mg/0.5 ml) was perfused transtympanically through a round window catheter using an infusion pump for 1 h twice a day for 7 d giving a total amount of 35.0 mg. For 23 patients (the injection group), DXM (2.5 mg/time) was injected by tympanic membrane puncture at intervals of 2 d on a total of four occasions giving a total amount of 10.0 mg. For 11 patients (the drip group), DXM (2.5 mg/0.5 ml) was dripped via a ventilation tube placed by myringotomy, once on the first day and twice a day for the remaining 6 d giving a total amount of 32.5 mg. Thirty-two patients with refractory SSNHL who refused to undertake further treatments were defined as the control group. Hearing recovery and complications were compared among the groups. Hearing results were evaluated based on a four-frequency (0.5, 1.0, 2.0, 4.0 kHz) pure tone average (PTA).

RESULTS

Post-treatment audiograms were obtained one month after treatments were completed. The improvements in average PTA for the perfusion, injection, and drip groups were 9.0, 8.6, and 1.7 dB, respectively. Hearing improvement was significantly greater in the perfusion and injection groups than in the control group (1.4 dB) (P<0.05). In the perfusion group, 8 out of 21 patients (38.1%) had a PTA improvement of 15‒56 dB (mean 29.8 dB); in the injection group, 8 out of 23 patients (34.8%) had a PTA improvement of 16‒54 dB (mean 24.9 dB); in the drip group, 1 of 11 patients (9.1%) had a PTA improvement of 26.0 dB; in the control group, 3 out of 32 patients (9.4%) had a PTA improvement of 15‒36 dB (mean 14.9 dB).

CONCLUSIONS

Topical intratympanic application of DXM is a safe and effective method for the treatment of SSNHL cases that are refractory to conventional therapies.

Combined intratympanic and systemic use of steroids for idiopathic sudden sensorineural hearing loss

OBJECTIVE

To compare hearing results in idiopathic sudden hearing loss patients treated with systemic steroids alone or combined intratympanic and steroids.

STUDY DESIGN

Prospective.

SETTING

Tertiary referral hospital.

PATIENTS

Idiopathic sudden sensorineural hearing loss patients.

INTERVENTIONS

The patients in the systemic therapy group received consecutive administration of 100 mg intravenous methylprednisolone in the first day, 80 mg/day oral prednisolone in 3 divided doses for the next 2 days, and continued with oral administration of steroids by tapering the dose 20 mg in every 2 days. The patients in the combined treatment group received intratympanic injection of methylprednisolone (an approximate dose of 0.5 ml of 125 mg/ml). A total of 5 injections on alternate days were performed.

MAIN OUTCOME MEASURES

The mean and median PTA gains of systemic corticosteroid therapy (SCT) group were 7.5 and 5 dB at 5th day, 12.1 and 7.5 dB at 10th day, and 13.0 and 8.8 dB at 15th day. The mean and median PTA gains for combined treatment (CT) group were 12.5 and 7.5, 17.8 and 13.8, 21.8 and 20.0 dB, respectively.

RESULTS

Both the mean and the median PTA gains were statistically significantly different between SCT and CT groups. According to improved hearing results (more than 10 dB gain), there was statistically significant difference between SCT and CT groups. None of the patients had an important complication.

CONCLUSION

The results of this study suggest that adding intratympanic methylprednisolone to systemic therapy increases the probability of hearing recovery in ISSHL patients.

Intratympanic Steroids for Sudden Sensorineural Hearing Loss

Objective. To determine the evidence for efficacy of intratympanic (IT) steroid treatment for the management of idiopathic sudden sensorineural hearing loss through a systematic review of the existing literature.

Data Sources. Online databases consisting of PubMed, Medline, OVID, Google Scholar, Cochrane Review, and collected additional publications cited in bibliographies.

Review Methods. Literature search by both authors with structured criteria to select studies evaluated for systematic review.

Results. The authors identified 176 articles, of which 32 represented studies of initial or salvage intratympanic steroid injections for sudden hearing loss that included 6 randomized trials and only 2 randomized controlled trials. Despite the paucity of well-executed trials, the vast majority of studies of intratympanic steroids for salvage treatment in all tiers demonstrated a benefit of intratympanic steroid therapy. A limited meta-analysis of the higher quality studies revealed a mean difference in improvement of 13.3 dB (95% confidence interval [CI], 7.7-18.9; P < .0001). Although statistically significant, it is still unclear if this difference is clinically significant. Initial intratympanic therapy was equivalent to standard therapy in the existing literature of all qualities.

Conclusion. Intratympanic steroid treatment as primary treatment for sudden sensorineural hearing loss appears equivalent to treatment with high-dose oral prednisone therapy. As salvage therapy, intratympanic steroids offer the potential for some degree of additional hearing recovery, although it remains uncertain if this improvement is clinically significant and what percentage of patients is likely to show benefit.

Round window membrane in Ménière's disease: a human temporal bone study

OBJECTIVES

To disclose the histopathologic findings of the thickness of the round window membrane and the presence of false round window membrane in Ménière's disease.

METHODS

Twelve temporal bones from 6 patients with bilateral Ménière's disease, 44 temporal bones from 23 patients with unilateral Ménière's disease, and 102 age-matched normal temporal bones from 56 individuals were histopathologically examined. The thickness of the round window membrane was calculated from 3 different places. In addition, the presence of false round window membrane was investigated in temporal bones with Ménière's disease and compared to the normal temporal bones.

RESULTS

A significant difference in the mean thickness of the round window membrane was observed in temporal bones with Ménière's disease compared with normal temporal bones. There was no significant difference in the thickness of the round window membrane between the diseased side and contralateral side in patients with unilateral Ménière's disease. A false round membrane was observed in 9 (25.7%) of 35 Ménière's disease cases and in 5 (4.9%) of 102 normal temporal bones.

CONCLUSION

The thickened nature of the round window membrane and the frequent presence of false round window membrane in patients with Ménière's disease may impede the intratympanic injection treatments. The thickened middle layer of the round window membrane may be related to perilymphatic pressure changes observed in patients with Ménière's disease.

Intratympanic steroid therapy for sudden hearing loss: a review of the literature

OBJECTIVE

Administration of steroids systematically is considered to be the most commonly accepted treatment for idiopathic sudden sensorineural hearing loss (ISSNHL). In recent years there has been increasing scientific interest in treating ISSNHL by means of local steroid delivery. Usually, intratympanic steroids are used in three main protocols, as initial treatment, as adjunctive treatment given concomitantly with systemic steroids and as salvage treatment after failure of standard therapy. The purpose of this review is to examine the published literature regarding the therapeutic value of each method of treatment and to seek answers about the best delivery technique and the optimal administration schedule.

DATA SOURCES

Literature review from 1996 to 2009, PubMed and Medline.

STUDY SELECTION

We searched for trials concerning clinical evaluation of intratympanic steroids in ISSNHL patients, as a salvage treatment, as a first line therapy and in combination with the conventional therapy. Randomized and non-randomized case control studies and case series studies were the types of trials available for review.

DATA EXTRACTION

All the articles described in the study selection were used for this review.

DATA SYNTHESIS

Statistical techniques were not used.

CONCLUSION

On the basis of the available literature, it seems that topical steroids can be a valuable solution for ISSNHL patients who either cannot tolerate systemic steroid therapy or are refractory to it. Concerning the combined therapy, due to the controversial results of the existing studies, it cannot be determined yet whether this treatment protocol could yield superior results as a first line therapy. The need for establishment of standard criteria of hearing recovery should be underlined.

[Consensus on diagnosis and treatment of sudden hearing loss. Asociación Madrileña de ORL]

Idiopathic sudden sensorineural hearing loss is an unexplained unilateral hearing loss with onset over a period of less than 72 hours, without other known otological diseases. We present a consensus on the diagnosis, treatment and follow-up of this disease, designed by AMORL, after a systematic review of the literature from 1966 to June 2010. Diagnosis of sudden sensorineural hearing loss is based on mandatory otoscopy, acoumetry, tonal audiometry, speech audiometry, and tympanometry. After clinical diagnosis is settled, and before treatment is started, a full analysis should be done and an MRI should be requested later. Treatment is based on systemic corticosteroids (orally in most cases), helped by intratympanic doses as rescue after treatment failures. Follow-up should be done at day 7, with tonal and speech audiometries, and regularly at 15, 30, and 90 days after start of therapy, and after 12 months. By consensus, results after treatment should be reported as absolute dBs recovered in pure tonal audiometry, as improvement in the recovery rate in unilateral cases, and as improvement in speech audiometry.

Low dose combination steroids control autoimmune mouse hearing loss

The severe side effects of glucocorticoids prevent long term management of hearing loss. Alternative steroid treatments that minimize or eliminate these effects would significantly benefit therapeutic control of hearing disorders. A steroid treatment study of autoimmune mouse hearing loss was conducted to determine the efficacy of combining aldosterone and prednisolone at low doses. An assessment also was made of low dose fludrocortisone, a synthetic mineralocorticoid that also has a slight glucocorticoid effect. MRL/MpJ-Fas(lpr) mice were tested for baseline ABR thresholds at 3 months of age and then treated with aldosterone (3.0 μg/kg) or prednisolone (1.0 mg/kg) to determine the lowest effective dose of each. Other mice were given the two steroids in combination at doses of Pred 0.5 mg+Aldo 1.5 μg; Pred 1.0 mg+Aldo 3.0 μg; or Pred 1.5 mg+Aldo 5.0 μg. Mice were retested with ABR at 1 and 2 months to determine the efficacy of the different steroid treatments in controlling hearing loss. Another series of mice were given the synthetic mineralocorticoid fludrocortisone at low (2.8 μg/kg) or high (10 μg/kg) doses and retested at monthly intervals for 3 months. Autoimmune mouse hearing loss developed in untreated controls. This threshold elevation was not prevented by prednisolone at 1 mg/kg or by aldosterone at 3 μg/kg when each was given alone. However, the two steroids combined at these doses effectively controlled hearing loss. The fludrocortisone treatments also were effective at low doses in preventing or reversing the autoimmune mouse hearing loss. This efficacy of combined steroids at low doses suggests the potential for reducing the side effects of glucocorticoids in the therapeutic control of hearing disorders.

Hearing evaluation of intratympanic methylprednisolone perfusion for refractory sudden sensorineural hearing loss

OBJECTIVE

To investigate the effectiveness and safety of intratympanic methylprednisolone perfusion (IMP) through a microcatheter in patients with sudden sensorineural hearing loss (SSNHL) who failed a conventional treatment.

STUDY DESIGN

Prospective clinical study.

SETTING

This study was conducted in Nanjing Drum Tower Hospital, Nanjing University Medical School.

SUBJECTS AND METHODS

Patients who had failed a minimum 10-day conventional treatment were included. Twenty-six patients in the study group (SG) received methylprednisolone perfusion through a microcatheter placed into the tympanum once a day for 10 days and the conventional treatment. Twenty-three patients who received a second conventional treatment (no steroid) served as the comparison group (CG). All patients were followed up for three months after the end of treatment.

RESULTS

The effective rates for SG and CG were 50 percent (61.9% when only patients with an interval from onset to IMP < or = 60 days were included) and 21.7 percent, respectively (chi(2) = 4.194, P = 0.041). The pure-tone average improvement was 20.2 +/- 15.6 dB in SG, and 9.2 +/- 13.7 dB in CG (z = 2.51, P = 0.011). In SG, hearing improvement at low frequencies was better than that at high frequencies. The interval from onset to IMP affected the efficacy of IMP.

CONCLUSION

IMP through a microcatheter is a promising treatment for refractory SSNHL. The data suggest that the treatment may be more effective when administered at the earlier stages of SSNHL when the conventional treatment has failed.

Principles of local drug delivery to the inner ear

As more and more substances have been shown in preclinical studies to be capable of preventing damage to the inner ear from exposure to noise, ototoxic drugs, ischemia, infection, inflammation, mechanical trauma and other insults, it is becoming very important to develop feasible and safe methods for the targeted delivery of drugs to specific regions in the inner ear. Recently developed methods for sampling perilymph from the cochlea have overcome major technical problems that have distorted previous pharmacokinetic studies of the ear. These measurements show that drug distribution in perilymph is dominated by passive diffusion, resulting in large gradients along the cochlea when drugs are applied intratympanically. Therefore, in order to direct drugs to specific regions of the ear, a variety of delivery strategies are required. To target drugs to the basal cochlear turn and vestibular system while minimizing exposure of the apical cochlear turns, single one-shot intratympanic applications are effective. To increase the amount of drug reaching the apical cochlear turns, repeated intratympanic injections or controlled-release drug delivery systems, such as biodegradable biopolymers or catheters and pumps, are more effective. However, if the applied substance does not easily pass through the round window membrane, or if a more widespread distribution of drug in the ear is required, then intralabyrinthine injections of the substance may be required. Intralabyrinthine injection procedures, which are currently in development in animals, have not yet been proven safe enough for human use.

Blocking the glucocorticoid receptor with RU-486 does not prevent glucocorticoid control of autoimmune mouse hearing loss

BACKGROUND/AIMS

Glucocorticoids effectively manage autoimmune hearing loss, although the cochlear mechanisms involved are unknown. Previous studies of steroid-responsive hearing loss in autoimmune (lupus) mice showed glucocorticoids and mineralocorticoids were equally effective, suggesting the ion homeostasis functions of glucocorticoids may be as relevant as immunosuppression for control of autoimmune-induced inner ear disease. Therefore, to better characterize the role of the glucocorticoid receptor in autoimmune hearing loss therapy, its function was blocked with the antagonist RU-486 (mifepristone) during glucocorticoid (prednisolone) treatments.

METHODS

Following baseline auditory brainstem response (ABR) thresholds, MRL/MpJ-Fas(lpr) autoimmune mice were implanted with pellets providing combinations of 1.25 mg/kg of RU-486, 4 mg/kg of prednisolone, or their respective placebos. After 1 month, animals were retested with ABR and blood was collected for immune complex analyses.

RESULTS

Mice receiving no prednisolone (placebo + placebo and placebo + RU-486) showed continued declines in hearing. On the other hand, mice receiving prednisolone (prednisolone + placebo and prednisolone + RU-486) had significantly better hearing (p < 0.05) than the non-prednisolone groups. Immune complexes were significantly elevated in the placebo + RU-486 group, suggesting RU-486 effectively blocked glucocorticoid receptor-mediated immune suppression. These results showed that blockage of the glucocorticoid receptor with RU-486 did not prevent prednisolone's effects in the ear, suggesting its ion homeostasis actions via the mineralocorticoid receptor were more relevant in hearing control.

CONCLUSION

The mineralocorticoid receptor-mediated actions of glucocorticoids are potentially relevant in steroid-responsive hearing disorders, implying disrupted cochlear ion transport functions may underlie the vascular problems proposed in some forms of immune-mediated hearing loss.