Intratympanic steroids as a salvage treatment for sudden sensorineural hearing loss? A meta-analysis. Eur Arch Otorhinolaryngol. 2015;272:2777-2782. [PMID: 25217083 DOI: 10.1007/s00405-014-3288-8]

Prognostic factors for profound sudden idiopathic sensorineural hearing loss: a multicenter retrospective study

The aim of this study was to assess the outcomes of various treatment modalities for profound idiopathic sudden sensorineural hearing loss (ISSNHL) and confirm the prognostic factors. In total, 191 patients were enrolled after a thorough medical chart review of patients diagnosed with unilateral, profound ISSNHL (≥90 dB). Epidemiological profiles, therapeutic regimens, and the results of pure tone audiometry tests were recorded for all patients. Final recovery was assessed according to Siegel's criteria and by comparing the final hearing level of the affected ear with that of the unaffected ear. The mean follow-up duration and the final hearing level were 75 ± 54 days and 77 ± 24 dB, respectively. None of the evaluated prognostic factors were significantly associated with complete recovery (<25 dB). However, improved hearing in both ears, the absence of dizziness, the use of lipo-prostaglandin E1 (lipo-PGE1), and the use of plasma volume expanders were independently associated with a final hearing level of up to 45 dB (p < 0.05). Steroid dose reduction, worse initial hearing, and non-use of lipo-PGE1 increased the possibility of no recovery. Although the efficacy of oral steroid treatment for profound ISSNHL has been questioned, steroid dose reduction was significantly associated with no recovery. Therefore, adequate oral corticosteroid doses should be considered in the absence of contraindications. In addition, the use of lipo-PGE1 and/or a plasma volume expander seems preferable for better recovery, and their use for the management of profound ISSNHL should be considered.

A comparison of effects of systemic and intratympanic steroid therapies for sudden sensorineural hearing loss: A meta-analysis

Objective

To evaluate the efficacy and safety of intratympanic and systemic steroid therapies in the initial treatment of Sudden Sensorineural Hearing Loss (SSNHL) patients.

Methods

A comprehensive search of PubMed, Wanfang database and CNKI (China National Knowledge Infrastructure) was performed covering the period from January 1990 to July 2014. A meta-analysis was conducted after filtering by the criteria of Cochrane Collaboration. Three hundred fifty six subjects in nine studies allocated to the group of intratympanic steroid therapies and 343 controls receiving systemic steroid therapies met the criteria for meta-analysis. The data were extracted and analyzed using the RevMan 5.3 meta-analysis software.

Results

The total effectiveness rate in SSNHL patients receiving intratympanic steroid therapies did not differ statistically from patients receiving systemic therapies (RR = 1.08, 95％CI = 0.99–1.99, P = 0.10), although the rate of full hearing recovery in this group differed significantly from patients receiving systemic therapies (RR = 1.29, 95％CI = 1.00–1.66, P = 0.05).

Conclusion

Local steroid therapy appears to generate higher rate of complete hearing recovery than systemic steroid treatment as an initial treatment for SSNHL, which may be especially useful for patients in whom systemic steroids are contraindicated.

Inner ear delivery of dexamethasone using injectable silk-polyethylene glycol (PEG) hydrogel

Minimally invasive delivery and sustained release of therapeutics to the inner ear are of importance to the medical treatment of inner ear disease. In this study, the injectable silk fibroin-polyethylene glycol (Silk-PEG) hydrogel was investigated as a drug delivery carrier to deliver poorly soluble micronized dexamethasone (mDEX) to the inner ear of guinea pigs. Encapsulation of mDEX with a loading up to 5% (w/v) did not significantly change the silk gelation time, and mDEX were evenly distributed in the PEG-Silk hydrogel as visualized by SEM. The loading of mDEX in Silk-PEG hydrogel largely influenced in vitro drug release kinetics. The optimized Silk-PEG-mDEX hydrogel (2.5% w/v loading, in situ-forming, 10 μl) was administered directly onto the round window membrane of guinea pigs. The DEX concentration in perilymph maintained above 100 ng/ml for at least 10 days for the Silk-PEG formulation while less than 12h for the control sample of free mDEX. Minimal systemic exposure was achieved with low DEX concentrations (<0.2 μg/ml) in cerebrospinal fluid (CSF) and plasma in the first 2h after the local application of the Silk-PEG-mDEX hydrogel. A transient hearing threshold shift was found but then resolved after 14 days as revealed by auditory brainstem response (ABR), showing minimal inflammatory responses on the round window membrane and scala taympani. The Silk-PEG hydrogel completely degraded in 21 days. Thus, the injectable PEG-Silk hydrogel is an effective and safe vehicle for inner ear delivery and sustained release of glucocorticoid.

Potential Benefits of Combination Therapy as Primary Treatment for Sudden Sensorineural Hearing Loss

Objective

We analyzed the effectiveness of combination therapy (CT) for idiopathic sudden sensorineural hearing loss (ISSNHL) and the utility of intratympanic dexamethasone injection (ITDI) reapplication as salvage treatment for ISSNHL refractory to CT.

Study Design

Case series with chart review.

Setting

Academic university hospital.

Subjects and Methods

We reviewed 229 patients with ISSNHL and divided these patients into 2 groups according to treatment: systemic steroid therapy (SST) and CT groups. The SST group received prednisolone therapy. The CT group also received ITDI daily. Patients who demonstrated no recovery (<10 dB) after initial treatment were defined as refractory and received salvage ITDI therapy: ITDI reapplication in the CT group and ITDI application in the SST group.

Results

Hearing recovery rates were 77.8% (77/99) in the CT group and 60.8% (79/130) in the SST group. The difference was statistically significant ( P = .011). Initial pure-tone audiometry and vertigo were affective factors on hearing recovery rates in the CT group. After salvage therapy, hearing improvement of 10 dB or greater was noted in 6 of the 22 (27.3%) patients in the CT group and 16 of the 51 (31.4%) patients in the SST group. The difference in efficacy of salvage therapy between the CT and SST groups was simply not significant ( P = .612).

Conclusions

Combination therapy was more effective for ISSNHL in achieving hearing gain than SST alone. Furthermore, ITDI reapplication for ISSNHL refractory to CT was as effective as salvage ITDI for ISSNHL refractory to SST.

Acquired Hearing Loss in Children

Hearing loss is the most common congenital sensory impairment. According to National Health and Nutrition Examination Survey data from 2001 to 2008, 20.3% of subjects aged greater than or equal to 12 had unilateral or bilateral hearing loss. The World Health Organization notes that, worldwide, there are 360 million people with disabling hearing loss, with 50% preventable. Although many hearing losses are acquired, many others are manifestations of preexisting conditions. The purpose of a pediatric hearing evaluation is to identify the degree and type of hearing loss and etiology and to outline a comprehensive strategy that supports language and social development and communication.

Nanoparticle mediated drug delivery of rolipram to tyrosine kinase B positive cells in the inner ear with targeting peptides and agonistic antibodies

Aim: Systemic pharmacotherapies have limitation due to blood-labyrinth barrier, so local delivery via the round window membrane opens a path for effective treatment. Multifunctional nanoparticle (NP)-mediated cell specific drug delivery may enhance efficacy and reduce side effects. Different NPs with ligands to target TrkB receptor were tested. Distribution, uptake mechanisms, trafficking, and bioefficacy of drug release of rolipram loaded NPs were evaluated.

Methods: We tested lipid based nanocapsules (LNCs), Quantum Dot, silica NPs with surface modification by peptides mimicking TrkB or TrkB activating antibodies. Bioefficacy of drug release was tested with rolipram loaded LNCs to prevent cisplatin-induced apoptosis. We established different cell culture models with SH-SY-5Y and inner ear derived cell lines and used neonatal and adult mouse explants. Uptake and trafficking was evaluated with FACS and confocal as well as transmission electron microscopy.

Results: Plain NPs show some selectivity in uptake related to the in vitro system properties, carrier material, and NP size. Some peptide ligands provide enhanced targeted uptake to neuronal cells but failed to show this in cell cultures. Agonistic antibodies linked to silica NPs showed TrkB activation and enhanced binding to inner ear derived cells. Rolipram loaded LNCs proved as effective carriers to prevent cisplatin-induced apoptosis.

Discussion: Most NPs with targeting ligands showed limited effects to enhance uptake. NP aggregation and unspecific binding may change uptake mechanisms and impair endocytosis by an overload of NPs. This may affect survival signaling. NPs with antibodies activate survival signaling and show effective binding to TrkB positive cells but needs further optimization for specific internalization. Bioefficiacy of rolipram release confirms LNCs as encouraging vectors for drug delivery of lipophilic agents to the inner ear with ideal release characteristics independent of endocytosis.