Reduce Hearing Loss Research Articles

Randomized placebo-controlled clinical trial investigating the effect of antioxidants and a vasodilator on overall safety and residual hearing preservation in cochlear implant patients

BackgroundThe standard therapy for patients suffering from sensorineural hearing loss is cochlear implantation. The insertion of the electrode array into the cochlea, with potential mechanical trauma and the presence of this foreign body inside the cochlea, may lead to free radical formation and reduced blood perfusion of the cochlea which can result in a loss of residual hearing. Studies have suggested that a particular combination of the antioxidants vitamins A, C and E as well as the vasodilator magnesium (together: ACEMg) may protect the residual hearing.MethodsThe potential protective effect of ACEMg on residual hearing preservation in cochlear implant (CI) patients was investigated in a single-centre, randomized, placebo-controlled, double-blind phase II clinical trial. CI candidates with some residual hearing in low frequencies receiving MED-EL implants of different FLEX electrode array lengths were treated with ACEMg tablets or placebo respectively 2 days preoperatively and up to 3 months postoperatively. The study objective was to demonstrate that ACEMg is more efficacious than placebo in preserving residual hearing during cochlear implantation by comparing the hearing loss (change in hearing thresholds at 500 Hz from baseline) 3 months after the first fitting between the two treatment groups and to investigate the treatments’ safety.ResultsFifty-one patients were included in the study, which had to be terminated before the recruitment goal was reached because of IMP-resupply mismanagement of one partner. In the intention-to-treat population, 25 patients were treated with ACEMg and 24 patients with placebo. The mean hearing loss at 500 Hz was (± 15.84) 30.21 dB (placebo) or (± 17.56) 26.00 dB (ACEMg) 3 months after the initial fitting. Adjusting the postoperative hearing loss for the baseline residual hearing, planned electrode length and surgeon results in 8.01 dB reduced hearing loss in ACEMg-treated patients compared to placebo-treated ones. The safety analysis revealed that ACEMg was generally well-tolerated with adverse event frequencies below the placebo level.ConclusionThis is the first clinical trial investigating a drug effect on residual hearing in CI patients. These first-in-man data may suggest that a perioperative oral administration of ACEMg is safe and may provide protection of residual hearing in CI patients.Trial registrationEU Clinical Trial Register No. 2012-005002-22. Registered on 6 December 2013. Funding: European Commission FP7-HEALTH-2012-INNOVATION-2.

Assessment of Hearing Loss in Patients Receiving Chemoradiotherapy in Adjuvant Setting for Head and Neck Malignancy

Abstract Introduction The aim of the study is to assess the hearing loss in patients who receive chemoradiation (chemoradiotherapy or CTRT) for head and neck malignancies. Materials and Methods Prospective study was conducted in the Department of ENT of a tertiary care center from September 2013 to August 2014. Forty patients suffering from head and neck malignancies (histologically proven) were included in the study. Patients with pre-existing hearing loss were excluded. All patients received radiotherapy dose of 66 to 70 Gy given as 2 Gy/d, 5 d/wk and chemotherapy dose of cisplatin 35 mg/m2 once a week for 6 weeks. Hearing was assessed by pure tone audiometry (PTA) and impedance audiometry conducted at regular intervals. Mcnemars chi-square test was used to compare the impedance and paired t-test and Pearson’s correlation were used to compare PTA at various stages. Results Predominantly male patients (28) falling in the age group of 40 to 60 years, suffered from various head and neck cancer, most common being oropharynx (14). Twenty patients developed sensorineural hearing loss (SNHL)—11(55%) had mild, seven (35%) had moderate, and two (10%) had severe grade of SNHL. Majority of these patients, 12 (60%) started developing SNHL mid-therapy, five (25%) at the completion of therapy and three (15%) 3 months post-therapy. Hearing loss was found to be more with two-dimensional radiotherapy (2DRT) and three-dimensional radiotherapy (3DRT) than with intensity-modulated radiotherapy (IMRT) as assessed by serial PTA. The average dose of radiation to right and left ears, respectively were 27.10 and 24.66 Gy. The incidence of otitis media with effusion increased during the treatment accounting for the conductive hearing loss irrespective of the modality of radiation used. Conclusion CTRT causes significant hearing loss in patients suffering from head and neck malignancies leading to further increase in the morbidity. Screening audiological assessment would be helpful to know the pretherapy status of the ear. Using newer modalities like IMRT can reduce hearing loss. Regular audiological screening can catch it at its onset and help in early use of hearing aids.

Cochrane method for systematic review and meta-analysis of interventions to prevent occupational noise-induced hearing loss - abridged.

Assess the effect of non-pharmaceutical interventions at work on noise exposure or occupational hearing loss compared to no or alternative interventions. Pubmed, Embase, Web of Science, OSHupdate, Cochrane Central and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched. Randomized Controlled Trials (RCT), Controlled Before-After studies (CBA) and Interrupted Time-Series studies (ITS) evaluating engineering controls, administrative controls, personal hearing protection devices, and hearing surveillance were included. Case studies of engineering controls were collected. Cochrane methods for systematic reviews, including meta-analysis, were followed. 29 studies were included. Stricter legislation can reduce noise levels by 4.5 dB(A) (very low-quality evidence). Engineering controls can immediately reduce noise (107 cases). Eleven RCTs and CBA studies (3725 participants) were evaluated through Hearing Protection Devices (HPDs). Training of earplug insertion reduces noise exposure at short term follow-up (moderate quality evidence). Earmuffs might perform better than earplugs in high noise levels but worse in low noise levels (very low-quality evidence). HPDs might reduce hearing loss at very long-term follow-up (very low-quality evidence). Seventeen studies (84028 participants) evaluated hearing loss prevention programs. Better use of HPDs might reduce hearing loss but other components not (very low-quality evidence). Hearing loss prevention and interventions modestly reduce noise exposure and hearing loss. Better quality studies and better implementation of noise control measures and HPDs is needed.

The Apolipoprotein Allele and Sensorineural Hearing Loss in Older Community-Dwelling Adults in Australia.

Previous research has investigated whether the apolipoprotein E (APOE) ε4 allele, which is associated with an increased risk of cognitive decline, is also associated with hearing loss in older people. Results of the very limited research to date are conflicting, and sample sizes for all but one study were small. The present study aimed to investigate whether there is an association between the APOE ε4 allele and hearing loss in a large, population-based sample of community-dwelling older adults. Cross-sectional audiometric data on hearing levels and APOE genotypes for 2006 participants (aged 55 to 85 years) of the Hunter Community Study were analyzed using multiple linear regression to examine the association between APOE ε4 carrier status and the 4-frequency pure-tone average (0.5 to 4 kHz) in the better hearing ear, and also across individual frequencies in the better ear. Observed and expected APOE allele frequency distributions did not differ significantly overall from established general population allele frequency distributions. Unadjusted modeling using better ear pure-tone average showed a statistically significant association between APOE ε4 allele status (0, 1, 2 copies) and reduced hearing loss, but when the model was adjusted for age, this was no longer statistically significant. Across individual hearing frequencies, unadjusted regression modeling showed APOE ε4 status was significantly associated with a reduction in mean hearing thresholds at 1 and 2 kHz, but again this effect was no longer statistically significant after adjusting for age. The results of this study did not provide any evidence of a statistically significant association between APOE ε4 allele status and hearing loss for older adults. Further investigation of the effect of homozygous carrier status on hearing thresholds is required.

A Path Analysis: Study of Correlation Between Noise Intensity and Quality of Life of Workers In Textile Industry

Noise intensity is a dangerous stressor in the working environment of the textile industry that can have an impact on the decrease in hearing loss of workers. The decrease in hearing loss will disrupt the workers’ activities in their daily work. Textile industry workers exposed to noise while working every day will potentially be affected by a decrease in hearing loss. Activities that are constantly exposed to noise intensity can also result in a decrease in the quality of workers’ life. This research was conducted to prove the correlation between noise intensity and quality of life through hearing loss using path analysis. Path analysis can explain the correlation between variables indirectly. The research method was used namely analytic survey with the cross-sectional design. The population of the study was workers in 5 textile industries in Central Java Province, Indonesia. The number of subjects was determined based on purposive sampling, each industry was 40 people thus, and the total number was 200 people. The correlation was included independent variables namely noise intensity, work period and age; the mediator variable was a loss of hearing loss, and the dependent variable was quality of life. Path analysis was used as the statistical analysis with Stata 13 software at a significance level of 5%. The research results showed that there was a direct correlation between hearing loss and decreased the quality of life of workers (p = 0.026). The decrease in the quality of workers’ life was also influenced indirectly by noise intensity (p = 0.000) and age (0.012). The working period did not affect the decrease in quality of life (p = 0.210). Increased noise intensity can reduce hearing loss that decreases the quality of life.

NEW HEARING LOSS PROBLEM SOLUTIONS OF FLIGHT CREWS MEMBERS IN CIVIL AVIATION

The flight crews members of Civil Aviation aircraft were object of study. The article discusses issues affecting the official indicators of occupational hearing loss among flight crews members of Russian Civil Aviation aircraft. We presented the main expert and diagnostic errors in addressing the correlation between the hearing organ diseases and the profession, showed new solutions to reduce hearing loss indicators, which consist in improving the methodology for assessing the acoustic load and improving the medical staff skills in the development of hearing impairment in persons of flight professions of Civil Aviation.

Tunnel driving occupational environment and hearing loss in train drivers in China

ObjectiveHearing loss caused by high levels of noise is a potential occupational health disorder among train drivers around the world. This study aims to investigate the relationship between tunnel driving...

Results of a multicentre randomised controlled trial of cochlear-sparing intensity-modulated radiotherapy versus conventional radiotherapy in patients with parotid cancer (COSTAR; CRUK/08/004)

PurposeAbout 40–60% of patients treated with post-operative radiotherapy for parotid cancer experience ipsilateral sensorineural hearing loss. Intensity-modulated radiotherapy (IMRT) can reduce radiation dose to the cochlea. COSTAR, a phase III trial, investigated the role of cochlear-sparing IMRT (CS-IMRT) in reducing hearing loss. MethodsPatients (pT1-4 N0-3 M0) were randomly assigned (1:1) to 3-dimensional conformal radiotherapy (3DCRT) or CS-IMRT by minimisation, balancing for centre and radiation dose of 60Gy or 65Gy in 30 daily fractions. The primary end-point was proportion of patients with sensorineural hearing loss in the ipsilateral cochlea of ≥10 dB bone conduction at 4000 Hz 12 months after radiotherapy compared using Fisher's exact test. Secondary end-points included hearing loss at 6 and 24 months, balance assessment, acute and late toxicity, patient-reported quality of life, time to recurrence and survival. ResultsFrom Aug 2008 to Feb 2013, 110 patients (54 3DCRT; 56 CS-IMRT) were enrolled from 22 UK centres. Median doses to the ipsilateral cochlea were 3DCRT: 56.2Gy and CS-IMRT: 35.7Gy (p < 0.0001). 67/110 (61%) patients were evaluable for the primary end-point; main reasons for non-evaluability were non-attendance at follow-up or incomplete audiology assessment. At 12 months, 14/36 (39%) 3DCRT and 11/31 (36%) CS-IMRT patients had ≥10 dB loss (p = 0.81). No statistically significant differences were observed in hearing loss at 6 or 24 months or in other secondary end-points including patient-reported hearing outcomes. ConclusionCS-IMRT reduced the radiation dose below the accepted tolerance of the cochlea, but this did not lead to a reduction in the proportion of patients with clinically relevant hearing loss.

New Drug Linked With Reduced Hearing Loss in Kids Post Chemo

New Drug Linked With Reduced Hearing Loss in Kids Post Chemo

Combined effect of non-bacteriolytic antibiotic and inhibition of matrix metalloproteinases prevents brain injury and preserves learning, memory and hearing function in experimental paediatric pneumococcal meningitis

BackgroundPneumococcal meningitis is associated with high mortality and morbidity rates. Up to 50% of survivors show neurologic sequelae including hearing loss, cognitive impairments and learning disabilities, being particularly detrimental in affected infants and children where adjuvant therapy with dexamethasone has no proven beneficial effect. We evaluated the effect of concomitantly targeting specific pathophysiological mechanisms responsible for brain damage—i.e. matrix-metalloproteinase (MMP) activity and the exacerbated cerebral inflammation provoked through antibiotic-induced bacterial lysis. Here, we combined adjunctive therapies previously shown to be neuroprotective when used as single adjuvant therapies.MethodsEleven-day-old Wistar rats were infected intracisternally with 6.44 ± 2.17 × 103 CFU Streptococcus pneumoniae and randomised for treatment with ceftriaxone combined with (a) single adjuvant therapy with daptomycin (n = 24), (b) single adjuvant therapy with Trocade (n = 24), (c) combined adjuvant therapy (n = 66) consisting of daptomycin and Trocade, or (d) ceftriaxone monotherapy (n = 42). Clinical parameters and inflammatory CSF cytokine levels were determined during acute meningitis. Cortical damage and hippocampal apoptosis were assessed 42 h after infection. Morris water maze and auditory brainstem responses were used to assess neurofunctional outcome 3 weeks after infection.ResultsWe found significantly reduced apoptosis in the hippocampal subgranular zone in infant rats receiving adjuvant Trocade (p < 0.01) or combined adjuvant therapy (p < 0.001). Cortical necrosis was significantly reduced in rats treated with adjuvant daptomycin (p < 0.05) or combined adjuvant therapy (p < 0.05) compared to ceftriaxone monotherapy. Six hours after treatment initiation, CSF cytokine levels were significantly reduced for TNF-α (p < 0.01), IL-1β (p < 0.01), IL-6 (p < 0.001) and IL-10 (p < 0.01) in animals receiving combined adjuvant intervention compared to ceftriaxone monotherapy. Importantly, combined adjuvant therapy significantly improved learning and memory performance in infected animals and reduced hearing loss (77.14 dB vs 60.92 dB, p < 0.05) by preserving low frequency hearing capacity, compared to ceftriaxone monotherapy.ConclusionCombined adjuvant therapy with the non-bacteriolytic antibiotic daptomycin and the MMP inhibitor Trocade integrates the neuroprotective effects of both single adjuvants in experimental paediatric pneumococcal meningitis by reducing neuroinflammation and brain damage, thereby improving neurofunctional outcome. This strategy represents a promising therapeutic option to improve the outcome of paediatric patients suffering from pneumococcal meningitis.

Osmotic stabilization prevents cochlear synaptopathy after blast trauma

Traumatic noise causes hearing loss by damaging sensory hair cells and their auditory synapses. There are no treatments. Here, we investigated mice exposed to a blast wave approximating a roadside bomb. In vivo cochlear imaging revealed an increase in the volume of endolymph, the fluid within scala media, termed endolymphatic hydrops. Endolymphatic hydrops, hair cell loss, and cochlear synaptopathy were initiated by trauma to the mechanosensitive hair cell stereocilia and were K+-dependent. Increasing the osmolality of the adjacent perilymph treated endolymphatic hydrops and prevented synaptopathy, but did not prevent hair cell loss. Conversely, inducing endolymphatic hydrops in control mice by lowering perilymph osmolality caused cochlear synaptopathy that was glutamate-dependent, but did not cause hair cell loss. Thus, endolymphatic hydrops is a surrogate marker for synaptic bouton swelling after hair cells release excitotoxic levels of glutamate. Because osmotic stabilization prevents neural damage, it is a potential treatment to reduce hearing loss after noise exposure.

Hearing Loss and Circulating Markers of Endothelial Dysfunction

Hearing loss is highly prevalent in older people, affecting around 25 percent of American adults aged 65 to 74 and 50 percent of those aged 75 and older (NIH, 2016). The number of people affected by this disability continues to rise, as does the associated cost that affects individuals in terms of their quality of life and society. Several co-morbidities often accompany age-related hearing loss, including endothelial dysfunction and increased cardiovascular risk, and there is evidence of significantly higher rates of cardiovascular disease among people with hearing loss (Circulation. 2016;134:A19010). Hearing loss has significantly negative effects on quality of life, mental health, and physical function. Therefore, finding potentially modifiable risk factors and markers for hearing loss should be a public health priority. Our world-first study investigated the association between hearing loss and circulating markers for endothelial dysfunction that are potentially modifiable through lifestyle and drug interventions (Otol Neurotol. 2018 Apr;39(4):e280).

Serum Methylarginines and Hearing Loss in a Population-based Cohort of Older Adults.

Age-related hearing loss is associated with endothelial dysfunction and increased cardiovascular risk, suggesting a vascular etiology. Methylarginines are endogenous nitric oxide synthase inhibitors that cause endothelial dysfunction and increase cardiovascular disease risk. This study is the first to examine the hypothesis that higher serum concentrations of methylarginines are associated with greater hearing loss prevalence. Cross-sectional audiometric data on hearing levels, and serum methylarginines were collected from a population-based sample of 630 older community-dwelling adults. Linear regression analysis showed a statistically significant association between higher serum concentrations of asymmetric dimethylarginine (ADMA) and L-arginine and greater degrees of hearing loss for males, particularly over 75 years. Higher body mass index and previous history of stroke were also associated with hearing loss. For females, ADMA concentration was not associated with hearing loss, but higher serum L-arginine concentrations were associated with reduced hearing loss prevalence in older females. Antihypertensive medication use was also associated with reduced hearing loss prevalence. LDL cholesterol and previous myocardial infarction were associated with greater hearing loss. This study showed a significant association between serum concentrations of ADMA and hearing loss for males, consistent with the association between endothelial dysfunction and hearing loss. The opposite effect of L-arginine on hearing loss in males versus females might reflect a different role of this precursor toward nitric oxide versus methylated arginines synthesis. These findings are potentially clinically significant if the association between ADMA and hearing loss is causal, as serum methylarginine levels are modifiable through pharmacotherapeutic/lifestyle interventions.

Intraoperative force and electrocochleography measurements in an animal model of cochlear implantation

To preserve residual hearing, techniques for monitoring and reducing the effects of trauma during cochlear implant surgery are being developed. This study examines the relationships between intraoperative recordings (electrode insertion force and electrocochleography), trauma, and hearing loss after cochlear implantation. The study also evaluated the efficacy of intravenous steroids for reducing hearing loss after implantation. Thirty-two normal-hearing guinea pigs were randomly implanted with electrode arrays of differing stiffness (‘hard’ or ‘soft’). These arrays used an intracochlear electrode to record electrode insertion force and electrocochleography responses to a multi-frequency acoustic stimulus during implantation. Additionally, sub-cohorts of animals were administered intravenous saline (‘control’) or dexamethasone (‘steroid’) prior to surgery. Subsequent hearing loss was assessed using electrocochleography recordings from the round window membrane prior to surgery and 4 weeks after implantation. After 4 weeks, cochleae were harvested and imaged with thin sheet laser imaging microscopy. After 4 weeks, compound action potential (CAP) thresholds did not differ between steroid and control groups. The CAP amplitude at low-mid frequencies decreased after implantation with a hard electrode, an effect which was partly negated by administering steroids. A decrease in the ‘intraoperative’ CAP amplitude preceded the reporting of insertion resistance by the surgeon by 5.94 s (±4.03 s SEM). Intraoperative CAP declines were also correlated with higher grades of trauma (r = 0.56, p < 0.01) and greater hearing loss (r = 0.56, p < 0.01). This relationship was not repeated with intraoperative cochlear microphonics. A rise in intraoperative force, which preceded the reporting of resistance by 0.71 s (±0.15 s SEM), was correlated with trauma (r = 0.400, p = 0.04) but not hearing loss (r = 0.297, p = 0.27). Preserving intraoperative CAP amplitudes during implantation was predictive of an atraumatic insertion and reduced post-implantation hearing loss. A rise in force usually preceded the reporting of resistance, although by less than 1 s. These results suggest that intraoperative CAPs may offer a more robust feedback mechanism for improving hearing preservation rates than cochlear microphonic and electrode insertion force recordings, especially considering the rapid changes in insertion force and relatively slow human reaction times. Pre-operative steroids were effective in reversing loss of CAP amplitude with hard electrodes and evoked by lower frequency tones, which suggests a possible role in reducing synaptopathy.

Magnetic Nanoparticle Mediated Steroid Delivery Mitigates Cisplatin Induced Hearing Loss.

Cisplatin (cis-diamminedichloroplatinum) is widely used as a chemotherapeutic drug for genitourinary, breast, lung and head and neck cancers. Though effective in inducing apoptosis in cancer cells, cisplatin treatment causes severe hearing loss among patients. Steroids have been shown to mitigate cisplatin-induced hearing loss. However, steroids may interfere with the anti-cancer properties of cisplatin if administered systemically, or are rapidly cleared from the middle and inner ear and hence lack effectiveness when administered intra-tympanically. In this work, we deliver prednisolone-loaded nanoparticles magnetically to the cochlea of cisplatin-treated mice. This magnetic delivery method substantially reduced hearing loss in treated animals at high frequency compared to control animals or animals that received intra-tympanic methylprednisolone. The method also protected the outer hair cells from cisplatin-mediated ototoxicity.

Non-autonomous Cellular Responses to Ototoxic Drug-Induced Stress and Death.

The first major recognition of drug-induced hearing loss can be traced back more than seven decades to the development of streptomycin as an antimicrobial agent. Since then at least 130 therapeutic drugs have been recognized as having ototoxic side-effects. Two important classes of ototoxic drugs are the aminoglycoside antibiotics and the platinum-based antineoplastic agents. These drugs save the lives of millions of people worldwide, but they also cause irreparable hearing loss. In the inner ear, sensory hair cells (HCs) and spiral ganglion neurons (SGNs) are important cellular targets of these drugs, and most mechanistic studies have focused on the cell-autonomous responses of these cell types in response to ototoxic stress. Despite several decades of studies on ototoxicity, important unanswered questions remain, including the cellular and molecular mechanisms that determine whether HCs and SGNs will live or die when confronted with ototoxic challenge. Emerging evidence indicates that other cell types in the inner ear can act as mediators of survival or death of sensory cells and SGNs. For example, glia-like supporting cells (SCs) can promote survival of both HCs and SGNs. Alternatively, SCs can act to promote HC death and inhibit neural fiber expansion. Similarly, tissue resident macrophages activate either pro-survival or pro-death signaling that can influence HC survival after exposure to ototoxic agents. Together these data indicate that autonomous responses that occur within a stressed HC or SGN are not the only (and possibly not the primary) determinants of whether the stressed cell ultimately lives or dies. Instead non-cell-autonomous responses are emerging as significant determinants of HC and SGN survival vs. death in the face of ototoxic stress. The goal of this review is to summarize the current evidence on non-cell-autonomous responses to ototoxic stress and to discuss ways in which this knowledge may advance the development of therapies to reduce hearing loss caused by these drugs.

Cost-effectiveness of Universal and Targeted Newborn Screening for Congenital Cytomegalovirus Infection

Congenital cytomegalovirus (cCMV) infection is a major cause of childhood deafness. Most cCMV infections are not diagnosed without newborn screening, resulting in missed opportunities for directed care. To estimate the cost-effectiveness of universal and targeted newborn cCMV screening programs compared with no cCMV screening. Models were constructed using rates and outcomes from prospective cohort studies of newborn cCMV screening in US postpartum care and early hearing programs. Costs of laboratory testing, treatment, and hearing loss were drawn from Medicaid data and published estimates. The benefits of cCMV screening were assumed to come from antiviral therapy for affected newborns to reduce hearing loss and from earlier identification of hearing loss with postnatal onset. Analyses were performed from July 2014 to March 2016. Models compared universal or targeted cCMV screening of newborns with a failed hearing screen, with standard care for cCMV infection. The incremental costs of identifying 1 cCMV infection, identifying 1 case of cCMV-related hearing loss, and preventing 1 cochlear implant; the incremental reduction in cases of severe to profound hearing loss; and the differences in costs per infant screened by universal or targeted strategies under different assumptions about the effectiveness of antiviral treatment. Among all infants born in the United States, identification of 1 case of cCMV infection by universal screening was estimated to cost $2000 to $10 000; by targeted screening, $566 to $2832. The cost of identifying 1 case of hearing loss due to cCMV was as little as $27 460 by universal screening or $975 by targeted screening. Assuming a modest benefit of antiviral treatment, screening programs were estimated to reduce severe to profound hearing loss by 4.2% to 13% and result in direct costs of $10.86 per newborn screened. However, savings of up to $37.97 per newborn screened were estimated when costs related to functionality were included. Newborn screening for cCMV infection appears to be cost-effective under a wide range of assumptions. Universal screening offers larger net savings and the greatest opportunity to provide directed care. Targeted screening also appears to be cost-effective and requires testing for fewer newborns. These findings suggest that implementation of newborn cCMV screening programs is warranted.

The role of adjunctive dexamethasone in the treatment of bacterial meningitis: an updated systematic meta-analysis.

BackgroundBacterial meningitis is a serious infection in children and adults worldwide, with considerable morbidity, mortality, and severe neurological sequelae. Dexamethasone is often used before antibiotics in cases of this disease, and improves outcomes.ObjectiveAlthough several studies have identified the role of adjunctive dexamethasone therapy in the treatment of bacterial meningitis, the results are still inconclusive. The aim of this study was to systematically evaluate the therapeutic and adverse effect of adjunctive dexa-methasone in patients with bacterial meningitis.Materials and methodsRelevant randomized, double-blind, placebo-controlled trials of dexamethasone in bacterial meningitis published between 2000 and 2016 were retrieved from the common electronic databases. The odds ratio (OR) and risk ratio (RR) with their 95% confidence interval (CI) were employed to calculate the effect.ResultsA total of ten articles including 2,459 bacterial meningitis patients (1,245 in the dex-amethasone group and 1,214 in the placebo group) were included in this meta-analysis. Our result found that dexamethasone was not associated with a significant reduction in follow-up mortality (292 of 1,245 on dexamethasone versus 314 of 1,214 on placebo; OR =0.91, 95% CI =0.80–1.03, P=0.14) and severe neurological sequelae (22.4% versus 24.1%, OR =0.84, 95% CI =0.54–1.29, P=0.42). However, dexamethasone seemed to reduce hearing loss among survivors (21.2% versus 26.1%; OR =0.76, 95% CI =0.59–0.98, P=0.03). No significant difference was found between these two groups in adverse events.ConclusionOur results suggested that adjunctive dexamethasone might not be beneficial in the treatment of bacterial meningitis. Future studies with more data are needed to further prove the role of dexamethasone in bacterial meningitis.

Cochlear implant and inflammation reaction: Safety study of a new steroid-eluting electrode

Dexamethasone is a common anti-inflammatory agent added to cochlear implants to reduce hearing loss due to electrode insertion trauma. We evaluated the safety of eluting silicone rods containing 10% dexamethasone in a Guinea pig model. Animals were implanted with a dexamethasone eluting silicone electrode (DER) or with a non-eluting electrode (NER). The control group only underwent a cochleostomy (CS). Prior to implantation and during the two weeks following implantation, the hearing status of the animals was assessed by means of Compound Action Potentials (CAPs) with an electrode placed near the round window. Two weeks after implantation, the mean click threshold shifts were 1 dB ± 10 dB in the DER group, 10 dB ± 10 dB in the NER group and -4 dB ± 10 dB in the control group. After two weeks the bullae of each animal were extracted to verify the presence of macrophages, the percent of tissue growth in the scala tympani and the tissue sealing around cochleostomy. Silicone electrodes samples were also explanted and examined for bacterial infection. Neither bacterial infection nor enhanced number of macrophages were observed. A limited, but not significant, tissue growth was found in the scala tympani between the experimental and the control group. The data suggest that, in the Guinea pig model, the use of DER is apparently safe as an anti-inflammatory slow-release additive to the cochlear implant.

ACEMg Diet Supplement Modifies Progression of Hereditary Deafness.

Dietary supplements consisting of beta-carotene (precursor to vitamin A), vitamins C and E and the mineral magnesium (ACEMg) can be beneficial for reducing hearing loss due to aminoglycosides and overstimulation. This regimen also slowed progression of deafness for a boy with GJB2 (CONNEXIN 26) mutations. To assess the potential for treating GJB2 and other forms of hereditary hearing loss with ACEMg, we tested the influence of ACEMg on the cochlea and hearing of mouse models for two human mutations: GJB2, the leading cause of childhood deafness, and DIAPH3, a cause of auditory neuropathy. One group of mice modeling GJB2 (Gjb2-CKO) received ACEMg diet starting shortly after they were weaned (4 weeks) until 16 weeks of age. Another group of Gjb2-CKO mice received ACEMg in utero and after weaning. The ACEMg diet was given to mice modeling DIAPH3 (Diap3-Tg) after weaning (4 weeks) until 12 weeks of age. Control groups received food pellets without the ACEMg supplement. Hearing thresholds measured by auditory brainstem response were significantly better for Gjb2-CKO mice fed ACEMg than for the control diet group. In contrast, Diap3-Tg mice displayed worse thresholds than controls. These results indicate that ACEMg supplementation can influence the progression of genetic hearing loss.