Pericytes control vascular stability and auditory spiral ganglion neuron survival

The inner ear has a rich population of pericytes, a multi-functional mural cell essential for sensory hair cell heath and normal hearing. However, the mechanics of how pericytes contribute to the homeostasis of the auditory vascular-neuronal complex in the spiral ganglion are not yet known. In this study, using an inducible and conditional pericyte depletion mouse (PDGFRB-CreERT2; ROSA26iDTR) model, we demonstrate, for the first time, that pericyte depletion causes loss of vascular volume and spiral ganglion neurons (SGNs) and adversely affects hearing sensitivity. Using an in vitro trans-well co-culture system, we show pericytes markedly promote neurite and vascular branch growth in neonatal SGN explants and adult SGNs. The pericyte-controlled neural growth is strongly mediated by pericyte-released exosomes containing vascular endothelial growth factor-A (VEGF-A). Treatment of neonatal SGN explants or adult SGNs with pericyte-derived exosomes significantly enhances angiogenesis, SGN survival, and neurite growth, all of which were inhibited by a selective blocker of VEGF receptor 2 (Flk1). Our study demonstrates that pericytes in the adult ear are critical for vascular stability and SGN health. Cross-talk between pericytes and SGNs via exosomes is essential for neuronal and vascular health and normal hearing.

Long Process Incus necrosis in Revision Stapedotomy: Retrospective Clinical Study

OBJECTIVES

We describe our experience with long process incus (LPI) necrosis in revision stapedotomy and discuss the different management methods proposed in the literature to identify surgical techniques that can lead to satisfactory results over time.

METHODS

Twenty-two stapedotomy revisions, in 21 patients with the necrosis of the long process of the incus, are performed from 1997 to 2017. In cases of erosion or minimal necrosis of LPI, a new prosthesis of the same type or an angled prosthesis was applied higher on the residual incus stump. In cases of partial necrosis of LPI, a Donaldson type ventilation tube reshaped and placed on the residual incus stump to stabilize prosthesis, or glass ionomer bone cement was used. In cases of subtotal necrosis of LPI, a cup piston prosthesis in polycel was applied on incus residual stump. Pre- and postoperative (≥1 year) pure tone audiometry was performed for all cases. Air conduction threshold, bone conduction (BC) threshold, and air-bone gap (ABG) were documented according to the American Academy of Otolaryngology Head and Neck Surgery Committee of Hearing and Equilibrium guidelines.

RESULTS

At 1-year follow-up, postoperative ABG was reduced to ≤10 dB in 13 (59%) cases and ≤20 dB in 19 (86.4%) cases. The mean postoperative ABG significantly decreased in each group. There was no significant change in postoperative BC thresholds, and there were no cases with postoperative SNHL.

CONCLUSION

Excellent functional results can also be achieved in cases of long incus process necrosis. The choice of technique should be considered according to the degree of necrosis. Piston replacement with the same type or angled type prosthesis, in cases of erosion or minimal LPI necrosis, and modified Donaldson type ventilation tube, in cases of partial LPI necrosis, provided excellent hearing results.

Sudden Sensorineural Hearing Loss in the COVID-19 Pandemic: A Systematic Review and Meta-Analysis

INTRODUCTION

Accumulating data indicate that patients with COVID-19 could be affected by sudden sensorineural hearing loss (SSNHL). The aim of the study was to analyze the epidemiological and clinical trend of SSNHL occurrence during the COVID-19 pandemic by applying a systematic review and meta-analysis approach.

METHODS

PubMed, Scopus, Web of Science, ScienceDirect, and Cochrane databases were searched.

RESULTS

The seven included studies had adequate relevance to the topic and the quality was fair. The mean age at SSNHL onset ranged from 39.23 to 62.18 years during the pandemic year period (PYP); a meta-analysis of four studies comparing these data with those of previous periods in the same institutions found a younger age during the PYP (pooled mean -0.2848). The heterogeneity was high (76.1935%) and no frank asymmetry was observed in the funnel plot. The SARS-CoV-2 positivity rate of SSNHL patients ranged from 0% to 57.53%. Standard steroid treatments were applied without significant adverse effects. Comprehensively, hearing improvement was achieved for more than half of the cases. No studies reported long-term follow-up data.

CONCLUSIONS

Further prospective analyses on large series and a long-term follow up on COVID-related SSNHL cases are necessary to address the open questions regarding the causative link between COVID-19 infection and SSNHL.

Purinergic Signalling in the Cochlea

The mammalian cochlea is the sensory organ of hearing with a delicate, highly organised structure that supports unique operating mechanisms. ATP release from the secretory tissues of the cochlear lateral wall (stria vascularis) triggers numerous physiological responses by activating P2 receptors in sensory, supporting and neural tissues. Two families of P2 receptors, ATP-gated ion channels (P2X receptors) and G protein-coupled P2Y receptors, activate intracellular signalling pathways that regulate cochlear development, homeostasis, sensory transduction, auditory neurotransmission and response to stress. Of particular interest is a purinergic hearing adaptation, which reflects the critical role of the P2X₂ receptor in adaptive cochlear response to elevated sound levels. Other P2 receptors are involved in the maturation of neural processes and frequency selectivity refinement in the developing cochlea. Extracellular ATP signalling is regulated by a family of surface-located enzymes collectively known as "ectonucleotidases" that hydrolyse ATP to adenosine. Adenosine is a constitutive cell metabolite with an established role in tissue protection and regeneration. The differential activation of A₁ and A_2A adenosine receptors defines the cochlear response to injury caused by oxidative stress, inflammation, and activation of apoptotic pathways. A₁ receptor agonism, A_2A receptor antagonism, and increasing adenosine levels in cochlear fluids all represent promising therapeutic tools for cochlear rescue from injury and prevention of hearing loss.

Potential nanotechnology-based diagnostic and therapeutic approaches for Meniere's disease

Meniere's disease (MD) is a progressive inner ear disorder involving recurrent and prolonged episodes or attacks of vertigo with associated symptoms, resulting in a significantly reduced quality of life for sufferers. In most cases, MD starts in one ear; however, in one-third of patients, the disorder progresses to the other ear. Unfortunately, the etiology of the disease is unknown, making the development of effective treatments difficult. Nanomaterials, including nanoparticles (NPs) and nanocarriers, offer an array of novel diagnostic and therapeutic applications related to MD. NPs have specific features such as biocompatibility, biochemical stability, targetability, and enhanced visualization using imaging tools. This paper provides a comprehensive and critical review of recent advancements in nanotechnology-based diagnostic and therapeutic approaches for MD. Furthermore, the crucial challenges adversely affecting the use of nanoparticles to treat middle ear disorders are investigated. Finally, this paper provides recommendations and future directions for improving the performances of nanomaterials on theragnostic applications of MD.

Neck Dissection Timing in Transoral Robotic or Laser Microsurgery in Oropharyngeal Cancer: A Systematic Review

Objective

This review assesses the effect on intra- and postoperative patient outcomes of the timing of neck dissection in relation to transoral surgery. Outcome measures include postoperative bleeding, intra- and postoperative fistula formation, and disease-specific and overall survival.

Data Sources

A search was conducted across the MEDLINE, Embase, US National Library of Medicine, and Cochrane databases with search terms in July 2021.

Review Methods

Articles that conformed with specified inclusion criteria were included. Included articles were scanned for bias with the ROBINS-I tool.

Results

Nineteen articles were selected for qualitative analysis, including 546 patients who had neck dissection in conjunction with transoral robotic surgery/transoral laser microsurgery (TORS/TLM). Seventy-one (18%) patients had neck dissection prior to TORS/TLM, 39 (10%) had neck dissection performed after TORS/TLM, and 281 (72%) had concurrent procedures. In patients with neck dissection before TORS/TLM, 3% experienced major postoperative bleeding, and fistula rates were 0%. In the cohort with neck dissection after TORS/TLM, 3% experienced minor postoperative hemorrhage, and 8% had intraoperative fistulae. In the concurrent cohort of patients, 1% had major postoperative bleeds and 0.3% had minor bleeds, while 4% developed intraoperative fistulas and 0.3% developed postoperative fistulas.

Conclusion

Current evidence indicated that there appears to be no correlation between timing of neck dissection and complications. This systematic review found insufficient data to comment on whether the timing of neck dissection in relation to TORS/TLM affects the outcomes of patients.

Cystic fibrosis exacerbations treated with medical therapy with and without concurrent sinus surgery

OBJECTIVE

This analysis investigates any potential differences in pulmonary function test (PFT) outcomes among pediatric patients with cystic fibrosis (CF) receiving both medical management (MM) and functional endoscopic sinus surgery (FESS) versus MM alone for CF exacerbation.

STUDY DESIGN

Prospective cohort.

SETTING

Pediatric tertiary care facility.

METHODS

The data was prospectively collected from July 2011 to March 2020. Diagnosis of CF and age ≤ to 18 were required. All patients were hospitalized and treated for CF exacerbations with both FESS with MM and MM alone at variable time intervals, although the order of initial treatment received differed. Two-way ANOVA with repeated measures were used to determine the effect of receiving FESS with MM versus MM alone on PFT outcomes over time (during admission, at discharge, at 3 months, at 6 months, and at 12 months).

RESULTS

13 pediatric patients, 7 of which had FESS with MM initially and 6 who had MM alone initially, and 20 events of both FESS and MM were included for analysis. For PFT outcomes, there was no statistically significant two-way interaction between treatment type and time following treatment, p = 0.492. The main effect of treatment did not show a statistically significant difference in FEV1 between treatment types, p = 0.737. There was no statistically significant association between treatment type and time between hospital readmission in months, p = 0.111.

CONCLUSION

There was no significant difference between PFT outcomes in pediatric patients hospitalized for CF exacerbation treated with MM with or without FESS at any time interval.

Local Delivery of Therapeutics to the Cochlea Using Nanoparticles and Other Biomaterials

Hearing loss negatively impacts the well-being of millions of people worldwide. Systemic delivery of ototherapeutics has limited efficacy due to severe systemic side effects and the presence of the blood-labyrinth barrier that selectively limits or enables transfer of molecules between plasma and inner ear tissues and fluids. Local drug delivery into the middle and inner ear would be preferable for many newly emerging classes of drugs. Although the cochlea is a challenging target for drug delivery, recent technologies could provide a safe and efficacious delivery of ototherapeutics. Local drug delivery routes include topical delivery via the external auditory meatus, retroauricular, transtympanic, and intracochlear delivery. Many new drug delivery systems specifically for the inner ear are under development or undergoing clinical studies. Future studies into these systems may provide a means for extended delivery of drugs to preserve or restore hearing in patients with hearing disorders. This review outlines the anatomy of the (inner) ear, describes the various local delivery systems and routes, and various quantification methodologies to determine the pharmacokinetics of the drugs in the inner ear.

Quality of Life in Deafblind People and Its Effect on the Processes of Educational Adaptation and Social Inclusion in Canary Islands, Spain

Deafblindness is a unique and complex disability. Research on the needs and quality of life are scarce; as well as the lack of adequate knowledge, training and lack of qualified professionals to serve this group. All this justifies the sense and interest of this study. This study is derived from the project with reference 2020EDU04. Design: The study is descriptive, cross-sectional and quantitative-qualitative research design was conducted. Objectives: Know and analyze the needs of adult deafblind people in order to contribute to improving their quality of life. Method: Sample of 16 adults with double sensory loss (hearing and vision) residing in the Autonomous Community of the Canary Islands (Spain) was used. Instruments: The FUMAT Scale was used to measure personal development; self-determination; interpersonal relationships; social inclusion; rights of deafblind people; emotional well-being; physical well-being and material well-being. In addition, a semi-structured interview is conducted. Results by dimensions: Personal development: The professionals did not have specialized training to provide an educational response. Physical well-being: 68% of the sample had other health problems associated with deafblindness. Interpersonal relationships: 100% of the sample reported communication problems in the family environment. Social inclusion: They reported difficulties in accessing educational and leisure activities. Material well-being: In general, they stated that they have the material resources necessary for their daily lives. Self-determination: they consider that they have decision-making capacity in basic aspects of daily life. Rights: Deafblind people state that they have limitations in exercising their rights. Based on the interviews, it was observed that the people with the greatest difficulties in daily life are those who presented the greatest visual commitment. Conclusion: The etiology does not determine the quality of life of deafblind people, but communication conditions interpersonal relationships and personal development, and therefore their quality of life.

Activation of 2-oxoglutarate receptor 1 (OXGR1) by α-ketoglutarate (αKG) does not detectably stimulate Pendrin-mediated anion exchange in Xenopus oocytes

SLC26A4/Pendrin is the major electroneutral Cl- /HCO3- exchanger of the apical membrane of the Type B intercalated cell (IC) of the connecting segment (CNT) and cortical collecting duct (CCD). Pendrin mediates both base secretion in response to systemic base load and Cl- reabsorption in response to systemic volume depletion, manifested as decreased nephron salt and water delivery to the distal nephron. Pendrin-mediated Cl- /HCO3- exchange in the apical membrane is upregulated through stimulation of the β-IC apical membrane G protein-coupled receptor, 2-oxoglutarate receptor 1 (OXGR1/GPR99), by its ligand α-ketoglutarate (αKG). αKG is both filtered by the glomerulus and lumenally secreted by proximal tubule apical membrane organic anion transporters (OATs). OXGR1-mediated regulation of Pendrin by αKG has been documented in transgenic mice and in isolated perfused CCD. However, aspects of the OXGR1 signaling pathway have remained little investigated since its original discovery in lymphocytes. Moreover, no ex vivo cellular system has been reported in which to study the OXGR1 signaling pathway of Type B-IC, a cell type refractory to survival in culture in its differentiated state. As Xenopus oocytes express robust heterologous Pendrin activity, we investigated OXGR1 regulation of Pendrin in oocytes. Despite functional expression of OXGR1 in oocytes, co-expression of Pendrin and OXGR1 failed to exhibit αKG-sensitive stimulation of Pendrin-mediated Cl- /anion exchange under a wide range of conditions. We conclude that Xenopus oocytes lack one or more essential molecular components or physical conditions required for OXGR1 to regulate Pendrin activity.

Comprehensive genetic testing improves the clinical diagnosis and medical management of pediatric patients with isolated hearing loss

Purpose

Genetic testing is widely used in diagnosing genetic hearing loss in patients. Other than providing genetic etiology, the benefits of genetic testing in pediatric patients with hearing loss are less investigated.

Methods

From 2018–2020, pediatric patients who initially presented isolated hearing loss were enrolled. Comprehensive genetic testing, including GJB2/SLC26A4 multiplex amplicon sequencing, STRC/OTOA copy number variation analysis, and exome sequencing, were hierarchically offered. Clinical follow-up and examinations were performed.

Results

A total of 80 pediatric patients who initially presented isolated hearing loss were considered as nonsyndromic hearing loss and enrolled in this study. The definitive diagnosis yield was 66% (53/80) and the likely diagnosis yield was 8% (6/80) through comprehensive genetic testing. With the aid of genetic testing and further clinical follow-up and examinations, the clinical diagnoses and medical management were altered in eleven patients (19%, 11/59); five were syndromic hearing loss; six were nonsyndromic hearing loss mimics.

Conclusion

Syndromic hearing loss and nonsyndromic hearing loss mimics are common in pediatric patients who initially present with isolated hearing loss. The comprehensive genetic testing provides not only a high diagnostic yield but also valuable information for clinicians to uncover subclinical or pre-symptomatic phenotypes, which allows early diagnosis of SHL, and leads to precise genetic counseling and changes the medical management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01293-x.

Combined effects of the exposure to silver nanoparticles and noise on hearing function and cochlea structure of the male rats

AIMS

This study intended to investigate whether exposure to the combination of noise and Ag-NPs in rats induces cochlear damage and hearing dysfunction.

MAIN METHODS

A total of 24Wistar rats were divided into four treatment groups and received/exposed to saline (IP), Ag-NPs (100 mg/kg, 5d/w for 4 weeks), 8 kHz narrowband noise (104 dB SPL, 6 h/day, 5d/w for 4 weeks) and Ag-NPs plus noise. The DPOAE, serum levels of MDA and SOD and changes in body weight were assessed. The rat cochlea was further stained for investigating the mRNA expression (TL-6, NOX3, and TNF-), IHC (TUJ-1 and MHC7), and histological alterations. The Ag-NPs characteristics were also analysed by SEM and XRD.

KEY FINDINGS

DPOAE values were remarkably reduced (p < 0.05) among the exposed groups. Furthermore, exposure to noise and Ag-NPs significantly increased MDA levels and decreased the SOD activity in the serum. In comparison to the control group, the expression of IL-6, TNF-, and NOX3 was shown to be elevated in the Ag-NPs plus noise group. The body weight also increased significantly in all groups with the exception of the Ag-NPs plus noise group. IHC tests showed remarkable down-regulation of TUJ1 and MYO7A. Morphological changes confirmed our findings as well. SEM and XRD data validated the production of Ag-NPs.

SIGNIFICANCE

According to the findings of this study, sub-acute exposure to noise and Ag-NPs causes permanent damage to the hair cells that are in charge of high-frequency perception.

Computational methodology for drug delivery to the inner ear using magnetic nanoparticle aggregates

BACKGROUND AND OBJECTIVE

The main goal of the proposed study is to improve the efficiency of the ear treatment via targeted drug delivery to the inner ear, i.e. the cochlea. Although pharmacotherapy has been proposed as a solution to prevent damage or restore functionality to hair cells, the main challenge in such treatments is ensuring adequate drug delivery to the cells. To this end, we present a methodology for the evaluation of the magnetic forces needed to move magnetic particle nanorobots (abbreviated as MNP) and their aggregates through the cochlea round window membrane (RWM).

METHODS

The FEM - Lagrangian-Eulerian approach (Abaqus software) was used to determine the specific parameters of movement of the nanoparticles crossing the RWM. This method results in a high consistency of FEM simulations and in-vivo experimental results in regards to the required magnetic force during the movement of spherical nanoparticles with a given viscosity η_ave. Based on the analysis of the experimental studies found in subject literature, the sizes of the MNPs and their aggregates able to cross RWM with and without the application of magnetic force F_M have been determined.

RESULTS

The present work accounts for both the experimental and theoretical aspects of these investigations. Presented research confirms the definite usability of the Lagrange-Euler method for the precise determination of the required magnetic force value FM to control the accelerated motion of MNP aggregates of complex shapes through RWM. It is possible to determine the predominant parameters with a precision of less than 5% for single-layer aggregates and spatial aggregates crossing the RWM. It can be concluded that the MNPs and their aggregates should not be larger than 500-750 nm to cross the RWM with high velocities of penetration close to 800 nm/s for magnetic forces of hundreds 10^-14 Newtons.

CONCLUSIONS

The proposed Lagrangian-Eulerian approach is capable of accurately predicting the movement parameters of MNP aggregates of irregular shape that are close to the experimental test cases. The presented method can serve as a supplementary tool for the design of drug delivery systems to the inner ear using MNPs.

Inner Ear Drug Delivery for Sensorineural Hearing Loss: Current Challenges and Opportunities

Most therapies for treating sensorineural hearing loss are challenged by the delivery across multiple tissue barriers to the hard-to-access anatomical location of the inner ear. In this review, we will provide a recent update on various pharmacotherapy, gene therapy, and cell therapy approaches used in clinical and preclinical studies for the treatment of sensorineural hearing loss and approaches taken to overcome the drug delivery barriers in the ear. Small-molecule drugs for pharmacotherapy can be delivered via systemic or local delivery, where the blood-labyrinth barrier hinders the former and tissue barriers including the tympanic membrane, the round window membrane, and/or the oval window hinder the latter. Meanwhile, gene and cell therapies often require targeted delivery to the cochlea, which is currently achieved via intra-cochlear or intra-labyrinthine injection. To improve the stability of the biomacromolecules during treatment, e.g., RNAs, DNAs, proteins, additional packing vehicles are often required. To address the diverse range of biological barriers involved in inner ear drug delivery, each class of therapy and the intended therapeutic cargoes will be discussed in this review, in the context of delivery routes commonly used, delivery vehicles if required (e.g., viral and non-viral nanocarriers), and other strategies to improve drug permeation and sustained release (e.g., hydrogel, nanocarriers, permeation enhancers, and microfluidic systems). Overall, this review aims to capture the important advancements and key steps in the development of inner ear therapies and delivery strategies over the past two decades for the treatment and prophylaxis of sensorineural hearing loss.

Astaxanthin Confers a Significant Attenuation of Hippocampal Neuronal Loss Induced by Severe Ischemia-Reperfusion Injury in Gerbils by Reducing Oxidative Stress

Astaxanthin is a powerful biological antioxidant and is naturally generated in a great variety of living organisms. Some studies have demonstrated the neuroprotective effects of ATX against ischemic brain injury in experimental animals. However, it is still unknown whether astaxanthin displays neuroprotective effects against severe ischemic brain injury induced by longer (severe) transient ischemia in the forebrain. The purpose of this study was to evaluate the neuroprotective effects of astaxanthin and its antioxidant activity in the hippocampus of gerbils subjected to 15-min transient forebrain ischemia, which led to the massive loss (death) of pyramidal cells located in hippocampal cornu Ammonis 1-3 (CA1-3) subfields. Astaxanthin (100 mg/kg) was administered once daily for three days before the induction of transient ischemia. Treatment with astaxanthin significantly attenuated the ischemia-induced loss of pyramidal cells in CA1-3. In addition, treatment with astaxanthin significantly reduced ischemia-induced oxidative DNA damage and lipid peroxidation in CA1-3 pyramidal cells. Moreover, the expression of the antioxidant enzymes superoxide dismutase (SOD1 and SOD2) in CA1-3 pyramidal cells were gradually and significantly reduced after ischemia. However, in astaxanthin-treated gerbils, the expression of SOD1 and SOD2 was significantly high compared to in-vehicle-treated gerbils before and after ischemia induction. Collectively, these findings indicate that pretreatment with astaxanthin could attenuate severe ischemic brain injury induced by 15-min transient forebrain ischemia, which may be closely associated with the decrease in oxidative stress due to astaxanthin pretreatment.

Anosmia following middle nasal concha resection: an anatomic and developmental review with clinical correlation

Losing the sense of smell can be associated with a significant decrease in quality of life. Fortunately, this occurs infrequently with modern paranasal sinus surgery that has stressed minimally invasive, tissue-sparing principles. However, over time, more extensive surgical applications have emerged that incorporate increased tissue removal. Post-operative period sequelae can occur, including anosmia. Understanding the potential implications of expanded tissue removal, such as middle nasal concha (turbinate) resection, is clinically important and is facilitated by an understanding of anatomy. Our understanding of anatomic nuances is enhanced through an appreciation of embryonic and fetal development. We herein review the developmental anatomy of the middle nasal concha of the ethmoid sinus and olfactory nerve area as it relates to middle nasal concha removal during endoscopic sinus surgery. We present images from our analysis of twelve embryonic and fetal specimens that highlight the important relationship between the middle nasal concha and olfactory nerves. We also review the clinical issues surrounding turbinate preservation versus resection and present a clinical correlation to underscore the uncommon but significant complication of anosmia following sinus surgery with middle nasal concha resection. We highlight knowledge gaps, discuss case selection and review surgical technique modifications for middle nasal concha surgery to reduce the chance of this complication in the future. This article is protected by copyright. All rights reserved.

Age-Related Inflammation and Oxidative Stress in the Cochlea Are Exacerbated by Long-Term, Short-Duration Noise Stimulation

We have previously reported that young adult rats exposed to daily, short-duration noise for extended time periods, develop accelerated presbycusis starting at 6 months of age. Auditory aging is associated with progressive hearing loss, cell deterioration, dysregulation of the antioxidant defense system, and chronic inflammation, among others. To further characterize cellular and molecular mechanisms at the crossroads between noise and age-related hearing loss (ARHL), 3-month-old rats were exposed to a noise-accelerated presbycusis (NAP) protocol and tested at 6 and 16 months of age, using auditory brainstem responses, Real-Time Reverse Transcription-Quantitative PCR (RT-qPCR) and immunocytochemistry. Chronic noise-exposure leading to permanent auditory threshold shifts in 6-month-old rats, resulted in impaired sodium/potassium activity, degenerative changes in the lateral wall and spiral ganglion, increased lipid peroxidation, and sustained cochlear inflammation with advancing age. Additionally, at 6 months, noise-exposed rats showed significant increases in the gene expression of antioxidant enzymes (superoxide dismutase 1/2, glutathione peroxidase 1, and catalase) and inflammation-associated molecules [ionized calcium binding adaptor molecule 1, interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha]. The levels of IL-1β were upregulated in the spiral ganglion and spiral ligament, particularly in type IV fibrocytes; these cells showed decreased levels of connective tissue growth factor and increased levels of 4-hydroxynonenal. These data provide functional, structural and molecular evidence that age-noise interaction contributes to exacerbating presbycusis in young rats by leading to progressive dysfunction and early degeneration of cochlear cells and structures. These findings contribute to a better understanding of NAP etiopathogenesis, which is essential as it affects the life quality of young adults worldwide.

Deafness-in-a-dish: modeling hereditary deafness with inner ear organoids

Sensorineural hearing loss (SNHL) is a major cause of functional disability in both the developed and developing world. While hearing aids and cochlear implants provide significant benefit to many with SNHL, neither targets the cellular and molecular dysfunction that ultimately underlies SNHL. The successful development of more targeted approaches, such as growth factor, stem cell, and gene therapies, will require a yet deeper understanding of the underlying molecular mechanisms of human hearing and deafness. Unfortunately, the human inner ear cannot be biopsied without causing significant, irreversible damage to the hearing or balance organ. Thus, much of our current understanding of the cellular and molecular biology of human deafness, and of the human auditory system more broadly, has been inferred from observational and experimental studies in animal models, each of which has its own advantages and limitations. In 2013, researchers described a protocol for the generation of inner ear organoids from pluripotent stem cells (PSCs), which could serve as scalable, high-fidelity alternatives to animal models. Here, we discuss the advantages and limitations of conventional models of the human auditory system, describe the generation and characteristics of PSC-derived inner ear organoids, and discuss several strategies and recent attempts to model hereditary deafness in vitro. Finally, we suggest and discuss several focus areas for the further, intensive characterization of inner ear organoids and discuss the translational applications of these novel models of the human inner ear.

Occupational Noise Induced Hearing Loss in India: A Systematic Review and Meta-Analysis

BACKGROUND

India has over 50 million workers employed in industries with exposure to very high sound levels, predisposing them to noise-induced hearing loss (NIHL).

METHODS

We conducted a systematic review and meta-analysis by using the following criteria: (1) Observational or experimental studies conducted in India; (2) English language studies; (3) Published during January 2010-December 2019; (4) Primary outcome: proportion of participants detected with NIHL. We reviewed bibliographic databases (PubMed, Scopus, and DOAJ) and Google Scholar, and extracted the relevant data.

RESULTS

A total of 160 documents were identified after removing duplicates, and 33 full texts were screened, of which 22 studies were included. The mean (SD) effective sample size of the studies was 107.1 (78.9). The pooled proportion of participants with NIHL irrespective of the category was 0.49 (95%CI: 0.22-0.76) and that of hearing loss was 0.53 (95%CI: 0.28- 0.78). Most studies reported that none of the workers, especially in the informal sectors, used auditory protection.

CONCLUSIONS

NIHL is a major neglected public health occupational health challenge in India linked with adverse social determinants of health. Sustained advocacy for implementation of legislative and behavior change communication for protecting the hearing of workers is warranted.

Prevention of external auditory canal exostosis in the Colorado whitewater community

Context

External auditory canal exostoses (EACE) are bony formations that develop insidiously in the auditory meatus from chronic exposure to cold water and, in severe cases, require surgery. This condition has been understudied in the whitewater kayakers and not yet studied in the riverboarding population. Precautions such as earplugs are thought to prevent the formation of EACE because they mechanically block cold water from contacting the sensitive skin in the external auditory canal; however, earplugs are not commonly utilized by athletes. Inquiring about hobbies and the use of protective equipment can be done during osteopathic physicians’ preventive care visits.

Objectives

This article aims to determine the prevalence of EACE in Colorado whitewater athletes and their attitudes about wearing ear protection before and after an educational intervention directed at increasing awareness and prevention of EACE.

Methods

In July 2020, participants of this cross-sectional study completed a 10-min survey that collected demographics, whitewater experience, and perceptions of EACE, followed by an educational intervention. Participant ears were photographed utilizing a digital otoscope to assess EACE, and severity ratings were categorized into one of four occlusion levels: none (0%), mild (<25%), moderate (25–75%), or severe (>75%). Spearman correlation coefficients and Wilcoxon signed-rank tests were utilized to assess changes in attitudes before and after the educational intervention.

Results

Eighty-one participants (mean [SD] age = 36.3 [12.6] years, 25.9% female) completed the study: 74 kayakers and seven riverboarders. After the intervention, 60.5% (49/81) (p<0.001) reported greater understanding of EACE and 75.0% (60/80) were more likely to wear ear protection (p<0.001). Most (58.0%, 47/81) never wore ear protection. Of the 61 (75.0%) participants with at least one ear severity rating, most (55.7%, 34/61) had moderate EACE, 29.5% (18/61) had no to mild EACE, and 14.8% (9/61) had severe EACE (p<0.001). Impaired hearing was the biggest barrier to utilizing ear protection (51.6%, 33/64).

Conclusions

Our results suggested that the educational intervention improved understanding of EACE and may increase utilization of ear protection in this population. Such prevention efforts may lead to better health of whitewater paddlers by reducing the incidence of EACE. Encouraging osteopathic physicians to inquire about hobbies and protective equipment during primary care preventive visits is essential to help keep athletes in the river doing what they love for longer, contributing to a healthier and happier whole person.

Use of platelet-rich plasma in irradiated patients to treat and prevent complications of head and neck surgery

Nowadays, many patients facing head and neck oncological surgery have a history of tissue irradiation. This represents an important risk factor for postsurgical complications, including dehiscences and fistulas. Platelet-rich plasma (PRP) obtained from the patient's blood represents an easy, fast and inexpensive method for the prevention and treatment of such complications. We present three cases of previously irradiated patients in which PRP was successfully used to prevent and treat postsurgical complications.

A salutogenesis approach to ageing with impairment: the managing and coping experiences of older people ageing with deafblindness

An understanding of the psychosocial impact of deafblindness on older people is impoverished by a dearth of research in the field. Particularly limited are studies adopting a salutogenesis perspective, in which older deafblind people's coping capacities are explored. Much research focuses on vulnerability to unfavourable outcomes, which may perpetuate negative stereotypes of deafblind people as passive and dependent. Identifying deafblind people as a vulnerable group gives rise to misunderstanding of the impairment, perceptions of incapability and neglect of deafblind people's agency. This paper draws on data from the first United Kingdom-based study of vulnerability from the perspectives of older adults ageing with deafblindness. Findings presented here relate to participants’ experiences of managing and coping with their felt vulnerability and ageing with deafblindness. The study adopted interpretative phenomenological analysis (IPA) as its qualitative approach. In-depth semi-structured interviews were undertaken between October 2014 and July 2016 with eight participants, aged between 48 and 83 years. Data were analysed using an iterative six-step IPA process. Three superordinate themes were identified: taking action to protect self; psychological coping strategies; and accessing and using care and support. Participants’ managing and coping strategies, and the care and support they value, respond to elements identified as generating felt vulnerability. Professionals should seek to bolster coping capacity and provide support in ways valued by those ageing with deafblindness.

Validated Ossicular Measurements on High-Resolution Computed Tomography (CT) in Live and Cadaveric Temporal Bones

Objective The present study was undertaken to study the utility of high-resolution computed tomography (HRCT) temporal bone in live patients for providing the parameters of ossicular dimensions (OD), using standard assessment protocols, devised by the authors, with regard to the plane of CT scans and axes of measurement of ossicles. Methods This observational study was conducted from January 2021 to February 2022 at Acharya Vinoba Bhave Rural Hospital, Sawanghi, Meghe, Maharashtra, India, in the Department of Otorhinolaryngology and Department of Radiodiagnosis. HRCT scan was performed on temporal bones, 10 in live subjects with no otological complaints and 10 in cadaveric temporal bones. HRCT was also performed for all three ossicles after dissecting them out from the respective cadaveric temporal bones. Measurements of OD were taken using Universalmednet Software and vernier calipers and compared with published anatomic data. Results The measurements taken using HRCT scans of the live subject and cadaveric bone as well as the ossicles taken using calipers fall within the range of published studies. Slight variation is seen in the measurements of stapes and incus, stapes total height is 3.17mm, less than 3.3. Conventional HRCT temporal bone in live patients when performed under set circumstances can be adopted as a standard method for measurement of ossicular sizes for the generation of normative data for different races, ethnicity and sex. Conclusion The results of our study can have implications in terms of translational research as the measurements obtained can help in better understanding of middle ear biomechanics, prosthesis designing, developing ideal tympanoplasty methods in terms of size, shape and placement of autograft.

Prevalence of Individuals with Deafblindness and Age-Related Dual-Sensory Loss

Introduction

The authors of this paper have compiled a report on the prevalence of deafblindness and dual-sensory loss based on the review of existing estimates. The purpose is to inform readers of the importance of using consistent, well-researched definitions and survey questions in future prevalence studies.

Methods

Articles were extracted through ProQuest and EBSCOhost, online library databases of Cambrian College and Laurentian University. Keywords search included “deafblindness,” “dual-sensory impairment,” “dual-sensory loss,” “age-related,” “congenital,” “acquired,” and “prevalence.” Additionally, the authors conducted a search with Google for research reports and Google Scholar for other relevant peer-reviewed articles.

Results

This review provides a current overview of prevalence estimates of deafblindness and age-related dual-sensory loss around the world, examining 19 articles or reports published over the last 20 years (2000–2020) in 18 countries, including the European Union (consisting of 8 countries). In line with the prevalence estimates by the World Federation for the Deafblind global report 2018, the review indicates an estimated 0.2–2% prevalence of dual-sensory impairment and underscores varying ranges of prevalence among populations, studies or countries, age groups, and types of deafblindness. The review highlights that the prevalence of deafblindness or dual-sensory loss was often not comparable across studies, but it is clear that the prevalence of dual-sensory impairment increases with age. The studies varied in methods (e.g., population surveys, cross-sectional, and longitudinal studies).

Implication for practitioners

The review provides evidence of varying ranges of prevalence rates. Future prevalence studies may benefit from consistent definitions, standard data-collection tools to do better comparisons across countries, and identify factors that predict higher or lower prevalence rates among populations and age groups.

Role of Radiologic Imaging in Otosclerosis

Purpose of Review

To review the role of imaging in otosclerosis with an emphasis on pre- and post-operative imaging evaluation.

Recent Findings

Pre-operative CT imaging can help define the extent of bone involvement in otosclerosis and may help avoid surgical complications due to variant anatomy or unsuspected alternative causes of conductive hearing loss. In patients with recurrent hearing loss after surgery, CT imaging can clarify prosthesis position and re-assess anatomy.

Summary

CT imaging complements otologic exam and audiometry findings in patients with suspected otosclerosis, for pre-operative planning, and post-operative assessment for patients with recurrent symptoms.

Factors that influence the participation of individuals with deafblindness: A qualitative study with rehabilitation service providers in India

Evidence to inform rehabilitation service delivery for individuals with deafblindness, especially in the Indian context, is inadequate. Rehabilitation professionals often find it challenging to design rehabilitation interventions that promote participation for those with deafblindness. Therefore, our purpose was to understand the contextual factors that influence the participation of individuals with deafblindness in India from the perspectives of those who are involved in providing rehabilitation services to them. Using the International Classification of Functioning, Disability, and Health (ICF) as a framework, we conducted two focus group discussions with 16 rehabilitation service providers in India. We used a content analysis approach to examine the data. Rehabilitation service providers perceived participation barriers to be linked primarily to the social environment. Specifically, participants identified four major factors acting as barriers, including (a) lack of awareness about deafblindness; (b) negative attitudes and stigma associated with disability; (c) lack of access to resources such as assistive technology and interpreter support; and (d) communication challenges associated with severe impairments. Facilitators include accessibility of the built environment for multisensory impairments, affordable technology, provision of an interpreter and personal support worker, and training on deafblindness for professionals. The participation of individuals with deafblindness could be enhanced by identifying and removing environmental barriers and improving knowledge about deafblindness among rehabilitation professionals for proper identification, assessment, and access to rehabilitation services.

Oxidative Stress and Inflammation Caused by Cisplatin Ototoxicity

Hearing loss is a significant health problem that can result from a variety of exogenous insults that generate oxidative stress and inflammation. This can produce cellular damage and impairment of hearing. Radiation damage, ageing, damage produced by cochlear implantation, acoustic trauma and ototoxic drug exposure can all generate reactive oxygen species in the inner ear with loss of sensory cells and hearing loss. Cisplatin ototoxicity is one of the major causes of hearing loss in children and adults. This review will address cisplatin ototoxicity. It includes discussion of the mechanisms associated with cisplatin-induced hearing loss including uptake pathways for cisplatin entry, oxidative stress due to overpowering antioxidant defense mechanisms, and the recently described toxic pathways that are activated by cisplatin, including necroptosis and ferroptosis. The cochlea contains G-protein coupled receptors that can be activated to provide protection. These include adenosine A1 receptors, cannabinoid 2 receptors (CB2) and the Sphingosine 1-Phosphate Receptor 2 (S1PR2). A variety of heat shock proteins (HSPs) can be up-regulated in the cochlea. The use of exosomes offers a novel method of delivery of HSPs to provide protection. A reversible MET channel blocker that can be administered orally may block cisplatin uptake into the cochlear cells. Several protective agents in preclinical studies have been shown to not interfere with cisplatin efficacy. Statins have shown efficacy in reducing cisplatin ototoxicity without compromising patient response to treatment. Additional clinical trials could provide exciting findings in the prevention of cisplatin ototoxicity.

Technical Considerations and Outcome Analysis of Using Extended Bipaddle Pectoralis Major Myocutaneous Flaps for Reconstructions of Large and Complex Oral Cavity Defects: Expanding the Horizons

Reconstruction of large and complex defects arising from resection of advanced oral cancers requires free flaps or multi-staged reconstructions using a combination of pedicled flaps. Bipaddle (pectoralis major myocutaneous (PMMC) flap is a good alternative for reconstruction of such defects, especially in low-middle-income countries (LMIC). However, care should be taken while expanding its limits to avoid unnecessary morbidity. We discuss technical considerations while extending the PMMC flap design beyond the usual boundaries and analyse surgical and quality of life (QOL) outcomes in our patients with large (≥ 10 cm) oral cavity defects while using extended bipaddle PMMC flaps. We retrospectively analysed the results of 72 oral cancer patients with large buccoalveolar defects with at least one dimension ≥ 10 cm who underwent single-stage reconstruction using extended bipaddle PMMC flaps between January 2018 and December 2019. Total flap loss was seen in one patient and partial loss in 10 (13.8%) patients, while 18 (25.1%) patients had major complications (Clavien-Dindo grade III). Discharge from hospital was delayed beyond a mean of 6 days in 15 (20.8%) patients and the start of adjuvant treatment was delayed in 5 patients (6.9%). On univariate analysis, age > 50 years, female gender, the largest dimension and flap area were significant factors increasing morbidity. The QOL outcomes were acceptable. The satisfactory results from our series reaffirm that extended bipaddle PMMC flaps are a viable alternate option for such reconstructive challenges in resource-limited centres. However, age, gender, the defect dimensions and flap area should be taken into consideration while using this flap.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13193-021-01345-1.

Genetic Determinants of Non-Syndromic Enlarged Vestibular Aqueduct: A Review

Hearing loss is the most common sensorial deficit in humans and one of the most common birth defects. In developed countries, at least 60% of cases of hearing loss are of genetic origin and may arise from pathogenic sequence alterations in one of more than 300 genes known to be involved in the hearing function. Hearing loss of genetic origin is frequently associated with inner ear malformations; of these, the most commonly detected is the enlarged vestibular aqueduct (EVA). EVA may be associated to other cochleovestibular malformations, such as cochlear incomplete partitions, and can be found in syndromic as well as non-syndromic forms of hearing loss. Genes that have been linked to non-syndromic EVA are SLC26A4, GJB2, FOXI1, KCNJ10, and POU3F4. SLC26A4 and FOXI1 are also involved in determining syndromic forms of hearing loss with EVA, which are Pendred syndrome and distal renal tubular acidosis with deafness, respectively. In Caucasian cohorts, approximately 50% of cases of non-syndromic EVA are linked to SLC26A4 and a large fraction of patients remain undiagnosed, thus providing a strong imperative to further explore the etiology of this condition.

Hepatitis C as a Potential Risk Factor for Adverse Surgical Outcomes in Head and Neck Free Tissue Transfer Reconstruction

Background: Infection with hepatitis C virus (HCV) is associated with an increased risk of developing head and neck cancer (HNC), and negatively impacts cancer-specific survival. Objective: To measure the impact of HCV status on free tissue transfer failure, flap takeback, and length of stay in HNC patients undergoing reconstruction. Methods: We retrospectively reviewed patients who underwent head and neck free tissue transfer reconstruction at a single academic institution between August 2011 and June 2020. Results: In the HCV-infected group, total flap failure rate was 2.9% versus 1.3% in the control group and the takeback rate was 11.1% versus 9.6%. On multivariate analysis, HCV status was not associated with flap failure, flap takeback, or total length of hospital stay >7 days. Conclusion: In this study, HCV status was not associated with differences in postoperative complications or length of stay. Future research with greater numbers of HCV-positive study subjects is required to elucidate the effect of HCV infection in this patient population.

Imaging of the Thyroid: Practical Approach

Imaging evaluation of the thyroid gland spans a plethora of modalities, including ultrasound imaging, cross-sectional studies, and nuclear medicine techniques. The overlapping of clinical and imaging findings of benign and malignant thyroid disease can make interpretation a complex undertaking. We aim to review and simplify the vast current literature and provide a practical approach to the imaging of thyroid disease for application in daily practice. Our approach highlights the keys to differentiating and diagnosing common benign and malignant disease affecting the thyroid gland.

Istradefylline Mitigates Age-Related Hearing Loss in C57BL/6J Mice

Age-related hearing loss (ARHL) is the most common sensory disorder among older people, and yet, the treatment options are limited to medical devices such as hearing aids and cochlear implants. The high prevalence of ARHL mandates the development of treatment strategies that can prevent or rescue age-related cochlear degeneration. In this study, we investigated a novel pharmacological strategy based on inhibition of the adenosine A_2A receptor (A_2AR) in middle aged C57BL/6 mice prone to early onset ARHL. C57BL/6J mice were treated with weekly istradefylline (A_2AR antagonist; 1 mg/kg) injections from 6 to 12 months of age. Auditory function was assessed using auditory brainstem responses (ABR) to tone pips (4–32 kHz). ABR thresholds and suprathreshold responses (wave I amplitudes and latencies) were evaluated at 6, 9, and 12 months of age. Functional outcomes were correlated with quantitative histological assessments of sensory hair cells. Cognitive function was assessed using the Morris water maze and the novel object recognition test, and the zero maze test was used to assess anxiety-like behaviour. Weekly injections of istradefylline attenuated ABR threshold shifts by approximately 20 dB at mid to high frequencies (16–32 kHz) but did not improve ABR suprathreshold responses. Istradefylline treatment improved hair cell survival in a turn-dependent manner, whilst the cognitive function was unaffected by istradefylline treatment. This study presents the first evidence for the rescue potential of istradefylline in ARHL and highlights the role of A_2AR in development of age-related cochlear degeneration.

IGF-1 Haploinsufficiency Causes Age-Related Chronic Cochlear Inflammation and Increases Noise-Induced Hearing Loss

Insulin-like growth factor 1 (IGF-1) deficiency is an ultrarare syndromic human sensorineural deafness. Accordingly, IGF-1 is essential for the postnatal maturation of the cochlea and the correct wiring of hearing in mice. Less severe decreases in human IGF-1 levels have been associated with other hearing loss rare genetic syndromes, as well as with age-related hearing loss (ARHL). However, the underlying mechanisms linking IGF-1 haploinsufficiency with auditory pathology and ARHL have not been studied. Igf1-heterozygous mice express less Igf1 transcription and have 40% lower IGF-1 serum levels than wild-type mice. Along with ageing, IGF-1 levels decreased concomitantly with the increased expression of inflammatory cytokines, Tgfb1 and Il1b, but there was no associated hearing loss. However, noise exposure of these mice caused increased injury to sensory hair cells and irreversible hearing loss. Concomitantly, there was a significant alteration in the expression ratio of pro- and anti-inflammatory cytokines in Igf1^+/- mice. Unbalanced inflammation led to the activation of the stress kinase JNK and the failure to activate AKT. Our data show that IGF-1 haploinsufficiency causes a chronic subclinical proinflammatory age-associated state and, consequently, greater susceptibility to stressors. This work provides the molecular bases to further understand hearing disorders linked to IGF-1 deficiency.

Low intensity ultrasound enhances cisplatin uptake in vitro by cochlear hair cells

Drug delivery to the inner ear has been challenging due to the blood-labyrinth barrier. Intracochlear drug delivery is an invasive alternative with less pharmacokinetic variables. In this study, the effect of low intensity ultrasound on drug uptake by hair cells is investigated. Cochlear explants harvested from newborn mice were cultured in a medium containing cisplatin to emulate drug delivered to the endolymph. The results demonstrated the exposure to ultrasound stimulation effectively enhanced cisplatin uptake by hair cells. The uptake started from the apical side of the hair cells and progressed inward as the exposure time increased.

SARS-CoV-2 and hearing: An audiometric analysis of COVID-19 hospitalized patients

PURPOSE

COVID-19 associated hearing loss is still an ongoing matter of debate. No original studies exist on audiological effects of SARS-CoV-2 infection in hospitalized patients. The main objective was to determine whether SARS-CoV-2 may affect auditory function in clinically ill COVID-19 patients.

MATERIALS AND METHODS

COVID-19 patients with moderate-severe disease and without prior history of hearing abnormalities were enrolled from a tertiary referral center, and matched with controls. Participants performed an audiometric evaluation, and thresholds were compared.

RESULTS

120 ears from 60 patients were enrolled. Patients with COVID-19 showed worse mean auditory thresholds starting from 1000 Hz through higher frequencies, when compared to controls (1000 Hz: 18.52 ± 5.49 dB HL in controls vs 25.36 ± 6.79 dB HL in COVID-19, p < 0.001; 2000Hz: 17.50 ± 5.57 dB HL in controls vs 21.96 ± 7.05 dB HL in COVID-19, p = 0.010; 3000Hz: 17.97 ± 8.07 dB HL in controls vs 25 ± 9.38 dB HL in COVID-19, p = 0.003; 4000 Hz: 20.16 ± 10.12 dB HL in controls vs 29.55 ± 11.26 dB HL in COVID-19, p = 0.001; 8000 Hz: 31.09 ± 12.75 dB HL in controls vs 40.71 ± 19.40 dB HL in COVID-19, p = 0.030; Pure Tone Average: 20.42 ± 4.29 dB HL in controls vs 24.85 ± 5.62 dB HL in COVID-19, p = 0.001). Statistical significance persisted after adjusting for confounders such as age, gender and various comorbidities (p < 0.05).

CONCLUSIONS

SARS-CoV-2 may affect hearing in COVID-19 patients with moderate-severe disease. Results are in line with the previous suggested effects of COVID-19 on auditory system. This study is expected to encourage further research on this topic.

The circadian timing of noise exposure influences noise-induced inflammatory responses in the mouse cochlea

INTRODUCTION

Noise-induced hearing loss is one of the most common forms of sensorineural hearing loss. Nevertheless, the mechanisms of noise-induced hearing loss are still not fully understood.

OBJECTIVE

To investigate the dynamics of inflammatory responses in the mammalian cochlea following noise trauma at two different times, once during the light cycle and once during the dark.

METHODS

We challenged C57BL/6J mice with moderate, continuous noise trauma at either 9 a.m. or 9 p.m. Auditory function, histological changes in hair cells, and modifications in gene expression levels of inflammatory mediators were assessed at specific time points. Shifts in auditory brainstem response thresholds were measured at 1, 3, 7 and 14 days after noise exposure to measure potential noise-induced hearing loss. Cochlear basilar-membrane immunofluorescent staining was performed at 3 and 14 days after noise exposure. The mRNA levels of several inflammatory mediators were measured via quantitative real-time polymerase chain reaction before (pre) and after (0, 3, 12, 24 and 72 h) noise exposure.

RESULTS

We found that all noise-exposed mice developed a temporary threshold shift and that there were no significant differences between daytime and nighttime noise exposures in terms of inducing hearing-threshold shifts. Similarly, we did not detect significant histological changes in hair cells between these two groups. However, we discovered an interesting phenomenon in that the peak mRNA levels of IL-1β, IL-6, CCL2 and TNF-α were higher in day noise-exposed mice compared to those in night noise-exposed mice, and these mRNA levels subsided more slowly in day noise-exposed mice.

CONCLUSION

Overall, these observations suggest that the circadian timing of noise exposure has a significant effect on noise-induced inflammatory responses in the mouse cochlea and that a greater inflammatory response might occur after daytime exposure.

Success rates in restoring hearing loss in patients with chronic otitis media: A systematic review

OBJECTIVE

To assess the effectiveness of tympanoplasty in treating chronic otitis media-related hearing loss, published literature was systematically reviewed to determine the clinical success rate of tympanoplasty at restoring hearing in chronic otitis media patients at a minimum follow-up period of 12-months.

DATA SOURCES

PubMed, Embase and the Cochrane Library.

METHODS

Two independent reviewers performed literature searches. Publications reporting long-term (≥12-month) hearing outcomes and complications data on adult and pediatric patients with chronic otitis media were included and assessed for risk of bias and strength of evidence. To assess how tympanoplasty influences long-term hearing outcomes, data on pure tone audiometry (air-bone gap) and complications were extracted and synthesized.

RESULTS

Thirty-nine studies met the inclusion criteria. Data from 3162 patients indicated that 14.0% of patients encountered postoperative complications. In adult patients, mean weighted air-bone gap data show closure from 26.5 dB hearing level (HL) (preoperatively) to 16.1 dB HL (postoperatively). In studies that presented combined adult and pediatric data, the mean preoperative air-bone gap of 26.7 dB HL was closed to 15.4 dB HL. In 1370 patients with synthesizable data, 70.7% of patients had a postoperative air-bone gap ˂ 20 dB HL at long-term follow-up. Finally, subgroup analysis identified that mean improvement in ABG closure for patients with and without cholesteatoma was 10.0 dB HL and 12.4 dB HL, respectively.

CONCLUSION

In patients with chronic otitis media, tympanoplasty successfully closed the air-bone gap to within 20 dB HL in 7/10 cases and had an overall complication rate of 14.0%.

LEVEL OF EVIDENCE

2a.

Informed Consent or Assent Strategies for Research With Individuals With Deafblindness or Dual Sensory Impairment: A Scoping Review

OBJECTIVE

To synthesize evidence on existing informed consent/assent strategies and processes that enable the participation of individuazls with deafblindness or dual sensory impairment in research.

DATA SOURCES

Five scientific databases (PubMed, MEDLINE, Cumulative Index to Nursing and Allied Health, Web of Science, and PsycINFO) and other sources such as Google Scholar, Journal of Visual Impairment and Blindness, and British Journal of Visual Impairment were hand-searched from January 2015 until July 2020.

STUDY SELECTION

Studies were selected using a priori inclusion criteria of sensory and cognitive disabilities and focused on consent/assent strategies and processes in research within this population. Articles related to the medical or sexual consent processes were excluded.

DATA EXTRACTION

An Excel spreadsheet was used to extract data from the eligible sources. Discrepancies were resolved in discussion with team members.

DATA SYNTHESIS

A total of 2163 sources were screened, and 16 articles were included in the review. Seven sources only examined consent strategies, whereas the remaining 8 included a combination of consent/assent and dissent strategies. Using thematic analysis, 3 key themes emerged: consent/assent strategies, researcher capacity, and capacity to consent tools. Key identified strategies included the accessibility of the consent/assent process, building relationships with participants and caregivers, identifying behavioral cues, and communication training for researchers.

CONCLUSIONS

Despite the absence of literature on consent/assent strategies within the population with deafblindness, the review found promising strategies applied to individuals with other cognitive or sensory disabilities that researchers can adopt. Researchers are encouraged to use best practices in creating an inclusive research environment to include individuals with deafblindness.

The Effect of Oral Montelukast Administration in Cholesteatoma Development and Inflammation: An Experimental Animal Model

HYPOTHESIS

We hypothesized that oral montelukast treatment could inhibit cholesteatoma formation in an experimental animal model.

BACKGROUND

Inflammation and excessive proliferation have been described in the histopathology of cholesteatoma. The aim of this study was to determine the effect of oral montelukast on cholesteatoma development.

METHODS

Eighteen healthy female Wistar albino rats weighing 250 g were chosen for the study. The animals were divided into two groups: group 1 received montelukast and group 2 was the control group. Intratympanic propylene glycol injection was administered into the left ears and physiologic serum was instilled into the right ears of the animals on the first, eighth, and fifteenth days. The effects of montelukast administration were evaluated by histological examination of the tympanic membrane and middle ear.

RESULTS

Group 1 (montelukast group) showed significant differences in terms of cholesteatoma formation, granulation, epithelial invagination, and inflammation. Cholesteatoma formation in the left ear was observed in 2 (22%) and 8 (89%) rats in groups 1 and 2, respectively (p = 0.015).

CONCLUSION

Development of cholesteatoma and inflammation was significantly lower in the montelukast-administered group. Thus, oral montelukast was found effective in preventing cholesteatoma formation.

Abdominal-based free flaps in head and neck reconstruction

PURPOSE OF REVIEW

The head and neck reconstructive surgeon is intimately familiar with the anterolateral thigh, radial forearm, and parascapular flaps. This review serves to describe the major abdominal-based free tissue transfers in head and neck reconstruction that can be used as alternatives to these traditional workhorse flaps.

RECENT FINDINGS

Abdominal-based free flaps, while not traditionally used in head and neck reconstruction, are great alternatives or second-line flaps. For example, the deep circumflex iliac artery flap is an excellent alternative to the fibular free flap due to its bone height and greater overall quality of life.

SUMMARY

This review article serves to review the major abdominal-based free tissue transfers in head and neck reconstruction in order to expand the toolbox of the head and neck surgeon.

Nanoparticles for the Treatment of Inner Ear Infections

The inner ear is sensitive to various infections of viral, bacterial, or fungal origin, which, if left untreated, may lead to hearing loss or progress through the temporal bone and cause intracranial infectious complications. Due to its isolated location, the inner ear is difficult to treat, imposing an acute need for improving current therapeutic approaches. A solution for enhancing antimicrobial treatment performance is the use of nanoparticles. Different inorganic, lipidic, and polymeric-based such particles have been designed, tested, and proven successful in the controlled delivery of medication, improving drug internalization by the targeted cells while reducing the systemic side effects. This paper makes a general presentation of common inner ear infections and therapeutics administration routes, further focusing on newly developed nanoparticle-mediated treatments.

The expression of VEGF and VEGFR in endotoxin induced otitis media with effusion in rats

OBJECTIVE

To investigate the expression and correlation of vascular endothelial growth factor (VEGF) and its receptor with hypoxia-inducible factor-1 α (HIF-1 α) in otitis media with effusion (OME).

METHODS

A rat model of OME was induced by injection of lipopolysaccharide (LPS) into the middle ear. Hematoxylin and eosin (HE) staining was used to observe the pathomorphological changes of the tympanic cavity in the middle ear of rats. Immunohistochemistry (IHC), western blotting and RT-qPCR were used to determine the mRNA and protein expression of VEGF, VEGFR-1, VEGFR-2 and HIF-1α in mucosa of tympanic cavity mucosa, respectively.

RESULTS

In the OME group, the epithelial space of the middle ear mucosa was significantly thickened and infiltration of a large number of inflammatory cells was found on postoperative day (POD), and the otitis media basically subsided 2 weeks after operation. VEGF mRNA expression was significantly increased on POD 1, and its protein expression peaked on POD 3. HIF-1α mRNA expression was significantly increased and peaked on POD 1, while its protein expression began to increase on POD 3 and was significantly expressed in the middle ear mucosal epithelium. HIF-1α mRNA showed a positive correlation with VEGF mRNA and VEGFR-1 mRNA expression.

CONCLUSION

VEGF mainly plays a role in the acute phase of OME, and it is abundantly expressed mediated by HIF-1α. And then it play a role in vasodilatation and increase of vascular permeability, thus promoting the generation of middle ear effusion.

High-Frequency Audiometry for Early Detection of Hearing Loss: A Narrative Review

The WHO considers hearing loss to be a major global problem. A literature search was conducted to see whether high-frequency audiometry (HFA) could be used for the early detection of hearing loss. A further aim was to see whether any differences exist in the hearing threshold using conventional audiometry (CA) and HFA in workers of different age groups exposed to workplace noise. Our search of electronic databases yielded a total of 5938 scientific papers. The inclusion criteria were the keywords “high frequency” and “audiometry” appearing anywhere in the article and the participation of unexposed people or a group exposed to workplace noise. Fifteen studies met these conditions; the sample size varied (51–645 people), and the age range of the people studied was 5–90 years. Commercial high-frequency audiometers and high-frequency headphones were used. In populations unexposed to workplace noise, significantly higher thresholds of 14–16 kHz were found. In populations with exposure to workplace noise, significantly higher statistical thresholds were found for the exposed group (EG) compared with the control group (CG) at frequencies of 9–18 kHz, especially at 16 kHz. The studies also showed higher hearing thresholds of 10–16 kHz in respondents aged under 31 years following the use of personal listening devices (PLDs) for longer than 5 years. The effect of noise-induced hearing loss (NIHL) first became apparent for HFA rather than CA. However, normative data have not yet been collected. Therefore, it is necessary to establish a uniform evaluation protocol accounting for age, sex, comorbidities and exposures, as well as for younger respondents using PLDs.

Local drug delivery systems for inflammatory diseases: Status quo, challenges, and opportunities

Inflammation that is not resolved in due course becomes a chronic disease. The treatment of chronic inflammatory diseases involves a long-term use of anti-inflammatory drugs such as corticosteroids and nonsteroidal anti-inflammatory drugs, often accompanied by dose-dependent side effects. Local drug delivery systems have been widely explored to reduce their off-target side effects and the medication frequency, with several products making to the market or in development over the years. However, numerous challenges remain, and drug delivery technology is underutilized in some applications. This review showcases local drug delivery systems in different inflammatory diseases, including the targets well-known to drug delivery scientists (e.g., joints, eyes, and teeth) and other applications with untapped opportunities (e.g., sinus, bladder, and colon). In each section, we start with a brief description of the disease and commonly used therapy, introduce local drug delivery systems currently on the market or in the development stage, focusing on polymeric systems, and discuss the remaining challenges and opportunities in future product development.

Contributions and limitations of using machine learning to predict noise-induced hearing loss

Purpose

Noise-induced hearing loss (NIHL) is a global issue that impacts people’s life and health. The current review aims to clarify the contributions and limitations of applying machine learning (ML) to predict NIHL by analyzing the performance of different ML techniques and the procedure of model construction.

Methods

The authors searched PubMed, EMBASE and Scopus on November 26, 2020.

Results

Eight studies were recruited in the current review following defined inclusion and exclusion criteria. Sample size in the selected studies ranged between 150 and 10,567. The most popular models were artificial neural networks (n = 4), random forests (n = 3) and support vector machines (n = 3). Features mostly correlated with NIHL and used in the models were: age (n = 6), duration of noise exposure (n = 5) and noise exposure level (n = 4). Five included studies used either split-sample validation (n = 3) or ten-fold cross-validation (n = 2). Assessment of accuracy ranged in value from 75.3% to 99% with a low prediction error/root-mean-square error in 3 studies. Only 2 studies measured discrimination risk using the receiver operating characteristic (ROC) curve and/or the area under ROC curve.

Conclusion

In spite of high accuracy and low prediction error of machine learning models, some improvement can be expected from larger sample sizes, multiple algorithm use, completed reports of model construction and the sufficient evaluation of calibration and discrimination risk.

Device abandonment in deafblindness: a scoping review of the intersection of functionality and usability through the International Classification of Functioning, Disability and Health lens

OBJECTIVES

Abandonment of vision, hearing or mobility aids suggests common barriers and facilitators to ongoing device use. However, the possible interactive effects of combined hearing and vision disabilities on device use by those living with deafblindness are unclear. Here we summarise existing knowledge on variables influencing assistive technology use from the perspective of persons living with deafblindness. We used the WHO's International Classification of Functioning, Disability and Health (ICF) framework to contextualise the findings, asking 'What is currently known about variables influencing the (non-)use of assistive devices recommended for persons with deafblindness?'

DESIGN

A scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews Checklist.

DATA SOURCES

PubMed; ProQuest: ERIC; ProQuest Dissertation; ProQuest: Sociological Thesaurus; Web of Science; Scientific Electronic Library Online; Bielefeld Academic Search Engine; Pascal & Francis; APA PsycINFO and Ebsco for CINAHL were searched through 9 November 2020.

ELIGIBILITY CRITERIA

We included peer-reviewed studies that reported on assistive technology, device abandonment/utilisation and provided data from persons living with deafblindness.

DATA EXTRACTION AND SYNTHESIS

Four team members independently scored 83 studies for eligibility.

RESULTS

Ten articles were chosen for data extraction. The emerging variables replicated established categories of barriers and facilitators: personal, device-related, environmental and intervention variables. The use of the ICF highlighted how an intermediate variable (eg, device acceptability) was necessary in order for a variable to become a barrier or a facilitator to device use.

CONCLUSIONS

The variables influencing device use by persons with deafblindness followed the same categories described for single impairments. Usability was challenged in devices that rely on the 'other' sense. Haptic and tactile aids are rarely studied. The limited available information and the dire need for assistive technologies for people with deafblindness emphasises the urgency of research and technology development for this marginalised population.

Associations between adolescents' earphone usage in noisy environments, hearing loss, and self-reported hearing problems in a nationally representative sample of South Korean middle and high school students

Few epidemiological studies have examined the relationship between earphone usage and hearing loss in adolescents. This study identified the prevalence of hearing loss in South Korean adolescents using representative national survey data and evaluated the relationship between earphone usage in a noisy environment and hearing loss. This study analyzed 532 subjects (12-19 years) who participated in a 2012 national survey and completed health and noise environment exposure questionnaires and pure tone audiometry (PTA) test. Hearing loss was defined as an average hearing threshold of 26 Decibel-A (dBA) or higher in PTA. The relationship between earphone usage and hearing loss was analyzed using a hierarchical logistic regression model. Adolescents who were exposed to high noise levels via headphones in a noisy environment had a hearing loss prevalence of 22.6% and adolescents who used earphones 80 minutes or more per day on average had the hearing loss prevalence of 22.3%. The results of the logistic regression analysis revealed that adolescents who used earphones in a noisy environment had a 4.5-fold higher risk of hearing loss and an 8.4 times higher risk of having a subjective hearing problem than those who did not use earphones (prevalence odds ratio (pOR) = 4.54, 95% confidence interval (CI): 1.35-15.24; pOR = 8.39, 95% CI: 1.12-62.83, respectively). Additionally, adolescents who used earphones more than 80 minutes per day in a noisy environment had a 4.7 times higher risk of hearing loss than those who used them less than 80 minutes per day (pOR = 4.68, 95% CI: 1.08-20.22). Longitudinal studies are needed to provide evidence of causality between earphone usage and hearing loss.