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.

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.

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.

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.

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.

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.

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.

Neuroinflammation and Tinnitus

Neuroinflammation is the central nervous system's response to: injury, infection, and abnormal neural activity. Inflammatory processes are known to mediate many diseases, and recently evidence indicates that neuroinflammation underlies hearing disorders such as presbyacusis, middle-ear disease, ototoxicity, noise-induced hearing loss, and tinnitus. This chapter provides a review of the role of neuroinflammation in the etiology and treatment of tinnitus. Specifically, our research team has demonstrated that both tumor necrosis factor alpha (TNF-α) and calpain signaling pathways are involved in noise-induced tinnitus and that blocking them yielded therapeutic effects on tinnitus. Other efforts such as controlling acute inflammatory response via specialized pro-resolving mediators may help provide insight into preventing and treating tinnitus-related inflammatory processes.

Regulator of G Protein Signalling 4 (RGS4) as a Novel Target for the Treatment of Sensorineural Hearing Loss

We and others have previously identified signalling pathways associated with the adenosine A₁ receptor (A₁R) as important regulators of cellular responses to injury in the cochlea. We have shown that the “post-exposure” treatment with adenosine A₁R agonists confers partial protection against acoustic trauma and other forms of sensorineural hearing loss (SNHL). The aim of this study was to determine if increasing A₁R responsiveness to endogenous adenosine would have the same otoprotective effect. This was achieved by pharmacological targeting of the Regulator of G protein Signalling 4 (RGS4). RGS proteins inhibit signal transduction pathways initiated by G protein-coupled receptors (GPCR) by enhancing GPCR deactivation and receptor desensitisation. A molecular complex between RGS4 and neurabin, an intracellular scaffolding protein expressed in neural and cochlear tissues, is the key negative regulator of A₁R activity in the brain. In this study, Wistar rats (6–8 weeks) were exposed to traumatic noise (110 dBSPL, 8–16 kHz) for 2 h and a small molecule RGS4 inhibitor CCG-4986 was delivered intratympanically in a Poloxamer-407 gel formulation for sustained drug release 24 or 48 h after noise exposure. Intratympanic administration of CCG-4986 48 h after noise exposure attenuated noise-induced permanent auditory threshold shifts by up to 19 dB, whilst the earlier drug administration (24 h) led to even better preservation of auditory thresholds (up to 32 dB). Significant improvement of auditory thresholds and suprathreshold responses was linked to improved survival of sensorineural tissues and afferent synapses in the cochlea. Our studies thus demonstrate that intratympanic administration of CCG-4986 can rescue cochlear injury and hearing loss induced by acoustic overexposure. This research represents a novel paradigm for the treatment of various forms of SNHL based on regulation of GPCR.

Prevalence and diagnostic challenges of thyroid lymphoma: a multi-institutional study in non-Western countries

Research on the primary thyroid lymphoma (PTL) diagnosis is limited, with only a few large sample size studies, reported from Asian countries. The aim of the present study was to clarify the current prevalence and challenges in PTL diagnosis, and recommended ancillary studies for PTL in non-Western countries. PTL (n = 153) cases were retrieved from 10 institutions in non-Western countries and analyzed. Ultrasound examination (UE) and fine needle aspiration cytology (FNAC) were used as main preoperative diagnostic tools in all participating institutions. Flow cytometry (FCM) was performed in the 5 institutions (50%). Lobectomy was the most common histological procedure to confirm the PTL diagnosis. All institutions routinely performed immuno-histochemical analysis. PTL was 0.54% of malignant thyroid tumor cases, with mucosa-associated lymphoid tissue lymphoma (MALTL) and diffuse large B-cell lymphoma (DLBCL) being 54.9% and 38.6%, respectively. Kuma Hospital, where the frequency of MALTL was highest (83.7%), routinely performed FCM using the materials obtained by FNAC. UE and FNAC sensitivities were 62.5% and 57.8%, respectively. In both UE and FNAC, sensitivity of MALTL was lower than of DLBCL. The study elucidated that the prevalence of PTL in non-Western countries was lower than previously reported. We propose that FCM should be more actively used to improve the preoperative diagnosis of MALTL. Our data predicted that the MALTL proportion will increase with improved diagnostic tools, while observation of PTL-suspected nodules without histological examination remains a viable option.

Do the upper lateral nasal cartilages exist? The concept of septolateral cartilages

BACKGROUND

In the cartilaginous nose, classical surgical anatomy describes 2 triangular upper lateral cartilages (ULCs) framing the lateral sides of the mid-third of the nasal pyramid, which articulate with to the superior edge of the quadrangular cartilage (QC) of the nasal septum. This anatomic arrangement in 3 distinct cartilage parts is, however, controversial.

OBJECTIVE

The present study aimed to describe the articulation between the ULCs and the QC, avoiding dissection artefacts.

MATERIALS AND METHODS

Six nasal pyramids were taken in monobloc from fresh cadavers and imaged on micro-MRI with 0.4mm slice thickness. Images were interpreted jointly by 2 head and neck surgeons and a radiologist.

RESULTS

The cartilage skeleton supporting the mid-third of the nasal dorsum in all specimens presented as 2 septal plates backing onto the midline and curving on either side to form a continuous dome under the inferior aspect of the piriform aperture.

CONCLUSION

Like the alar cartilages framing the tip of the nose, there are two continuous septolateral cartilages (SLCs) framing the mid-third of the nasal pyramid, likewise showing 2 cruras, medial and lateral, joined in a dome. The SLCs (also known as triangular cartilages) thus cannot be separated as 2 individual anatomic structures. These findings are in line with the shared embryological origin of all the elements composing the fibrocartilaginous nose in evo-devo theory.

Choice of imaging modality for pre-treatment staging of head and neck cancer impacts TNM staging

PURPOSE

The purpose of this retrospective cohort study was to determine whether there is a difference in the sensitivity of chest computed tomography (CT) versus ¹⁸F-fluorodeoxyglucose positron emission tomography with low-dose nonenhanced CT (¹⁸F-FDG PET/CT or PET/CT) in the detection of distant metastases in head and neck cancer, within a tertiary care setting.

MATERIALS AND METHODS

Patients with head and neck cancer, and known distant metastases, who underwent both ¹⁸F-FDG PET/CT with integrated low-dose nonenhanced CT and diagnostic chest CT prior to initiation of therapy from 2008 to 2017 were included. Two head and neck radiologists, blinded to all patient information and to each other's readings, reviewed the PET/CT or CT chest images for each patient and identified whether distant metastases were present. No radiologist read both modalities for a single patient. Concordance between imaging modalities was quantitatively analyzed using McNemar's test.

RESULTS

27 patients were included. McNemar's mid p-value analysis showed no significant difference in the detection of distant metastases (p = .6875). However, PET/CT detected distant metastases in three patients that chest CT did not, while chest CT identified distant metastatic disease in two patients that were negative on PET/CT.

CONCLUSIONS

While this study did not identify a statistically significant difference in sensitivity, five patients had distant metastases identified on only one of the two modalities. Use of a single modality would have resulted in inaccurate staging in 7-11% of patients in our study. The use of both modalities offers the greatest accuracy when providing stage-adapted oncologic treatment.

On the Role of Fibrocytes and the Extracellular Matrix in the Physiology and Pathophysiology of the Spiral Ligament

The spiral ligament in the cochlea has been suggested to play a significant role in the pathophysiology of different etiologies of strial hearing loss. Spiral ligament fibrocytes (SLFs), the main cell type in the lateral wall, are crucial in maintaining the endocochlear potential and regulating blood flow. SLF dysfunction can therefore cause cochlear dysfunction and thus hearing impairment. Recent studies have highlighted the role of SLFs in the immune response of the cochlea. In contrast to sensory cells in the inner ear, SLFs (more specifically type III fibrocytes) have also demonstrated the ability to regenerate after different types of trauma such as drug toxicity and noise. SLFs are responsible for producing proteins, such as collagen and cochlin, that create an adequate extracellular matrix to thrive in. Any dysfunction of SLFs or structural changes to the extracellular matrix can significantly impact hearing function. However, SLFs may prove useful in restoring hearing by their potential to regenerate cells in the spiral ligament.

Plants of the Genus Terminalia: An Insight on Its Biological Potentials, Pre-Clinical and Clinical Studies

The evaluation and confirmation of healing properties of several plant species of genus Terminalia based on their traditional uses and the clinical claims are of utmost importance. Genus Terminalia has received more attention to assess and validate the therapeutic potential and clinical approval due to its immense folk medicinal and traditional applications. Various species of Terminalia genus are used in the form of herbal medicine and formulations, in treatment of diseases, including headache, fever, pneumonia, flu, geriatric, cancer, to improve memory, abdominal and back pain, cough and cold, conjunctivitis, diarrhea, heart disorder, leprosy, sexually transmitted diseases, and urinary tract disorders. These are reported to possess numerous biological properties, counting: antibacterial, antifungal, antiinflammatory, antiviral, antiretroviral, antioxidant, and antipa7rasitic. This current research review aims to update the detailed biological activities, pre-clinical and clinical studies of various extracts and secondary metabolites from several plant species under the genus Terminalia, along with information on the traditional uses and chemical composition to develop a promising strategy for their potential applications in the form of medicine or use in modern drug formulations for treating diseases like pneumonia, flu, and other types of viral infections or controlling human contagions.

Morphological and morphometrical aspects of the auditory ossicles in goat (Capra hircus)

The present paper deals with a detailed description of the auditory ossicles in Capra hircus. The paper focuses on the morphological and morphometrical description of the ossicular assembly, formed by malleus, incus and stapes. The malleus (overall length, as average- 8.16 mm) comprises the head of malleus (Caput mallei), a slightly strictured part-neck (Collum mallei) with 3 distinctive processes (lateral, rostral and muscular) (Processus lateralis, Processus rostralis and Processus muscularis) and a handle (Manubrium mallei). The head of malleus has an oval aspect with an obtuse articular surface on its medial surface (Facies articularis). The neck is evident with three bony processes described-the anterior, almost triangular, the muscular one quite reduced and the lateral one which is the most developed one. The manubrium is the longest sector-4.4 mm and appears as a slightly curved piece. The incus presents a body of 1.3 mm and two processes-the short and long crus (Crus breve and Crus longum). The overall shape of the ossicle resembles a biradicular molar. The lenticular process is a continuation of the distal part of the long crus. The stapes-the smallest in size of the three ossicles (2.7 mm), has a head (Caput stapedis), an anterior (Crus rostrale) and a caudal (Crus caudale) arm and a footplate (Basis stapedis). The two processes are slightly different in size and morphology, delimiting the intercrural space that shows the presence of a bony spicule. The footplate (1.6 mm² area) is ellipsoidal, with an anterior narrower extremity.

Audiovestibular Quantification in Rare Third Window Disorders in Children

Third window disorders are structural abnormalities in the bony otic capsule that establish a connection between the middle/inner ear or the inner ear/cranial cavity. Investigated extensively in adults, they have hardly been studied in children. This study is a retrospective study of children (aged 5-17 years) diagnosed with rare third window disorders (third window disorders reported rarely or not reported in children) in a tertiary pediatric vestibular unit in the United Kingdom. It aimed to investigate audiovestibular function in these children. Final diagnosis was achieved by high resolution CT scan of the temporal bones. Of 920 children attending for audiovestibular assessment over a 42 month period, rare third windows were observed in 8 (<1%). These included posterior semicircular canal dehiscence (n = 3, 0.3%), posterior semicircular canal thinning (n = 2, 0.2%), X linked gusher (n = 2, 0.2%), and a combination of dilated internal auditory meatus/irregular cochlear partition/deficient facial nerve canal (n = 1, 0.1%). The majority of them (87.5%) demonstrated a mixed/conductive hearing loss with an air-bone gap in the presence of normal tympanometry (100%). Transient otoacoustic emissions were absent with a simultaneous cochlear pathology in 50% of the cohort. Features of disequilibrium were observed in 75% and about a third showed deranged vestibular function tests. Video head impulse test abnormalities were detected in 50% localizing to the side of the lesion. Cervical vestibular evoked myogenic potential test abnormalities were observed in all children in the cohort undergoing the test where low thresholds and high amplitudes classically found in third window disorders localized to the side of the defects in 28.5%. In the series, 71.4% also demonstrated absent responses/amplitude asymmetry, some of which did not localize to the ipsilesional side. Two children presented with typical third window symptoms. This study observes 2 new rare pediatric third window phenotypes and the presence of a cochlear hearing loss in these disorders. It emphasizes that these disorders should be considered as an etiology of hearing loss/disequilibrium in children. It also suggests that pediatric third window disorders may not present with classical third window features and are variable in their presentations/audiovestibular functions.

Anti-PD-1 Therapy Does Not Influence Hearing Ability in the Most Sensitive Frequency Range, but Mitigates Outer Hair Cell Loss in the Basal Cochlear Region

The administration of immune checkpoint inhibitors (ICIs) often leads to immune-related adverse events. However, their effect on auditory function is largely unexplored. Thorough preclinical studies have not been published yet, only sporadic cases and pharmacovigilance reports suggest their significance. Here we investigated the effect of anti-PD-1 antibody treatment (4 weeks, intraperitoneally, 200 μg/mouse, 3 times/week) on hearing function and cochlear morphology in C57BL/6J mice. ICI treatment did not influence the hearing thresholds in click or tone burst stimuli at 4–32 kHz frequencies measured by auditory brainstem response. The number and morphology of spiral ganglion neurons were unaltered in all cochlear turns. The apical-middle turns (<32 kHz) showed preservation of the inner and outer hair cells (OHCs), whilst ICI treatment mitigated the age-related loss of OHCs in the basal turn (>32 kHz). The number of Iba1-positive macrophages has also increased moderately in this high frequency region. We conclude that a 4-week long ICI treatment does not affect functional and morphological integrity of the inner ear in the most relevant hearing range (4–32 kHz; apical-middle turns), but a noticeable preservation of OHCs and an increase in macrophage activity appeared in the >32 kHz basal part of the cochlea.

Septorhinoplasty by disarticulation

Septorhinoplasty by disarticulation is an esthetic and functional solution for naturally occuring nasal pyramid dysmorphia, releasing the anatomic traces of growth-related stresses. Disarticulating the septolateral cartilage from its bony framework via a closed approach to the septal pocket is associated to Rethi's external approach in order to disarticulate the fibrocartilaginous nasal dorsum, while conserving its integrity, under the bony dorsum. The bony pyramid is then disarticulated down to the nasion, after resecting any bone hump, by 2 paramedian and 2 low lateral osteotomies in the basal groove. The lateral sides of the bony pyramid are then fractured at their posterior edges by percutaneous pinching to close the open roof and realign them along the midline. The septolateral cartilage, reduced as necessary at the inferior and anterior edges, is thereafter repositioned on the premaxillary bone. Traction on its anterior edge restores rectilinear frontal and lateral tension in the fibrocartilaginous dorsum, fully conserved from its attachment to the nasion. This technique corrects any septal deformity and restores frontal and lateral dorsum straightness.

[Modern aspects of pathogenetic treatment of sensorineural hearing loss]

OBJECTIVE

Optimization of the treatment of sensorineural hearing loss (SHL) using a calcium channel blocker - nimodipine.

MATERIAL AND METHODS

The study consists of experimental and clinical sections. The experiment involved 42 white outbred rats, which were used for modeling SHL according to the original method and treatment with nimodipine followed by histological control. The clinical study involved 115 patients with chronic SHL. Calcium metabolism was evaluated by quantifying the mineral density of bone tissue during osteodensitometry of the radial bones of patients.

RESULTS AND DISCUSSION

Histological studies after rats were removed from the experiment showed that modeling SHL by noise exposure against the background of immobilization of experimental animals is effective and is accompanied by early signs of apoptosis of the external hair and auxiliary cells, degenerative changes in spiral ganglion neurocytes. The role of calcium metabolism disorders in the initiation of the described disorders is shown. The use of nimodipine in experimental animals reduces the severity of histological changes. When examining patients with SHL, signs of impaired calcium metabolism in bone tissue were detected in 60% of the examined patients.

CONCLUSION

The obtained data determine the special role of disorders in the ratios of micro-elements in the body, especially calcium, in the development of SHL, and dictate the need for their correction using calcium channel blockers. The clinical use of nimodipine is possible both for prevention and for the treatment of sensorineural hearing loss.

Near-infrared-light pre-treatment attenuates noise-induced hearing loss in mice

Noise induced hearing loss (NIHL) is accompanied by a reduction of cochlear hair cells and spiral ganglion neurons. Different approaches have been applied to prevent noise induced apoptosis / necrosis. Physical intervention is one technique currently under investigation. Specific wavelengths within the near-infrared light (NIR)-spectrum are known to influence cytochrome-c-oxidase activity, which leads in turn to a decrease in apoptotic mechanisms. It has been shown recently that NIR can significantly decrease the cochlear hair cell loss if applied daily for 12 days after a noise exposure. However, it is still unclear if a single NIR-treatment, just before a noise exposure, could induce similar protective effects. Therefore, the present study was conducted to investigate the effect of a single NIR-pre-treatment aimed at preventing or limiting NIHL. The cochleae of adult NMRI-mice were pre-treated with NIR-light (808 nm, 120 mW) for 5, 10, 20, 30 or 40 minutes via the external ear canal. All animals were noised exposed immediately after the pre-treatment by broad band noise (5–20 kHz) for 30 minutes at 115 dB SPL. Frequency specific ABR-recordings to determine auditory threshold shift were carried out before the pre-treatment and two weeks after the noise exposure. The amplitude increase for wave IV and cochlear hair cell loss were determined. A further group of similar mice was noise exposed only and served as a control for the NIR pre-exposed groups. Two weeks after noise exposure, the ABR threshold shifts of NIR-treated animals were significantly lower (p < 0.05) than those of the control animals. The significance was at three frequencies for the 5-minute pre-treatment group and across the entire frequency range for all other treatment groups. Due to NIR light, the amplitude of wave four deteriorates significantly less after noise exposure than in controls. The NIR pre-treatment had no effect on the loss of outer hair cells, which was just as high with or without NIR-light pre-exposure. Relative to the entire number of outer hair cells across the whole cochlea, outer hair cell loss was rather negligible. No inner hair cell loss whatever was detected. Our results suggest that a single NIR pre-treatment induces a very effective protection of cochlear structures from noise exposure. Pre-exposure of 10 min seems to emerge as the optimal dosage for our experimental setup. A saturated effect occurred with higher dosage-treatments. These results are relevant for protection of residual hearing in otoneurosurgery such as cochlear implantation.

Enlarged vestibular aqueduct: Intraoperative electrocochleography findings during cochlear implantation

Enlarged vestibular aqueduct (EVA) is the most frequent inner ear abnormality found on computed tomography in children with sensorineural hearing loss. The effects EVA abnormalities have on electrocochleography (ECochG) are unknown. Positive deflections in summation potential evoked by tone bursts were observed in 3/5 subjects, while a large negative deflection, similar to endolymphatic hydrops (EH), was observed for 2/5 subjects. The presence of an enlarged summation potential, with and without a compound action potential, was observed in response to a broadband click stimulus. Results suggest likely effects of a third window on ECochG responses and presence of EH in EVA.