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.

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.

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.

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.

Sound and Vibration as Research Variables in Terrestrial Vertebrate Models

Sound and vibration have been shown to alter animal behavior and induce physiological changes as well as to cause effects at the cellular and molecular level. For these reasons, both environmental factors have a considerable potential to alter research outcomes when the outcome of the study is dependent on the animal existing in a normal or predictable biological state. Determining the specific levels of sound or vibration that will alter research is complex, as species will respond to different frequencies and have varying frequencies where they are most sensitive. In consideration of the potential of these factors to alter research, a thorough review of the literature and the conditions that likely exist in the research facility should occur specific to each research study. This review will summarize the fundamental physical properties of sound and vibration in relation to deriving maximal level standards, consider the sources of exposure, review the effects on animals, and discuss means by which the adverse effects of these factors can be mitigated.

Detecting middle ear fluid using smartphones

The presence of middle ear fluid is a key diagnostic marker for two of the most common pediatric ear diseases: acute otitis media and otitis media with effusion. We present an accessible solution that uses speakers and microphones within existing smartphones to detect middle ear fluid by assessing eardrum mobility. We conducted a clinical study on 98 patient ears at a pediatric surgical center. Using leave-one-out cross-validation to estimate performance on unseen data, we obtained an area under the curve (AUC) of 0.898 for the smartphone-based machine learning algorithm. In comparison, commercial acoustic reflectometry, which requires custom hardware, achieved an AUC of 0.776. Furthermore, we achieved 85% sensitivity and 82% specificity, comparable to published performance measures for tympanometry and pneumatic otoscopy. Similar results were obtained when testing across multiple smartphone platforms. Parents of pediatric patients (n = 25 ears) demonstrated similar performance to trained clinicians when using the smartphone-based system. These results demonstrate the potential for a smartphone to be a low-barrier and effective screening tool for detecting the presence of middle ear fluid.

Review of Temporal Bone Microanatomy : Aqueducts, Canals, Clefts and Nerves

Temporal bone microanatomy is a common source of consternation for radiologists. Serpentine foramina, branching cranial nerves, and bony canals containing often clinically relevant but often miniscule arterial branches may all cause confusion, even among radiologists familiar with temporal bone imaging. In some cases, the tiniest structures may be occult or poorly visualized, even on thin-slice computed tomography (CT) images. Consequently, such structures are often either ignored or mistaken for pathologic entities. Yet even the smallest temporal bone structures have significant anatomic and pathologic importance. This paper reviews the anatomy and function of the temporal bone aqueducts, canals, clefts, and nerves, as well as the relevant developmental, inflammatory, and neoplastic processes that affect each structure.

GLOS: GLOve for Speech Recognition

Technological advancements in the field of Biomedical Engineering have allowed impaired individuals to use assistive devices in order to improve their quality of life. In the case of deafblind subjects, who experience both visual and auditory loss, the majority of available assistive devices are invasive (e.g. cochlear implants). Non-invasive technological improvements are extremely limited, in part due to the lack of scientific research interest in dual sensory loss [1]. In this paper we aim to present GLOS, a low-cost and non-invasive device that will allow the deafblind individuals to comprehend speeches in real-time. The proposed wearable device uses off-the-shelf components such as a Raspberry Pi 3 board, a simple microphone, and haptic feedback vibrating disks. The recorded speech from the microphone is processed by the board and encoded into 5 haptic vibrating modules attached to a glove. Each haptic vibrating module is placed on a different finger of the right hand. The current available non-invasive solutions do not use speech and therefore they do not allow for live communication (e.g. MyVox [2], Sparsha [3] and Mobile Lorm Glove [4]) or require long procedures to convert the messages (e.g. Finger Braille Teaching System [5]). This new biomedical device aims at overcoming these limitations. The authors tested the device in a preliminary testing and it was shown that GLOS has an average accuracy of 91.67% when tested for the recognition of twenty encoded sentences. The authors were deprived of both visual and hearing inputs and were trained for half hour per day for a period of 30 days.

Extracellular Matrix Composition and Remodeling: Current Perspectives on Secondary Palate Formation, Cleft Lip/Palate, and Palatal Reconstruction

Craniofacial development comprises a complex process in humans in which failures or disturbances frequently lead to congenital anomalies. Cleft lip with/without palate (CL/P) is a common congenital anomaly that occurs due to variations in craniofacial development genes, and may occur as part of a syndrome, or more commonly in isolated forms (non-syndromic). The etiology of CL/P is multifactorial with genes, environmental factors, and their potential interactions contributing to the condition. Rehabilitation of CL/P patients requires a multidisciplinary team to perform the multiple surgical, dental, and psychological interventions required throughout the patient's life. Despite progress, lip/palatal reconstruction is still a major treatment challenge. Genetic mutations and polymorphisms in several genes, including extracellular matrix (ECM) genes, soluble factors, and enzymes responsible for ECM remodeling (e.g., metalloproteinases), have been suggested to play a role in the etiology of CL/P; hence, these may be considered likely targets for the development of new preventive and/or therapeutic strategies. In this context, investigations are being conducted on new therapeutic approaches based on tissue bioengineering, associating stem cells with biomaterials, signaling molecules, and innovative technologies. In this review, we discuss the role of genes involved in ECM composition and remodeling during secondary palate formation and pathogenesis and genetic etiology of CL/P. We also discuss potential therapeutic approaches using bioactive molecules and principles of tissue bioengineering for state-of-the-art CL/P repair and palatal reconstruction.

Utility of negative-pressure wound therapy for orocutaneous and pharyngocutaneous fistula following head and neck surgery

BACKGROUND

Because of the difficulty of airtight sealing and risk of salivary contamination, negative-pressure wound therapy (NPWT) has rarely been applied for postoperative fistula following head and neck surgery; thus, its utility remains unclear.

METHODS

We applied NPWT in 34 patients who developed orocutaneous and pharyngocutaneous fistula after head and neck surgery. Here we retrospectively analyzed the utility of NPWT for managing those fistulas.

RESULTS

Thirty-two patients (94.1%) underwent NPWT as scheduled without adverse events. In 28 patients (82.4%), fistula closure was completed only by NPWT, and the mean period to fistula closure was 30.4 days. The mean period to closure did not differ significantly between fistulas with (21.7 days) and without (39.1 days) previous irradiation.

CONCLUSIONS

Airtight sealing can be maintained and postoperative fistula can be closed by NPWT with a high success rate, even after previous irradiation. NPWT is an effective and minimally invasive treatment for postoperative fistula.

Local Delivery of Therapeutics to the Inner Ear: The State of the Science

Background: Advances in the understanding of the genetic and molecular etiologies of inner ear disorders have enabled the identification of therapeutic targets and innovative delivery approaches to the inner ear. As this field grows, the need for knowledge about effective delivery of therapeutics to the inner ear has become a priority. This review maps all clinical and pre-clinical research published in English in the field to date, to guide both researchers and clinicians about local drug delivery methods in the context of novel therapeutics. Methods: A systematic search was conducted using customized strategies in Cochrane, pubmed and EMBASE databases from inception to 30/09/2018. Two researchers undertook study selection and data extraction independently. Results: Our search returned 12,200 articles, of which 837 articles met the inclusion criteria. 679 were original research and 158 were reviews. There has been a steady increase in the numbers of publications related to inner ear therapeutics delivery over the last three decades, with a sharp rise over the last 2 years. The intra-tympanic route accounts for over 70% of published articles. Less than one third of published research directly assesses delivery efficacy, with most papers using clinical efficacy as a surrogate marker. Conclusion: Research into local therapeutic delivery to the inner ear has undergone a recent surge, improving our understanding of how novel therapeutics can be delivered. Direct assessment of delivery efficacy is challenging, especially in humans, and progress in this area is key to understanding how to make decisions about delivery of novel hearing therapeutics.

Evidence for a dynorphin-mediated inner ear immune/inflammatory response and glutamate-induced neural excitotoxicity: an updated analysis

Acoustic overstimulation (AOS) is defined as the stressful overexposure to high-intensity sounds. AOS is a precipitating factor that leads to a glutamate (GLU)-induced Type I auditory neural excitotoxicity and an activation of an immune/inflammatory/oxidative stress response within the inner ear, often resulting in cochlear hearing loss. The dendrites of the Type I auditory neural neurons that innervate the inner hair cells (IHCs), and respond to the IHC release of the excitatory neurotransmitter GLU, are themselves directly innervated by the dynorphin (DYN)-bearing axon terminals of the descending brain stem lateral olivocochlear (LOC) system. DYNs are known to increase GLU availability, potentiate GLU excitotoxicity, and induce superoxide production. DYNs also increase the production of proinflammatory cytokines by modulating immune/inflammatory signal transduction pathways. Evidence is provided supporting the possibility that the GLU-mediated Type I auditory neural dendritic swelling, inflammation, excitotoxicity, and cochlear hearing loss that follow AOS may be part of a brain stem-activated, DYN-mediated cascade of inflammatory events subsequent to a LOC release of DYNs into the cochlea. In support of a DYN-mediated cascade of events are established investigations linking DYNs to the immune/inflammatory/excitotoxic response in other neural systems.

Factors predisposing to the development of orocutaneous fistula following surgery for oral cancer: Experience from a tertiary cancer center

BACKGROUND

Orocutaneous fistula (OCF) is one of the frequently encountered postoperative complications following surgery for oral cancer, leading to prolonged hospital stay and delay in the initiation of adjuvant therapy.

METHODS

We included all patients with oral cancer operated between January 2016 to December 2017 and at risk to develop an OCF. We assessed the incidence of OCF, its management, and factors predisposing to its development.

RESULTS

Of 587 eligible patients, 9% developed OCF. On univariate and multivariate analysis, patients undergoing bilateral neck dissection or with surgical site infection (SSI) (P < .001) were at maximum risk. On univariate analysis, the incidence was higher following resections for tongue-floor of mouth sub site (P = .002), irrespective of the type of flap used for reconstruction. Majority (57%) required surgical intervention for management.

CONCLUSION

The presence of SSI and performing bilateral neck dissection posed the maximum risk for developing OCF in patients undergoing surgery for oral cancer.

Vestibular evoked myogenic potentials in patients with diabetes mellitus

Although the exact mechanism and most involved region of the vestibular system have not yet been fully clarified, vestibular dysfunction has been demonstrated in patients with diabetes mellitus (DM). Vestibular evoked myogenic potential (VEMP) is a short latency electromyographic response to sound or vibration stimuli that may reflect otolith organ or related reflex functions. Since its first description in 1992, VEMP has become a significant part of the vestibular test battery as an objective measurement tool. In diabetic patients, VEMP responses have been studied in order to determine any otolith organ or related reflex dysfunctions. Here, we review the literature with regard to VEMP findings representing any peripheral vestibular end-organ dysfunction in patients with DM. Distinctive vestibular end-organ impairments seem to be demonstrated in patients with DM either with or without DNP via objective vestibular testing tools including VEMP recordings according to relevant studies. However, further studies with larger sample sizes are required to reveal the more definitive findings of VEMP recordings regarding the vestibular pathologies in patients with DM.

PET/CT Evaluation of Head and Neck Cancer of Unknown Primary

The diagnosis of carcinoma of unknown primary in the head and neck is made when there is a metastasis but no primary lesion is identified after physical exam and diagnostic CT or MR imaging. PET/CT is the first step in searching for a primary lesion, followed by more invasive techniques such as endoscopy and surgery. Knowledge of the different tumor histologic types, preferential locations of nodal spread, imaging pitfalls, and other special considerations such as cystic metastases can be helpful in the ultimate identification of primary tumors, which leads to improved overall patient survival.

Oral Administration of Caffeine Exacerbates Cisplatin-Induced Hearing Loss

Adenosine A₁ receptors (A₁AR) are well characterized for their role in cytoprotection. Previous studies have demonstrated the presence of these receptors in the cochlea where their activation were shown to suppress cisplatin-induced inflammatory response and the resulting ototoxicity. Inhibition of A₁AR by caffeine, a widely consumed psychoactive substance, could antagonize the endogenous protective role of these receptors in cochlea and potentiate cisplatin-induced hearing loss. This hypothesis was tested in a rat model of cisplatin ototoxicity following oral administration of caffeine. We report here that single-dose administration of caffeine exacerbates cisplatin-induced hearing loss without increasing the damage to outer hair cells (OHCs), but increased synaptopathy and inflammation in the cochlea. These effects of caffeine were mediated by its blockade of A₁AR, as co-administration of R-PIA, an A₁AR agonist, reversed the detrimental actions of caffeine and cisplatin on hearing loss. Multiple doses of caffeine exacerbated cisplatin ototoxicity which was associated with damage to OHCs and cochlear synaptopathy. These findings highlight a possible drug-drug interaction between caffeine and cisplatin for ototoxicity and suggest that caffeine consumption should be cautioned in cancer patients treated with a chemotherapeutic regimen containing cisplatin.

Morphological and morphometrical study of the auditory ossicles in chinchilla

This study is meant to illustrate and describe the features of the auditory ossicles of the chinchilla (Chinchilla lanigera), one of the species used more and more frequently in otology and ear surgery as animal model. Cephalic extremities of 12 C. lanigera individuals obtained from a private farm, where this species was bred for fur, were used in this study. The ossicles were obtained either by direct surgical harvesting by mastoid approach or after a dermestid beetle exposure followed by anatomical dissection. The three ossicles that form the assembly are the malleus, incus and stapes. After the removal of these ossicles, a series of anatomical descriptions were made, followed by seriate sets of measurements. The malleus and incus form a joined-single unit called the maleo-incal complex, with an elongated straight appearance, also due to the development of the anterior process. The handle of the malleus and the long process of incus are almost perpendicular to the main axis of the maleo-incal complex. The presence of the muscular process on the handle of the malleus is recorded. The overall shape of the incus is given by the uneven development of the two processes and the reduced neck part. The stapes is the smallest of the components that maintains the well-known architecture in accordance with the general model. The morphology of all three ossicles is backed by a series of measurements, some standard, some adapted to the morphology of the ossicles. From the very reduced comparative metrical data at our disposal, our study presents an average of 10% lower values for the ones presented earlier by other researchers in the same species.

Purinergic Signaling and Cochlear Injury-Targeting the Immune System?

Hearing impairment is the most common sensory deficit, affecting more than 400 million people worldwide. Sensorineural hearing losses currently lack any specific or efficient pharmacotherapy largely due to the insufficient knowledge of the pathomechanism. Purinergic signaling plays a substantial role in cochlear (patho)physiology. P2 (ionotropic P2X and the metabotropic P2Y) as well as adenosine receptors expressed on cochlear sensory and non-sensory cells are involved mostly in protective mechanisms of the cochlea. They are implicated in the sensitivity adjustment of the receptor cells by a K⁺ shunt and can attenuate the cochlear amplification by modifying cochlear micromechanics. Cochlear blood flow is also regulated by purines. Here, we propose to comprehend this field with the purine-immune interactions in the cochlea. The role of harmful immune mechanisms in sensorineural hearing losses has been emerging in the horizon of cochlear pathologies. In addition to decreasing hearing sensitivity and increasing cochlear blood supply, influencing the immune system can be the additional avenue for pharmacological targeting of purinergic signaling in the cochlea. Elucidating this complexity of purinergic effects on cochlear functions is necessary and it can result in development of new therapeutic approaches in hearing disabilities, especially in the noise-induced ones.

Purinergic Signaling and Aminoglycoside Ototoxicity: The Opposing Roles of P1 (Adenosine) and P2 (ATP) Receptors on Cochlear Hair Cell Survival

Purinergic signaling regulates important physiological processes and the homeostatic response to stress in the cochlea via extracellular nucleosides (adenosine) and nucleotides (ATP, UTP). Using a previously established organotypic culture model, the current study investigated the effect of purinergic P1 (adenosine) and P2 (ATP) receptor activation on the survival of the sensory hair cell population in the cochlea exposed to the ototoxic aminoglycoside neomycin. Organ of Corti explants were obtained from C57BL/6 mice at postnatal day 3 (P3) and maintained in normal culture medium (with or without purine receptor agonists or analogs) for 19.5 h prior to neomycin exposure (1 mM, 3 h) followed by a further incubation for 19.5 h in culture medium. The cochlear explants were then fixed in 4% paraformaldehyde (PFA) and sensory hair cells labeled with Alexa 488-phalloidin. Neomycin induced a substantial loss of the sensory hair cells, mostly in the middle segment of the cochlea. This neomycin-induced ototoxicity was unaffected by the addition of P2 receptor agonists (ATP and UTP) in the culture medium, whilst the addition of their slowly-hydrolyzable analogs (ATPγS, UTPγS) aggravated neomycin-induced sensory hair cell loss. In contrast, the activation of P1 receptors by adenosine or adenosine amine congener (ADAC) conferred partial protection from neomycin ototoxicity. This study demonstrates a pro-survival effect of P1 receptor stimulation, whilst prolonged activation of P2 receptors has an opposite effect. Based on these findings, we postulate that P1 and P2 receptors orchestrate differential responses to cochlear injury and that the balance of these receptors is important for maintaining cochlear homeostasis following ototoxic injury.

Using the ICF to Identify Contextual Factors That Influence Participation of Persons With Deafblindness

OBJECTIVE

To identify and describe the contextual factors that influence the participation of people with deafblindness in India.

DESIGN

Qualitative study, using directed content analysis approach and the International Classification of Functioning, Disability and Health (ICF) as a framework to analyze the data.

SETTING

Community and social participation settings.

PARTICIPANTS

Community-dwelling individuals with deafblindness (N=16). Age ranges from 18-45 years.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Personal and environmental factors that influence the participation of individuals with deafblindness using the ICF framework.

RESULTS

Results indicate that the age of onset and nature of impairment (deafblindness) and willingness to explain the condition (functional consequences of deafblindness) emerged as important personal factors. Access to resources such as assistive technology, social support, and deafblind-specific services were found to be enablers of participation. Lack of services, systems, and policies specific to deafblindness along with negative societal attitude toward disability were highly perceived environmental barriers that influence participation of people with deafblindness in India.

CONCLUSIONS

Professionals must acknowledge aspects of the environment in conducting assessments and delivering interventions and understand the dynamic interactions between environment of the individual and his/her concurrent vision and hearing impairments. Approaches to enable participation require rehabilitation professionals to work with those with deafblindness to advocate for removal of environmental barriers and ensure provision of appropriate resources from the government to facilitate their participation. Social policy and government must ensure emphasis on awareness about deafblindness, access to deafblind-specific services, positive societal attitude, and opportunities for full participation for people with deafblindness in society.

Thermal water delivery in the nose: experimental results describing droplet deposition through computational fluid dynamics

Thermal water therapies have a role in treating various inflammatory disorders dating back to ancient Greece. Several studies have demonstrated beneficial effects of thermal water inhalations for upper respiratory disorders, such as improvement of mucociliary function and reduction of inflammatory cell infiltration. This experimental study describes the numerical investigation and clinical implications of thermal water droplet deposition in the nasal cavity of a single patient. To our knowledge, the numerical flow simulations described are the first investigations specifically designed for thermal water applications. To simulate nasal airflow, a patient-specific 3D computer model was created from a CT scan. The numerical approach is based on the Large Eddy Simulation (LES) technique and builds entirely upon open-source software. Deposition on mucosa was studied for two droplet sizes (5 and 10 μm diameter), corresponding to common thermal therapy applications (aerosol and vapour inhalation). The simulations consider steady inspiration at two different (low and moderate) breathing intensities. The results of this preliminary study show specific deposition patterns that favour droplet deposition in the middle meatus region to the inferior meatus, with particle size- and breathing intensity-related effects. These global data on particle deposition differ from findings related to the single-phase nasal airflow, which is more evenly distributed between the middle and inferior meatus. The potential clinical consequences of deposition data are discussed. The study furthermore provides evidence for the effectiveness of thermal aerosol and vapour inhalation therapies in reaching important areas of nasal mucosa with considerable clinical significance.

Meaning and experiences of participation: a phenomenological study with persons with deafblindness in India

Purpose: Deafblindness, also known as dual sensory loss, creates a distinct condition more disabling than either deafness or blindness alone. The participation experiences of persons with deafblindness have not been understood well. This phenomenological study aims to understand the meanings of participation for persons with deafblindness and identify the domains of life that are important to them.Methods: We used the International Classification of Functioning, Disability and Health as a guiding framework. Sixteen adults with deafblindness were interviewed between March and May 2017 in India using a qualitative interview guide.Results: Findings suggest participation as a dynamic, individualized construct that is not just an end outcome. Rather, it is a means to achieve other goals important to the participants such as gaining respect, autonomy, independence, support and relationships, to fulfill aspirations and responsibilities, and to feel included and recognized in society. Life domains that they deemed important for participation were communication and access to information, mobility, relationships, education and productivity, and recreation and leisure.Conclusions: In order to enhance societal participation of people with deafblindness, a significant change in the focus of rehabilitation services is required which involves professionals viewing participation as both a means and an end outcome while designing interventions.

Lund-Mackay Computed Tomography Score Is Associated With Obstructive Pulmonary Function Changes in Chronic Cough Patients

BACKGROUND

A remarkable relationship between upper airway conditions and lung diseases has been reported. At the same time, sinonasal findings in chronic cough patients have not been fully examined.

OBJECTIVE

The purpose of this study is to show paranasal sinus findings and lung function in chronic cough patients without asthma and chest X-ray abnormalities.

METHODS

A total of 1412 patients with persistent cough were enrolled in this study. Of these patients, 376 patients were evaluated for further examination, as the patients with asthma and/or chest X-ray abnormality were excluded from the study. Normal control subjects without any chronic respiratory symptoms were also recruited. Pulmonary function was examined by spirometry. A bronchial obstruction reversibility test was applied. The Lund-Mackay computed tomography (CT) score, peripheral blood eosinophil count, and immunoglobulin E concentration in serum samples were examined. The Sino-Nasal Outcome Test was used to determine the severity of clinical symptoms.

RESULTS

The patients with an abnormal soft tissue shadow in the paranasal sinus had significant obstructive lung function. The percent predicted forced expiratory volume in 1 second (FEV_1.0) and the FEV_1.0/forced vital capacity ratio negatively correlated with Lund-Mackay CT scores both before and after bronchodilator inhalation. There was a statistically significant correlation between pulmonary function and eosinophil count.

CONCLUSION

The patients with chronic cough frequently had paranasal sinus abnormalities. The Lund-Mackay CT score may be useful for assessing the condition of the lower airway in chronic cough patients. Upper airway examinations should play a part in the management of chronic cough.

Analysis of the development of human foetal nasal turbinates using CBCT imaging

PURPOSE

The morphological structure of the nasal cavity (NC) is important for endoscopic surgical treatment. The location of nasal turbinates, including the superior turbinate (ST), middle turbinate (MT) and inferior turbinate (IT), are well presented during the formation of the human NC in cone beam CT (CBCT) images. There is a complex relationship between the nasal sinuses, the maxillary sinus (MS), ethmoidal sinus and sphenoid sinus, during formation of the NC structure at the morphological level. There is a need to clearly define the relationships of these nasal elements at the ossification level, during development.

METHODS

We investigated the three-dimensional construction of human foetal NC elements, including ST, MT, IT and vomer, using CBCT images from 16 weeks gestation (E16) to E31 (25 foetuses) and compared it to histochemical observations (E25).

RESULTS

At the stage of ossification, the studied elements are elongated in the posterior region near the sphenoidal bone, showing that the locations of the ST, MT, and IT are important during formation of the NC. CBCT analysis revealed that the horizontal and vertical directions of nasal turbinates affect the formation of the human NC.

CONCLUSION

The location and elongated development of the MT is one of the most important elements for NC formation. The relationship between the nasal sinus and nasal turbine at the level of ossification may provide useful information in clinical treatment of children.

Participation experiences of people with deafblindness or dual sensory loss: A scoping review of global deafblind literature

BACKGROUND

Deafblindness, also known as dual sensory loss, is a varying combination of visual and hearing impairment in the same individual. Interest in this topic has increased recently due to evidence suggesting an increase in prevalence of this condition among older adults. Persons with deafblindness frequently experience participation barriers and social isolation. Developing an understanding of their experiences can inform the design of programs and policies to enhance participation of people with deafblindness in society.

OBJECTIVE

To identify and summarize available research literature on participation experiences of people with deafblindness or dual sensory loss.

METHODS

A comprehensive literature search of eight databases (CINAHL/EBSCO, Embase, ERIC, Global Health, MEDLINE, ProQuest, PsycINFO, PubMed) was performed in accordance with the Preferred Reporting Items for Systematic Reviews (PRISMA) during January 2017 and last updated in June 2017. In addition, non-peer reviewed (grey) literature was also retrieved in the form of online published reports of research projects by 16 deafblind-specific organizations across the globe. To be included, sources had to be published after 1990, had persons with deafblindness as the focal population, and focused on their participation experiences.

RESULTS

A total 1172 sources were identified of which 54 studies were included. The findings reveal that persons with deafblindness, regardless of origin of their impairment, experience difficulty in communication, mobility, daily living functioning, and social interactions. While these experiences may vary between individuals with congenital versus acquired conditions, they generally feel socially isolated, insecure and uncertain about their future.

CONCLUSION

Participation experiences of persons with deafblindness are shaped by dynamic interactions between personal factors (such as onset and type of impairments) and environmental influences (such as attitude, technology, and supports). A better understanding of participation experiences may help professionals in placing emphasis on affected participation domains to design services to enhance participation of people with deafblindness.

Aetiologies of acquired deafblindness in a national sample

The present study provides an overview of aetiologies and co-morbidities of acquired deafblindness in a Danish national sample of 514 individuals above 50 years of age identified with acquired deafblindness. Information was obtained from a survey and a register. The most frequent aetiology of vision loss was age-related macular degeneration (55.4%). The most frequent aetiology of hearing loss was presbycusis (53.7%). The most frequent aetiology of acquired deafblindness was the combination of age-related macular degeneration and presbycusis (41.5%). However, among the younger participants (50–59 years of age), Usher syndrome was the most common aetiology (62.5%). The aetiologies of acquired deafblindness are many and constituted by several different combinations of hearing and vision loss aetiologies. The most frequent aetiologies are age related.

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

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

Mitigating noise-induced hearing loss after blast injury

Introduction

Whilst hearing injuries are not life threatening they may have a profound impact on the victim’s ability to understand and interact with the world around them. Noise-induced hearing loss is a common occupational injury and hearing impairment as a consequence of noise and blast exposure remains the most common injury in both war and peace for military personnel. Health and Safety legislation has made an impact and in the future innovative approaches to mitigate against acoustic injury sustained in the work place will be fundamental. For the Armed Forces, noise exposure during conflict is unpredictable. Furthermore, recent events in the UK and elsewhere have highlighted the potential civilian impact of blast injuries on hearing in the acute setting. No well-established protocol for the management of acute, blast-induced hearing injury currently exists.

Methods

Narrative review is supported by electronic literature searches of PubMed, Embase and the Cochrane Library. Synthesis of published literature and production of flow charts for the acute setting are part of the Emergency Preparedness, Resilience and Response programme.

Results

Whilst there is a lack of high-quality randomised controlled trials, there are a number of studies that may inform our choice of acute management. Animal studies of acute acoustic trauma have shown the potential protective effects of corticosteroids. Human data may be extrapolated from sudden onset sensorineural hearing loss where again there is evidence for the use of corticosteroids. Less certainty exists around the use of other treatments including antioxidants. Intratympanic administration of corticosteroids may be superior to oral administration, particularly in the salvage setting. No evidence exists specifically pertaining to the paediatric population.

Conclusion

Prompt identification of any hearing deficit followed by administration of glucocorticoids either orally or via intratympanic preparations is the mainstay of management. Further research is needed to identify the optimum acute management.

Oxidative Stress and Inflammation Induced by Environmental and Psychological Stressors: A Biomarker Perspective

SIGNIFICANCE

The environment can elicit biological responses such as oxidative stress (OS) and inflammation as a consequence of chemical, physical, or psychological changes. As population studies are essential for establishing these environment-organism interactions, biomarkers of OS or inflammation are critical in formulating mechanistic hypotheses. Recent Advances: By using examples of stress induced by various mechanisms, we focus on the biomarkers that have been used to assess OS and inflammation in these conditions. We discuss the difference between biomarkers that are the result of a chemical reaction (such as lipid peroxides or oxidized proteins that are a result of the reaction of molecules with reactive oxygen species) and those that represent the biological response to stress, such as the transcription factor NRF2 or inflammation and inflammatory cytokines.

CRITICAL ISSUES

The high-throughput and holistic approaches to biomarker discovery used extensively in large-scale molecular epidemiological exposome are also discussed in the context of human exposure to environmental stressors.

FUTURE DIRECTIONS

We propose to consider the role of biomarkers as signs and to distinguish between signs that are just indicators of biological processes and proxies that one can interact with and modify the disease process. Antioxid. Redox Signal. 28, 852-872.

Functional Testing of SLC26A4 Variants-Clinical and Molecular Analysis of a Cohort with Enlarged Vestibular Aqueduct from Austria

The prevalence and spectrum of sequence alterations in the SLC26A4 gene, which codes for the anion exchanger pendrin, are population-specific and account for at least 50% of cases of non-syndromic hearing loss associated with an enlarged vestibular aqueduct. A cohort of nineteen patients from Austria with hearing loss and a radiological alteration of the vestibular aqueduct underwent Sanger sequencing of SLC26A4 and GJB2, coding for connexin 26. The pathogenicity of sequence alterations detected was assessed by determining ion transport and molecular features of the corresponding SLC26A4 protein variants. In this group, four uncharacterized sequence alterations within the SLC26A4 coding region were found. Three of these lead to protein variants with abnormal functional and molecular features, while one should be considered with no pathogenic potential. Pathogenic SLC26A4 sequence alterations were only found in 12% of patients. SLC26A4 sequence alterations commonly found in other Caucasian populations were not detected. This survey represents the first study on the prevalence and spectrum of SLC26A4 sequence alterations in an Austrian cohort and further suggests that genetic testing should always be integrated with functional characterization and determination of the molecular features of protein variants in order to unequivocally identify or exclude a causal link between genotype and phenotype.

Chronic nasal dysfunction

Chronic nasal dysfunction is a clinical concept in the diagnostic and therapeutic management of sinonasal diseases, based on the evo-devo theory of formation of the nose according to which the nose is not a single organ but rather an association of three organs: olfactory nose, respiratory nose and paranasal sinuses. In chronic nasal dysfunction theory, etiological diagnosis takes account of the possible pathophysiological independence of nasal symptoms, in accordance with the different origins and physiology of the three organs constituting the nose. The diagnostic approach of the chronic nasal dysfunction concept breaks down the pathology so as to propose treatment(s) adapted to the diseased organ(s) and to the capacity for physiological resolution of dysfunction induced in one organ by pathology in a neighboring nasal organ. The ethmoid is not a sinus according to evo-devo, and therefore functional endoscopic endonasal surgery (FEES) cannot be restricted to functional endoscopic sinus surgery (FESS). Evo-devo theory and the chronic nasal dysfunction concept offer an alternative to the concept of chronic rhinosinusitis with or without polyps for the management of sinonasal diseases.

Prevention of ischemia-induced hearing loss by intravenous administration of hydrogen-rich saline in gerbil

OBJECTIVE

Hydrogen-rich water, which is a potent antioxidant agent, was investigated for its protective effects against ischemic damage of the cochlea in gerbils.

METHODS

The animals were subjected to transient cochlear ischemia by occluding the bilateral vertebral arteries for l5min. Five milliliters of hydrogen-rich saline was then intravenously administered immediately after the insult. Saline without hydrogen was used as a control. Effects of hydrogen were evaluated using the auditory brainstem response (ABR) and histological studies of the inner ear.

RESULTS

In non-ischemia animals, ABR thresholds and histological findings of the cochlea did not change by administration of saline or hydrogen-rich saline. In contrast, transient cochlear ischemia caused a 24.2±3.8dB increase in the ABR threshold at 8kHz, and a decrease of 14.1%±1.8% in the number of inner hair cells (IHCs) at the basal turn on day 7. Ischemic damage was more severe at 16 and 32kHz. When the animals were treated with hydrogen-rich saline, cochlear damage was significantly reduced: the increase in ABR threshold was 11.7±2.6dB at 8kHz and the IHC loss was 7.5%±2.1% at the basal turn on day 7. The effects of hydrogen-rich saline were more prominent at higher frequencies.

CONCLUSIONS

Intravenous administration of hydrogen-rich saline was effective in preventing acute hearing loss due to transient cochlear ischemia.

Practice guideline: Cervical and ocular vestibular evoked myogenic potential testing: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology

OBJECTIVE

To systematically review the evidence and make recommendations with regard to diagnostic utility of cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP, respectively). Four questions were asked: Does cVEMP accurately identify superior canal dehiscence syndrome (SCDS)? Does oVEMP accurately identify SCDS? For suspected vestibular symptoms, does cVEMP/oVEMP accurately identify vestibular dysfunction related to the saccule/utricle? For vestibular symptoms, does cVEMP/oVEMP accurately and substantively aid diagnosis of any specific vestibular disorder besides SCDS?

METHODS

The guideline panel identified and classified relevant published studies (January 1980-December 2016) according to the 2004 American Academy of Neurology process.

RESULTS AND RECOMMENDATIONS

Level C positive: Clinicians may use cVEMP stimulus threshold values to distinguish SCDS from controls (2 Class III studies) (sensitivity 86%-91%, specificity 90%-96%). Corrected cVEMP amplitude may be used to distinguish SCDS from controls (2 Class III studies) (sensitivity 100%, specificity 93%). Clinicians may use oVEMP amplitude to distinguish SCDS from normal controls (3 Class III studies) (sensitivity 77%-100%, specificity 98%-100%). oVEMP threshold may be used to aid in distinguishing SCDS from controls (3 Class III studies) (sensitivity 70%-100%, specificity 77%-100%). Level U: Evidence is insufficient to determine whether cVEMP and oVEMP can accurately identify vestibular function specifically related to the saccule/utricle, or whether cVEMP or oVEMP is useful in diagnosing vestibular neuritis or Ménière disease. Level C negative: It has not been demonstrated that cVEMP substantively aids in diagnosing benign paroxysmal positional vertigo, or that cVEMP or oVEMP aids in diagnosing/managing vestibular migraine.

Mechanisms of Cisplatin-Induced Ototoxicity and Otoprotection

Evidence of significant hearing loss during the early days of use of cisplatin as a chemotherapeutic agent in cancer patients has stimulated research into the causes and treatment of this side effect. It has generally been accepted that hearing loss is produced by excessive generation of reactive oxygen species (ROS) in cell of the cochlea, which led to the development of various antioxidants as otoprotective agents. Later studies show that ROS could stimulate cochlear inflammation, suggesting the use of anti-inflammatory agents for treatment of hearing loss. In this respect, G-protein coupled receptors, such as adenosine A₁ receptor and cannabinoid 2 receptors, have shown efficacy in the treatment of hearing loss in experimental animals by increasing ROS scavenging, suppressing ROS generation, or by decreasing inflammation. Inflammation could be triggered by activation of transient receptor potential vanilloid 1 (TRPV1) channels in the cochlea and possibly other TRP channels. Targeting TRPV1 for knockdown has also been shown to be a useful strategy for ensuring otoprotection. Cisplatin entry into cochlear hair cells is mediated by various transporters, inhibitors of which have been shown to be effective for treating hearing loss. Finally, cisplatin-induced DNA damage and activation of the apoptotic process could be targeted for cisplatin-induced hearing loss. This review focuses on recent development in our understanding of the mechanisms underlying cisplatin-induced hearing loss and provides examples of how drug therapies have been formulated based on these mechanisms.