BAAV Mediated GJB2 Gene Transfer Restores Gap Junction Coupling in Cochlear Organotypic Cultures from Deaf Cx26Sox10Cre Mice

The deafness locus DFNB1 contains GJB2, the gene encoding connexin26 and GJB6, encoding connexin30, which appear to be coordinately regulated in the inner ear. In this work, we investigated the expression and function of connexin26 and connexin30 from postnatal day 5 to adult age in double transgenic Cx26Sox10Cre mice, which we obtained by crossing connexin26 floxed mice with a deleter Sox10–Cre line. Cx26Sox10Cre mice presented with complete connexin26 ablation in the epithelial gap junction network of the cochlea, whereas connexin30 expression was developmentally delayed; immunolabeling patterns for both connexins were normal in the cochlear lateral wall. In vivo electrophysiological measurements in Cx26Sox10Cre mice revealed profound hearing loss accompanied by reduction of endocochlear potential, and functional experiments performed in postnatal cochlear organotypic cultures showed impaired gap junction coupling. Transduction of these cultures with a bovine adeno associated virus vector restored connexin26 protein expression and rescued gap junction coupling. These results suggest that restoration of normal connexin levels by gene delivery via recombinant adeno associated virus could be a way to rescue hearing function in DFNB1 mouse models and, in future, lead to the development of therapeutic interventions in humans

Docteur ça tourne…

Le médecin généraliste contacté par/pour un patient présentant des vertiges aigus a besoin d’outils lui permettant un dépistage rapide et fiable d’un problème vestibulaire central urgent et vital. Certaines plaintes subjectives sont des feux rouges qui indiquent un examen médical urgent avant envoi éventuel dans une unité d’urgence neurologique. L’utilisation de la batterie de tests HINTS doit être encouragée car elle a été rapportée comme étant assez sensible et spécifique dans la détection de problèmes vestibulaires centraux. Après un rappel des symptômes subjectifs et des signes cliniques qui évoquent des troubles centraux, les causes vestibulaires périphériques fréquentes seront présentées.[Doctor, my head is spinning…] When contacted by a patient suffering from acute vertigo or dizziness, the general practitioner needs easy clinical tools enabling him to screen for urgent and life-threatening central vestibular disorders in a timely and reliable manner. Some subjective complaints are red flags that indicate the need for a rapid medical examination before a possible referral to a neurology emergency unit. Using the HINTS tool must be further promoted, given that it proved to be specific and sensitive in detecting central vestibular disorders. After a review of the subjective symptoms and clinical signs that evoke central vestibular disorders, the article presents the most frequent peripheral vestibular disorders

Comparison of hearing outcomes obtained with intra-cochlea, auditory nerve or ponto-cerebellar angle electrical stimulation by an auditory implant

To verify if it is possible to provide hearing perception by selective stimulation of only the internal auditory canal (IAC) or ponto-cerebellar angle (PCA) electrodes

Tinnitus following COVID-19 vaccination: report of three cases.

OBJECTIVE: To ensure the safety and quality of vaccines, especially the newest RNA-vaccines against COVID-19, is one of the World Health Organization's current highest priorities. DESIGN: Case description. STUDY SAMPLE: We report three cases of sudden unilateral tinnitus following BNT162b2 mRNA-vaccine injection, which rapidly resolved in 2 out of 3 cases. RESULTS: The mechanism responsible for its development remains unclear. A hypersensitivity reaction with an abnormal autoimmune response or a vasculitic event may be implicated. CONCLUSIONS: Large-scale and well-designed studies are needed to improve surveillance of the COVID-19 vaccine and better define possible adverse reactions involving the cochleo-vestibular system and/or immunisation anxiety-related reactions

Clinicians embracing social media in the response against COVID-19

DEAR EDITOR, On 11 March 2020, the WHO director declared the rapidly spreading COVID-19 a pandemic. The very next day, a group of Italian doctors working in Belgium, sensitised by personal contact with Italian clinicians in the forefront of the pandemic, decided to take action. Concerned about the imminent impact on the hospitals and the complex management of patients with COVID-19, they created a Facebook group in French to share information. It allowed clinicians from Belgium, France and Switzerland to efficiently communicate with each other, and exchange guidelines and research, as well as personal experiences. The group was named ‘Coronavirus/COVID-19 pour les médecins’ which translates from French to ‘Coronavirus/COVID-19 for doctors’. [...

Auditory Neuropathy Spectrum Disorders: From Diagnosis to Treatment: Literature Review and Case Reports.

Auditory neuropathy spectrum disorder (ANSD) refers to a range of hearing impairments characterized by deteriorated speech perception, despite relatively preserved pure-tone detection thresholds. Affected individuals usually present with abnormal auditory brainstem responses (ABRs), but normal otoacoustic emissions (OAEs). These electrophysiological characteristics have led to the hypothesis that ANSD may be caused by various dysfunctions at the cochlear inner hair cell (IHC) and spiral ganglion neuron (SGN) levels, while the activity of outer hair cells (OHCs) is preserved, resulting in discrepancies between pure-tone and speech comprehension thresholds. The exact prevalence of ANSD remains unknown; clinical findings show a large variability among subjects with hearing impairment ranging from mild to profound hearing loss. A wide range of prenatal and postnatal etiologies have been proposed. The study of genetics and of the implicated sites of lesion correlated with clinical findings have also led to a better understanding of the molecular mechanisms underlying the various forms of ANSD, and may guide clinicians in better screening, assessment and treatment of ANSD patients. Besides OAEs and ABRs, audiological assessment includes stapedial reflex measurements, supraliminal psychoacoustic tests, electrocochleography (ECochG), auditory steady-state responses (ASSRs) and cortical auditory evoked potentials (CAEPs). Hearing aids are indicated in the treatment of ANSD with mild to moderate hearing loss, whereas cochlear implantation is the first choice of treatment in case of profound hearing loss, especially in case of IHC presynaptic disorders, or in case of poor auditory outcomes with conventional hearing aids

Childhood hearing loss is a key feature of CAPOS syndrome : A case report

Le syndrome CAPOS, acronyme d’ataxie cérébelleuse, aréflexie, pes cavus, atrophie optique et surdité neurosensorielle, est une affection neurologique rare, associée à la mutation spécifique c.2452G>A dans le gène ATP1A3. Les patients présentent typiquement, dans l’enfance, un ou plusieurs épisodes de dégradation neurologique aigüe comportant ataxie, aréflexie, léthargie et/ou ophtalmoplégie. Ce tableau initial peut être évocateur d’un syndrome de Guillain-Barré, de Miller-Fischer ou d’une encéphalite. Toutefois, l’électromyographie et l’analyse du liquide céphalo-rachidien sont normales. Les déficits neurosensoriels apparaissent généralement dans le décours, dans un délai variable qui rend souvent peu clair leur lien avec l’épisode initial. La surdité neurosensorielle acquise est, en particulier, un signe constant de la maladie. Nous rapportons l’histoire d’une enfant ayant développé une surdité neurosensorielle rapidement progressive 3 ans après un épisode encéphalitique survenu à l’âge de 15 mois. Le diagnostic de syndrome CAPOS fut évoqué et confirmé à l’âge de 6 ans, alors qu’elle présentait une atrophie optique depuis l’âge de 4 ans. Le syndrome CAPOS devrait être considéré dans le diagnostic différentiel des surdités neurosensorielles acquises de l’enfant, en particulier en cas d’antécédent de dégradation neurologique aigüe

Childhood hearing loss is a key feature of CAPOS syndrome: A case report.

CAPOS syndrome (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) is a rare neurological disorder, recently associated with the c.2452G > A hotspot mutation in the ATP1A3 gene, with sensorineural hearing loss as a prominent feature. We herein report on a girl who has experienced hearing loss for three years following an initial encephalitic episode when aged 15 months old. CAPOS was diagnosed only when she was six years old by targeted testing whilst she displayed optic atrophy, cerebellar signs and areflexia. CAPOS syndrome should be considered in the differential diagnosis of acquired childhood deafness, prompting clinicians to search for associated neurological features

Systematic review of international guidelines for perioperative antibiotic prophylaxis in Head & Neck Surgery. A YO-IFOS Head & Neck Study Group Position Paper.

BACKGROUND: Surgical site infection (SSI) is defined as an infection that occurs after a surgical incision or organ manipulation during surgery. The frequency reported for clean head and neck surgical procedures without antimicrobial prophylaxis is <1%. In contrast, infection rates in patients undergoing complicated cancer surgery are high, ranging from 24% to 87% of patients without antimicrobial prophylaxis. METHODS: Guidelines and recommendations about the use of antibiotics in head and neck surgery from 2004 to 2019 were reviewed. RESULTS: Four guidelines from Oceania, 5 from South America, 5 from North America, 2 from the United Kingdom, 11 from Europe, 1 from Africa, 1 from the Middle East, and 3 from Asia were included. A total of 118 papers were included for analysis and recommendation. CONCLUSION: Antibiotic prophylaxis can decrease the incidence of SSI. However, the risks associated with antibiotic exposure and the risk of antibiotic resistance need to be taken into consideration