SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Ear

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Recent neuroscience research suggests that tinnitus may reflect synaptic loss in the cochlea that does not express in the audiogram but leads to neural changes in auditory pathways that reduce sound level tolerance (SLT). Adolescents (N = 170) completed a questionnaire addressing their prior experience with tinnitus, potentially risky listening habits, and sensitivity to ordinary sounds, followed by psychoacoustic measurements in a sound booth. Among all adolescents 54.7% reported by questionnaire that they had previously experienced tinnitus, while 28.8% heard tinnitus in the booth. Psychoacoustic properties of tinnitus measured in the sound booth corresponded with those of chronic adult tinnitus sufferers. Neither hearing thresholds (≤15 dB HL to 16 kHz) nor otoacoustic emissions discriminated between adolescents reporting or not reporting tinnitus in the sound booth, but loudness discomfort levels (a psychoacoustic measure of SLT) did so, averaging 11.3 dB lower in adolescents experiencing tinnitus in the acoustic chamber. Although risky listening habits were near universal, the teenagers experiencing tinnitus and reduced SLT tended to be more protective of their hearing. Tinnitus and reduced SLT could be early indications of a vulnerability to hidden synaptic injury that is prevalent among adolescents and expressed following exposure to high level environmental sounds.

Concepts: Auditory system, Acoustics, Ultrasound, Ear, Sound, Audiogram, Hearing

185

Candida auris, an emerging fungus that can cause invasive infections, is associated with high mortality and is often resistant to multiple antifungal drugs. C. auris was first described in 2009 after being isolated from external ear canal discharge of a patient in Japan (1). Since then, reports of C. auris infections, including bloodstream infections, have been published from several countries, including Colombia, India, Israel, Kenya, Kuwait, Pakistan, South Africa, South Korea, Venezuela, and the United Kingdom (2-7). To determine whether C. auris is present in the United States and to prepare for the possibility of transmission, CDC issued a clinical alert in June 2016 informing clinicians, laboratorians, infection control practitioners, and public health authorities about C. auris and requesting that C. auris cases be reported to state and local health departments and CDC (8). This report describes the first seven U.S. cases of C. auris infection reported to CDC as of August 31, 2016. Data from these cases suggest that transmission of C. auris might have occurred in U.S. health care facilities and demonstrate the need for attention to infection control measures to control the spread of this pathogen.

Concepts: United States, Developed country, United Kingdom, Olympic Games, Ear, Pakistan, Liberal democracies, G20 nations

168

Spontaneous nystagmus, which has been considered a typical sign of acute vestibulopathy, has recently been reported in benign paroxysmal positional vertigo involving the lateral semicircular canals (LC-BPPV) without unilateral vestibulopathy (pseudo-spontaneous nystagmus, PSN), but research about its clinical application is still limited. Here we investigate the frequency and characteristics of PSN in LC-BPPV patients, and estimate its prognostic value.

Concepts: Medical terms, Semicircular canal, Prognosis, Ear, Canal, Pathologic nystagmus, Benign paroxysmal positional vertigo, Horizontal semicircular canal

168

The development of minimally invasive procedures such as the balloon dilation Eustachian tuboplasty (BET) is an alternative to the grommet tympanum membrane. BET is applied in the cases where, after elimination of all factors influencing the ET and middle ear functioning, no sufficient improvement is observed. The aim of this study was to present the therapeutic benefits of the BET method in the treatment of ETD caused by disorders in the middle ear ventilation. The BET procedure was offered to four patients (3 men and 1 woman) after subjective, physical, otorhinolaryngological and audiometric examinations including pure tone audiometry, tympanometry and pressure-swallow test. As the method was novel, preinterventional CT angiography of the carotid arteries was performed in all patients. Any complications were noticed during and after the procedure (bleeding or damage of regional mucosa) in any patients. Our clinical studies assessed the feasibility and safety of the BET during a short-term period-only a 6-week observation. Although patients revealed a significant improvement of ET score, longer long-term studies are necessary to determine whether this method will demonstrate lasting benefits and safety in the treatment of chronic Eustachian tube dysfunction. In other investigations, improvement was found to be time dependent.

Concepts: Scientific method, Auditory system, Common carotid artery, Middle ear, Eustachian tube, Otitis media, Ear, Patulous Eustachian tube

167

To evaluate the onset of vertigo, hearing loss and tinnitus in Ménière’s disease and the associated endolymphatic hydrops (EH) of the inner ear.

Concepts: Auditory system, Cochlea, Hearing impairment, Ear, Tinnitus, Ménière's disease, Inner ear, Endolymph

70

Otitis media is the most common reason U.S. children receive antibiotics. The requisite 7- to 10-day course of oral antibiotics can be challenging to deliver in children, entails potential systemic toxicity, and encourages selection of antimicrobial-resistant bacteria. We developed a drug delivery system that, when applied once to the tympanic membrane through the external auditory canal, delivers an entire course of antimicrobial therapy to the middle ear. A pentablock copolymer poloxamer 407-polybutylphosphoester (P407-PBP) was designed to flow easily during application and then to form a mechanically strong hydrogel on the tympanic membrane. U.S. Food and Drug Administration-approved chemical permeation enhancers within the hydrogel assisted flux of the antibiotic ciprofloxacin across the membrane. This drug delivery system completely eradicated otitis media from nontypable Haemophilus influenzae (NTHi) in 10 of 10 chinchillas, whereas only 62.5% of animals receiving 1% ciprofloxacin alone had cleared the infection by day 7. The hydrogel system was biocompatible in the ear, and ciprofloxacin was undetectable systemically (in blood), confirming local drug delivery and activity. This fast-gelling hydrogel could improve compliance, minimize side effects, and prevent systemic distribution of antibiotics in one of the most common pediatric illnesses, possibly minimizing the development of antibiotic resistance.

Concepts: Medicine, Bacteria, Auditory system, Otitis media, Ear, Penicillin, Clostridium difficile, Haemophilus influenzae

52

Autologous techniques for the reconstruction of pediatric microtia often result in suboptimal aesthetic outcomes and morbidity at the costal cartilage donor site. We therefore sought to combine digital photogrammetry with CAD/CAM techniques to develop collagen type I hydrogel scaffolds and their respective molds that would precisely mimic the normal anatomy of the patient-specific external ear as well as recapitulate the complex biomechanical properties of native auricular elastic cartilage while avoiding the morbidity of traditional autologous reconstructions.

Concepts: Collagen, Extracellular matrix, Skeletal system, Tissues, Ear, Reconstruction era of the United States, Reconstruction, Type-I collagen

51

On March 11, 2011, Japan’s northeast Pacific coast was hit by a gigantic earthquake and subsequent tsunami. Soma City in Fukushima Prefecture is situated approximately 44 km north of Fukushima Daiichi Nuclear Power Plant. Soma General Hospital is the only hospital in Soma City that provides full-time otolaryngological medical care. We investigated the changes in new patients from one year before to three years after the disaster. We investigated 18,167 new patients treated at our department during the four years from April 1, 2010 to March 31, 2014. Of the new patients, we categorized the diagnoses into Meniere’s disease, acute low-tone sensorineural hearing loss, vertigo, sudden deafness, tinnitus, and facial palsy as neuro-otologic symptoms. We also investigated the changes in the numbers of patients whom we examined at that time concerning other otolaryngological disorders, including epistaxis, infectious diseases of the laryngopharynx, and allergic rhinitis. The total number of new patients did not change remarkably on a year-to-year basis. Conversely, cases of vertigo, Meniere’s disease, and acute low-tone sensorineural hearing loss increased in number immediately after the disaster, reaching a plateau in the second year and slightly decreasing in the third year. Specifically, 4.8% of patients suffering from these neuro-otologic diseases had complications from depression and other mental diseases. With regard to new patients in our department, there was no apparent increase in the number of patients suffering from diseases other than neuro-otologic diseases, including epistaxis, and allergic rhinitis. Patients suffering from vertigo and/or dizziness increased during the first few years after the disaster. These results are attributed to the continuing stress and tension of the inhabitants. This investigation of those living in the disaster area highlights the need for long-term support.

Concepts: Cohort study, Medicine, Disease, Infectious disease, Hearing impairment, Japan, Ear, Tinnitus

49

Congenital infection with Zika virus causes microcephaly and other brain abnormalities (1). Hearing loss associated with other congenital viral infections is well described; however, little is known about hearing loss in infants with congenital Zika virus infection. A retrospective assessment of a series of 70 infants aged 0-10 months with microcephaly and laboratory evidence of Zika virus infection was conducted by the Hospital Agamenon Magalhães in Brazil and partners. The infants were enrolled during November 2015-May 2016 and had screening and diagnostic hearing tests. Five (7%) infants had sensorineural hearing loss, all of whom had severe microcephaly; however, one child was tested after receiving treatment with an ototoxic antibiotic. If this child is excluded, the prevalence of sensorineural hearing loss was 5.8% (four of 69), which is similar to that seen in association with other congenital viral infections. Additional information is needed to understand the prevalence and spectrum of hearing loss in children with congenital Zika virus infection; all infants born to women with evidence of Zika virus infection during pregnancy should have their hearing tested, including infants who appear normal at birth.

Concepts: Disease, Bacteria, Virus, Infection, Otology, Ear, Tinnitus, Measles

48

The rapid growth of aquaculture raises questions about the welfare status of mass-produced species. Sagittal otoliths are primary hearing structures in the inner ear of all teleost (bony) fishes and are normally composed of aragonite, though abnormal vaterite replacement is sometimes seen in the wild. We provide the first widespread evaluation of the prevalence of vaterite in otoliths, showing that farmed fish have levels of vaterite replacement over 10 times higher than wild fish, regardless of species. We confirm this observation with extensive sampling of wild and farmed Atlantic salmon in Norway, the world’s largest producer, and verify that vateritic otoliths are common in farmed salmon worldwide. Using a mechanistic model of otolith oscillation in response to sound, we demonstrate that average levels of vaterite replacement result in a 28-50% loss of otolith functionality across most of a salmonid’s known hearing range and throughout its life cycle. The underlying cause(s) of vaterite formation remain unknown, but the prevalence of hearing impairment in farmed fish has important implications for animal welfare, the survival of escapees and their effects on wild populations, and the efficacy of restocking programs based on captive-bred fish.

Concepts: Fish, Auditory system, Salmon, Ear, Inner ear, Audiogram, Aquaculture, Otolith