Effects of Age, Age-Related Hearing Loss, and Contralateral Cafeteria Noise on the Discrimination of Small Frequency Changes: Psychoacoustic and Electrophysiological Measures

The aim of the study was to examine central auditory processes compromised by age, age-related hearing loss, and the presentation of a distracting cafeteria noise using auditory event-related potentials (ERPs). In addition, the relation of ERPs to behavioral measures of discrimination was investigated. Three groups of subjects participated: young normal hearing, elderly subjects with normal hearing for their age, and elderly hearing-impaired subjects. Psychoacoustic frequency discrimination thresholds for a 1000-Hz pure tone were determined in quiet and in the presence of a contralateral cafeteria noise. To elicit ERPs, small frequency contrasts were presented with and without noise under unattended and attended conditions. In the attended condition, behavioral measures of d′ detectability and reaction times were also obtained. Noise affected all measures of behavioral frequency discrimination significantly. Except N1, all ERP components in the standard and difference waveforms decreased significantly in amplitude and increased in latency to the same degree in all three subject groups, arguing against a specific age-related sensitivity to the effects of contralateral background noise. For N1 amplitude, the effect of noise was different in the three subject groups, with a complex interaction of age, hearing loss, and attention. Behavioral frequency discrimination was not affected by age but deteriorated significantly in the elderly subjects with hearing loss. In the electrophysiological test, age-related changes occurred at various levels. The most prominent finding in the response to the standard stimuli was a sustained negativity (N2) following P2 in the young subjects that was absent in the elderly, possibly indicating a deficit in the inhibition of irrelevant information processing. In the attended difference waveform, significantly larger N2b and smaller P3b amplitudes and longer N2b and P3b latencies were observed in the elderly indicating different processing strategies. The pronounced age-related changes in the later cognitive components suggest that the discrimination of difficult contrasts, although behaviorally maintained, becomes more effortful in the elderl

Prevalence of age-related hearing loss in Europe: a review

Populations are becoming progressively older thus presenting symptoms of diminished organ function due to degenerative processes. These may be physiological or caused by additional factors damaging the organ. Presbyacusis refers to the physiological age-related changes of the peripheral and central auditory system leading to hearing impairment and difficulty understanding spoken language. In contrast to epidemiological data of other continents, the prevalence of age-related hearing loss (ARHL) in Europe is not well defined, due in part to the use of different classification systems. We performed a systematic literature review with the aim of gaining a picture of the prevalence of ARHL in Europe. The review included only population and epidemiological studies in English since 1970 with samples in European countries with subjects aged 60years and above. Nineteen studies met our selection criteria and additional five studies reported self-reported hearing impairment. When these data were crudely averaged and interpolated, roughly 30% of men and 20% of women in Europe were found to have a hearing loss of 30dB HL or more by age 70years, and 55% of men and 45% of women by age 80years. Apparent problems in comparing the available data were the heterogeneity of measures and cut-offs for grades of hearing impairment. Our systematic review of epidemiological data revealed more information gaps than information that would allow gaining a meaningful picture of prevalence of ARHL. The need for standardized procedures when collecting and reporting epidemiological data on hearing loss has become evident. Development of hearing loss over time in conjunction with the increase in life expectancy is a major factor determining strategies of detection and correction of ARHL. Thus, we recommend using the WHO classification of hearing loss strictly and including standard audiometric measures in population-based health survey

Auditory Cortical Plasticity in Patients with Single-Sided Deafness Before and After Cochlear Implantation

PURPOSE This study investigated neuroplastic changes induced by postlingual single-sided deafness (SSD) and the effects of a cochlear implantation for the deaf ear. Neural processing of acoustic signals from the normal hearing ear to the brain was studied before and after implantation using a positron emission tomography (PET)/CT scanner. METHODS Eight patients with postlingual SSD received a cochlear implant (CI) in a prospective clinical trial. Dynamic imaging was performed in a PET/CT scanner using radioactively labeled water ([15O]H2O) to localize changes in the regional cerebral blood flow (rCBF) with and without an auditory task of logatomes containing speech-like elements without meaningful context. The normal hearing ear was stimulated before implantation and after the use of the cochlear implant for at least 8 months (mean 13.5, range 8.1-26.6). Eight age- and gender-matched subjects with normal hearing on both sides served as healthy control subjects (HCS). RESULTS When the normal hearing ear of SSD patients was stimulated before CI implantation, the [15O]H2O-PET showed a more symmetrical rCBF in the auditory regions of both hemispheres in comparison to the HCS. The use of CI increased the asymmetry index (AI) in six of eight patients indicating an increase of activity of the contralateral hemisphere. Non-parametric statistics revealed a significant difference in the AI between patients before CI implantation and HCS (p < .01), which disappeared after CI implantation (p = .195). CONCLUSION The functional neuroimaging data showed a tendency towards normalization of neuronal activity after CI implantation, which supports the effectiveness of CI in SSD patients. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT01749592, December 13, 2012

Incapacitating hypersensitivity to one's own body sounds due to a dehiscence of bone overlying the superior semicircular canal. A case report

We present a case study of a 49-year-old patient with an 8-year history of hypersensitivity to sound produced by intrinsic but not extrinsic sources. Findings that indicated an organic problem were: a supranormal bone conduction threshold of −25 to −15dB HL from 0.25 to 1kHz with an air-bone gap of 15 to 45dB HL, a lower threshold and larger amplitude for vestibular-evoked myogenic potentials, eye movement reactions to sound and trunk pitch sway in response to sound. Results of immitance audiometry and otoacoustic emission testing were within normal limits and indicative of intact middle ear conductance. A high-resolution CT scan of the temporal bone demonstrated a dehiscence of bone overlying the superior semicircular canal. These findings support previous research indicating that auditory energy reaches the cochleo-vestibular receptor systems more easily via transmission through cerebrospinal fluid than through bone. Therefore, a dehiscence of the bone overlying the superior semicircular canal may lead to hypersensitivity to intrinsic sound. We recommend that similar findings in other patients be followed up with an evaluation of middle ear function and the temporal bone with high-resolution CT sca

Magnet displacement: a rare complication following cochlear implantation

The purpose of this paper is to describe cases which reported complication after cochlear implantation in children: displacement of magnet from the receiver pocket, possibly aided by the use of magnetic toys. We observed magnet displacement in two female children from the same family and in one male child. Age at implantation was 23, 51, and 24months, respectively. Magnet displacement occurred at 37, 16, and 32months, respectively after the initial surgery. The magnets were replaced under general anaesthesia and we did not observe recurrent magnet dislodgement. Measurements indicated that forces required to remove the magnet from its pocket were not greater than those exerted by magnetic toys or the magnet used in the external sender coil. Although magnet displacement is not common after cochlear implantation, it is a major complication in children where subsequent general anaesthesia and surgery are necessary to replace the magnet. Therefore, we propose that pockets for removable magnets of cochlear implants used in children should be redesigned to increase forces to remove the magnet or that removable magnets not be used at al

Initial characterisation of commercially available ELISA tests and the immune response of the clinically correlated SARS-CoV-2 biobank "SERO-BL-COVID-19" collected during the pandemic onset in Switzerland

Background To accurately measure seroprevalance in the population, both the expected immune response as well as the assay performances have to be well characterised. Here, we describe the collection and initial characterisation of a blood and saliva biobank obtained after the initial peak of the SARS-CoV-2 pandemic in Switzerland.Methods Two laboratory ELISAs measuring IgA & IgG (Euroimmun), and IgM & IgG (Epitope Diagnostics) were used to characterise the biobank collected from 349 re- and convalescent patients from the canton of Basel-Landschaft.Findings The antibody response in terms of recognized epitopes is diverse, especially in oligosymptomatic patients, while the average strength of the antibody response of the population does correlate with the severity of the disease at each time point.Interpretation The diverse immune response presents a challenge when conducting epidemiological studies as the used assays only detect ∼90% of the oligosymptomatic cases. This problem cannot be rectified by using more sensitive assay setting as they concomitantly reduce specificity.Funding Funding was obtained from the "Amt für Gesundheit" of the canton Basel-Landschaft, Switzerland.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThis study was sponsored by Jurg Sommer, head of the Amt fur Gesundheit, and the logistics of the sample collection were provided by the crisis staff and the civil protection service of the canton Basel-Landschaft.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:This study is part of the project COVID-19 in Baselland Investigation and Validation of Serological Diagnostic Assays and Epidemiological Study of Sars-CoV-2 specific Antibody Responses (SERO-BL-COVID-19) approved by the ethics board Ethikkommission Nordwest- und Zentralschweiz (EKNZ), Hebelstrasse 53, 4056 Basel representative of Swissethics under the number (2020-00816).All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData are available upon reques

Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.

The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD