Auditory network connectivity in tinnitus patients: a resting-state fMRI study

Objective: Resting-state functional magnetic resonance imaging (fMRI) uncovers correlated activity between spatially distinct functionally related brain regions and offers clues about the integrity of functional brain circuits in people with chronic subjective tinnitus. We chose to investigate auditory network connectivity, adopting and extending previously used analyses methods to provide an independent evaluation of replicability. Design: Independent components analysis (ICA) was used to identify coherent patterns arising from spontaneous brain signals within the resting-state data. The auditory network component was extracted and evaluated. Bivariate and partial correlation analyses were performed on pre-defined regions of bilateral auditory cortex to assess functional connectivity. Study sample: Our design carefully matched participant groups for possible confounds, such as hearing status. Twelve patients (seven male, five female; mean age 66 years) all with chronic constant tinnitus and eleven controls (eight male, three female; mean age 68 years) took part. Results: No significant differences were found in auditory network connectivity between groups after correcting for multiple statistical comparisons in the analysis. This contradicts previous findings reporting reduced auditory network connectivity; albeit at a less stringent statistical threshold. Conclusions: Auditory network connectivity does not appear to be reliably altered by the experience of chronic subjective tinnitus

Prevalence of tinnitus and hyperacusis in children and adolescents: a systematic review

Objectives: To systematically review studies of the epidemiology of tinnitus and hyperacusis in children and young people, in order to determine the methodological differences implicated in the variability of prevalence estimates and the influence of population characteristics on childhood tinnitus and hyperacusis. Data sources: Articles were retrieved from PubMed, EMBASE and Scopus databases and from the relevant reference lists using the methods described in the study protocol, which has previously been published. Reporting Items for Systematic Review (PRISMA) guidelines were followed. Eligibility criteria: Studies addressing childhood prevalence, for example, children and young people aged 5-19 years. Data selection: 2 reviewers independently assessed the studies for eligibility, extracted data and assessed study consistency. Owing to the heterogeneity in the methodologies among the reported studies, only narrative synthesis of the results was carried out. Results: Having identified 1032 publications, 131 articles were selected and 25 articles met the inclusion criteria and had sufficient methodological consistency to be included. Prevalence estimates of tinnitus range from 4.7% to 46% in the general paediatric population and among children with normal hearing, and from 23.5% to 62.2% of population of children with hearing loss. Reported prevalence ranged from 6% to 41.9% when children with hearing loss and normal hearing were both included. The prevalence of hyperacusis varied from 3.2% to 17.1%. Conclusions: Data on prevalence vary considerably according to the study design, study population and the research question posed. The age range of children studied was varied and a marked degree of variation between definitions (tinnitus, hyperacusis) and measures (severity, perception, annoyance) was observed. The lack of consistency among studies indicates the necessity of examining the epidemiology of tinnitus and hyperacusis in children and adolescents with a set of standardised criteria

Prevalence of tinnitus and hyperacusis in children and adolescents: a systematic review

Objectives: To systematically review studies of the epidemiology of tinnitus and hyperacusis in children and young people, in order to determine the methodological differences implicated in the variability of prevalence estimates and the influence of population characteristics on childhood tinnitus and hyperacusis. Data sources: Articles were retrieved from PubMed, EMBASE and Scopus databases and from the relevant reference lists using the methods described in the study protocol, which has previously been published. Reporting Items for Systematic Review (PRISMA) guidelines were followed. Eligibility criteria: Studies addressing childhood prevalence, for example, children and young people aged 5-19 years. Data selection: 2 reviewers independently assessed the studies for eligibility, extracted data and assessed study consistency. Owing to the heterogeneity in the methodologies among the reported studies, only narrative synthesis of the results was carried out. Results: Having identified 1032 publications, 131 articles were selected and 25 articles met the inclusion criteria and had sufficient methodological consistency to be included. Prevalence estimates of tinnitus range from 4.7% to 46% in the general paediatric population and among children with normal hearing, and from 23.5% to 62.2% of population of children with hearing loss. Reported prevalence ranged from 6% to 41.9% when children with hearing loss and normal hearing were both included. The prevalence of hyperacusis varied from 3.2% to 17.1%. Conclusions: Data on prevalence vary considerably according to the study design, study population and the research question posed. The age range of children studied was varied and a marked degree of variation between definitions (tinnitus, hyperacusis) and measures (severity, perception, annoyance) was observed. The lack of consistency among studies indicates the necessity of examining the epidemiology of tinnitus and hyperacusis in children and adolescents with a set of standardised criteria

Hyperacusis：a mini review

Hyperacusis refers to the experience of the sound environment being perceived as overwhelming loud or painful, and this can severely affect the patient's quality of life. In China little attention has been paid to hyperacusis, and there has been little research undertaken on the topic. Therefore, this article summarizes the recent research on hyperacusis considering the aspects of definition, epidemiology, etiology, mechanism, evaluation and treatment to provide ideas for future research directions

Functional auditory disorders

There are a number of auditory symptom syndromes that can develop without an organic basis. Some of these, such as nonorganic hearing loss, affect populations similar to those presenting with functional somatosensory and motor symptoms, while others, such as musical hallucination, affect populations with a significantly different demographic and require different treatment strategies. Many of these conditions owe their origin to measurably abnormal peripheral sensory pathology or brain network activity, but their pathological impact is often due, at least in part, to overamplification of the salience of these phenomena. For each syndrome, this chapter briefly outlines a definition, demographics, investigations, putative mechanisms, and treatment strategies. Consideration is given to what extent they can be considered to have a functional basis. Treatments are in many cases pragmatic and rudimentary, needing more work to be done in integrating insights from behavioral and cognitive psychology to auditory neuroscience. The audiology literature has historically equated the term functional with malingering, although this perception is, thankfully, slowly changing. These disorders transcend the disciplines of audiology, otorhinolaryngology, neurology and psychiatry, and a multidisciplinary approach is often rewarding

Human auditory nerve compound action potentials and long latency responses

The compound action potential (CAP) is followed by a long latency response (LLR), attributable to the post-auricular musculature. The LLR to one pulse may overlap with the CAP to a subsequent one, contributing to the clinically observed reduction in CAP at high pulse rates. Objectives. To measure refractory and other influences on CAPs in humans and guinea pigs. Materials and methods. CAPs were obtained from humans using trans-tympanic and extra-tympanic electrocochleography and from anaesthetized guinea pigs. Stimuli were single pulses presented at a slow rate, pairs of pulses, and 100 ms pulse trains where the inter-pulse interval alternated between 4 and 6 ms. Results. For single pulses, the CAP shape was similar across species. For pairs of pulses, the CAP to the second pulse was smaller than that to the first, and decreased with increasing inter-pulse interval in a way that was similar across species. For pulse trains, CAPs were observed in response to each pulse in the train for the guinea pigs, but not for humans. For both filtered and unfiltered single pulses, there was a large LLR in humans, but not in guinea pigs, with peaks at latencies of 10–12 and 20–25 ms. Posture affected the LLR in a way consistent with the post-auricular response<br/