Tinnitus and anxiety disorders: A review

An interpretable tinnitus prediction framework using gap-prepulse inhibition in auditory late response and electroencephalogram

BACKGROUND AND OBJECTIVE

Tinnitus is a neuropathological condition that results in mild buzzing or ringing of the ears without an external sound source. Current tinnitus diagnostic methods often rely on subjective assessment and require intricate medical examinations. This study aimed to propose an interpretable tinnitus diagnostic framework using auditory late response (ALR) and electroencephalogram (EEG), inspired by the gap-prepulse inhibition (GPI) paradigm.

METHODS

We collected spontaneous EEG and ALR data from 44 patients with tinnitus and 47 hearing loss-matched controls using specialized hardware to capture responses to sound stimuli with embedded gaps. In this cohort study of tinnitus and control groups, we examined EEG spectral and ALR features of N-P complexes, comparing the responses to gap durations of 50 and 20 ms alongside no-gap conditions. To this end, we developed an interpretable tinnitus diagnostic model using ALR and EEG metrics, boosting machine learning architecture, and explainable feature attribution approaches.

RESULTS

Our proposed model achieved 90 % accuracy in identifying tinnitus, with an area under the performance curve of 0.89. The explainable artificial intelligence approaches have revealed gap-embedded ALR features such as the GPI ratio of N1-P2 and EEG spectral ratio, which can serve as diagnostic metrics for tinnitus. Our method successfully provides personalized prediction explanations for tinnitus diagnosis using gap-embedded auditory and neurological features.

CONCLUSIONS

Deficits in GPI alongside activity in the EEG alpha-beta ratio offer a promising screening tool for assessing tinnitus risk, aligning with current clinical insights from hearing research.

Development of the West China Tinnitus Impact Inventory and Analysis of Its Reliability and Validity

OBJECTIVES

Owing to differences in cultural background, education level, and lifestyle, certain items of existing tinnitus evaluation scales are difficult for Chinese patients to understand, despite being translated. However, few independently developed scales have been developed specifically for Chinese patients. Therefore, with this study, we aimed to construct a tinnitus scale, the West China Tinnitus Impact Inventory (WCTII), suitable for the accurate reflection of the impact and severity of the disease in this population.

DESIGN

Basic items were obtained through semistructured interviews with patients with tinnitus. We invited 23 domestic experts on tinnitus to form an expert group. The basic items were modified using the Delphi method. Cronbach's α values for the scale scores and correlation coefficients between the items and the scale scores were calculated. Items with correlation coefficients <0.5 were deleted. Exploratory factor analysis was conducted to determine the scale structure of the items remaining after item deletion. The intragroup correlation coefficient was used to assess the scale's test-retest reliability. The Pearson correlation coefficient between the scale scores and the scores for the Chinese-Mandarin version of the Tinnitus Handicap Inventory was used to evaluate concurrent validity.

RESULTS

After five rounds of expert correspondence and exploratory factor analysis, we determined the content and structure of the scale. The WCTII consists of 19 items in 4 subscales, namely, F1: the impact of tinnitus on emotion (items 1 to 9); F2: the impact of tinnitus on sleep (items 10 to 12); F3: patients' beliefs about their tinnitus (items 13 to 16, 19); and F4: the impact of tinnitus on auditory processing ability (items 17 to 18). The overall Cronbach's α was 0.934. The Cronbach's α values for F1 to F4 were 0.912, 0.843, 0.829, and 0.838, respectively. The intragroup correlation coefficient (95% confidence interval) of the total scale and F1 to F4 were 0.779 (0.549 to 0.886), 0.738 (0.496 to 0.860), 0.826 (0.713 to 0.897), 0.720 (0.536 to 0.836), and 0.715 (0.532 to 0.832), respectively. The correlation between the WCTII and Chinese-Mandarin version of the Tinnitus Handicap Inventory scores was 0.849 (p < 0.001).

CONCLUSIONS

The WCTII yielded satisfactory reliability and validity, indicating that it can be used to assess the severity of tinnitus in Chinese patients.

A cross-sectional study on predictors of patients' tinnitus severity

Objective

To identify factors that influence the severity of tinnitus via a hierarchical multiple linear regression model.

Methods

The study was a retrospective cross-sectional analysis. The study included 331 patients experiencing tinnitus as their primary concern, who visited Shanghai Changzheng Hospital of the Navy Medical University between 2019 and 2021. Data on general health status and disease characteristics were collected from all patients. With their consent, participants underwent audiological evaluatons and completed questionnaires to analyze the characteristics of their tinnitus and the factors influencing its severity.

Results

The correlation analysis showed a positive relationship between tinnitus frequency, tinnitus loudness, SAS scores, and PSQI scores with THI scores (P < 0.05) among nine examined variables (gender, handedness, employment status, age, BMI, tinnitus frequency, tinnitus loudness, SAS scores, and PSQI scores). The variables that were extracted from the multiple regression were; for the constant; β = -51.797, t = -4.484, P < 0.001, variable is significant; for the tinnitus loudness; β = 0.161, t = 2.604, P < 0.05, variable is significant; for the tinnitus frequency; β = 0.000, t = 1.269, P = 0.206, variable is not significant; for the SAS scores; β = 1.310, t = 7.685, P < 0.001, variable is significant; for the PSQI scores; β = 1.680, t = 5.433, P < 0.001, variable is significant. Therefore, the most accurate model for predicting severity in tinnitus patients is a linear combination of the constant, tinnitus loudness, SAS scores, and PSQI scores, Y(Tinnitus severity) = β 0 + β 1 (Tinnitus loudness) + β 2 (SAS scores) + β 3 (PSQI scores). β 0, β 1, β 2, and β 3 are -51.797, 0.161, 1.310 and 1.680, respectively.

Conclusion

Tinnitus severity is positively associated with loudness, anxiety levels, and sleep quality. To effectively manage tinnitus in patients, it is essential to promptly identify and address these accompanying factors and related symptoms.

Stressful life events and tinnitus : Reflections and speculations

The role of life events has not been extensively studied in the context of tinnitus. There is, however, evidence about the psychological impact of tinnitus and about the influence of psychological processes as mediators of the tinnitus experience. On the basis of this evidence, the possibility that stressful life events can act as a trigger for tinnitus is discussed; although the evidence is fragmentary and indirect, the possibility cannot be discounted. It is argued that the onset of tinnitus and the associated clinical encounters can constitute an acute stressful life event, and the ongoing experience of tinnitus can be regarded as a chronic stressful life event. Interactions between ongoing tinnitus and other life events are discussed. Possible mechanisms in terms of stress influencing predictive processing and signal detection judgments are considered.

Listening handicap in tinnitus patients with normal extended high frequencies from the perspective of the autonomic nervous system-Effort or fatigue?

OBJECTIVE

In previous studies, the results regarding the presence of listening effort or fatigue in tinnitus patients were inconsistent. The reason for this inconsistency could be that extended high frequencies, which can cause listening handicap, were not within normal limits. Therefore, this study aimed to evaluate the listening skills in tinnitus patients by matching the normal hearing thresholds at all frequencies, including the extended high frequency.

METHODS

Eighteen chronic tinnitus patients and thirty matched healthy controls having normal pure-tone average with symmetrical hearing thresholds was included. Subjects were evaluated with 0.125-20 kHz pure-tone audiometry, Montreal cognitive assessment test (MoCA), Tinnitus Handicap Inventory (THI), Matrix Test, Pupillometry.

RESULTS

Pupil dilatation in the 'coding' phase of the sentence presented in tinnitus patients was less than in the control group (p < 0.05). There was no difference between the groups for Matrix test scores (p > 0.05) Also, there was no statistically significant correlation between THI and Pupillometry components nor between MoCA (p > 0.05).

CONCLUSION

Even though tinnitus patients had normal hearing in the range of 0.125-20 kHz, their autonomic nervous system responses during listening differed from healthy subjects. This difference was interpreted for potential listening fatigue in tinnitus patients.

The Frequency of Health Anxiety, Coronavirus Anxiety and Anxiety Disorder in Patients With Tinnitus During the COVID-19 Pandemic and the Impact of Pandemic on Tinnitus

OBJECTIVES

This study aimed to examine the frequency of anxiety disorder, coronavirus anxiety and health anxiety in tinnitus patients during the pandemic and also, determined the psychophysiological impact of COVID-19 on tinnitus.

METHODS

This cross-sectional study was conducted in a tertiary central pandemic hospital from 15 July 2021 to 15 December 2022. In total, 124 patients with tinnitus and 77 healthy controls participated in the study. The sociodemographic data, a set of valid and reliable assessment instruments were used to measure outcomes of anxiety disorder, coronavirus anxiety, health anxiety and severity of tinnitus.

RESULTS

Patients with tinnitus were found to experience higher levels of coronavirus anxiety, health anxiety and anxiety disorder than controls (p < 0.05). In tinnitus patients, the frequency of coronavirus anxiety was 22.6% and anxiety disorder was 18.5%. Notably, the levels of tinnitus severity were moderate to severe in more than half of the patients (51.6%) and also most of them (81.3%) reported that the severity of tinnitus during the pandemic was higher compared with the pre-pandemic.

CONCLUSION

Tinnitus patients had high levels of anxiety disorder, coronavirus anxiety and health anxiety. In line with these findings, it was evaluated that there was a relationship between the COVID-19 pandemic with psychological problems and tinnitus. Therefore, the predominance of tinnitus symptoms at presentation should not lead the clinician to neglect the underlying psychopathological problems in these patients.

Amygdala structural and functional reorganization as an indicator of affective dysfunction in patients with tinnitus

The aim of this study was to systematically investigate structural and functional alterations in amygdala subregions using multimodal magnetic resonance imaging (MRI) in patients with tinnitus with or without affective dysfunction. Sixty patients with persistent tinnitus and 40 healthy controls (HCs) were recruited. Based on a questionnaire assessment, 26 and 34 patients were categorized into the tinnitus patients with affective dysfunction (TPAD) and tinnitus patients without affective dysfunction (TPWAD) groups, respectively. MRI-based measurements of gray matter volume, fractional anisotropy (FA), fractional amplitude of low-frequency fluctuations (fALFF), regional homogeneity (ReHo), degree centrality (DC), and functional connectivity (FC) were conducted within 14 amygdala subregions for intergroup comparisons. Associations between the MRI properties and clinical characteristics were estimated via partial correlation analyses. Compared with that of the HCs, the TPAD and TPWAD groups exhibited significant structural and functional changes, including white matter integrity (WMI), fALFF, ReHo, DC, and FC alterations, with more pronounced WMI changes in the TPAD group, predominantly within the left auxiliary basal or basomedial nucleus (AB/BM), right central nucleus, right lateral nuclei (dorsal portion), and left lateral nuclei (ventral portion containing basolateral portions). Moreover, the TPAD group exhibited decreased FC between the left AB/BM and left middle occipital gyrus and right superior frontal gyrus (SFG), left basal nucleus and right SFG, and right lateral nuclei (intermediate portion) and right SFG. In combination, these amygdalar alterations exhibited a sensitivity of 65.4% and specificity of 96.9% in predicting affective dysfunction in patients with tinnitus. Although similar structural and functional amygdala remodeling were observed in the TPAD and TPWAD groups, the changes were more pronounced in the TPAD group. These changes mainly involved alterations in functionality and white matter microstructure in various amygdala subregions; in combination, these changes could serve as an imaging-based predictor of emotional disorders in patients with tinnitus.

Tinnitus: Clinical Insights in Its Pathophysiology-A Perspective

Tinnitus, the perception of sound without a corresponding external sound source, and tinnitus disorder, which is tinnitus with associated suffering, present a multifaceted clinical challenge due to its heterogeneity and its incompletely understood pathophysiology and especially due to the limited therapeutic options. In this narrative review, we give an overview on various clinical aspects of tinnitus including its heterogeneity, contributing factors, comorbidities and therapeutic pathways with a specific emphasis on the implications for its pathophysiology and future research directions. Tinnitus exhibits high perceptual variability between affected individuals (heterogeneity) and within affected individuals (temporal variability). Hearing loss emerges as predominant risk factor and the perceived pitch corresponds to areas of hearing loss, supporting the compensatory response theory. Whereas most people who have tinnitus can live a normal life, in 10-20% tinnitus interferes severely with quality of life. These patients suffer frequently from comorbidities such as anxiety, depression or insomnia, acting as both risk factors and consequences. Accordingly, neuroimaging studies demonstrate shared brain networks between tinnitus and stress-related disorders shedding light on the intricate interplay of mental health and tinnitus. The challenge lies in deciphering causative relationships and shared pathophysiological mechanisms. Stress, external sounds, time of day, head movements, distraction, and sleep quality can impact tinnitus perception. Understanding these factors provides insights into the interplay with autonomic, sensory, motor, and cognitive processes. Counselling and cognitive-behavioural therapy demonstrate efficacy in reducing suffering, supporting the involvement of stress and anxiety-related networks. Hearing improvement, especially through cochlear implants, reduces tinnitus and thus indirectly validates the compensatory nature of tinnitus. Brain stimulation techniques can modulate the suffering of tinnitus, presumably by alteration of stress-related brain networks. Continued research is crucial for unravelling the complexities of tinnitus. Progress in management hinges on decoding diverse manifestations, identifying treatment-responsive subtypes, and advancing targeted therapeutic approaches.

Greenness, Genetic Predisposition, and Tinnitus

This study aimed to investigate the association between residential greenness and tinnitus and the potential interaction between greenness and genetic predisposition to tinnitus. The normalized difference vegetation index (NDVI) is used to measure residential greenness. The tinnitus is defined based on self-reported. In the cross-sectional analyses, logistic regression models are used for the baseline sample of the United Kingdom Biobank cohort. In the secondary analysis, a Cox proportional hazard model is used for a subsample of participants who completed the tinnitus questionnaire at follow-up. In the cross-sectional analysis including 106471 participants, higher residential greenness is associated with lower odds of tinnitus for each interquartile range increase in continuous NDVI, with an adjusted odds ratio of 0.97 (95% confidence interval: 0.95 to 0.99) for tinnitus. A similar association is observed in the longitudinal analysis, with an adjusted hazard ratio of 0.92 (95% confidence interval: 0.86 to 0.98) for the association of NDVI increased per interquartile range with incident tinnitus. Moreover, there is a significant interaction between greenness and genetic predisposition to tinnitus (P < 0.05). This study suggested that residential greenness is negatively associated with tinnitus. Greenness and genetic predisposition to tinnitus are found to have a significant interaction.

Neuromodulation for Treatment of Tinnitus: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the treatment efficacy of neuromodulation versus sham for the treatment of tinnitus.

DATA SOURCES

Cochrane Library, CINAHL, PubMed, Scopus.

REVIEW METHODS

The Cochrane Library, CINAHL, PubMed, and Scopus were searched from inception through May 2023 for English language articles documenting "neuromodulation" and "tinnitus" stratified by sham-controlled randomized control trials with 40 or more patients. Data collected included Beck Anxiety Inventory, Beck Depression Inventory (BDI), Tinnitus Handicap Inventory (THI), Tinnitus Questionnaire, and Visual Analog Scale. A Meta-analysis of continuous measures (mean) and proportions (%) were conducted.

RESULTS

A total of 19 randomized control trials (N = 1186) were included. The mean age was 48.4 ± 5.3 (range: 19-74), mean duration of tinnitus was 3.8 ± 3.4 years, 61% [56.2-65.7] male, and 55.7% [46-65] with unilateral tinnitus. The short-term effect of transcutaneous electrical nerve stimulation and transcranial direct current stimulation on THI score is -16.2 [-23.1 to -9.3] and -19 [-30.1 to -7.8], respectively. The long-term effect of repetitive transcranial magnetic stimulation on THI score is -8.6 [-11.5 to -5.7]. Transcranial direct current stimulation decreases BDI score by -11.8 [-13.3 to -10.3].

CONCLUSION

As measured by the Tinnitus Handicap Index, our findings suggest the effects of transcutaneous electrical nerve stimulation and transcranial direct current stimulation reach significant benefit in the short term, whereas repetitive transcranial magnetic stimulation reaches significant benefit in the long term. Based on the BDI, transcranial direct current stimulation significantly reduces comorbid depression in patients with tinnitus.

Tinnitus sound amplification and masking therapy: Treatment and outcomes at the University of North Carolina at Chapel Hill

BACKGROUND

Tinnitus is burdensome to many patients. Sound amplification and masking therapy has been useful for some patients.

METHOD

Retrospective chart review of patients treated for tinnitus at a single academic medical center over a 12-month period. Information on treatment course and outcomes was collected and analyzed. Statistical comparisons were made using a t-test for paired means.

RESULTS

In 2021, 141 patients were evaluated for tinnitus sound amplification and masking therapy at our medical center. Average age at presentation was 55.2. Average onset was 6-7 years before presentation. Tinnitus perception was decreased in patients who received a trial of amplification and masking therapy, from 9.2 out of 20 at baseline to 6.1 with amplification and 3.2 with amplification and masking at the initial visit. The difference in each of these values is statistically significant. Nine patients recorded a Tinnitus Handicap Index (THI), which measures tinnitus burden, before and after being treated with amplification and masking therapy. These nine patients saw a decrease in THI from 39.6/100 to 19.1/100, which was also statistically significant.

LIMITATIONS

This study has several limitations. Our data are from a single clinic over one year with limited follow up information, and it is a retrospective study.

CONCLUSION

Our data showed benefit in sound amplification and masking therapy for the treatment of tinnitus. Patients treated with amplification and masking therapy showed a statistically significant decrease in perception of their tinnitus during their in-office demonstration. Long term data are still needed. Our data contribute to the broader discussion on the proper treatment course of tinnitus and the most effective measures.

Tinnitus-associated cognitive and psychological impairments: a comprehensive review meta-analysis

Background

Tinnitus is strongly associated with an increased risk of cognitive disabilities. The findings of this research will provide valuable support for future investigations aimed at determining the correlation between tinnitus and the risk of cognitive impairments.

Objectives

We investigated the potential correlation between tinnitus and the risk of various cognitive impairments, such as dementia, compromised learning attention, anxiety, depression, and insomnia. The study examined this relationship collectively and by categorizing the data based on different age groups.

Methods

We compiled data from case-control studies and cohort studies obtained from reputable databases such as PubMed, Cochrane Library, and Embase. To minimize potential bias, two reviewers independently assessed the selected articles. After extracting the data, we calculated the pooled odds ratios (ORs) using a random-effects model.

Results

Seventeen relevant studies, comprising an adult population, were included in this analysis. Pooled estimated outcomes revealed a strong association between tinnitus and an elevated risk of dementia-compromised learning, auditory attention, anxiety, depression, and poor sleep quality (P<0.05). Furthermore, the pooled analysis stratified by age demonstrated that patients aged above 60 years, in comparison to those aged 18 to 60 years, exhibited more significant outcomes in relation to the progression of cognitive impairments.

Conclusion

Tinnitus has the potential to increase the risk of cognitive impairments. Moreover, geriatric patients aged above 60 shows a higher susceptibility to developing cognitive disabilities compared to their younger counterparts.

WITHDRAWN: Listening handicap in tinnitus patients by controlling extended high frequencies - Effort or fatigue?

This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been withdrawn at the request of the editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. This error bears no reflection on the article or its authors. The publisher apologizes to the authors and the readers for this unfortunate error.

Differential cortical activation patterns: pioneering sub-classification of tinnitus with and without hyperacusis by combining audiometry, gamma oscillations, and hemodynamics

The ongoing controversies about the neural basis of tinnitus, whether linked with central neural gain or not, may hamper efforts to develop therapies. We asked to what extent measurable audiometric characteristics of tinnitus without (T) or with co-occurrence of hyperacusis (TH) are distinguishable on the level of cortical responses. To accomplish this, electroencephalography (EEG) and concurrent functional near-infrared spectroscopy (fNIRS) were measured while patients performed an attentionally demanding auditory discrimination task using stimuli within the individual tinnitus frequency (fTin) and a reference frequency (fRef). Resting-state-fMRI-based functional connectivity (rs-fMRI-bfc) in ascending auditory nuclei (AAN), the primary auditory cortex (AC-I), and four other regions relevant for directing attention or regulating distress in temporal, parietal, and prefrontal cortex was compiled and compared to EEG and concurrent fNIRS activity in the same brain areas. We observed no group differences in pure-tone audiometry (PTA) between 10 and 16 kHz. However, the PTA threshold around the tinnitus pitch was positively correlated with the self-rated tinnitus loudness and also correlated with distress in T-groups, while TH experienced their tinnitus loudness at minimal loudness levels already with maximal suffering scores. The T-group exhibited prolonged auditory brain stem (ABR) wave I latency and reduced ABR wave V amplitudes (indicating reduced neural synchrony in the brainstem), which were associated with lower rs-fMRI-bfc between AAN and the AC-I, as observed in previous studies. In T-subjects, these features were linked with elevated spontaneous and reduced evoked gamma oscillations and with reduced deoxygenated hemoglobin (deoxy-Hb) concentrations in response to stimulation with lower frequencies in temporal cortex (Brodmann area (BA) 41, 42, 22), implying less synchronous auditory responses during active auditory discrimination of reference frequencies. In contrast, in the TH-group gamma oscillations and hemodynamic responses in temporoparietal regions were reversed during active discrimination of tinnitus frequencies. Our findings suggest that T and TH differ in auditory discrimination and memory-dependent directed attention during active discrimination at either tinnitus or reference frequencies, offering a test paradigm that may allow for more precise sub-classification of tinnitus and future improved treatment approaches.

Prevalence of tinnitus and hyperacusis in 9-12-year-old children

OBJECTIVES

To estimate the prevalence of tinnitus and hyperacusis in children aged 9-12 years in Flanders, as well as to explore the associations with hearing abilities and listening behaviours.

DESIGN

A cross-sectional survey was undertaken in four different Flemish schools. The questionnaire was distributed among 415 children, with a response rate of 97.3%.

RESULTS

The prevalence of permanent tinnitus was 10.5% and of hyperacusis was 3.3%. The hyperacusis prevalence was higher in girls (p < .05). Some children reported effects of tinnitus in terms of anxiety (20.1%), sleep (36.5%), and concentration (24.8%). When listening to personal listening devices, 33.5% of the children reported to listen for at least 1 h at 60% or higher of the volume range. Moreover, 54.9% of children stated to never wear hearing protection.

CONCLUSIONS

Tinnitus and hyperacusis are prevalent in children aged 9-12 years. Some of these children might be overlooked and, as such, not receiving the required follow-up or counselling. Development of guidelines for the assessment of these auditory symptoms in children would help to determine the prevalence numbers with greater accuracy. Sensibility campaigns for safe listening are warranted, as more than half of the children never use hearing protection.

[Chronic tinnitus: An interplay between somatic and psychological factors]

Chronic tinnitus is a common, sometimes highly distressing phenomenon that can be triggered and maintained by an interplay of physical and psychological factors. Partnering with clinical psychology and psychosomatic medicine, modern otolaryngology integrates both medical (e.g., hearing loss) and psychological influences (e.g., interactions between biographical experiences, personality traits, subjective evaluation of intrapsychic and interpersonal stimuli, emotional states, and intrapsychic or interpersonal emotion regulation strategies). Both groups of variables can influence the intensity and course of chronic tinnitus symptomatology both directly and indirectly, whereby the quality and relative degrees of psychological and physical components in a person's self-experience can fluctuate. With this in mind, the present article distinguishes between chronic tinnitus symptomatology with or without hearing loss-and strongly advocates for an integrated understanding of the symptomatology within a holistic psychological frame of reference. After a brief introduction to the principles of psychosomatic medicine and psychotherapy, the article discusses psychological case conceptualization using a vulnerability-stress-coping (VSC) model as an example, outlines clinical aspects and diagnostics of chronic tinnitus symptomatology, and concludes with a conceptualization of chronic tinnitus-related distress as a function of person-centered VSC interactions.

Effect of sound therapy on whole scalp oscillatory brain activity and distress in chronic tinnitus patients

Introduction

Sound therapy is a common tinnitus treatment, where the tinnitus percept is either fully or partially masked by an external sound. Some tinnitus patients experience a decrease in tinnitus related distress after the use of sound therapy. Differences in the neural response to sound therapy may form a basis for classifying tinnitus patients.

Methods

In this study, the long-term (2 months) effects of sound therapy on the oscillatory brain activity and tinnitus related distress were investigated in chronic tinnitus patients. Baseline oscillatory activity in the group of tinnitus participants was also compared to a matched control group.

Results

No differences were found in the oscillatory activity when comparing the tinnitus group to the control group. Differences were found for the frequency range between 27.5 and 41.5 Hz corresponding to high beta and gamma power when comparing the tinnitus group before and after the use of sound therapy. Furthermore, a reduction of the tinnitus-related distress was found after the long-term use of sound therapy. However, there was no correlation between the changes in the oscillatory activity and the reductions of the tinnitus-related distress.

Discussion

Overall, the lack of correlation between the changes in tinnitus-related distress and changes in power activity hampers the interpretability of the findings and undermines the utility of using oscillatory activity as a biomarker for the effect of sound therapy treatment.

Identifying Health-Related Conditions Associated with Tinnitus in Young Adults

OBJECTIVE

The present study investigated the epidemic of tinnitus in college-aged young adults. Our first objective was to identify health conditions associated with tinnitus in young adults. The second objective was to evaluate the predictive utility of some known risk factors.

STUDY DESIGN

A cross-sectional design was used to investigate the prevalence and risk factors for tinnitus.

SETTING

A questionnaire was distributed, reaching out to a large college-aged population. A total of 2258 young adults aged 18-30 years were recruited from April 2021 to February 2022.

INTERVENTIONS

A questionnaire was administered to investigate the epidemiology of tinnitus in a population of college-aged young adults.

RESULTS

About 17.7% of young adults reported bothersome tinnitus perception lasting for ≥5 min in the last 12 months. The prevalence of chronic tinnitus (bothersome tinnitus for ≥1 year) and acute tinnitus (bothersome tinnitus for <1 year) was 10.6% and 7.1%, respectively. About 19% of the study sample reported at least one health condition. Individuals reporting head injury, hypertension, heart disease, scarlet fever, and malaria showed significantly higher odds of reporting chronic tinnitus. Meningitis and self-reported hearing loss showed significant associations with bothersome tinnitus. The prevalence of chronic tinnitus was significantly higher in males reporting high noise exposure, a positive history of reoccurring ear infections, European ethnic background, and a positive health history. Risk modeling showed that noise exposure was the most important risk factor for chronic tinnitus, followed by sex, reoccurring ear infections, and a history of any health condition. A positive history of COVID-19 and self-reported severity showed no association with tinnitus. Individuals reporting reoccurring ear infections showed a significantly higher prevalence of COVID-19.

CONCLUSIONS

While young adults with health conditions are at a higher risk of reporting tinnitus, the predictive utility of a positive health history remains relatively low, possibly due to weak associations between health conditions and tinnitus. Noise, male sex, reoccurring ear infections, European ethnicity, and a positive health history revealed higher odds of reporting chronic tinnitus than their counterparts. These risk factors collectively explained about 16% variability in chronic tinnitus, which highlights the need for identifying other risk factors for chronic tinnitus in young adults.

Tinnitus cases after COVID-19 vaccine administration, one institution's observations

OBJECTIVE

After the role out of the COVID-19 vaccine in the United States, there has been increase in case reports of tinnitus attributed to the vaccine reported. We present our institution's experience over the initial 13 month period the vaccines were available.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic otology and general otolaryngology practice.

PATIENTS

Patients who received a COVID-19 vaccine and a tinnitus diagnosis code.

INTERVENTIONS

Observation, steroids (oral and intratympanic), diagnostic imaging and audiometry.

MAIN OUTCOME MEASURES

Patients who received a COVID-19 vaccine in the time frame of 12/1/2020-12/31/21 with a diagnosis of tinnitus, an audiogram, and at least one visit with one of our Otolaryngologists were included in the study. Twenty-seven of the 1254 patients identified met these criteria. The patients ranged in age from 41 to 84 years old including seven male and twenty female patients. Sixteen received the Pfizer vaccine, seven received the Moderna vaccine and four patients received the Janssen vaccine.

CONCLUSIONS

No definite correlation could be established between COVID-19 vaccine and tinnitus. Any concurrent sudden hearing loss should be treated as usual with oral or intratympanic steroids. Health care providers should be aware of the tinnitus onset and if new or recent onset, to refer for prompt audiogram and Otolaryngology evaluation.

Venous balloon test occlusion for pulsatile tinnitus assessment: A clinical feasibility study

BACKGROUND

Pulsatile tinnitus (PT) can have huge impact on the patients' quality of life and can be associated with curable vascular anomalies. In the present study, we aim firstly to describe our protocol for venous BTO and secondly to report possible predictors for a positive BTO test.

METHODS

All consecutive PT patients undergoing BTO for the purpose of determining eligibility for venous neuro-intervention were included. We recommend BTO for patients when there is uncertainty in the association of the venous pathology identified on non-invasive cross-sectional imaging (CTV or MRV) and the patient's symptoms.

RESULTS

Between May 2016 and October 2022, we recorded 29 venous balloon test occlusions fulfilling our inclusions criteria. Over the 29 procedures scheduled, 8 finally did not lead to a successful balloon test occlusion. The main reason was that the patient did not hear the PT on the day the angiogram was performed. Two patients could not have the BTO due to difficulties in venous navigation. After BTO, only four patients of our cohort were scheduled for an endovascular treatment.

CONCLUSION

We describe a technique and present a single cohort of venous BTO in severe PT patients with unclear anatomical cause. This angiographic test was useful to exclude patients from endovascular surgery and discuss the most probable cause of the PT. Complexity of vascular PT should support a patient-based approach when discussing interventional treatment.

Tinnitus and Influencing Comorbidities

Numerous studies show that impairments in chronic tinnitus are closely connected with psychosomatic and other concomitant symptoms. This overview summarizes some of these studies. Beyond hearing loss, individual interactions of medical and psychosocial stress factors as well as resources are of central importance. Tinnitus related distress reflects a large number of intercorrelated, psychosomatic influences - such as personality traits, stress reactivity and depression or anxiety - which can be accompanied by cognitive difficulties and should be conceptualized and assessed within a vulnerability-stress-reaction model. Superordinate factors such as age, gender or education level can increase vulnerability to stress. Therefore, diagnosis and therapy of chronic tinnitus be individualised, multidimensional and interdisciplinary. Multimodal psychosomatic therapy approaches aim to address individually constellated medical, audiological and psychological influences in order to sustainably increase the quality of life of those affected. Counselling in the first contact is also indispensable for diagnosis and therapy.

Do you Hear what I Hear? A Qualitative Study Examining Psychological Associations Underlying Evaluations of Everyday Sounds in Patients with Chronic Tinnitus

Tinnitus is a multifactorial phenomenon and psychological, audiological, or medical factors can facilitate its onset or maintenance. A growing body of research investigates individuals' perceptions, associations, and experiences of living with tinnitus. This body of research examines tinnitus as a condition rather than a symptom. We examine a sample of chronic tinnitus patients in terms of associations that are induced by neutral sounds. In particular, we investigate how patients with chronic tinnitus ascribe meaning to those neutral sounds. The present study uses Mayring's content analysis to explore the content of psychological associations underlying valence ratings of everyday neutral sounds. Nine tinnitus patients completed a hearing exercise, during which they listened to seven neutral sounds, following which we examined their sound-induced associations using semi-structured interviews. Three groups of factors influenced patients' associations and valence ratings of neutral sounds: affect, episodic memory, and 'other'. The former two factors further comprised two subcategories. In line with previous psychoaudiological research designs, our findings suggest that neutral, everyday auditory stimuli evoke strong affective reactions-possibly through serving as retrieval cues for episodic memories. Based on these findings, we discuss our results in the context of previous psychoaudiological findings and propose further research concerning psychological associations that may specifically underlie the tinnitus sound.

Pairing with Enriched Sound Exposure Restores Auditory Processing Degraded by an Antidepressant

Antidepressants, while effective in treating depression and anxiety disorders, also induce deficits in sensory (particularly auditory) processing, which in turn may exacerbate psychiatric symptoms. How antidepressants cause auditory signature deficits remains largely unknown. Here, we found that fluoxetine-treated adult female rats were significantly less accurate when performing a tone-frequency discrimination task compared with age-matched control rats. Their cortical neurons also responded less selectively to sound frequencies. The degraded behavioral and cortical processing was accompanied by decreased cortical perineuronal nets, particularly those wrapped around parvalbumin-expressing inhibitory interneurons. Furthermore, fluoxetine induced critical period-like plasticity in their already mature auditory cortices; therefore, a brief rearing of these drug-treated rats under an enriched acoustic environment renormalized auditory processing degraded by fluoxetine. The altered cortical expression of perineuronal nets was also reversed as a result of enriched sound exposure. These findings suggest that the adverse effects of antidepressants on auditory processing, possibly because of a reduction in intracortical inhibition, can be substantially alleviated by simply pairing drug treatment with passive, enriched sound exposure. They have important implications for understanding the neurobiological basis of antidepressant effects on hearing and for designing novel pharmacological treatment strategies for psychiatric disorders.SIGNIFICANCE STATEMENT Clinical experience suggests that antidepressants adversely affect sensory (particularly auditory) processing, which can exacerbate patients' psychiatric symptoms. Here, we show that the antidepressant fluoxetine reduces cortical inhibition in adult rats, leading to degraded behavioral and cortical spectral processing of sound. Importantly, fluoxetine induces a critical period-like state of plasticity in the mature cortex; therefore, a brief rearing under an enriched acoustic environment is sufficient to reverse the changes in auditory processing caused by the administration of fluoxetine. These results provide a putative neurobiological basis for the effects of antidepressants on hearing and indicate that antidepressant treatment combined with enriched sensory experiences could optimize clinical outcomes.

The Comorbidity of Depression and Anxiety Symptoms in Tinnitus Sufferers: A Network Analysis

OBJECTIVE

Sufferers of tinnitus, especially of the prolonged type, frequently suffer from comorbid depression and anxiety. From the perspective of the network model, this comorbidity is thought to be an interacting system of these two symptoms. In our study, we conducted a network analysis of depression and anxiety comorbidity in tinnitus sufferers, aiming to identify the central and bridge symptoms and make informed suggestions for clinical interventions and psychotherapy.

METHOD

A total of 566 tinnitus sufferers were enrolled in our study. The Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder 7-Item Questionnaire (GAD-7) were selected to evaluate depression and anxiety symptoms, respectively, followed by network analysis to construct the interacting networks.

RESULTS

The findings identified six edges of strongest regularized partial correlations in this network. Of these, three were depression symptoms and three were anxiety symptoms. The anxiety symptoms "Unable to control worry" and "Relaxation difficulty" and the depression symptom "Feeling depressed or hopeless" had the highest expected influence centrality. The analysis results also revealed three bridge symptoms: "Afraid something awful might happen", "Feeling of worthlessness", and "Trouble concentrating". As for "Suicidal ideation", the direct relations between this symptom and "Afraid something awful might happen" and "Feeling depressed or hopeless" were the strongest.

CONCLUSIONS

The central and bridge symptoms of the interacting network of depression and anxiety symptoms in tinnitus sufferers can be considered a significant transdiagnostic intervention target for the management of this comorbidity. In particular, clinical prevention and psychotherapy should be implemented, targeting the symptoms that have the strongest associations with suicidal ideation.

Tinnitus-frequency specific activity and connectivity: A MEG study

Tinnitus pathophysiology has been associated with an atypical cortical network that involves functional changes in auditory and non-auditory areas. Numerous resting-state studies have replicated a tinnitus brain network to be significantly different from healthy-controls. Yet it is still unknown whether the cortical reorganization is attributed to the tinnitus frequency specifically or if it is frequency-irrelevant. Employing magnetoencephalography (MEG), the current study aimed to identify frequency-specific activity patterns by using an individual tinnitus tone (TT) and a 500 Hz-control tone (CT) as auditory stimuli, across 54 tinnitus patients. MEG data were analyzed in a data-driven approach employing a whole-head model in source space and in sources' functional connectivity. Compared to the CT, the event related source space analysis revealed a statistically significant response to TT involving fronto-parietal regions. The CT mainly involved typical auditory activation-related regions. A comparison of the cortical responses to a healthy control group that underwent the same paradigm rejected the alternative interpretation that the frequency-specific activation differences were due to the higher frequency of the TT. Overall, the results suggest frequency-specificity of tinnitus-related cortical patterns. In line with previous studies, we demonstrated a tinnitus-frequency specific network comprising left fronto-temporal, fronto-parietal and tempo-parietal junctions.

Anxiety, Depression, and Symptom Severity in Patients with Pulsatile and Non-Pulsatile Tinnitus

OBJECTIVE(S)

To compare the rates of anxiety and depression between patients with pulsatile (PT) and non-pulsatile tinnitus (NPT), and their correlation with tinnitus severity.

METHODS

A prospective cross-sectional study of consecutive patients presenting either to the otolaryngology clinic for pulsatile (PT) and NPT or to a tertiary care tinnitus habituation program (THP) were administered the tinnitus handicap inventory (THI), 7-item general anxiety disorder scale (GAD-7), and 9-item patient health questionnaire (PHQ-9). Median scores between groups and correlation of scores within groups were calculated and compared.

RESULTS

Median THI scores were significantly higher for THP and PT patients as compared with unselected NPT patients (58 and 44 vs. 20, p ≤ 0.001). Median GAD-7 (10 vs. 2.5 and 2, p ≤ 0.001) and PHQ-9 (7 vs. 4 and 4, p = 0.04) scores were highest in THP patients compared with PT and NPT. The strongest correlation between tinnitus handicap and psychiatric measures was seen in THP patients.

CONCLUSION

THP patients report higher levels of anxiety and depression compared with PT and other NPT patients. Tinnitus severity correlates more strongly with GAD-7 and PHQ-9 scores in THP patients compared with other patient groups. PT patients have a greater self-perceived tinnitus handicap than the general cohort of NPT patients, statistically comparable to THP patients. Despite this, anxiety and depression are not more severe in patients with PT as they are in THP patients.

LEVEL OF EVIDENCE

2B Laryngoscope, 133:683-688, 2023.

Vascular Factors in Patients with Midlife Sensorineural Hearing Loss and the Progression to Mild Cognitive Impairment

Background and Objectives: Midlife hearing loss (HL) has been considered as a major modifiable risk factor for a later-life progression to dementia. Our aim was to detect a link between precocious sensorineural hearing loss (SNHL) and mild cognitive impairment (MCI) and their association to putative risk factors for a common pathology. Materials and methods: In this study, a retrospective case-control study was carried out. A total of 112 patients were enrolled as following: 81 patients with bilateral SNHL and 31 subjects with normal hearing, whose ages ranged from 50 to 65 years. Both groups performed pure tone audiometry, a tinnitus handicap inventory (THI), Mini-Mental State examination (MMSE), and the Montreal Cognitive Assessment (MoCA), Hospital Anxiety and Depression Scale (HADS-A and HADS-D). Results: The mean age was 58 ± 5.2 in SNHL patients and 53.2 ± 4.8 in the control group. The mean pure tone average in the SNHL group was 40.2 ± 18.7 dB HL on the right side and 41.2 ± 17.2 dB HL on the left side, while in the control group it was 12.5 ± 2.8 dB HL on right side and 12.4 ± 3.1 dB HL on left side. About 64% of patients with SNHL exhibited comorbidities, and the most common condition was hypertension. Altered MoCA test scores were significantly related to the pure tone averages in patients with SNHL compared to the control group (p = 0.0004), while the differences in the HADS-A and HADS-D were not significant. Furthermore, a significant correlation was observed in SNHL patients between an altered MoCA test and hypercholesterolemia (p = 0.043). Conclusions: Hearing impairment and screening tests to detect MCI should be considered in the midlife in order to carry out strategies to prevent the progression to dementia. Hypertension and hypercholesterolemia are two risk factors in the development of endothelial dysfunction, oxidative stress, and vascular inflammation, and may represent the common pathology linking the inner ear and brain damage.

Evaluation and Management of Tinnitus: Are There Opportunities for Improvement?

OBJECTIVE

To review current information about diagnosis and management of tinnitus aiming to identify opportunities for achieving a cost-effective, efficient, evidence-based approach that meets the needs of tinnitus sufferers.

DATA SOURCES

PubMed/MEDLINE.

REVIEW METHODS

In total, 249 relevant published reports were reviewed. Pertinent keywords and MeSH terms identified reports via PubMed and EMBASE. Acknowledged experts were consulted on ways to improve tinnitus management.

CONCLUSIONS

There may be opportunities to improve evaluation and management of patients with tinnitus using modern modes of communication and a multidisciplinary therapeutic approach.

IMPLICATIONS FOR PRACTICE

Tinnitus can adversely affect quality of life while being time-consuming and costly to evaluate and manage. Based on both personal experience and the reports of others, patients with tinnitus who choose to see a physician primarily want to know two things: (1) that the tinnitus that is so distressing will not remain at the same level of severity forever and (2) that something can be done to help cope with the tinnitus that is so annoying. Recent advancements in internet communications, social media, information technology, artificial intelligence, machine learning, holistic medical care, mind-body integrative health care, and multidisciplinary approaches in medical therapeutics may be possibly making new ways of meeting the needs of patients with tinnitus.

Vulnerability to chronic stress and the phenotypic heterogeneity of presbycusis with subjective tinnitus

Age-related functional reserve decline and vulnerability of multiple physiological systems and organs, as well as at the cellular and molecular levels, result in different frailty phenotypes, such as physical, cognitive, and psychosocial frailty, and multiple comorbidities, including age-related hearing loss (ARHL) and/or tinnitus due to the decline in auditory reserve. However, the contributions of chronic non-audiogenic cumulative exposure, and chronic audiogenic stress to phenotypic heterogeneity of presbycusis and/or tinnitus remain elusive. Because of the cumulative environmental stressors throughout life, allostasis systems, the hypothalamus-pituitary-adrenal (HPA) and the sympathetic adrenal-medullary (SAM) axes become dysregulated and less able to maintain homeostasis, which leads to allostatic load and maladaptation. Brain-body communication via the neuroendocrine system promotes systemic chronic inflammation, overmobilization of energetic substances (glucose and lipids), and neuroplastic changes via the non-genomic and genomic actions of glucocorticoids, catecholamines, and their receptors. These systemic maladaptive alterations might lead to different frailty phenotypes and physical, cognitive, and psychological comorbidities, which, in turn, cause and exacerbate ARHL and/or tinnitus with phenotypic heterogeneity. Chronic audiogenic stressors, including aging accompanying ontological diseases, cumulative noise exposure, and ototoxic drugs as well as tinnitus, activate the HPA axis and SAM directly and indirectly by the amygdala, promoting allostatic load and maladaptive neuroplasticity in the auditory system and other vulnerable brain regions, such as the hippocampus, amygdala, and medial prefrontal cortex (mPFC). In the auditory system, peripheral deafferentation, central disinhibition, and tonotopic map reorganization may trigger tinnitus. Cross-modal maladaptive neuroplasticity between the auditory and other sensory systems is involved in tinnitus modulation. Persistent dendritic growth and formation, reduction in GABAergic inhibitory synaptic inputs induced by chronic audiogenic stresses in the amygdala, and increased dendritic atrophy in the hippocampus and mPFC, might involve the enhancement of attentional processing and long-term memory storage of chronic subjective tinnitus, accompanied by cognitive impairments and emotional comorbidities. Therefore, presbycusis and tinnitus are multisystem disorders with phenotypic heterogeneity. Stressors play a critical role in the phenotypic heterogeneity of presbycusis. Differential diagnosis based on biomarkers of metabonomics study, and interventions tailored to different ARHL phenotypes and/or tinnitus will contribute to healthy aging and improvement in the quality of life.

Effectiveness of bimodal auditory and electrical stimulation in patients with tinnitus: A feasibility study

Background

Tinnitus is a common symptom, affecting about 10–15% of the adult population. When input from the somatosensory system can influence and/or elicit tinnitus, this type of subjective tinnitus is called somatosensory tinnitus. Recently, a new type of bimodal neurostimulation treatment has shown promising results for a specific subgroup within the somatosensory tinnitus population. It is, however, not clear if this bimodal stimulation is also effective in patients with other types of subjective tinnitus.

Aim

The aim of this study was to evaluate the feasibility and efficacy of non-invasive bimodal auditory-somatosensory stimulation in reducing tinnitus severity among a general population of people with subjective tinnitus.

Methods

Chronic subjective tinnitus patients were recruited from the ENT department of the Antwerp University Hospital. Somatosensory stimulation was delivered by Transcutaneous Electrical Nerve Stimulation (TENS), and it was combined with auditory stimulation via headphones. The therapy comprised six sessions of thirty minutes twice a week for a period of 3 consecutive weeks. Follow up measurements were scheduled 9–12 weeks after the last treatment session. The change of the Tinnitus Functional Index (TFI) score, a questionnaire evaluating tinnitus burden and effects on the quality of life, was the primary outcome measure.

Results

Twenty-nine patients were enrolled in the study. A linear mixed-effects model was used to analyze the efficacy of bimodal treatment. The results of this analysis showed a statistically significant decrease (by 6, 9 points) in average TFI score at the follow up visit when compared to baseline. The ability to modulate tinnitus did not have an influence on the treatment results.

Conclusion

Our study showed that bimodal stimulation is a feasible and safe method of tinnitus treatment. The method might be an effective treatment for some participants with tinnitus, especially those who have accompanying neck/temporomandibular problems, although, the evidence from this trial is quite weak. Additional research is needed toward establishing the optimal treatment protocol, as well as selecting the most appropriate inclusion criteria.

Long-Term Effects of Repetitive Transcranial Magnetic Stimulation on Tinnitus in a Guinea Pig Model

The auditory phantom sensation of tinnitus is associated with neural hyperactivity. Modulating this hyperactivity using repetitive transcranial magnetic stimulation (rTMS) has shown beneficial effects in human studies. Previously, we investigated rTMS in a tinnitus animal model and showed that rTMS over prefrontal cortex (PFC) attenuated tinnitus soon after treatment, likely via indirect effects on auditory pathways. Here, we explored the duration of these beneficial effects. Acoustic trauma was used to induce hearing loss and tinnitus in guinea pigs. Once tinnitus developed, high-frequency (20 Hz), high-intensity rTMS was applied over PFC for two weeks (weekdays only; 10 min/day). Behavioral signs of tinnitus were monitored for 6 weeks after treatment ended. Tinnitus developed in 77% of animals between 13 and 60 days post-trauma. rTMS treatment significantly reduced the signs of tinnitus at 1 week on a group level, but individual responses varied greatly at week 2 until week 6. Three (33%) of the animals showed the attenuation of tinnitus for the full 6 weeks, 45% for 1–4 weeks and 22% were non-responders. This study provides further support for the efficacy of high-frequency repetitive stimulation over the PFC as a therapeutic tool for tinnitus, but also highlights individual variation observed in human studies.

Associations between sleep disorders and anxiety in patients with tinnitus: A cross-sectional study

Objective

To investigate the characteristics of sleep disorders and anxiety in patients with tinnitus, their influencing factors, and the role of sleep disorders as mediators.

Methods

The general conditions and disease characteristics of 393 patients with tinnitus presented to the Changzheng Hospital of the Naval Medical University from 2018 to 2021 were collected. All patients accepted questionnaires such as Tinnitus Handicap Inventory (THI), Pittsburgh Sleep Quality Index (PSQI) and Self-rating Anxiety Scale (SAS), and then the characteristics and the influencing factors of sleep disorders and anxiety were analyzed.

Results

Among the 393 tinnitus patients, 213 cases (54.19%) were diagnosed with sleep disorders, and 78 cases (19.85%) were diagnosed with anxiety, including 25 men (32.1%) and 53 women (67.9%). Binary regression showed that gender, hearing loss, tinnitus severity, and sleep disorders severity were positively associated with anxiety. Multiple logistic regression analysis showed that female gender (OR = 2.526, P = 0.008), hearing loss (OR = 2.901, P = 0.003, tinnitus severity (OR = 1.863, P = 0.003) and sleep disorders (OR = 2.510, P = 0.001) were the independent risk factors of anxiety. The mediating effect of sleep disorders between tinnitus severity and anxiety accounted for 27.88% of the total effect size.

Conclusion

Females patients with hearing loss, moderate to severe tinnitus, and sleep disorders were at greater risk for anxiety, with sleep disorders partially mediating the anxiety associated with tinnitus.

Post-Mortem Analysis of Neuropathological Changes in Human Tinnitus

Tinnitus is the phantom perception of a sound, often accompanied by increased anxiety and depressive symptoms. Degenerative or inflammatory processes, as well as changes in monoaminergic systems, have been suggested as potential underlying mechanisms. Herein, we conducted the first post-mortem histopathological assessment to reveal detailed structural changes in tinnitus patients’ auditory and non-auditory brain regions. Tissue blocks containing the medial geniculate body (MGB), thalamic reticular nucleus (TRN), central part of the inferior colliculus (CIC), and dorsal and obscurus raphe nuclei (DRN and ROb) were obtained from tinnitus patients and matched controls. Cell density and size were assessed in Nissl-stained sections. Astrocytes and microglia were assessed using immunohistochemistry. The DRN was stained using antibodies raised against phenylalanine hydroxylase-8 (PH8) and tyrosine-hydroxylase (TH) to visualize serotonergic and dopaminergic cells, respectively. Cell density in the MGB and CIC of tinnitus patients was reduced, accompanied by a reduction in the number of astrocytes in the CIC only. Quantification of cell surface size did not reveal any significant difference in any of the investigated brain regions between groups. The number of PH8-positive cells was reduced in the DRN and ROb of tinnitus patients compared to controls, while the number of TH-positive cells remained unchanged in the DRN. These findings suggest that both neurodegenerative and inflammatory processes in the MGB and CIC underlie the neuropathology of tinnitus. Moreover, the reduced number of serotonergic cell bodies in tinnitus cases points toward a potential role of the raphe serotonergic system in tinnitus.

Association of Dry Eye Diseases and Auditory Sensitivity

This study aimed to evaluate the association between dry eye and inner ear diseases in a Korean population. Methods: Data from the Korean National Health and Nutrition Survey (KNHANES V, 2010−2012), a national cross-sectional health examination and survey, were collected by the Korea Centers for Disease Control and Prevention. The association between dry eye and inner ear disease was determined using the chi-square test and logistic regression analysis. The individuals were divided into two age groups (<60 and ≥60 years). Results: In total, 17,542 individuals (n = 11,932 in the <60 years group and n = 5610 in the ≥60 years group) were enrolled. After adjusting for confounding factors, the logistic regression model revealed that the associated factors were dizziness and loss of balance experience (OR, 1.315; 95% CI, 1.143−1.513), self-awareness of abnormal voice (OR, 1.372; 95% CI, 1.120−1.679), subjective hearing discomfort (OR, 1.278; CI, 1.084−1.506), and tinnitus (OR, 1.265; 95% CI, 1.101−1.453). The inversely associated factor for dry eye was bilateral hearing loss (OR, 0.497; 95% CI, 0.367−0.672). The hearing threshold was lower in the dry eye group than in the non-dry eye group (p < 0.05). Conclusions: Tinnitus was associated with dry eye and bilateral hearing loss was inversely associated with dry eye. These results suggest that hypersensitivity of the senses and nerves, which is neuropathic hyperesthesia, is one of the main mechanisms of dry eye. Treatment of neuropathy may help in treating dry eye associated with dizziness or tinnitus.

Predicting the optimal therapeutic intervention for tinnitus patients using random forest regression: A preliminary study of UNITI's decision support system model

Tinnitus is the conscious perception of a phantom sound in absence of an external or internal stimulus. More than 1 in 7 adults in the EU experience tinnitus and for a large proportion of them tinnitus is an intrusive, persistent, and disabling condition, which impairs their life quality. Therefore, tinnitus is posed as a major global burden, which requires a precision-medicine approach in terms of treatments that are tailored to individual patients, due to its high heterogeneity. UNITI is a research and innovation project which aims towards this goal, unifying treatments and interventions for tinnitus. In the context UNITI, a randomized controlled trial (RCT) is being conducted and all the participants' data will be utilized for the development of a clinical decision support system (CDSS). This CDSS will predict the optimal therapeutic intervention for a tinnitus patient based on their profile. In this paper, we present a preliminary study of the CDSS model development process. We describe the available input data, the pre-processing steps conducted, the algorithms tested to model the CDSS' prediction, the models' results, and the future work in the context of this project. The R2 score of the selected model is currently 0.65, indicating that its development process is in the right direction but further tuning and hyperparameter optimization is needed. Clinical Relevance- The proposed model will be integrated in a CDSS aiming at indicating the optimal treatment strategy for a tinnitus patient based their personal profile.

Negative Associations of Stress and Anxiety Levels With Cytotoxic and Regulatory Natural Killer Cell Frequency in Chronic Tinnitus

Background

Depression and anxiety are known to be associated with stress-induced changes in the immune system. Bothersome tinnitus can be related to stress and often co-occurs with depression and anxiety. This study investigates associations of psychological and audiological tinnitus-related factors with inflammatory parameters and immune cell subsets in chronic tinnitus patients as well as treatment-related effects.

Methods

This longitudinal study of inpatients treated with compact multimodal tinnitus-specific cognitive behavioral therapy included four repeated measurement sessions: baseline (N = 41), treatment end, 7.8-week (N = 35), and 13.8-week follow-up (N = 34). Data collection included audiometric testing, blood sampling, and psychometric questionnaires: Tinnitus Handicap Inventory (THI), Perceived Stress Questionnaire (PSQ-20), and Hospital Anxiety Depression Scale (HADS). Flow cytometry was used to analyze immune cell subsets. Statistical analyses comprised correlation and network analysis (cross-sectional), and linear mixed effect models (longitudinal).

Results

Bootstrapped network analysis showed negative averaged cross-sectional associations of cytotoxic natural killer (NKc) cell frequency (CD56 + CD16+) and PSQ-20 (−0.21 [−0.48, 0]) and of regulatory natural killer (NKreg) cell frequency (CD56 + CD16dim/−) and HADS anxiety (−0.14 [−0.38, 0]). No significant treatment effects were found. A negative predictive effect of baseline PSQ-20 scores (β = −6.22 [−12.18, −0.26], p = 0.041) and a positive predictive effect of baseline ferritin levels (β = 8.90 [2.76, 15.03], p = 0.004) on NKc cell frequency across the repeated measurement sessions were observed.

Conclusion

We observed negative relationships between perceived stress levels and NKc cell frequency and between anxiety levels and NKreg cell frequency in chronic tinnitus patients. These exploratory results suggest stress−/anxiety-related immune alterations in bothersome tinnitus but need to be tested in further confirmatory studies with larger sample sizes. The potential of NK cells as biomarkers of emotional distress in chronic tinnitus should be further investigated.

Impact of the COVID-19 Lockdown on Patients with Chronic Tinnitus-Preliminary Results

The COVID-19 pandemic and the lockdown measures are both causes of psychological distress. The aim of the current study was to evaluate the psychological effects of lockdown measures on patients with subjective chronic tinnitus diagnosed before the COVID-19 pandemic. A sample of n = 77 patients with chronic tinnitus was contacted by mail/phone for a survey between June 2021 and September 2021. All patients filled out questionnaires on tinnitus distress (Tinnitus Handicap Inventory, THI), anxiety (Beck Anxiety Inventory, BAI) and depression (Beck Depression Inventory, BDI) and eight items of the Tinnitus Sample Case History (TSCH) about tinnitus history (i.e., loudness, pitch, perception, tinnitus location), stress, and related conditions (noise annoyance, vertigo/dizziness, headache). Forty patients with chronic tinnitus filled out the survey. No significant differences of total THI mean scores (p > 0.05) were found compared to the results obtained before the COVID-19 pandemic and after lockdown. Regarding depression and anxiety, the female population showed a significant increase in scores obtained from the BDI (p < 0.0170) and the BAI (p < 0.049). Only two patients (0.5%) were infected by COVID-19 (positive RT-PCR), and they did not report any worsening of tinnitus. According to the data of the literature, our patients experienced a heterogeneous course of tinnitus, and the severity of tinnitus was not significantly affected by lifestyle changes during the COVID-19 pandemic and lockdown.

Ototoxicity After Cisplatin-Based Chemotherapy: Factors Associated With Discrepancies Between Patient-Reported Outcomes and Audiometric Assessments

OBJECTIVES

To provide new information on factors associated with discrepancies between patient-reported and audiometrically defined hearing loss (HL) in adult-onset cancer survivors after cisplatin-based chemotherapy (CBCT) and to comprehensively investigate risk factors associated with audiometrically defined HL.

DESIGN

A total of 1410 testicular cancer survivors (TCS) ≥6 months post-CBCT underwent comprehensive audiometric assessments (0.25 to 12 kHz) and completed questionnaires. HL severity was defined using American Speech-Language-Hearing Association criteria. Multivariable multinomial regression identified factors associated with discrepancies between patient-reported and audiometrically defined HL and multivariable ordinal regression evaluated factors associated with the latter.

RESULTS

Overall, 34.8% of TCS self-reported HL. Among TCS without tinnitus, those with audiometrically defined HL at only extended high frequencies (EHFs) (10 to 12 kHz) (17.8%) or at both EHFs and standard frequencies (0.25 to 8 kHz) (23.4%) were significantly more likely to self-report HL than those with no audiometrically defined HL (8.1%) [odds ratio (OR) = 2.48; 95% confidence interval (CI), 1.31 to 4.68; and OR = 3.49; 95% CI, 1.89 to 6.44, respectively]. Older age (OR = 1.09; 95% CI, 1.07 to 1.11, p < 0.0001), absence of prior noise exposure (OR = 1.40; 95% CI, 1.06 to 1.84, p = 0.02), mixed/conductive HL (OR = 2.01; 95% CI, 1.34 to 3.02, p = 0.0007), no hearing aid use (OR = 5.64; 95% CI, 1.84 to 17.32, p = 0.003), and lower education (OR = 2.12; 95% CI, 1.23 to 3.67, p = 0.007 for high school or less education versus postgraduate education) were associated with greater underestimation of audiometrically defined HL severity, while tinnitus was associated with greater overestimation (OR = 4.65; 95% CI, 2.64 to 8.20 for a little tinnitus, OR = 5.87; 95% CI, 2.65 to 13.04 for quite a bit tinnitus, and OR = 10.57; 95% CI, 4.91 to 22.79 for very much tinnitus p < 0.0001). Older age (OR = 1.13; 95% CI, 1.12 to 1.15, p < 0.0001), cumulative cisplatin dose (>300 mg/m2, OR = 1.47; 95% CI, 1.21 to 1.80, p = 0.0001), and hypertension (OR = 1.80; 95% CI, 1.28 to 2.52, p = 0.0007) were associated with greater American Speech-Language-Hearing Association-defined HL severity, whereas postgraduate education (OR = 0.58; 95% CI, 0.40 to 0.85, p = 0.005) was associated with less severe HL.

CONCLUSIONS

Discrepancies between patient-reported and audiometrically defined HL after CBCT are due to several factors. For survivors who self-report HL but have normal audiometric findings at standard frequencies, referral to an audiologist for additional testing and inclusion of EHFs in audiometric assessments should be considered.

Tinnitus in immigrants attending Swedish language education classes

Objectives

The aim of this study was to investigate the prevalence of tinnitus in immigrants attending Swedish language education classes in comparison with data from the general population and tinnitus's relation to hearing in this specific population.

Methods

The study was based on prospectively collected data regarding hearing and health status in newcomers attending language classes. The examination consisted of pure tone audiometry, an otoscopic examination, and a study‐specific questionnaire including questions from the Swedish National Health Survey. Data from the Swedish general population were retrieved from the National Health Survey. Grading of hearing according to the World Health Organization was applied.

Results

A total of 188 study participants were included in the study. Tinnitus was reported by 38% of the immigrants, and severe tinnitus was reported by 8%. Corresponding percentages from the general population were 17% and 3%. High‐frequency hearing loss (PTA_h3 > 25 worse ear) was found to be a significant predictor for tinnitus (p = 0.032, odds ratio (OR): 2.74 [95% confidence interval (CI): 1.40–5.35]). Additionally, self‐reported general health significantly predicted tinnitus, with an increased risk of tinnitus relating to worse general health (p < .001, OR: 2.43 [95% CI: 1.66–3.57]).

Conclusion

Severe tinnitus was more than three times as common in the immigrant participants compared to the Swedish population. High‐frequency hearing loss and self‐reported worse general health were predictors for tinnitus.

Level of Evidence

1b

Severe tinnitus was more than three times as common in immigrants compared to the Swedish population. High‐frequency hearing loss and self‐reported worse general health were predictors for tinnitus.

Sex-Specific Prevalence, Demographic Characteristics, and Risk Factors of Tinnitus in the Hispanic Community Health Study/Study of Latinos

PURPOSE

The aim of this study was to determine the prevalence of any and chronic tinnitus among female and male individuals from varied Hispanic/Latino backgrounds and to estimate associations between risk factors for chronic tinnitus.

METHOD

Our analysis used cross-sectional baseline data collected from 2008 to 2011 from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Prevalence estimates and multivariable logistic regression were conducted using survey methodology. Participants included 15,768 adults (8,229 women and 7,539 men) aged 18-76 years. The primary outcome of interest was chronic tinnitus, defined as self-reported tinnitus lasting ≥ 5 min at a time and at least once per week. We hypothesized that after adjusting for covariates, the risk factors of depressed and anxious symptoms, smoking history, hypertension, and noise exposure history would be associated with higher odds of chronic tinnitus.

RESULTS

Unstratified prevalence for any tinnitus was 32.9%, and for chronic tinnitus, it was 12.1%. Sex-stratified results demonstrated that 2,995 female individuals (36.4%) and 2,187 male individuals (29.0%) reported any tinnitus, and of these, 1,043 female individuals (12.7%) and 870 male individuals (11.5%) reported chronic tinnitus. In the fully adjusted model, depressed and anxious symptoms as well as recreational noise exposure were associated with higher odds of chronic tinnitus in female individuals (odds ratios [ORs] = 1.06, confidence interval [CI; 1.04, 1.07]; 1.02, CI [1.01, 1.04]; and 1.40, CI [1.20, 1.62]) and in male individuals (ORs = 1.06, CI [1.03, 1.08]; 1.05, CI [1.02, 1.08]; and 1.30, CI [1.05, 1.65]). Current smoking was a risk factor for chronic tinnitus in male individuals (OR = 1.53, CI [1.16, 2.02]).

CONCLUSIONS

Prevalence of any and chronic tinnitus in the HCHS/SOL baseline cohort is higher than that reported in previous studies, particularly among female individuals. Understanding risk factors associated with tinnitus is important for the development of culturally and linguistically appropriate public health programs that consider sex differences and promote lifestyle modifications known to lower the odds of experiencing tinnitus.

Hair-cortisol and hair-BDNF as biomarkers of tinnitus loudness and distress in chronic tinnitus

The role of stress and its neuroendocrine mediators in tinnitus is unclear. In this study, we measure cortisol as an indicator of hypothalamus–pituitary–adrenal (HPA) axis alterations and brain-derived neurotrophic factor (BDNF) as a marker of adaptive neuroplasticity in hair of chronic tinnitus patients to investigate relationships with tinnitus-related and psychological factors. Cross-sectional data from chronic tinnitus inpatients were analyzed. Data collection included hair sampling, pure tone audiometry, tinnitus pitch and loudness matching, and psychometric questionnaires. Elastic net regressions with n-fold cross-validation were performed for cortisol (N = 91) and BDNF (N = 87). For hair-cortisol (R² = 0.10), the strongest effects were sampling in autumn and body-mass index (BMI) (positive), followed by tinnitus loudness (positive) and smoking (negative). For hair-BDNF (R² = 0.28), the strongest effects were hearing aid use, shift work (positive), and tinnitus loudness (negative), followed by smoking, tinnitus-related distress (Tinnitus Questionnaire), number of experienced traumatic events (negative), and physical health-related quality of life (Short Form-12 Health Survey) (positive). These findings suggest that in chronic tinnitus patients, higher perceived tinnitus loudness is associated with higher hair-cortisol and lower hair-BDNF, and higher tinnitus-related distress with lower hair-BDNF. Regarding hair-BDNF, traumatic experiences appear to have additional stress-related effects, whereas hearing aid use and high physical health-related quality of life appear beneficial. Implications include the potential use of hair-cortisol and hair-BDNF as biomarkers of tinnitus loudness or distress and the need for intensive future research into chronic stress-related HPA axis and neuroplasticity alterations in chronic tinnitus.

[A cross-sectional study and risk factors analysis of tinnitus in flight support personnel of PLA air force]

Objective:The aim of this study is to understand the epidemiological characteristics of tinnitus among flight support personnel and analyze its audiological characteristics and related risk factors. Methods:The information of tinnitus was collected by a method of cross-sectional investigation using questionnaire survey and audiology test among the flight support personnel of two stations of PLA air force. Results:The incidence of tinnitus among 666 subjects included was 24.2%, the THI grade was mainly grade 1 and grade 2. There were differences in THI scores among groups with different working years, but only differences in tinnitus incidence among groups with different frequency of hearing loss. Multivariate logistic regression analysis showed that grade of high frequency hearing loss（OR=1.39）, conscious hearing loss（OR=1.79） and frequency of asking others to repeat words（OR=1.64） were independent risk factors of tinnitus. The incidence of HF-HL and EHF-HL in ears with tinnitus among 0-5 working years was higher than that without tinnitus, while the incidence of EHF-HL in ears with tinnitus was not different from that without tinnitus among 6-10 and >10 working years. There was moderate correlation between THI scores and SAS standard scores（r=0.759）, and weak correlation between THI scores and PSQI scores（r=0.445）. Conclusion:The risk of tinnitus in high-frequency hearing loss and recessive hearing loss is increased; working years can affect the severity of tinnitus, while hearing conditions at different frequencies only affect the incidence of tinnitus; with increasing age, noise exposure plays a role in the occurrence of tinnitus decreasing gradually.

Long-term effect of transcranial direct current stimulation in the treatment of chronic tinnitus: A randomized, placebo-controlled trial

INTRODUCTION

Tinnitus is an intrusive and chronic illness affecting a significant portion of the population, decreasing affected individuals' quality of life and socioeconomic functioning. Transcranial Direct Current Stimulation (tDCS) is a non-invasive neuromodulatory method utilizing weak electrical currents to elicit short and long-term central nervous system changes. Several studies have proven its effect on tinnitus. We aimed to broaden the knowledge and provide data on the effect and its retention.

METHODS

In the randomized, double-blinded, sham-controlled trial, 39 patients (active n = 19, sham n = 20) underwent bifrontal tDCS (anode over right dorsolateral prefrontal cortex (DLPFC), cathode left DLPFC, current of 1.5 mA, 20 min, 6 sessions in 2 weeks). Tinnitus Functional Index (TFI), Iowa Tinnitus Handicap Questionnaire (ITHQ), Beck Anxiety Inventory (BAI), Zung Self-Rating Depression Scale (SDS), and WHO-Quality of Life-BREF were employed in 4 evaluation points, including the follow-ups of 6 weeks and 6 months.

RESULTS

We reached a delayed, significant long-term improvement (p < 0.05) in auditory difficulties associated with tinnitus and noticed it even after 6 months compared to placebo. We also reached a short-term, negative effect in the psychological domain of WHO-Quality of Life-BREF (p < 0.05). Not all subdomains of TFI and ITHQ reached statistical significance during the data analysis, even though specific positive trends were noticed.

CONCLUSION

We proved partial, positive, long-term effects of tDCS on tinnitus and short-term, negative, transient effect on a specific aspect of the general quality of life. We expanded upon the results of previous trials and provided data concerning the longevity and the precise effect of multiple sessions, bifrontal DLPFC tDCS. Our sample size (n = 39) was limited, which might have contributed to the lesser statistical power of the analyzed items.

CLINICAL TRIAL REGISTRATION

[www.ClinicalTrials.gov], identifier [NCT05437185].

A genome-wide association study of a rage-related misophonia symptom and the genetic link with audiological traits, psychiatric disorders, and personality

Introduction

People with misophonia experience strong negative emotional responses to sounds and associated stimuli-mostly human produced-to an extent that it may cause impairment in social functioning. The exact nature of the disorder remains a matter of ongoing research and debate. Here, we investigated the genetic etiology of misophonia to understand contributing genetic factors and shed light on individual differences in characteristics that are related to the disorder.

Methods

For misophonia, we used an unpublished genome-wide association study (GWAS) from genetic service provider 23andMe, Inc., on a self-report item probing a single common misophonic symptom: the occurrence of rage when others produce eating sounds. First, we used gene-based and functional annotation analyses to explore neurobiological determinants of the rage-related misophonia symptom. Next, we calculated genetic correlations (r _G) of this rage-related misophonia symptom GWAS with a wide range of traits and disorders from audiology (tinnitus, hearing performance, and hearing trauma), psychiatry, neurology, and personality traits.

Results

The rage-related misophonia symptom was significantly correlated with tinnitus, major depression disorder (MDD), post-traumatic stress disorder (PTSD), and generalized anxiety disorder (GAD; 0.12 < r _G < 0.22). Stronger genetic correlations (0.21 < r _G < 0.42) were observed for two clusters of personality traits: a guilt/neuroticism and an irritability/sensitivity cluster. Our results showed no genetic correlation with attention deficit and hyperactivity disorder, obsessive-compulsive disorder, and psychotic disorders. A negative correlation with autism spectrum disorder (ASD) was found, which may be surprising given the previously reported comorbidities and the sensory sensitivity reported in ASD. Clustering algorithms showed that rage-related misophonia consistently clustered with MDD, generalized anxiety, PTSD, and related personality traits.

Discussion

We conclude that-based on the genetics of a common misophonia symptom-misophonia most strongly clusters with psychiatric disorders and a personality profile consistent with anxiety and PTSD.

Evaluation of Childhood Traumas, Depressive Symptoms, and Dissociative Experiences in Tinnitus Cases

Objective:

Tinnitus is described as the perceived sound without any external stimulus and is a common problem, but its mechanism is not fully understood. This study aimed to evaluate childhood traumas and dissociative experiences, which may be predisposing factors in patients with tinnitus.

Methods:

The study included 90 voluntary patients (45 patients with tinnitus and 45 in the control group) aged older than 18 years who applied to the otorhinolaryngology clinic between November 2018 and February 2019 and were diagnosed with subjective tinnitus. A personal information form together with childhood trauma, hospital anxiety and depression, and dissociative experiences scales were used to assess the patients.

Results:

Of all participants, 55.60% were males, 28.90% were 20-30 years old, 71.10% were married, 40% were primary school graduates, and 68.90% were employed. In addition, 77.78% of patients did not visit a psychiatrist and 75.56% did not have any chronic diseases. The mean total score of Childhood Trauma Scale for the tinnitus group was 54.37±10.17, the mean total score of The Hospital Anxiety and Depression Scale for the tinnitus group in the depression subscale was 12.22±5.41 and in the anxiety subscale was 10.54±3.5, and Dissociative Experiences was 13.48±4.68. A positive significant relationship was found between the childhood traumas of the tinnitus cases in their depressive symptoms, and dissociative experiences (p<0.05).

Conclusions:

The study results found a positive relationship between the childhood traumas and dissociative experiences of tinnitus cases, which can be considered as predisposing factors in patients with tinnitus who should also be investigated for childhood trauma, and the treatment approach should be multidisciplinary.

Unification of Treatments and Interventions for Tinnitus Patients (UNITI): a study protocol for a multi-center randomized clinical trial

BACKGROUND

Tinnitus represents a relatively common condition in the global population accompanied by various comorbidities and severe burden in many cases. Nevertheless, there is currently no general treatment or cure, presumable due to the heterogeneity of tinnitus with its wide variety of etiologies and tinnitus phenotypes. Hence, most treatment studies merely demonstrated improvement in a subgroup of tinnitus patients. The majority of studies are characterized by small sample sizes, unstandardized treatments and assessments, or applications of interventions targeting only a single organ level. Combinatory treatment approaches, potentially targeting multiple systems as well as treatment personalization, might provide remedy and enhance treatment responses. The aim of the present study is to systematically examine established tinnitus therapies both alone and in combination in a large sample of tinnitus patients. Further, it wants to provide the basis for personalized treatment approaches by evaluating a specific decision support system developed as part of an EU-funded collaborative project (Unification of treatments and interventions for tinnitus patients; UNITI project).

METHODS/STUDY DESIGN

This is a multi-center parallel-arm randomized clinical trial conducted at five different clinical sites over the EU. The effect of four different tinnitus therapy approaches (sound therapy, structured counseling, hearing aids, cognitive behavioral therapy) applied over a time period of 12 weeks as a single or rather a combinatory treatment in a total number of 500 chronic tinnitus patients will be investigated. Assessments and interventions are harmonized over the involved clinical sites. The primary outcome measure focuses on the domain tinnitus distress assessed via the Tinnitus Handicap Inventory.

DISCUSSION

Results and conclusions from the current study might not only provide an essential contribution to combinatory and personalized treatment approaches in tinnitus but could also provide more profound insights in the heterogeneity of tinnitus, representing an important step towards a cure for tinnitus.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04663828 . Registered on 11 December 2020.

Analysis of cerebellum with magnetic resonance 3D T1 sequence in individuals with chronic subjective tinnitus

Tinnitus is a symptom in which the patient can hear ringing, buzzing and similar sounds in the ear for 3 months longer. In our study, we aimed to analyse the cerebellum volume and cerebellum connections in patients with chronic tinnitus using VolBrain program. A total number of 10 patients and 10 otherwise healthy peoples records were then enrolled. Volumetric analysis was performed with automated segmentation of the cerebellum and its lobules, using magnetic resonance imaging (MRI). The mean volumes of 10 cerebellar volume were compared between the tinnitus and control groups. Quadrangular lobular portion of the cerebellum, the flocculonodular part and the volume of the central cerebellar lobule were decreased in the tinnitus group. White and grey matter decreased and the amygdala size was increased. We found statistically important volumetric changes in our study. VolBrain can be used in the future for analysing, diagnosis and treatment tinnitus patients. We recommend to use this practical, free of charge and easy programme to analyse for tinnitus patients. This may provide us with practical and useful information about the disease. In patients with tinnitus, the volume loss was 17.48% in the quadrangular lobe, 21% in the central lobule, and 9.33% in the total cerebellum volume.

Serotonin Transporter Defect Disturbs Structure and Function of the Auditory Cortex in Mice

Serotonin transporter (SERT) modulates the level of 5-HT and significantly affects the activity of serotonergic neurons in the central nervous system. The manipulation of SERT has lasting neurobiological and behavioral consequences, including developmental dysfunction, depression, and anxiety. Auditory disorders have been widely reported as the adverse events of these mental diseases. It is unclear how SERT impacts neuronal connections/interactions and what mechanism(s) may elicit the disruption of normal neural network functions in auditory cortex. In the present study, we report on the neuronal morphology and function of auditory cortex in SERT knockout (KO) mice. We show that the dendritic length of the fourth layer (L-IV) pyramidal neurons and the second-to-third layer (L-II/III) interneurons were reduced in the auditory cortex of the SERT KO mice. The number and density of dendritic spines of these neurons were significantly less than those of wild-type neurons. Also, the frequency-tonotopic organization of primary auditory cortex was disrupted in SERT KO mice. The auditory neurons of SERT KO mice exhibited border frequency tuning with high-intensity thresholds. These findings indicate that SERT plays a key role in development and functional maintenance of auditory cortical neurons. Auditory function should be examined when SERT is selected as a target in the treatment for psychiatric disorders.

Too Blind to See the Elephant? Why Neuroscientists Ought to Be Interested in Tinnitus

A curative therapy for tinnitus currently does not exist. One may actually exist but cannot currently be causally linked to tinnitus due to the lack of consistency of concepts about the neural correlate of tinnitus. Depending on predictions, these concepts would require either a suppression or enhancement of brain activity or an increase in inhibition or disinhibition. Although procedures with a potential to silence tinnitus may exist, the lack of rationale for their curative success hampers an optimization of therapeutic protocols. We discuss here six candidate contributors to tinnitus that have been suggested by a variety of scientific experts in the field and that were addressed in a virtual panel discussion at the ARO round table in February 2021. In this discussion, several potential tinnitus contributors were considered: (i) inhibitory circuits, (ii) attention, (iii) stress, (iv) unidentified sub-entities, (v) maladaptive information transmission, and (vi) minor cochlear deafferentation. Finally, (vii) some potential therapeutic approaches were discussed. The results of this discussion is reflected here in view of potential blind spots that may still remain and that have been ignored in most tinnitus literature. We strongly suggest to consider the high impact of connecting the controversial findings to unravel the whole complexity of the tinnitus phenomenon; an essential prerequisite for establishing suitable therapeutic approaches.