Magdalena Sereda

Background/Objectives: Vagus Nerve Stimulation (VNS) has been suggested as a treatment for tinnitus, but its effect on the condition remains unclear. Ultrasonic Vagus Nerve Stimulation (U-VNS) involves non-invasive stimulation of the auricular branch of the vagus nerve, potentially providing an alternative to traditional VNS. To pre-emptively address some of the methodological challenges of future trials investigating U-VNS, a highly blindable sham device is needed. This study aimed to (1) investigate the effectiveness of blinding of a U-VNS device and (2) record any adverse effects, including any negative effects on tinnitus loudness, alongside their onset and duration. Methods: In this single-blind randomized controlled study, 20 volunteers with chronic tinnitus received two 29 min sessions of true U-VNS followed by sham U-VNS, or vice versa. Sessions were a week apart, and in a randomized order. The effectiveness of blinding and adverse effects, including changes in tinnitus loudness, were measured using self-report questionnaires. Results: James’ Blinding Index revealed that blinding was highly effective in both the real U-VNS condition, BI = 0.79, 95% CI (0.61–0.92), and the sham condition, BI = 0.76, 95% CI (0.60–0.89). Adverse effects were uncommon and mild, primarily consisting of sensations on the skin beneath the transducer. For most participants, tinnitus loudness either decreased or stayed the same in both conditions. Conclusions: A high level of blinding was achieved, suggesting that the ZenBud sham device may be suitable as an effective placebo control in future trials. Adverse effects were uncommon and mild. These findings will help inform the design of future clinical trials to evaluate the safety and efficacy of U-VNS.

Tonotopy is a fundamental feature of auditory cortical organization, yet its influence on cortical auditory-evoked responses (AERs) remains unclear. Consequently, key properties of cortical AERs—such as their marked amplitude reduction with increasing stimulus frequency—still lack a coherent mechanistic explanation. To address this gap, we combined a meta-analysis of frequency-specific AER amplitudes with forward simulations of AERs informed by current knowledge of auditory cortical tonotopic layout and functional organization. The meta-analysis used a semi-systematic search covering all known automatic cortical AER components—both transient-evoked and steady-state—along with selected subcortical components for comparison. Forward simulations were based on a functional parcellation of the human supratemporal auditory region into subdivisions forming distinct tonotopic maps, and an idealized model of each division's intrinsic tonotopic layout. Parcellation was achieved using a novel, largely automated procedure applied to high-field (3 T) and ultra-high-field (7 T) functional and microstructural MRI mapping data from 30 individual hemispheres. Meta-analytic results revealed that, whilst all cortical AER components consistently show frequency-related amplitude reduction, reduction is greater in steady-state compared to transient-evoked components. Simulations indicated that frequency-related amplitude reduction arising from cortical morphology is confined to the highly myelinated central portion of Heschl's gyrus, suggesting that differences in reduction amount between steady-state and transient-evoked components may reflect differences in the relative strengths of their primary contributions. Our findings provide a new perspective on cortical AER generation. They represent an important step toward explaining morphology-related variability in AER amplitudes and establishing a quantitative link to underlying source strengths.

Background: Transcranial direct current stimulation (tDCS) involves the application of weak electric currents (typically 0.5–2 mA) via scalp electrodes to promote neuroplastic changes that modulate behaviour or cortical activity. Although there have been promising results in eliminating tinnitus or reducing its loudness or severity, there is also a high degree of inter-individual variability. This may be due to anatomical differences and their influence on the resulting electric field. To optimise and personalise tDCS protocols, computational electric field models based on individual clinical imaging may be utilised to give insight into the induced electric field during tDCS and inform more effective protocols for targeted stimulation. To our knowledge, there are currently no standards for current modelling or reviews which detail the optimal parameters for conducting current modelling studies for tDCS. Objectives: The aim of this review is to investigate the methodology of current modelling studies for tDCS so that informed, personalised protocols can be designed by modelling the electric field of the brain during tDCS for tinnitus. By considering the impact of individual anatomical differences on the electric field induced by tDCS, targeted protocols could be developed to reduce tinnitus loudness and severity in a systematic and predictable way. Design: The protocol for this review is based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) Checklist. Using online databases, records were identified based on a keyword search for records relevant to current modelling for tDCS, including peer-reviewed papers, clinical trials, the grey literature, theses, dissertations, and conference abstracts. Four thousand two hundred and fifty-three records were retrieved from thirteen online databases and include 4186 records from the initial search completed between May and July 2024, and 67 records from an updated search completed in August 2025. A further 596 records were retrieved from Google Scholar (501 from the initial search and 95 from the updated search). One hundred and fourteen records met our criteria for inclusion. Each record was charted by two separate reviewers, with attention to the modelling pipeline and predicted values in peak and range of electric field magnitude. Results: There was a consensus that, despite model parameters and pipelines, there was inter-individual variability in the predicted electric fields. The reviewed records highlighted the impact of individual differences, including age, sex, and anatomical variation, on the predicted electric field during tDCS. Increased age was often associated with age-related brain atrophy and high relative cerebrospinal fluid volume, which was a significant influence on the resulting E-field intensity and distribution. Conclusions: When creating personalised tDCS protocols for tinnitus, the model parameters and sources of variability (i.e., morphology, age, and sex) should be carefully considered to achieve the desired stimulation outcomes, particularly in regard to applied current intensity.

Background/Objectives: Both invasive and non-invasive electrical stimulation of the vagus nerve have been studied as potential treatments for neurological conditions, with mixed results. Ultrasonic Vagus Nerve Stimulation (U-VNS), which non-invasively stimulates the auricular branch of the vagus nerve using ultrasound, may offer a more targeted and effective approach than electric currents. To facilitate future clinical trials of U-VNS, this study aimed to (1) investigate the effectiveness of blinding of a U-VNS device versus a sham device and (2) record the type, onset, and duration of any adverse effects resulting from U-VNS. Methods: In this single-blind randomised controlled study, twenty healthy volunteers were randomly assigned to receive either a 30 min session of true U-VNS and a 30 min session of sham stimulation 1 week later, or vice versa. The effectiveness of blinding and the occurrence of adverse effects were measured using self-report questionnaires. Results: James’ Blinding Index showed that blinding using the sham device was highly effective in both the real U-VNS condition, BI = 0.9 (95% CI: 0.7–1.0), and the sham condition, BI = 1.0 (95% CI: 1.0–1.0). The adverse effects reported were mild, transient, and mostly related to sensations on the skin immediately under the transducer of the device. Conclusions: A high level of blinding effectiveness can be achieved for U-VNS by using a sham device. Adverse effects are generally mild and transient. These findings will inform the design of future clinical trials of U-VNS.

(1) Background: Tinnitus involves the conscious awareness of a tonal or composite noise for which there is no identifiable corresponding external acoustic source. For many people, tinnitus is a disorder associated with symptoms of emotional distress, cognitive dysfunction, autonomic arousal, behavioural changes, and functional disability. Many symptoms can be addressed effectively using education or cognitive behavioural therapy. However, there is no treatment that effectively reduces or alters tinnitus-related neurophysiological activity and thus the tinnitus percept. In this systematic review, we evaluated the effectiveness of neuromodulation therapies for tinnitus that explicitly target pathological synchronous neural activity. (2) Methods: Multiple databases were searched for randomised controlled trials of neuromodulation interventions for tinnitus in adults, with 24 trials included. The risk of bias was assessed, and where appropriate, meta-analyses were performed. (3) Results: Few trials used acoustic, vagal nerve, or transcranial alternating current stimulation, or bimodal stimulation techniques, with limited evidence of neuromodulation or clinical effectiveness. Multiple trials of transcranial direct current stimulation (tDCS) were identified, and a synthesis demonstrated a significant improvement in tinnitus symptom severity in favour of tDCS versus control, although heterogeneity was high. (4) Discussion: Neuromodulation for tinnitus is an emerging but promising field. Electrical stimulation techniques are particularly interesting, given recent advances in current flow modelling that can be applied to future studies.

Tinnitus (the perception of sound in the absence of any corresponding external source) is highly prevalent and can be distressing. There are unanswered questions about how tinnitus, suicidal thoughts, and suicidal behaviours co-occur and interact. To establish the extent of scientific literature, this scoping review catalogued primary reports addressing the associations between tinnitus, suicidal ideation, attempted suicide, and death by suicide. We searched OvidSP, Medline, EMBASE, PsycINFO, CINAHL, Google Scholar, EThoS, and ProQuest for all studies and case reports on ideation and/or attempted and/or completed suicide in the context of tinnitus. Twenty-three studies were included, and data were charted according to study type. Several epidemiological and other observational studies gave evidence of risk factors and an association between suicidal ideation, suicidal behaviour, and tinnitus. However, there was no evidence of the direction of causality. Qualitative studies are indicated to explore the patient’s experience and understand the dynamics of any interaction between tinnitus and suicidal thoughts and behaviours. A theory-informed model of tinnitus and suicide needs to be developed to inform the development of interventions and how tinnitus patients are supported clinically.

Introduction: Past studies have shown connections between the somatosensory system (the neck and temporomandibular joint region) and the auditory system. It is therefore likely that tinnitus patients might benefit from neck therapy. The aim of this study was to investigate the effects of...

Hyperacusis (decreased sound tolerance) is a prevalent complaint. Yet, to date, no research has qualitatively evaluated the types of problems experienced by adults with hyperacusis. Our service evaluation aims to determine the hyperacusis-related problem domains reported by patients and the degree to which these domains were reported together. Retrospective analysis was conducted on an anonymised clinical dataset from 306 patients who attended a UK tinnitus and hyperacusis treatment centre between 1994 and 2017. Conventional content analysis was used to categorise responses to the question ‘Why is hyperacusis a problem?’ into domains which were then subjected to a cluster analysis. Twenty-five problem domains were identified, of which 12 were further classified into three overarching categories. ‘Fear’, ‘Reduced quality of life’ and ‘Physical reaction to sound’ were most frequently reported problems. Cluster analysis revealed that ‘Sleep difficulties’ and ‘Despondency’, were commonly reported together. Adults with hyperacusis face many challenges in their everyday lives. The nature of these problems indicates the need to develop complex interventions and assessments to aid management of hyperacusis. Current hyperacusis questionnaires may be useful in identifying some problem domains, but further assessment thorough patient interviews is required to fully explore all potential problems and make informed decisions about treatment.