Cognitive Performance in Chronic Tinnitus Patients: A Cross-Sectional Study Using the RBANS-H

Impact of short-term tinnitus treatment on cognitive function and neural synchronization

We aimed to evaluate the impact of short-term tinnitus treatment on cognitive function and identify the effects of various treatment combinations on cognitive and tinnitus outcomes. A non-randomized prospective study was conducted with 32 tinnitus patients at a tertiary university hospital between May 2022 and May 2024. Patients received treatments, including neuromodulation, diuretics, gabapentin, selective serotonin reuptake inhibitors (SSRI), anxiolytics, muscle relaxants, hearing aids, and counseling. Cognitive function and tinnitus distress were assessed using the Mini-Mental State Examination (MMSE) and Tinnitus Handicap Inventory (THI) at baseline and 1 month after treatment. Quantitative electroencephalogram (qEEG) recordings were analyzed to evaluate changes in neural synchronization using phase-locking value (PLV). Strong correlations were also observed between baseline MMSE and changes in MMSE post-treatment (r = -0.796, p < 0.01) and between tinnitus loudness perception and changes in MMSE (r = 0.458, p < 0.01). After Bonferroni correction, muscle relaxants (p = 0.017) and neuromodulation (p = 0.007) showed significant negative effects on cognitive function, while anxiolytics demonstrated a tendency for negative effects (p = 0.052). Additionally, neither baseline tinnitus loudness nor changes in loudness perception (ΔVAS for loudness) were significantly correlated with ΔTHI after Bonferroni correction (p > 0.05). qEEG analysis showed increased PLV in prefrontal-limbic and parietal-occipital connections in patients with improved THI as well as increased PLV in temporal-limbic connections in patients with improved MMSE scores, indicating enhanced neural synchronization and cognitive resource reorganization. These findings underscore the need for careful consideration of cognitive effects when selecting tinnitus treatments and highlight the importance of targeted multimodal interventions to address both tinnitus distress and cognitive function.

Tinnitus suppression by means of cochlear implantation: does it affect cognition?

PURPOSE

Recent literature suggests that tinnitus can impact cognition, but results were varied due to a diversity in investigated aspects of cognition and utilized tests, as well as the possible influence of confounding factors. The purpose of this study was to assess the impact of tinnitus loudness on cognition by use of a within-subjects design in patients with a cochlear implant (CI). In this population, tinnitus loudness can be modulated by switching the CI on or off as CI is known to highly suppress tinnitus.

METHODS

A total of 18 CI users completed two versions of the Repeatable Battery for Assessment of Neuropsychological Status for Hearing Impaired individuals (RBANS-H), once in unaided condition and once in best aided condition. Tinnitus suppression was defined as a difference in score on a visual-analogue scale (VAS) of at least one point out of ten between these two conditions.

RESULTS

No significant differences in RBANS-H scores were found between the suppression and no suppression group, nor for the suppression group alone. No significant correlations between tinnitus loudness and RBANS-H were found, neither for the suppression group alone, nor for the group as a whole.

CONCLUSION

The current study shows no significant effect of tinnitus loudness on cognition, which contradicts previous literature. This discrepancy could be explained by the use of a within-subjects design, which controls for confounding factors. Future research should include a larger and more diverse study sample to draw definitive conclusions on this topic.

Health-Related Quality of Life in Subjective, Chronic Tinnitus Patients: A Scoping Review

PURPOSE

This scoping review aims to assess whether the severity or distress of subjective tinnitus is negatively associated or correlated with the level of health-related quality of life (HRQoL). A second objective is to examine whether tinnitus patients score differently on HRQoL questionnaires in comparison to subjects without tinnitus and whether HRQoL differs between specific subgroups of tinnitus.

METHODS

This scoping review adheres to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines (PRISMA guidelines): the statement and extension for scoping reviews (PRISMA-ScR). The following databases were consulted (on the 20th of October 2023): PubMed, Cochrane Library, Web of Science, and Scopus. The search string was composed of the terms tinnitus, HRQoL, and synonyms. A double-blinded screening for eligibility was performed, first on the title and abstract and subsequently on the full-text articles. Studies were considered eligible if they looked at HRQoL questionnaire results for adult patients (> 18 years) reporting chronic (> 3 months), subjective tinnitus as a primary complaint.

RESULTS

In total, 37 studies with a total sample size of 33,900 participants were included in this scoping review, with some studies answering multiple study objectives. Seventeen studies demonstrated the presence of a significant negative correlation between tinnitus-related distress and HRQoL. Two studies indicated that HRQoL is mediated by tinnitus-related distress. Eighteen studies found that, in general, patients with tinnitus scored significantly lower on HRQoL questionnaires in comparison to subjects without tinnitus. Nineteen studies demonstrated that subgroups of patients with more severe tinnitus complaints or specific additional complaints scored worse on HRQoL questionnaires.

CONCLUSION

Based on the current literature, chronic subjective tinnitus-related distress has a significant impact on health-related quality of life. In addition, subjects without tinnitus generally score significantly higher on HRQoL questionnaires than patients with tinnitus. The heterogeneity in outcome measures between studies precludes meta-analysis. Increased homogeneity in the choice of HRQoL questionnaires would make a comparison between studies possible, which would give valuable information on both a clinical and an economic level, guiding future tinnitus treatment.

REGISTRATION

The protocol for the scoping review is registered at Open Science Framework: https://doi.org/10.17605/OSF.IO/F5S9C .

Cognitive functioning and psychosomatic syndromes in a subjective tinnitus sample

Introduction

Tinnitus is the perception of a sound in the absence of any corresponding external sound source. Current research suggests a relationship among emotional, cognitive, and psychosomatic symptoms and the occurrence or maintenance of chronic tinnitus. This study aimed to detect the prevalence and role of psychosomatic conditions, as defined by the Diagnostic Criteria for Psychosomatic Research (DCPR), and cognitive functioning in a group of patients with tinnitus.

Methods

Sixty-two patients with subjective tinnitus and 62 non-tinnitus controls were recruited from the Otorhinolaryngology Unit of the University of Bari. Pure-tone audiometry was performed in all tinnitus subjects, and sound level tolerance was evaluated. Additionally, tinnitus handicap (Tinnitus Handicap Inventory [THI]), psychopathological symptoms (Symptom Checklist-90, Revised [SCL-90-R]), anxiety (State-Trait Anxiety Inventory [STAI-Y1/2]), depression (Beck Depression Inventory [BDI]), cognitive impairment (Mini-Mental State Examination [MMSE]), executive functions (Frontal Assessment Battery [FAB]), and psychosomatic syndromes (DCPR) were evaluated. Parametric and non-parametric tests were used to detect cognitive and symptomatological differences between patients and controls. The predictivity of these factors for tinnitus severity was studied using multiple regression (Backward Elimination). All tests were considered significant at p < 0.05 (family wise error corrected for each comparison).

Results

69.4% tinnitus patients met multiple DCPR criteria, compared to 32.3% of controls. Tinnitus patients exhibited elevated rates of illness denial (ꭓ2 = 9.02; p < 0.009), demoralization (ꭓ2 = 8.05; p < 0.018), somatization (ꭓ2 = 4.92; p < 0.063) and functional symptoms (ꭓ2 = 5.21; p < 0.06) scoring significantly higher on the BDI, STAI-Y1, and STAI-Y2, and SCL-90-R compared to controls. Patients with tinnitus showed lower MMSE scores, compared to controls (t = -2.282; p < 0.001). No association between tinnitus severity and global cognitive impairment emerged. Conversely, executive function deficits were associated to tinnitus severity. Among the cognitive and psychological factors, only trait anxiety, one or more psychosomatic syndromes, and somatization clusters were strongly correlated with tinnitus severity.

Discussion

Our findings suggest a relationship between tinnitus severity, psychological, psychosomatic symptoms, and frontal impairment. Additionally, the influence of tinnitus on cognitive functions paves the way for integrated, multidisciplinary diagnostic and treatment options for patients. Although preliminary, our findings highlight the importance of early cognitive and psychological screening to improve patients' quality of life.

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.

Functional changes in the auditory cortex and associated regions caused by different acoustic stimuli in patients with presbycusis and tinnitus

Presbycusis and tinnitus are the two most common hearing related pathologies. Although both of these conditions presumably originate in the inner ear, there are several reports concerning their central components. Interestingly, the onset of presbycusis coincides with the highest occurrence of tinnitus. The aim of this study was to identify age, hearing loss, and tinnitus related functional changes, within the auditory system and its associated structures. Seventy-eight participants were selected for the study based on their age, hearing, and tinnitus, and they were divided into six groups: young controls (Y-NH-NT), subjects with mild presbycusis (O-NH-NT) or expressed presbycusis (O-HL-NT), young subjects with tinnitus (Y-NH-T), subjects with mild presbycusis and tinnitus (O-NH-T), and subjects with expressed presbycusis and tinnitus (O-HL-T). An MRI functional study was performed with a 3T MRI system, using an event related design (different types of acoustic and visual stimulations and their combinations). The amount of activation of the auditory cortices (ACs) was dependent on the complexity of the stimuli; higher complexity resulted in a larger area of the activated cortex. Auditory stimulation produced a slightly greater activation in the elderly, with a negative effect of hearing loss (lower activation). The congruent audiovisual stimulation led to an increased activity within the default mode network, whereas incongruent stimulation led to increased activation of the visual cortex. The presence of tinnitus increased activation of the AC, specifically in the aged population, with a slight prevalence in the left AC. The occurrence of tinnitus was accompanied by increased activity within the insula and hippocampus bilaterally. Overall, we can conclude that expressed presbycusis leads to a lower activation of the AC, compared to the elderly with normal hearing; aging itself leads to increased activity in the right AC. The complexity of acoustic stimuli plays a major role in the activation of the AC, its support by visual stimulation leads to minimal changes within the AC. Tinnitus causes changes in the activity of the limbic system, as well as in the auditory AC, where it is bound to the left hemisphere.

Associations of Bilateral Vestibulopathy With Cognition in Older Adults Matched With Healthy Controls for Hearing Status

Question

Is bilateral vestibulopathy (BV) associated with cognitive function in older adults?

Findings

In this cross-sectional study including 34 participants with BV and 34 age-, sex-, and hearing performance–matched controls, participants with BV had worse cognitive function in general, which was most pronounced in the subdomains of immediate memory, visuospatial cognition, and attention.

Meaning

These findings support existing evidence on an association between vestibular loss and cognitive impairment.

Importance

Recent literature suggests there may be a significant effect of the vestibular system on cognition and visuospatial processing. Given the increasing prevalence of dementia and individuals at risk for it, exploring possible modifiable risk factors, including vestibular dysfunction, is vital.

Objectives

To explore the association of bilateral vestibulopathy (BV) with cognitive function in older adults, taking hearing status into account, and to explore multiple vestibular characteristics and their potential associations with cognition in patients with BV.

Design, Setting, and Participants

This cross-sectional study assessed older adults (age 55-84 years) with diagnosed BV from a single center using baseline measurements from the Gehoor, Evenwicht en Cognitie (GECKO) study, an ongoing prospective longitudinal cohort study. Each participant was individually matched with a healthy control based on age, sex, and hearing performance. Data were analyzed in January 2022.

Main Outcomes and Measures

The primary outcome measure was cognition, measured by the Repeatable Battery for the Assessment of Neuropsychological Status for Hearing-Impaired Individuals (RBANS-H).

Results

A total of 68 patients were assessed, including 34 patients with BV (mean [SD] age, 63.3 [6.0] years; 18 [53%] men) matched with 34 control individuals without BV. Overall, participants with BV had a clinically meaningful lower score on the RBANS-H total scale compared with those without BV (mean [SD] score, 98.62 [12.70] vs 105.91 [11.03]). This decline was most pronounced in the subdomains of immediate memory (mean [SD] score, 107.74 [10.66] vs 112.26 [10.66]), visuospatial cognition (mean [SD] score, 90.06 [13.34] vs 100.47 [13.91]), and attention (mean [SD] score, 94.79 [16.39] vs 102.06 [12.97]). There were no differences in language or delayed memory subdomains. Within the BV population, 1 vestibular parameter (the Performance-Oriented Mobility Assessment, in particular the balance subscale) was associated with lower cognitive scores (r₃₂ = 0.51; 95% CI, 0.20 to 0.72; η² = 0.26). Other vestibular parameters, including measurements of the peripheral vestibular end organ and questionnaires, showed no association.

Conclusions and Relevance

These findings suggest there was an association between vestibular loss and cognitive impairment. Further research on the causal mechanisms underlying this association and the possible impact of vestibular rehabilitation on cognition is needed.

Extended High Frequency Hearing, but Not Tinnitus, Is Associated With Every-Day Cognitive Performance

Research into the potential associations between tinnitus and cognition has investigated specific cognitive domains in laboratory settings despite adults with tinnitus reporting broad cognitive difficulties in every-day life. To address this limitation, the present study compared performance and perceived exertion on a visual office-like task in 38 adults with tinnitus (19 with normal hearing and 19 with hearing loss) and 38 adults without tinnitus (19 with normal hearing and 19 with hearing loss) matched for age, sex and educational background. All participants were also assessed for hearing, anxiety and depression, and participants with tinnitus were also assessed for tinnitus handicap. No associations were found between presence of tinnitus and cognitive performance (mean total rate correct score on the visual office-like task being 2.9 for the tinnitus group, 2.8 for the control group, p = 0.612) and perceived exertion (mean ratings of perceived exertion on the Borg CR10-scale being 5.8 for the tinnitus group, 6.5 for the control group, p = 0.063) on the visual office-like task when corrected for standard (0.125 to 8 kHz) and extended high frequency (10 to 16 kHz) hearing thresholds, anxiety, and depression. The correction for extended high frequency average (10, 12.5, 14, and 16 kHz) hearing threshold was significant for performance (p = 0.009) but not perceived exertion on the visual office-like task. Overall, the results showed extended high frequency hearing, but not tinnitus, was associated with every-day cognitive performance. This indicates clinical testing of hearing thresholds above 8 kHz could support clinicians' identification and management of cognitive difficulties. One management method suggested by the current findings would include provision of auditory stimulation at frequencies exceeding the frequency response of many current hearing aids.

Self-help interventions chosen by subjects with chronic tinnitus - a retrospective study of clinical patients

OBJECTIVE

Self-help (without specialist support) can play an important role in tinnitus therapy. The purpose of this study was to investigate what fraction of subjects with tinnitus use self-help, what techniques are most commonly used to reduce tinnitus severity, and what distinguishes patients that use self-help from others.

DESIGN

retrospective, observational study.

STUDY SAMPLE

Adult patients admitted to our hospital clinic (460 participants) aged 19-83 years and reporting chronic tinnitus. The survey concerned therapy attempts prior to the clinic visit as well as self-help techniques chosen freely by the patient to reduce tinnitus severity.

RESULTS

Data showed that 40.9% of the respondents chose some action themselves to reduce their tinnitus severity. Among the reported self-help techniques, acoustic stimulation was the most popular. In addition, patients chose distraction attention, relaxation, meditation, yoga, and physical activity. The likelihood of undertaking self-help increases with better education and higher tinnitus severity.

CONCLUSIONS

Knowledge about patients' preferences of forms of self-help may help the health practitioner suggest a more suitable form of therapy. Due to the great interest in using sound therapy in tinnitus, it would be worthwhile looking at new forms of this therapy, for example increasingly popular mobile applications.

The Influence of Depression, Anxiety and Cognition on the Treatment Effects of Ginkgo biloba Extract EGb 761® in Patients with Tinnitus and Dementia: A Mediation Analysis

Background: Comorbid occurrence of tinnitus and emotional symptoms of anxiety and depression is highly prevalent. The Ginkgo biloba extract EGb 761^® has been shown to be effective in reducing neuropsychiatric symptoms in patients with dementia and tinnitus. Methods: We performed a mediation analysis to evaluate direct effects of EGb 761^® on tinnitus severity, as well as indirect effects mediated by symptoms of depression and anxiety and by changed cognition. We pooled data from subsets of patients suffering from tinnitus that were enrolled in three double-blind, randomized, placebo-controlled clinical trials, which investigated the efficacy of EGb 761^® (240 mg/day for 22–24 weeks) in dementia with concomitant neuropsychiatric symptoms. Results: In total, 594 patients suffered from tinnitus (EGb 761^®, 289; placebo, 305). Direct effects of EGb 761^® on tinnitus severity (p < 0.001) in patients with mild to moderate dementia were found to represent about 60% of the total effect, whereas the indirect effects (p < 0.001) mediated by improvement of anxiety, depression and cognition represented about 40% of the total effect. Conclusions: EGb 761^® could be considered as a supporting treatment for tinnitus in elderly patients suffering from dementia, with added benefit in those with symptoms of depression or anxiety.

Low Thyroid-stimulating Hormone Levels Are Associated With Annoying Tinnitus in Adult Women: Korea National Health and Nutrition Examination Surveys

OBJECTIVE

This study aimed to investigate the relationship between thyroid function and tinnitus.

STUDY DESIGN

A cross-sectional study.

SETTING

The Korean National Health and Nutrition Examination Survey from 2013 was used.

PATIENTS AND INTERVENTIONS

A total of 1,165 participants ≥ 40 years old who were surveyed for the presence of tinnitus and underwent thyroid function tests were included. The presence of discomfort from tinnitus was defined as annoying tinnitus. The control group included participants with "no tinnitus" or "no discomfort from tinnitus." The participants were divided into the annoying tinnitus group and the control group.

MAIN OUTCOME MEASURES

The associations of free thyroxine and thyroid-stimulating hormone (TSH) with annoying tinnitus were analyzed using logistic regression with complex sampling methods. Subgroup analyses were performed according to sex.

RESULTS

The low TSH level group had 2.35-fold greater odds of annoying tinnitus than the control group (95% confidence interval  = 1.10-5.12, p = 0.027). Even in patients with a normal free thyroxine level, a low TSH level was related to 2.78-fold higher odds of annoying tinnitus (95% confidence interval  = 1.21-6.38, p = 0.016). In subgroup analyses, this association was apparent in the female subgroup. The male subgroup did not show a relationship between low TSH levels and annoying tinnitus.

CONCLUSIONS

Subclinical hyperthyroidism was related to an increased risk of annoying tinnitus. This relationship was apparent in the female subgroup.

Functional Gait Can Be Affected by Noise: Effects of Age and Cognitive Function: A Pilot Study

Background: The ageing process may degrade an individual's balance control, hearing capacity, and cognitive function. Older adults perform worse on simultaneously executed balance and secondary tasks (i.e., dual-task performance) than younger adults and may be more vulnerable to auditory distraction.

Aim: The purpose of this study was to determine the effect of passive listening on functional gait in healthy older vs. younger adults, and to investigate the effect of age, functional gait, hearing ability and cognitive functioning on dual-task performance.

Methods: Twenty young and 20 older healthy adults were recruited. Functional gait (Functional Gait Assessment in silent and noisy condition), hearing function (audiogram; Speech in Babble test), and cognitive ability (Cambridge Neuropsychological Test Automated Battery) were measured.

Results: Overall, a significant difference between functional gait performance in silent vs. noisy conditions was found (p = 0.022), with no significant difference in dual-task cost between the two groups (p = 0.11). Correlations were found between increasing age, worse functional gait performance, poorer hearing capacity and lower performance on cognitive function tasks. Interestingly, worse performance on attention tasks appeared to be associated with a worse functional gait performance in the noisy condition.

Conclusion: Passive listening to multi-talker babble noise can affect functional gait in both young and older adults. This effect could result from the cognitive load of the babble noise, due to the engagement of attention networks by the unattended speech.

Glucose Control Has an Impact on Cerebral Blood Flow Alterations in Chronic Tinnitus Patients

PURPOSE

Both tinnitus and type 2 diabetes mellitus (T2DM) are linked with cognitive decline and brain dysfunction. This study used arterial spin labeling (ASL) perfusion functional magnetic resonance imaging (fMRI) to examine the abnormal cerebral blood flow (CBF) patterns existed in tinnitus patients and potential relationships between the abnormal CBF and cognitive performance. The impact of T2DM on CBF alterations in tinnitus patients was further explored.

METHODS

Sixty tinnitus patients and 40 non-tinnitus subjects were recruited. CBF images were collected and analyzed using ASL perfusion fMRI. Brain regions with CBF alterations between tinnitus patients and non-tinnitus controls were identified by one-way analysis of variance. Interaction effects between tinnitus and T2DM for CBF changes were also selected. Then, correlation analyses were calculated to specify the link between CBF changes and cognitive performance and between CBF changes and diabetic characteristics.

RESULTS

Tinnitus patients showed decreased CBF, primarily in the auditory area and default mode network (DMN), compared with non-tinnitus controls. Decreased CBF in these regions was correlated with executive function and attention. The interaction effect between tinnitus and T2DM was significant in the right medial prefrontal gyrus. Additionally, CBF in the right medial prefrontal gyrus was correlated with tinnitus distress and cognitive performance. In tinnitus patients, Hemoglobin A1c was associated with CBF in the right medial prefrontal gyrus.

CONCLUSION

Tinnitus affects brain perfusion in the auditory area and DMN. T2DM and uncontrolled glucose levels may aggravate a CBF decrease in tinnitus patients. These new findings implied that tinnitus patients may benefit from blood glucose control in terms of their cognitive function and tinnitus distress.

High Definition transcranial Direct Current Stimulation (HD-tDCS) for chronic tinnitus: Outcomes from a prospective longitudinal large cohort study

BACKGROUND

Transcranial Direct Current Stimulation (tDCS) aims to induce cortical plasticity by modulating the activity of brain structures. The broad stimulation pattern, which is one of the main limitations of tDCS, can be overcome with the recently developed technique called High-Definition tDCS (HD-tDCS).

OBJECTIVE

Investigation of the effect of HD-tDCS on tinnitus in a large patient cohort.

METHODS

This prospective study included 117 patients with chronic, subjective, non-pulsatile tinnitus who received six sessions of anodal HD-tDCS of the right Dorsolateral Prefrontal Cortex (DLPFC). Therapy effects were assessed by use of a set of standardized tinnitus questionnaires filled out at the pre-therapy (T_pre), post-therapy (T_3w) and follow-up visit (T_10w). Besides collecting the questionnaire data, the perceived effect (i.e., self-report) was also documented at T_10w.

RESULTS

The Tinnitus Functional Index (TFI) and Tinnitus Questionnaire (TQ) total scores improved significantly over time (p_TFI<0.01; p_TQ<0.01), with the following significant post hoc comparisons: T_pre vs. T_10w (p_TFI<0.05; p_TQ<0.05) and T_3w vs. T_10w (p_TFI<0.01; p_TQ<0.01). The percentage of patients reporting an improvement of their tinnitus at T_10w was 47%. Further analysis revealed a significant effect of gender with female patients showing a larger improvement on the TFI and TQ (p_TFI<0.01; p_TQ<0.05).

CONCLUSIONS

The current study reported the effects of HD-tDCS in a large tinnitus population. HD-tDCS of the right DLPFC resulted in a significant improvement of the tinnitus perception, with a larger improvement for the female tinnitus patients.

The Association Between Effectiveness of Tinnitus Intervention and Cognitive Function-A Systematic Review

Tinnitus refers to the perception of sound in the absence of an external stimulus. This can be problematic and can lead to health problems in some sufferers, including effects on cognitive functions such as attention and memory. Although several studies have examined the effectiveness of tinnitus interventions, e.g., cognitive behavioral therapy and sound therapy, it is still unclear as to the overall quality and limitations of these studies and whether their results could be generalized. Clarification is also needed as to whether poor cognitive function will lead to a less favorable intervention outcome in tinnitus patients. The present systematic review was therefore designed to critically appraise and synthesize findings from randomized controlled trials (RCTs) of tinnitus intervention and its effects on cognition. The methodology followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Medline (PubMed), Embase, and PsycINFO were searched. Only RCTs that compared the effectiveness of a tinnitus intervention and a measure of cognitive function in adult participants with tinnitus were included. A total of 8 studies involving 610 participants tested using 11 cognitive function assessment tools (e.g., Stroop Color and Word Test and Visual Continuous Performance Task) and 5 tinnitus intervention outcome measurements (e.g., Tinnitus Handicap Inventory and Tinnitus Questionnaire) were included and analyzed. The outcomes of the review suggest that tinnitus intervention not only facilitates tinnitus management but also improves cognitive functions. It is likely that cognition and emotion play an important role in a patient's adjustment to tinnitus. Whether cognition can predict treatment outcomes is unclear due to insufficient evidence. Future research is needed using a standardized assessment protocol focusing on the effect of sound-based interventions on tinnitus severity and cognitive functions. Studies on whether cognitive function measurement can be used as a predictor for the effectiveness of tinnitus therapy are also needed.

Systematic review and meta-analysis of late auditory evoked potentials as a candidate biomarker in the assessment of tinnitus

Subjective tinnitus, the perception of sound in the absence of any sound source, is routinely assessed using questionnaires. The subjective nature of these tools hampers objective evaluation of tinnitus presence, severity and treatment effects. Late auditory evoked potentials (LAEPs) might be considered as a potential biomarker for assessing tinnitus complaints. Using a multivariate meta-analytic model including data from twenty-one studies, we determined the LAEP components differing systematically between tinnitus patients and controls. Results from this model indicate that amplitude of the P300 component is lower in tinnitus patients (standardized mean difference (SMD) = -0.83, p < 0.01), while latency of this component is abnormally prolonged in this population (SMD = 0.97, p < 0.01). No other investigated LAEP components were found to differ between tinnitus and non-tinnitus subjects. Additional sensitivity analyses regarding differences in experimental conditions confirmed the robustness of these results. Differences in age and hearing levels between the two experimental groups might have a considerable impact on LAEP outcomes and should be carefully considered in future studies. Although we established consistent differences in the P300 component between tinnitus patients and controls, we could not identify any evidence that this component might covary with tinnitus severity. We conclude that out of several commonly assessed LAEP components, only the P300 can be considered as a potential biomarker for subjective tinnitus, although more research is needed to determine its relationship with subjective tinnitus measures. Future trials investigating experimental tinnitus therapies should consider including P300 measurements in the evaluation of treatment effect.