Objective and Measurable Biomarkers in Chronic Subjective Tinnitus

Advances in acupuncture treatment for tinnitus

Tinnitus is the abnormal perception of sound in the absence of a corresponding external acoustic stimulus, which seriously affects the patients' quality of life, physical and mental health, and the safety of life. There is almost no effective cure for tinnitus, primarily due to its complicated etiopathogenesis and unclear mechanisms. As a major and ancient physical therapy in Traditional Chinese Medicine, acupuncture has been widely used in tinnitus because of its simple operation, rapid effect, and low cost. This paper reviews the relevant literature on the treatment of different kinds of tinnitus by acupuncture, and summarizes the therapeutic efficacy and mechanism of acupuncture on tinnitus, which is expected to provide new ideas and research directions for the study of tinnitus treatment by acupuncture. Tinnitus is the abnormal perception of sound in the absence of a corresponding external acoustic stimulus, which seriously affects the patients' quality of life, physical and mental health, and the safety of life. There is almost no effective cure for tinnitus, primarily due to its complicated etiopathogenesis and unclear mechanisms. As a major and ancient physical therapy in Traditional Chinese Medicine, acupuncture has been widely used in tinnitus because of its simple operation, rapid effect, and low cost. This paper reviews the relevant literature on the treatment of different kinds of tinnitus by acupuncture, and summarizes the therapeutic efficacy and mechanism of acupuncture on tinnitus, which is expected to provide new ideas and research directions for the study of tinnitus treatment by acupuncture.

Evaluating the Efficacy and Underlying Mechanisms of Acupuncture for Chronic Subjective Tinnitus Using Functional Near-Infrared Spectroscopy: Study Protocol for a Randomized Controlled Trial

Objective

This study aims to evaluate the efficacy and safety of acupuncture for chronic subjective tinnitus and explore the central mechanism underlying acupuncture for chronic subjective tinnitus using functional near-infrared spectroscopy (fNIRS).

Methods

We will randomly assign 60 tinnitus patients to either an acupuncture group or a waiting-list control group. The acupuncture group will undergo 12 treatment sessions over 4 weeks, whereas the waiting-list control group will receive no intervention concurrently. Clinical outcome measures include the Tinnitus Handicap Inventory (THI) score, tinnitus loudness assessed by 11-point NRS, average pure-tone threshold, and Hamilton Anxiety Scale (HAM-A) score. Neuroimaging outcomes assessed by fNIRS included blood oxygen concentration and resting-state functional connectivity (RSFC). All outcome measurements will be assessed at the baseline, after 4-week treatment, and at 3-month follow-ups.

Results

Our investigation will determine if significant differences exist between the two groups regarding THI, NRS, average pure-tone threshold, and HAM-A scores. Moreover, the analysis will reveal whether the acupuncture group demonstrates significant change in blood oxygen concentration and RSFC between specific brain regions compared to the waiting-list control group.

Conclusion

With the novel technique of fNIRS, in addition to efficacy evaluation of acupuncture, this study's findings are anticipated to partly elucidate the neural mechanisms underlying acupuncture treatment for subjective tinnitus and offer an objective assessment method for its therapeutic impact, thereby contributing to filling the research gap.

Trial Registration

Clinicaltrials registry (identification code NCT05829278).

Acoustic and optoacoustic stimulations in auditory brainstem response test in salicylate induced tinnitus

As a common debilitating disorder worldwide, tinnitus requires objective assessment. In the auditory brainstem response (ABR) test, auditory potentials can be evoked by acoustic or optoacoustic (induced by laser light) stimulations. In order to use the ABR test in the objective assessment of tinnitus, in this study, acoustic ABR (aABR) and optoacoustic ABR (oABR) were compared in the control and tinnitus groups to determine the changes caused by sodium salicylate (SS)-induced tinnitus in rat. In both aABR and oABR, wave II was the most prominent waveform, and the amplitude of wave II evoked by oABR was significantly higher than that of aABR. Brainstem transmission time (BTT), which represents the time required for a neural stimulation to progress from the auditory nerve ending to the inferior colliculus, was significantly shorter in oABR. In the tinnitus group, there was a significant increase in the threshold of both ABRs and a significant decrease in the amplitude of wave II only in the oABR. Based on our findings, the ABR test has the potential to be used in the assessment of SS-induced tinnitus, but oABR has the advantages of producing more prominent waveforms and significantly reducing the amplitude of wave II in tinnitus.

Limited Link of Common Blood Parameters with Tinnitus

Background: Tinnitus severity is generally assessed by psychometric and audiological instruments. However, no objective measure exists to evaluate the subjective discomfort and suffering caused by this hearing phenomenon. The objective of this work was to determine the possible blood parameters for diagnostics and therapy. Methods: We measured tinnitus distress by using the Tinnitus Questionnaire (TQ) and collected tinnitus-related audiological measures, namely the hearing threshold (HT), tinnitus loudness (TL), and sensation level (SL, i.e., the tinnitus loudness/hearing threshold at a tinnitus frequency). Blood samples were taken from 200 outpatients of the Tinnitus Centre of the Charité, and 46 routine blood count parameters were examined. The possible interactions were determined by (robust) linear models. Results: Tinnitus distress and audiological measurements were largely uncorrelated but could partly be predicted by selected blood parameters. First, the erythrocyte counts predicted tinnitus distress to a small extent. Second, the levels of vitamin D3 explained about 6% of tinnitus loudness and, age-dependently, the hearing threshold variability. Last, the levels of uric acid explained about 5% of the sensation level variability. Conclusions: Tinnitus is a multidimensional phenomenon. The marginal influences of blood markers suggest the possible roles of inflammation and oxidative stress produced by psychological or somatic burdens. Clinically, a vitamin D substitution (in older patients) might have a hearing-protective effect.

Efficacy of hearing aid treatment on sound perception and residual hearing preservation in patients with tinnitus and coexisting hearing loss: study protocol for a randomized controlled trial

BACKGROUND

Chronic subjective tinnitus poses significant challenges in clinical practice, and it is usually associated with hearing impairment, particularly with high-frequency sensorineural hearing loss (SNHL). Patients suffering from tinnitus with SNHL experience one of the most severe sensory disabilities, and this has devastating effects on their quality of life. Nowadays, mild to moderate SNHL can be managed with a properly fitted hearing aid (HA) that provides sound amplification, and several studies suggest that HAs may also benefit those with tinnitus. However, inadequate attention has been paid by medical personnel to the impact of HA use in residual hearing protection for patients with tinnitus and coexisting SNHL, and existing evidence is still at a preliminary stage. This study aims to identify and evaluate the efficacy of the use of HAs in both sound perception and residual hearing preservation among patients with tinnitus and coexisting SNHL.

METHODS AND DESIGN

The present study is a prospective, single-center, outcome assessor and data analyst-blinded, randomized, controlled trial. Eligible participants will be recruited and randomly allocated into the HA intervention group and the waiting list control group at a ratio of 1:1. The primary outcome is to evaluate the severity of tinnitus using the Tinnitus Handicap Inventory as a continuous variable at 6 months from randomization. Secondary outcome measures include changes in hearing status and mental states. The trial will last 6 months, with follow-up visits at 3 months and 6 months.

DISCUSSION

This will be the first randomized, controlled trial to identify and evaluate HAs' efficacy on residual hearing preservation among tinnitus patients with coexisting high-frequency SNHL in China. We are aiming for novelty and generalizability, and strengths of this study are that it will examine the effectiveness of HA in patients with tinnitus and hearing impairment and will further explore the residual hearing protection provided by HA treatment in the tinnitus group.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05343026. Registered on April 25, 2022.

Efficacy of Tailor-Made Notched Music Training Versus Tinnitus Retraining Therapy in Adults With Chronic Subjective Tinnitus: A Randomized Controlled Clinical Trial

OBJECTIVES

Chronic subjective tinnitus can have a serious effect on daily life, even causing serious psychological disorders. Currently there are no specific effective solutions or cures. Tailor-made notched music training (TMNMT) is a recently proposed sound therapy that has simpler processes and a higher compliance rate than tinnitus retraining therapy (TRT), a widely used treatment for chronic subjective tinnitus. This study explores the therapeutic effect of TMNMT in comparison to TRT to highlight its clinical value.

DESIGN

The study was a randomized controlled, single-blinded clinical trial. One hundred twenty eligible participants were randomly assigned to receive TMNMT (n = 60) or TRT (n = 60) for 3 mo with concurrent follow-up. It should be noted that the duration of sound treatment in TRT was modified to 2 hr per day for better feasibility in practice. The primary outcome was mean change in tinnitus handicap inventory (THI) measured at baseline ( T0 ), 1 mo ( T1 ) and 3 mo ( T2 ) after intervention. Change in visual analog scale (VAS) was measured as a secondary outcome. A comparison of therapeutic effectiveness between TMNMT and TRT was evaluated by repeated measure analysis of variance.

RESULTS

One hundred and twelve (93%) of participants took part in the study, of which 64 were men and 48 women. Mean (SD) age was 42.80 (12.91) years. Fifty-eight were allocated to receive TMNMT and 54 to receive TRT. The between-group difference in primary outcome was -6.90 points (95% confidence interval [CI], -13.53 to -0.27) at T1 and -6.17 points (95% CI, -13.04 to 0.71) at T2 . These results closely reached to clinical significance of tinnitus-related effective relief. For the secondary outcome, the mean value in the TMNMT group was 0.83 points (95% CI, 0.12 to 1.54), significantly lower than the mean value of the TRT group. The differences in THI and VAS between the two groups were statistically significant after intervention. Further analysis showed that age and baseline THI and VAS scores were associated with change in THI and VAS scores after interventions.

CONCLUSIONS

Both TMNMT and TRT were able to alleviate chronic subjective tinnitus effectively after a 3 month intervention. When the two forms of therapy were compared TMNMT appeared to be more effective and consequently potentially superior to TRT for reducing tinnitus loudness and functional and emotional disturbance associated with chronic subjective tinnitus.

Prediction of network pharmacology and molecular docking-based strategy to determine potential pharmacological mechanism of Liuwei Dihuang pill against tinnitus

BACKGROUND

Liuwei Dihuang Pill is widely used to treat tinnitus in China. However, the underlying mechanism of Liuwei Dihuang Pill in treating tinnitus still remains unclear.

OBJECTIVE

To explore the potential pharmacological mechanism of Liuwei Dihuang Pill in the treatment of tinnitus based on network pharmacology and molecular docking.

METHODS

The active components of the Liuwei Dihuang Pill were obtained from the traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP) database. Cytoscape software was used to draw the active component-target network diagram of Liuwei Dihuang Pill, and obtain the core components. Then the corresponding targets were also obtained from the TCMSP database. Targets related to tinnitus were obtained from the GeneCards, DisGeNET, TTD and DrugBank databases. The String database was used to construct protein-protein interaction (PPI) network of common targets of drugs and diseases, then the core targets were screened out. The Annotation, Visualization and Integrated Discovery (DAVID) database was used for gene ontology (GO) enrichment and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis of common targets. Finally, the molecular docking between the core component and the core target was carried out by AutoDock.

RESULTS

The core components of Liuwei Dihuang Pill in the treatment of tinnitus including quercetin, stigmasterol, kaempferol, β-sitosterol, tetrahydroalstonine, which may act on core targets such as STAT3, transcription factor AP-1 (JUN), tumor necrosis factor (TNF), interleukin-6 and MAPK3. HIF-1 signaling pathway, Influenza A, P53 signaling pathway, and Toll-like receptor signaling pathway play a role in anti-inflammatory, improving microcirculation in the blood-labyrinth barrier, increasing cochlear blood flow, and preventing hair cell damage. The molecular docking results showed that the affinity between core components and core targets was good.

CONCLUSION

The potential mechanism of Liuwei Dihuang Pill in the treatment of tinnitus was preliminarily discussed in this study, which may provide a theoretical basis and evidence for further experimental research.

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.

Vascular-Metabolic Risk Factors and Psychological Stress in Patients with Chronic Tinnitus

Little is known about molecular correlates of chronic tinnitus. We examined interrelationships between vascular−metabolic risk factors, perceived stress, and other routine blood values in patients with chronic tinnitus. Two-hundred patients (51% female) were screened for 49 blood parameters pertaining to vascular−metabolic risk, immune function, and redox processes. They further completed perceived stress- and tinnitus-related distress questionnaires. Following descriptive analyses, gender-specific sets of age- and tinnitus-severity-adjusted regression models investigated associations between perceived stress and blood parameters. Patients reported mildly elevated levels of perceived stress. Elevated levels of total cholesterol (65% and 61% of female and male patients, respectively), non-HDL-c (43/50%), LDL-c (56/59%), and lipoprotein_a (28/14%) were accompanied by high rates of overweight (99/100%) and smoking (28/31%). A low-level inflammatory state was accompanied by reduced reactive oxygen species (ROS)-neutralizing capacity (reduced co-enzyme Q10 and SOD1 levels). Most vascular risk factors were not correlated with perceived stress, except for fibrinogen (ß = −0.34) as well as C-reactive protein (ß = −0.31, p < 0.05) in men, and MCV (ß = −0.26, p < 0.05) in women. Interrelations between blood parameters and stress levels need to be investigated within psychobehavioural frameworks across varying distress levels. Alongside psychological interventions, a low-level inflammatory state may be a route for pharmacological therapeutics.

Biomarkers in Rare Diseases 2.0

It is estimated that there are over 7000 rare diseases, collectively affecting more than 350 million individuals worldwide [...].

Higher Peripheral Inflammation Is Associated With Lower Orbitofrontal Gamma Power in Chronic Tinnitus

Chronic tinnitus, the continuous perception of a phantom sound, is a highly prevalent audiological symptom, for which the underlying pathology has not yet been fully understood. It is associated with neurophysiological alterations in the central nervous system and chronic stress, which can be related with a disinhibition of the inflammatory system. We here investigated the association between resting-state oscillatory activity assessed with Magnetoencephalography (MEG), and peripheral inflammation assessed by C-reactive protein (CRP) in a group of patients with chronic tinnitus (N = 21, nine males, mean age: 40.6 ± 14.6 years). Additionally, CRP was assessed in an age- and sex-matched healthy control group (N = 21, nine males, mean age: 40.9 ± 15.2 years). No MEG data was available for the control group. We found a significant negative correlation between CRP and gamma power in the orbitofrontal cortex in tinnitus patients (p < 0.001), pointing to a deactivation of the orbitofrontal cortex when CRP was high. No significant clusters were found for other frequency bands. Moreover, CRP levels were significantly higher in the tinnitus group than in the healthy controls (p = 0.045). Our results can be interpreted based on findings from previous studies having disclosed the orbitofrontal cortex as part of the tinnitus distress network. We suggest that higher CRP levels and the associated deactivation of the orbitofrontal cortex in chronic tinnitus patients is maintaining the tinnitus percept through disinhibition of the auditory cortex and attentional or emotional top-down processes. Although the direction of the association (i.e., causation) between CRP levels and orbitofrontal gamma power in chronic tinnitus is not yet known, inflammation reducing interventions are promising candidates when developing treatments for tinnitus patients. Overall, our study highlights the importance of considering immune-brain communication in tinnitus research.

Potential inflammatory biomarkers for tinnitus in platelets and leukocytes: a critical scoping review and meta-analysis

OBJECTIVE

To explore the association between platelets or leukocytes and tinnitus.

DESIGN

A meta-analysis and scoping review examining the association between tinnitus and platelets and leukocytes. All 11 studies included were critically appraised using the Joanna Briggs Institute (JBI) checklist (2017a). A random effects model was used to pool the results of the studies examining mean platelet volume (MPV) and tinnitus.

STUDY SAMPLE

1935 studies were identified in the initial search, 11 of which were included in the scoping review. 6 of the 11 studies had their MPV values pooled in the meta-analysis.

RESULTS

Pooled results of 818 subjects from 6 studies indicated that MPV was significantly higher in those with tinnitus compared to a comparison group without tinnitus. The overall mean difference was 0.43 fL with a 95% confidence interval (CI) from 0.31 to 0.55 and a p value of < 0.0001 which was statistically significant. MPV is the only haematological parameter which is reliably associated with tinnitus.

CONCLUSIONS

MPV could be a useful biomarker for tinnitus. Further studies should aim to standardise methodology with more rigorous exclusion criteria to reproduce and define this association. NLR, PLR, WBC count, RDW and PDW do not show a reliable association with tinnitus.