Experimental, Controversial, and Futuristic Treatments for Chronic Tinnitus

History of Tinnitus Research at the VA National Center for Rehabilitative Auditory Research (NCRAR), 1997-2021: Studies and Key Findings

The Veterans Affairs (VA) Rehabilitation Research & Development (RR&D) National Center for Rehabilitative Auditory Research (NCRAR) was first funded by the RR&D Service in 1997 and has been funded continuously since that time. The overall purpose of the NCRAR is to "improve the quality of life of Veterans and others with hearing and balance problems through clinical research, technology development, and education that leads to better patient care" ( www.ncrar.research.va.gov ). An important component of the research conducted at the NCRAR has been a focus on clinical and rehabilitative aspects of tinnitus. Multiple investigators have received grants to conduct tinnitus research and the present article provides an overview of this research from the NCRAR's inception through 2021.

Unresolved Issues Associated with Transcranial Magnetic Stimulation (TMS) Treatment of Chronic Tinnitus

Transcranial magnetic stimulation (TMS) has been investigated as a potential treatment for chronic tinnitus for 20 years. Numerous studies have reported that repetitive TMS (rTMS) has demonstrated efficacy for reducing the severity of tinnitus and its associated co-conditions such as depression, anxiety, and insomnia. However, some researchers have reported that active rTMS is no more effective than sham (placebo) rTMS as a tinnitus treatment method. There are numerous unresolved issues in this field that need to be addressed before rTMS can become a viable treatment for tinnitus. These issues include the type or brand of TMS system and its configuration; coil type, orientation, and placement method; scalp or neural target; laterality of rTMS application; dual site vs. single site stimulation; stimulation frequency and intensity; number of sessions; number of pulses per session; determination of the resting motor threshold (rMT); characteristics of the study population and their tinnitus; and outcome measures and follow-up assessments. To address and resolve these issues, large-scale, multi-site clinical trials of rTMS for tinnitus need to be conducted to determine which rTMS protocols are the most effective. In the absence of such investigations, the issues that need to be studied and addressed remain unresolved and continue to impede the clinical application of this treatment method.

Pragmatic Uncontrolled Study of Specialized Cognitive Behavioral Therapy for Adults With Chronic Tinnitus

OBJECTIVES

Tinnitus is the perception of sound without an external source, affecting quality of life that can cause severe distress in approximately 1 to 3% of the population of people with tinnitus. Randomized controlled trials of cognitive behavioral therapy for tinnitus have demonstrated its effectiveness in improving quality of life, but the effects of their implementation on a large scale in routine practice remains unknown. Therefore, the main purpose of this study was to examine the effects of stepped-care cognitive behavioral therapy for tinnitus delivered in a tertiary audiological center of a regional hospital. Second, we wished to examine predictors of favorable outcome.

DESIGN

Four hundred three adults with chronic tinnitus were enrolled in this prospective observational study (at 3 months, N=334, 8 months, N=261; 12 months, N=214). The primary outcome was health-related quality of life as measured by the Health Utilities Index III (HUI-III) at 12 months. Secondary outcomes were self-reported levels of tinnitus-related distress, disability, affective distress and tinnitus-related negative beliefs and fear. Measures were completed pre-intervention at 3 months, 8 months, and 12 months. Multilevel modeling was used to examine effects and their predictors.

RESULTS

Younger participants with lower levels of tinnitus distress were more likely to dropout while those with higher tinnitus distress at baseline and quality of life were more likely to receive step 2 of treatment. MLM analyses revealed, with one exception, no relation between any baseline variable and outcome change over time. Most participants' improvement exceeded minimally clinical important difference criteria for quality of life, tinnitus-related handicap, and tinnitus distress.

CONCLUSIONS

Results from this large pragmatic study complements those from randomized controlled trials of cognitive behavioral therapy for chronic tinnitus distress and supports its implementation under "real-world" conditions.

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.

Reevaluating the Use of Sound Therapy for Tinnitus Management: Perspectives on Relevant Systematic Reviews

PURPOSE

Tinnitus is a highly prevalent condition that can severely reduce health functioning. In spite of extant clinical practice guidelines (CPGs), implementation of these CPGs is relatively uncommon. As a result, patients seeking professional services for tinnitus often have no assurance of receiving evidence-based care. The purpose of this tutorial was to clarify the evidence for sound therapy so that it may be included in future CPGs for tinnitus.

METHOD

"Best clinical evidence" is obtained from high-quality systematic reviews, which are generally considered the highest level of evidence. Our review of recent, comprehensive, high-quality systematic reviews of interventions for tinnitus concludes that cognitive behavioral therapy is the only effective intervention, though the strength of evidence was generally rated as low in these reviews. Although trials of sound therapy for tinnitus have been included in these reviews, they have been rated as having high risk of bias (RoB) and not included in syntheses or rated as insufficient strength of evidence.

RESULTS

Conclusions from these and other reviews have influenced recommendations made in CPGs for tinnitus. These conclusions, however, can make it appear that an intervention for tinnitus is not effective, even if the opposite is true. We contend that the strict inclusion criteria for these reviews are counterproductive and have the effect of obscuring decades of evidence demonstrating the clinical effectiveness of sound therapies for tinnitus. Ultimately, this process has resulted in many patients not receiving sound therapy, despite what should be sufficient evidence that this is an effective form of intervention.

CONCLUSION

If we rely on systematic reviews using contemporary RoB assessment criteria for studies published prior to these reporting guidelines, then we risk excluding important conclusions regarding interventions that could help patients in need.

Effects of Low-Level Laser Therapy as a Therapeutic Strategy for Patients With Tinnitus: A Systematic Review

Purpose This systematic review aimed to analyze the effects of low-level laser therapy (LLLT) on the severity of tinnitus when compared to no therapy or other modalities of therapies. Method A systematic review protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) under the Registration Number CRD42019119376. A search was performed in each of the following databases: EMBASE, LILACS, PubMed, Science Direct, Scopus, Web of Science, Google Scholar, and ProQuest. The inclusion criteria consisted of studies in adults over 16 years of age, randomized clinical trials in which subjects presented chronic (≥ 6 months) and subjective tinnitus (unilateral or bilateral) as well as with or without bilateral sensorineural hearing loss, and studies that used only LLLT for treatment of tinnitus compared to no-therapy group or other modalities of therapy. No language or time restrictions were stipulated. The references were managed by Endnote Web and Rayyan QCRI. Results After the screening process, seven studies remained that attained the eligibility criteria. Regarding the risk of bias, only one study was categorized as low risk of bias; the six remaining studies were classified as moderate risk of bias. The seven included studies mainly assessed the LLLT effects on tinnitus by Visual Analogue Scale, Tinnitus Handicap Inventory, pitch and loudness matching, minimum masking level, and pure-tone audiometry. All the seven selected studies found different degrees of significant results regarding tinnitus severity; however, there was no consensus among the results. Conclusion Even though the LLLT showed positive effects in the tinnitus severity in some studies, it is not possible yet to make any recommendation over its uses for the treatment of tinnitus severity.

Acupuncture as Complementary Treatment for Acute Tinnitus: A Randomized Controlled Pilot Study

BACKGROUND

Up to now, tinnitus has been an almost non-treatable symptom affecting more than 18% of the population in industrialized countries. So far, there are only a few studies evaluating the effectiveness of acupuncture in tinnitus treatment, none of which include acute tinnitus (<3 months). The aim of this pilot study was to explore the feasibility of recruitment and adherence to acupuncture conducted according to the principles of traditional Chinese medicine in patients with acute idiopathic tinnitus and to assess effect sizes on subjective and objective outcomes within a randomized controlled design.

PATIENTS AND METHODS

After randomization patients of the control group received usual care (n = 23), and patients of the intervention group (n = 25) received 4 additional acupuncture treatments in a 4- to 6-week period. Tinnitus severity was assessed by means of a visual analogue scale as well as standardized and validated tinnitus questionnaires (Tinnitus Functional Index and 12-item Mini Tinnitus Questionnaire) at baseline and 6 weeks after. These subjective parameters were completed by tone audiometry. Comparisons of the groups were carried out using the Wilcoxon-Mann-Whitney test.

RESULTS

Both groups were comparable without significant differences in baseline values. All outcomes, except for the overall well-being, showed better improvements in the intervention group with clinically significant differences from baseline to end point. However, among the outcomes only the subjective change in tinnitus severity showed a significant group difference. No serious side effects were observed.

CONCLUSION

The design of our pilot study was feasible in terms of recruitment, although patient adherence to treatment remained challenging. However, considering the small intergroup differences, procedures regarding the numbers of acupuncture sessions and the total period of the acupuncture treatment should be reconsidered. The results of this pilot study provide a good basis for future confirmatory trials.

Self-directed down-regulation of auditory cortex activity mediated by real-time fMRI neurofeedback augments attentional processes, resting cerebral perfusion, and auditory activation

In this work, we investigated the use of real-time functional magnetic resonance imaging (fMRI) with neurofeedback training (NFT) to teach volitional down-regulation of the auditory cortex (AC) using directed attention strategies as there is a growing interest in the application of fMRI-NFT to treat neurologic disorders. Healthy participants were separated into two groups: the experimental group received real feedback regarding activity in the AC; the control group was supplied sham feedback yoked from a random participant in the experimental group and matched for fMRI-NFT experience. Each participant underwent five fMRI-NFT sessions. Each session contained 2 neurofeedback runs where participants completed alternating blocks of "rest" and "lower" conditions while viewing a continuously-updated bar representing AC activation and listening to continuous noise. Average AC deactivation was extracted from each closed-loop neuromodulation run and used to quantify the control over AC (AC control), which was found to significantly increase across training in the experimental group. Additionally, behavioral testing was completed outside of the MRI on sessions 1 and 5 consisting of a subjective questionnaire to assess attentional control and two quantitative tests of attention. No significant changes in behavior were observed; however, there was a significant correlation between changes in AC control and attentional control. Also, in a neural assessment before and after fMRI-NFT, AC activity in response to continuous noise stimulation was found to significantly decrease across training while changes in AC resting perfusion were found to be significantly greater in the experimental group. These results may be useful in formulating effective therapies outside of the MRI, specifically for chronic tinnitus which is often characterized by hyperactivity of the primary auditory cortex and altered attentional processes. Furthermore, the modulation of attention may be useful in developing therapies for other disorders such as chronic pain.

A Study of Social Media Utilization by Individuals With Tinnitus

PURPOSE

As more people experience tinnitus, social awareness of tinnitus has consequently increased, due in part to the Internet. Social media platforms are being used increasingly by patients to seek health-related information for various conditions including tinnitus. These online platforms may be used to seek guidance from and share experiences with individuals suffering from a similar disorder. Some social media platforms can also be used to communicate with health care providers. The aim of this study was to investigate the prevalence of tinnitus-related information on social media platforms.

METHOD

The present investigation analyzed the portrayal of tinnitus-related information across 3 social media platforms: Facebook (pages and groups), Twitter, and YouTube. We performed a comprehensive analysis of the platforms using the key words "tinnitus" and "ringing in the ears." The results on each platform were manually examined by 2 reviewers based on social media activity metrics, such as "likes," "followers," and "comments."

RESULTS

The different social media platforms yielded diverse results, allowing individuals to learn about tinnitus, seek support, advocate for tinnitus awareness, and connect with medical professionals. The greatest activity was seen on Facebook pages, followed by YouTube videos. Various degrees of misinformation were found across all social media platforms.

CONCLUSIONS

The present investigation reveals copious amounts of tinnitus-related information on different social media platforms, which the community with tinnitus may use to learn about and cope with the condition. Audiologists must be aware that tinnitus sufferers often turn to social media for additional help and should understand the current climate of how tinnitus is portrayed. Clinicians should be equipped to steer individuals with tinnitus toward valid information.

Tinnitus: still 'A Ghost in the Machine' or a Darwinian survival phenomenon?

INTRODUCTION

The causation of tinnitus continues to intrigue. Despite the plethora of publications there is no definitive path available to concentrate our efforts, in alleviating the symptom. Several mechanical theories are available in standard tinnitus literature with varying empiricism. Purpose/aim of the study: To investigate a possible way forward.

MATERIALS AND METHODS

Employing a forensic methodology ("crime scene analysis" technique) and utilizing available evidence from the related sciences, inductive and abstract reasoning, a pragmatic model incorporating the known features of tinnitus is available.

RESULTS

A plausible evolutionary explanation of the origins and functions for the causation of tinnitus is offered with a possible link to its evasive nature, in our search for a cause.

CONCLUSION

The functional value of tinnitus may be provided by our evolutionary history. It is possible that tinnitus was a protective adaptive phenomenon in earlier forms but in our current environment merely contributes to nuisance value.

An economic evaluation of the healthcare cost of tinnitus management in the UK

Background

There is no standard treatment pathway for tinnitus patients in the UK. Possible therapies include education and reassurance, cognitive behavioural therapies, modified tinnitus retraining therapy (education and sound enrichment), or amplification of external sound using hearing aids. However, the effectiveness of most therapies is somewhat controversial. As health services come under economic pressure to deploy resources more effectively there is an increasing need to demonstrate the value of tinnitus therapies, and how value may be continuously enhanced. The objective of this project was to map out existing clinical practice, estimate the NHS costs associated with the management approaches used, and obtain initial indicative estimates of cost-effectiveness.

Methods

Current treatment pathways, costs and health outcomes were determined from the tinnitus literature, national statistics, a patient survey, and expert opinion. These were used to create an Excel-based economic model of therapy options for tinnitus patients. The probabilities associated with the likelihood of an individual patient receiving a particular combination of therapies was used to calculate the average cost of treatment per patient, average health outcome per patient measured in QALYs gained, and cost-effectiveness, measured by the average cost per QALY gained.

Results

The average cost of tinnitus treatment per patient per year is GB£717, equating to an NHS healthcare bill of GB£750 million per year. Across all pathways, tinnitus therapy costs £10,600 per QALY gained. Results were relatively insensitive to restrictions on access to cognitive behaviour therapy, and a subsequent reliance on other therapies.

Conclusions

NHS provisions for tinnitus are cost-effective against the National Institute for Health and Care Excellence cost-effective threshold. Most interventions help, but education alone offers very small QALY gains. The most cost-effective therapies in the model were delivered within audiology.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2527-2) contains supplementary material, which is available to authorized users.

Heidelberg Neuro-Music Therapy Restores Attention-Related Activity in the Angular Gyrus in Chronic Tinnitus Patients

Background: Tinnitus is the perception of a phantom sound without external acoustic stimulation. Recent tinnitus research suggests a relationship between attention processes and tinnitus-related distress. It has been found that too much focus on tinnitus comes at the expense of the visual domain. The angular gyrus (AG) seems to play a crucial role in switching attention to the most salient stimulus. This study aims to evaluate the involvement of the AG during visual attention tasks in tinnitus sufferers treated with Heidelberg Neuro-Music Therapy (HNMT), an intervention that has been shown to reduce tinnitus-related distress. Methods: Thirty-three patients with chronic tinnitus, 45 patients with recent-onset tinnitus, and 35 healthy controls were tested. A fraction of these (21/21/22) were treated with the "compact" version of the HNMT lasting 1 week with intense treatments, while non-treated participants were included as passive controls. Visual attention was evaluated during functional Magnet-Resonance Imaging (fMRI) by a visual Continous Performance Task (CPT) using letter-based alarm cues ("O" and "X") appearing in a sequence of neutral letters, "A" through "H." Participants were instructed to respond via button press only if the letter "O" was followed by the letter "X" (GO condition), but not to respond if a neutral letter appeared instead (NOGO condition). All participants underwent two fMRI sessions, before and after a 1-week study period. Results: The CPT results revealed a relationship between error rates and tinnitus duration at baseline whereby the occurrence of erroneous "GO omissions" and the reaction time increased with tinnitus duration. Patients with chronic tinnitus who were treated with HNMT had decreasing error rates (fewer GO omissions) compared to treated recent-onset patients. fMRI analyses confirmed greater activation of the AG during CPT in chronic patients after HNMT treatment compared to treated recent-onset patients. Conclusions: Our findings suggest that HNMT treatment helps shift the attention from the auditory phantom percept toward visual cues in chronic tinnitus patients and that this shift in attention may involve the AG.

Transcranial magnetic stimulation for tinnitus: using the Tinnitus Functional Index to predict benefit in a randomized controlled trial

Background

Identifying characteristics associated with transcranial magnetic stimulation (TMS) benefit would offer insight as to why some individuals experience tinnitus relief following TMS treatment, whereas others do not. The purpose of this study was to use the Tinnitus Functional Index (TFI) and its subscales to identify specific factors associated with TMS treatment responsiveness.

Methods

Individuals with bothersome tinnitus underwent 2000 pulses of 1-Hz TMS for 10 consecutive business days. The primary outcome measure was the TFI which yields a total score and eight individual subscale scores. Analyses were performed on baseline data from the active arm (n = 35) of a prospective, double-blind, randomized placebo-controlled clinical trial of TMS for tinnitus.

Results

Baseline total TFI score and three of the eight TFI subscales were useful in differentiating between responders and nonresponders to TMS intervention for tinnitus. These findings are not definitive, but suggest potential factors that contribute to perceived benefit following TMS.

Conclusions

Overall, the main factor associated with TMS benefit was a higher tinnitus severity score for responders at baseline. The TFI subscales helped to clarify the factors that contributed to a higher severity score at baseline. Large-scale prospective research using systematic approaches is needed to identify and describe additional factors associated with tinnitus benefit following TMS.

Trial registration

ClinicalTrials.gov, ID: NCT01104207. Registered on 13 April 2010.

Sensorineural Tinnitus: Its Pathology and Probable Therapies

Tinnitus is not a single disease but a group of different diseases with different pathologies and therefore different treatments. Regarding tinnitus as a single disease is hampering progress in understanding of the pathophysiology of tinnitus and perhaps, more importantly, it is a serious obstacle in development of effective treatments for tinnitus. Subjective tinnitus is a phantom sound that takes many different forms and has similarities with chronic neuropathic pain. The pathology may be in the cochlea, in the auditory nerve, or, most commonly, in the brain. Like chronic neuropathic pain tinnitus is not life threatening but influences many normal functions such as sleep and the ability to concentrate on work. Some forms of chronic tinnitus have two components, a (phantom) sound and a component that may best be described as suffering or distress. The pathology of these two components may be different and the treatment that is most effective may be different for these two components. The most common form of treatment of tinnitus is pharmacological agents and behavioral treatment combined with sound therapy. Less common treatments are hypnosis and acupuncture. Various forms of neuromodulation are becoming in use in an attempt to reverse maladaptive plastic changes in the brain.

Cortical reorganization in recent-onset tinnitus patients by the Heidelberg Model of Music Therapy

Pathophysiology and treatment of tinnitus still are fields of intensive research. The neuroscientifically motivated Heidelberg Model of Music Therapy, previously developed by the German Center for Music Therapy Research, Heidelberg, Germany, was applied to explore its effects on individual distress and on brain structures. This therapy is a compact and fast application of nine consecutive 50-min sessions of individualized therapy implemented over 1 week. Clinical improvement and long-term effects over several years have previously been published. However, the underlying neural basis of the therapy's success has not yet been explored. In the current study, the therapy was applied to acute tinnitus patients (TG) and healthy active controls (AC). Non-treated patients were also included as passive controls (PTC). As predicted, the therapeutic intervention led to a significant decrease of tinnitus-related distress in TG compared to PTC. Before and after the study week, high-resolution MRT scans were obtained for each subject. Assessment by repeated measures design for several groups (Two-Way ANOVA) revealed structural gray matter (GM) increase in TG compared to PTC, comprising clusters in precuneus, medial superior frontal areas, and in the auditory cortex. This pattern was further applied as mask for general GM changes as induced by the therapy week. The therapy-like procedure in AC also elicited similar GM increases in precuneus and frontal regions. Comparison between structural effects in TG vs. AC was calculated within the mask for general GM changes to obtain specific effects in tinnitus patients, yielding GM increase in right Heschl's gyrus, right Rolandic operculum, and medial superior frontal regions. In line with recent findings on the crucial role of the auditory cortex in maintaining tinnitus-related distress, a causative relation between the therapy-related GM alterations in auditory areas and the long-lasting therapy effects can be assumed.