Alterations in Auditory Electrophysiological Responses Associated With Temporary Suppression of Tinnitus Induced by Low-Level Laser Therapy: A Before-After Case Series

Photobiomodulation therapy in improvement of harmful neural plasticity in sodium salicylate-induced tinnitus

Tinnitus is a common annoying symptom without effective and accepted treatment. In this controlled experimental study, photobiomodulation therapy (PBMT), which uses light to modulate and repair target tissue, was used to treat sodium salicylate (SS)-induced tinnitus in a rat animal model. Here, PBMT was performed simultaneously on the peripheral and central regions involved in tinnitus. The results were evaluated using objective tests including gap pre-pulse inhibition of acoustic startle (GPIAS), auditory brainstem response (ABR) and immunohistochemistry (IHC). Harmful neural plasticity induced by tinnitus was detected by doublecortin (DCX) protein expression, a known marker of neural plasticity. PBMT parameters were 808 nm wavelength, 165 mW/cm2 power density, and 99 J/cm2 energy density. In the tinnitus group, the mean gap in noise (GIN) value of GPIAS test was significantly decreased indicated the occurrence of an additional perceived sound like tinnitus and also the mean ABR threshold and brainstem transmission time (BTT) were significantly increased. In addition, a significant increase in DCX expression in the dorsal cochlear nucleus (DCN), dentate gyrus (DG) and the parafloccular lobe (PFL) of cerebellum was observed in the tinnitus group. In PBMT group, a significant increase in the GIN value, a significant decrease in the ABR threshold and BTT, and also significant reduction of DCX expression in the DG were observed. Based on our findings, PBMT has the potential to be used in the management of SS-induced tinnitus.

The effect of photobiomodulation on tinnitus: a systematic review

OBJECTIVE

To establish outcomes following photobiomodulation therapy for tinnitus in humans and animal studies.

METHODS

A systematic review and narrative synthesis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The databases searched were: Medline, Embase, Cochrane Central Register of Controlled Trials ('Central'), ClinicalTrials.gov and Web of Science including the Web of Science Core collection. There were no limits on language or year of publication.

RESULTS

The searches identified 194 abstracts and 61 full texts. Twenty-eight studies met the inclusion criteria, reporting outcomes in 1483 humans (26 studies) and 34 animals (2 studies). Photobiomodulation therapy parameters included 10 different wavelengths, and duration ranged from 9 seconds to 30 minutes per session. Follow up ranged from 7 days to 6 months.

CONCLUSION

Tinnitus outcomes following photobiomodulation therapy are generally positive and superior to no photobiomodulation therapy; however, evidence of long-term therapeutic benefit is deficient. Photobiomodulation therapy enables concentrated, focused delivery of light therapy to the inner ear through a non-invasive manner, with minimal side effects.

Effects of Red and Infrared Laser Therapy in Patients with Tinnitus: A Double-Blind, Clinical, Randomized Controlled Study Combining Light with Ultrasound, Drugs and Vacuum Therapy

Background: tinnitus is a symptom with no specific cause known to date, and there are no associated pharmacogenomics of hearing disorders and no FDA-approved drugs for tinnitus treatment. The effectiveness of drug treatments is not reproducible on idiopathic patients and inexistent in refractory patients. Personalized treatments for these patients are a great clinical need. Our study investigated the outcome of potential alternative and complementary treatment modalities for idiopathic and refractory tinnitus patients. Methods: we were the first to evaluate the tinnitus handicap inventory (THI) score changes over the course of treatment up to 15 days after complete cessation of treatment for novel transmeatal low-level laser therapy (LLLT) modalities using light alone, as well as LLLT combined with vacuum therapy (VT), ultrasound (US), Ginkgo biloba (GB) and flunarizine dihydrochloride (FD), while also comparing all treatment outcomes with laser puncture (LP), FD alone and GB alone. Results: a positive treatment outcome (superior to a placebo effect) was achieved by using either LP or transmeatal LLLT, whereas short-term antagonistic effects of VT, US, GB and FD when combined with LLLT. For transmeatal LLLT, an improvement in the treatment outcome was observed by increasing the irradiation time from 6 min to 15 min (with 100-mW of applied laser power at 660 nm). Finally, a lasting therapeutic effect higher than the placebo was observed at 15 days after treatment upon combining LLLT with VT, GB or by using FD alone, by using the transmeatal LLLT alone or by using LP. Conclusions: LP and Transmeatal LLLT can be promising alternative treatments for idiopathic and refractory tinnitus patients. Future studies should investigate the long-term effects of LLLT in tinnitus patients, as well as the dosimetry and wavelength of transmeatal LLLT.

Objective Detection of Tinnitus Based on Electrophysiology

Tinnitus, a common disease in the clinic, is associated with persistent pain and high costs to society. Several aspects of tinnitus, such as the pathophysiology mechanism, effective treatment, objective detection, etc., have not been elucidated. Any change in the auditory pathway can lead to tinnitus. At present, there is no clear and unified mechanism to explain tinnitus, and the hypotheses regarding its mechanism include auditory plasticity theory, cortical reorganization theory, dorsal cochlear nucleus hypothesis, etc. Current theories on the mechanism of tinnitus mainly focus on the abnormal activity of the central nervous system. Unfortunately, there is currently a lack of objective diagnostic methods for tinnitus. Developing a method that can detect tinnitus objectively is crucial, only in this way can we identify whether the patient really suffers from tinnitus in the case of cognitive impairment or medical disputes and the therapeutic effect of tinnitus. Electrophysiological investigations have prompted the development of an objective detection of tinnitus by potentials recorded in the auditory pathway. However, there is no objective indicator with sufficient sensitivity and specificity to diagnose tinnitus at present. Based on recent findings of studies with various methods, possible electrophysiological approaches to detect the presence of tinnitus have been summarized. We analyze the change of neural activity throughout the auditory pathway in tinnitus subjects and in patients with tinnitus of varying severity to find available parameters in these methods, which is helpful to further explore the feasibility of using electrophysiological methods for the objective detection of tinnitus.

The effects of photobiomodulation therapy in individuals with tinnitus and without hearing loss

To verify the effect of photobiomodulation therapy (PBMT) in individuals with chronic tinnitus without hearing loss, 20 patients who met the inclusion criteria were randomly divided into group 1: active low-level laser (LLL) and group 2: equipment without laser (placebo). Upon anamnesis, data collection, and audiological exams, the Tinnitus Handicap Inventory (THI) and the Visual-Analog Scale (EVA) were applied to measure the level of discomfort with tinnitus and the level of discomfort before and after laser treatment. The protocol used included 12 active LLL sessions for group 1 and not active for group 2, varying red and infrared wavelengths. There was a reduction in the disadvantage of individuals with tinnitus after the intervention and between the initial and final sessions, regardless of the intervention, although group 1 showed a greater reduction than group 2, regardless of point in time of assessment and number of session. There was no statistical difference as to group and point in time for the high-frequency audiometry and acuphenometry outcomes. Individuals with chronic tinnitus reduced the complaint, regardless of point in time and group of intervention; however, the group that received PBMT improved the level of satisfaction, regardless of point in time of assessment and number of session.

Effectiveness of Dry Needling in Bothersome Chronic Tinnitus in Patients with Myofascial Trigger Points

Introduction  Therapeutic dry needling (DN) is effective in reducing the discomfort of chronic somatosensory tinnitus in patients with myofascial trigger points (MTP)s.

Objective  To evaluate the efficacy of DN in chronic somatosensory tinnitus discomfort in patients with MTP.

Methods  Placebo-controlled paired trial that included 16 patients with a diagnosis of somatosensory chronic tinnitus and with the presence of at least one active or latent MTP. Treatment was performed in two phases: (1) four sessions (one session per week for four consecutive weeks) of placebo DN and (2) four sessions of therapeutic DN with a gap (washout) of 15 days between these phases.

Results  The Tinnitus Handicap Inventory (THI) variable and its emotional domain had a statistically significant reduction in therapeutic DN when compared with placebo DN ( p  = 0.024 and p = 0.011, respectively).

The tinnitus visual analogic scale (VAS) signaled a reduction in tinnitus discomfort when compared with moments before and after therapeutic DN ( p  < 0.05).

Conclusion  The therapeutic DN technique for MTP in patients with chronic tinnitus of somatosensory origin proved effective in reducing symptom discomfort, as measured by the THI (total score) and its emotional domain when compared with placebo DN.

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.

Tinnitus and hearing survey: cultural adaptation to Brazilian Portuguese

Introduction

Hearing loss is associated with several comorbidities and may be frequently associated with tinnitus. When patients complain of both tinnitus and hearing difficulties in audiology and otolaryngology clinics, there, is often great difficulty separating the two complaints. The tinnitus and hearing survey was specially developed for this purpose to identify the main complaint and help direct the choice of appropriate intervention.

Objective

To translate and culturally adapt the tinnitus and hearing survey for the Brazilian-Portuguese.

Methods

Seventy patients who had previously completed a battery of audiological diagnostic exams were invited to complete the tinnitus and hearing survey and were categorized into four groups: normal hearing without tinnitus, normal hearing with tinnitus, hearing loss without tinnitus, and hearing loss with tinnitus. Cultural adaptation of tinnitus and hearing survey followed the steps indicated by Guillemin et al. (1993), including assessment of inter-researchers’ reproducibility, internal consistency, and reliability of the instrument.

Results

There were no substantial changes to the content of the tinnitus and hearing survey questions, although a few adaptations were made to two-item sound tolerance section to facilitate participants’ understanding. Internal consistency and reliability tested by Cronbach’s α was considered good for all domains. The reproducibility of the tinnitus and hearing survey was measured by the Kappa coefficient at two different moments and agreement between evaluators 1 and 2 was considered almost perfect, indicating good reproducibility.

Conclusion

The tinnitus and hearing survey was culturally adapted to Brazilian Portuguese and analyzed for internal consistency, reliability, and reproducibility. Results support this questionnaire as a useful tool to help professionals differentiate the main complaint of the individual, allowing the choice of a more appropriate intervention.