The Effects of Compensatory Auditory Stimulation and High-Definition Transcranial Direct Current Stimulation (HD-tDCS) on Tinnitus Perception – A Randomized Pilot Study

Abstract

BackgroundTinnitus correlates with elevated hearing thresholds and reduced cochlear compression. We hypothesized that reduced peripheral input leads to elevated neuronal gain resulting in the perception of a phantom sound.ObjectiveThe purpose of this pilot study was to test whether compensating for this peripheral deficit could reduce the tinnitus percept acutely using customized auditory stimulation. To further enhance the effects of auditory stimulation, this intervention was paired with high-definition transcranial direct current stimulation (HD-tDCS).MethodsA randomized sham-controlled, single blind study was conducted in a clinical setting on adult participants with chronic tinnitus (n = 14). Compensatory auditory stimulation (CAS) and HD-tDCS were administered either individually or in combination in order to access the effects of both interventions on tinnitus perception. CAS consisted of sound exposure typical to daily living (20-minute sound-track of a TV show), which was adapted with compressive gain to compensate for deficits in each subject's individual audiograms. Minimum masking levels and the visual analog scale were used to assess the strength of the tinnitus percept immediately before and after the treatment intervention.ResultsCAS reduced minimum masking levels, and visual analog scale trended towards improvement. Effects of HD-tDCS could not be resolved with the current sample size.ConclusionsThe results of this pilot study suggest that providing tailored auditory stimulation with frequency-specific gain and compression may alleviate tinnitus in a clinical population. Further experimentation with longer interventions is warranted in order to optimize effect sizes.

Effect of Transcranial Direct Current Stimulation in Patients With Tinnitus: A Meta-Analysis and Systematic Review

“…The THI is a 3-label category scale questionnaire involving 25 items. Patients can be classified into 5 grades based on a transformation into a 100point scale: slight (0-16), mild (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36), moderate (38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56), severe (58-76), and catastrophic (78-100). 31 However, this grouping reduces the resolution of differences among subjects.…”

“…50 The authors concluded that perhaps the use of 2 treatments (high-definition tDCS and compensatory auditory stimulation) per session might have limited their results because of a lack of time for a washout effect and that the small number of subjects might also have been a limitation. 50 While this meta-analysis and review of literature assessed several studies including those published in 2017, there were some limitations. De Ridder and Vanneste 37 comprised 675 patients and was much larger than the other studies.…”

Effects of Electrical Stimulation in Tinnitus Patients: Conventional Versus High-Definition tDCS

“…Tingling, sleepiness, and scalp pain were the most common transient sensations experienced during HD tDCS. 23 In contrast to these promising results, Henin et al 24 found no significant effect of HD tDCS on reducing the tinnitus percept compared with a sham group. However, they used different electrode positions by splitting the current across 2 sets of electrodes.…”

The effects of transcranial direct current stimulation on corticospinal and cortico-cortical excitability and response variability: conventional versus high-definition montages

“…Memory (Chua et al, 2017;Hill et al, 2017Hill et al, , 2018Naka et al, 2018;Nikolin et al, 2015;Price et al, 2016), Pain (Borckardt et al, 2012;Flood et al, 2016) and Tinnitus (Henin et al, 2016;Jacquemin et al, 2018). Despite this, direct comparisons between conventional tDCS and HD-tDCS is limited into their differing effect on CSE, cortico-cortical excitability and response variability.…”