Dual-site transcranial direct current stimulation to treat tinnitus: a randomized controlled trial

Abstract

Transcranial direct current stimulation (tDCS) has been proposed as a potential intervention for subjective tinnitus, but supporting evidence remains limited. We aimed to investigate the effect of anodal high-definition tDCS of the left temporal area and right dorsolateral prefrontal cortex on tinnitus severity. This double-blind randomized controlled trial included 77 patients (age range 18–79, 43 male) with chronic subjective tinnitus as their primary complaint. Thirty-eight subjects received six consecutive sessions of dual-site sequential high-definition-tDCS with electrodes positioned over the left temporal area and right dorsolateral prefrontal cortex. Both areas were stimulated for 15 min per session, with total stimulation time amounting to 30 min. Thirty-nine subjects received sham stimulation. The primary outcome measure was the change in tinnitus severity, as evaluated by the Tinnitus Functional Index, from baseline to a follow-up visit at 8 ± 2 weeks after treatment completion. Secondary outcomes included changes in perceived tinnitus loudness, as measured with a visual analogue scale and a tinnitus matching procedure, as well as scores on the Hospital Anxiety and Depression Scale, and the Hyperacusis Questionnaire. No differences in Tinnitus Functional Index change scores were identified between the active treatment and sham control groups (linear regression: P = 0.86). The Tinnitus Functional Index scores decreased significantly over time in both groups (P = 0.0012), indicating the presence of a considerable placebo effect. These change scores were significantly influenced by sex (linear regression: P = 0.037) and baseline symptoms of anxiety (linear regression: P = 0.049) in both groups. In general, Tinnitus Functional Index scores decreased more profoundly in males and in subjects with a higher degree of anxiety at baseline. None of the included secondary measures differed significantly between experimental arms. Our results suggest that dual-site sequential high-definition-tDCS of the left temporal area and right dorsolateral prefrontal cortex does not alleviate tinnitus severity. Interestingly, in our study population, fluctuations in tinnitus severity were influenced by gender and concurrent mental condition. It is therefore important to take these factors into account when conducting or planning randomized controlled trials in tinnitus populations.

Development of a Prognostic Nomogram for Modified Tinnitus Relieving Sound Therapy for Subjective Tinnitus

“…9,10 Despite numerous studies, there are no approved medications available to fully cure or eliminate tinnitus. 11 Various treatments for tinnitus, including auditory stimulation, such as sound maskers, 12 as well as medications, such as anticonvulsants, antidepressants, neurotrophic drugs, hyperbaric oxygen therapy, 13 transcranial direct current stimulation, 14 neuromodulation, 15 and cognitive behavioral therapy, have been evaluated, but none have provided conclusive evidence of treatment effects on tinnitus loudness. Cognitive-behavioral therapy has been shown to improve the QoL of patients with tinnitus.…”

Consecutive Dual-Session Transcranial Direct Current Stimulation in Chronic Subjective Severe to Catastrophic Tinnitus with Normal Hearing

“…tDCS initially attracted attention for the purpose of modulating the activity of specific brain regions implicated in cognitive, motor, and affective disorders [13]. The targets to be stimulated through tDCS in tinnitus are mainly the auditory cortex [14,15], dorsolateral prefrontal cortex (DLPFC) [16,17], and left temporoparietal area (LTPA) [18], which are different for each study. Most studies reported significant improvement in patients who have tinnitus with tDCS treatment, but the duration of tinnitus suppression varies from minutes to several days [19][20][21].…”