6% selleck bio (range, 9.1%�C30.4%), while that by active bifrontal tDCS was 13.1% (range, 8.0%�C27.8%).3.6. A Comparison between Active tDCS and Sham tDCS with regard to Tinnitus Intensity ReductionAs aforementioned, only RCTs were adopted for this meta-analytic comparison between active tDCS and sham tDCS with regard to tinnitus intensity reduction. As a result, only 2 of 3 RCTs were eligible for this meta-analysis. The pooled estimate of effect size (Hedges’ g) for the reduction of tinnitus intensity as indicated by percentage reductions in tinnitus intensity between active and sham tDCS was 0.77 [Z = 2.81, P = 0.005, 95% CI 0.23�C1.31], indicating a significant medium to large effect size (Table 2). Table 2Forest plot of effect sizes (Hedges’ g) for active versus sham transcranial direct current stimulation.

CI, confidence interval.4. DiscussionThe current systemic review and meta-analysis indicate that overall 39.5% of the tinnitus patients responded to active tDCS with a mean tinnitus intensity reduction of 13.5%. Meanwhile, the comparison between LTA tDCS and bifrontal tDCS yields comparable results with regard to percent responders and percent reduction of tinnitus intensity. Additionally, although only 2 studies were included, meta-analysis showed that LTA tDCS was associated with a significantly better treatment outcome as compared with sham tDCS.4.1. Response to tDCS in Patients with TinnitusAlthough a meta-analytic approach to the mean percentage of the responders and the amount of tinnitus intensity reduction was impossible due to limited number of studies, the current systemic review of 6 studies revealed a 39.

5% weighted mean response to tDCS and a 13.5% weighted mean reduction rate of the intensity. TDCS has been used in treating other pathologies such as chronic pain or depression and meta-analytic approaches to reveal the treatment efficacy have recently been made. A recent systemic review and meta-analysis of 10 tDCS studies in the treatment of major depression has reported a weighted mean response rate of 19.8% to tDCS and weighted mean symptom severity reduction rate of 28.9% [33]. Another meta-analysis of 5 tDCS studies in the treatment of pain failed to reveal a significant difference between active and sham stimulations [41]. In this regard, our results of tDCS in patients with tinnitus are comparable to other meta-analysis results of tDCS on other pathologies.

Considering that tDCS for tinnitus Batimastat is generally very well tolerated without any significant adverse effects [42], this systemic review reconfirms that tDCS for tinnitus is a promising noninvasive neuromodulatory treatment option.4.2. Stimulation Site: LTA versus BifrontalThe weighted mean percentage of responders to active LTA and bifrontal tDCS were 37.0% and 40.2%, respectively.