Effectiveness of Transcranial Direct Current Stimulation Combined With Exercising in People With Fibromyalgia: A Randomized Sham-Controlled Clinical Trial

OBJECTIVE:To evaluate the effectiveness of transcranial direct current stimulation (tDCS) combined with exercising in people with fibromyalgia. DESIGN:Randomized, triple-blind, sham-controlled, clinical trial. SETTING:Primary health care center. PARTICIPANTS:A total of 120 volunteer participants (N=120) between 18 and 65 years old and diagnosed with fibromyalgia. Four participants dropped out of the study for causes unrelated to the intervention. INTERVENTION:Participants were randomized into 3 groups (active tDCS+exercising, sham tDCS+exercising, no-intervention control). The intervention was delivered in 5 sessions over 2 weeks. MAIN OUTCOME MEASURES:Pain intensity and referred pain area after suprathreshold pressure stimulation. RESULTS:Pain intensity further decreased in the active tDCS group vs control (mean, -14.43; 95% confidence interval, -25.27 to -3.58) at post intervention, unlike the sham tDCS group. Both tDCS groups did not achieve greater reductions in referred pain vs control. In the active tDCS group, health status (mean, -14.80; 95% confidence interval, -23.10 to -6.50) and pain catastrophizing (mean, -6.68, 95% confidence interval, -11.62 to -1.73) improved at post intervention, and so did health status (mean, -8.81; 95% confidence interval, -17.11 to -0.51), pain catastrophizing (mean, -7.00; 95% confidence interval, -12.13 to -1.87), and depression (mean, -3.52; 95% confidence interval, -6.86 to -0.19) after 1 month. In the sham tDCS group, improvements were recorded in health status (mean, -13.21; 95% confidence interval, -21.52 to -4.91) and depression (mean, -3.35; 95% confidence interval, -6.35 to -0.35) at post intervention and in health status (mean, -8.77; 95% confidence interval, -17.06 to -0.47), pain catastrophizing (mean, -5.68; 95% confidence interval, -10.80 to -0.55), and depression (mean, -3.98; 95% confidence interval, -7.31 to -0.64) after 1 month. No intergroup differences were observed between active and sham tDCS. CONCLUSIONS:Active and sham tDCS improved health status, pain catastrophizing, and depression vs control, but pain intensity decreased only in the active tDCS group.