September 10, 2025
3 min read
Key takeaways:
- Anodal transcranial direct current stimulation, with exercise and patient education, improved disability caused by fibromyalgia pain.
- Adverse events were “mild to moderate.”
Anodal transcranial direct current stimulation, combined with exercise and patient education, is superior to placebo for improving fibromyalgia pain interference, according to data published in JAMA Network Open.
“This study addressed key limitations of previous trials, such as small sample sizes, short follow-up periods, and lack of control for placebo effects,” Wolnei Caumo, MD, PhD, full professor of anesthesia and pain at the Federal University of Rio Grande do Sul School of Medicine, and head of pain and palliative care service at Hospital de Clínicas, in Porto Alegre, Brazil, told Healio. “Importantly, it used a novel methodological design by stratifying participants based on placebo responsiveness, allowing for a more accurate assessment of the active treatment’s effects beyond expectancy.”
To examine the efficacy of bifrontal anodal transcranial direct current stimulation (A-tDCS) in a home-based setting, combined with exercise and neuroscience education, vs. placebo in reducing fibromyalgia pain, Caumo and colleagues conducted a double-blind, sham-controlled randomized clinical trial. The researchers enrolled 112 women aged 18 to 65 years with fibromyalgia, who were then randomly assigned to receive A-tDCS or a sham procedure between April 2022 and April 2024.
A-tDCS was conducted at patients’ homes as well as at the outpatient Clinical Research Center of Hospital de Clínicas. Patients in the treatment group received 2 mA for 20 minutes per day, 5 days per week for a total of 4 weeks, with the anode over the left dorsolateral prefrontal cortex (DLPFC) and the cathode over the right DLPFC. Meanwhile, those in the sham group received 30 seconds at the start, followed by 10 minutes, then 20 minutes and finally a 20-second ramp-up and ramp-down.
All participants additionally completed an exercise regimen focused on strength, flexibility and aerobic activities — 15 to 20 minutes daily before tDCS — as well as aerobic walking 2 to 3 times per week as tolerated. Meanwhile, pain neuroscience education involved videos and remote supervision after an in-person training session.
The primary outcome was the change in Multidimensional Pain Interference Index (MPII) at the end of treatment and 3-month follow-up.
According to the researchers, MPII fell by 38.76% (95% CI, –41.9% to –30.92%) among patients who underwent A-tDCS, compared with a reduction of 16.08% (95% CI, –21.42% to –10.41%) in the sham group. This represented a mean difference of 22.68% (95% CI, 12.79% to 40%).
“A significant treatment-by-time interaction favored A-tDCS across five assessments, with no interaction by placebo response,” Caumo and colleagues wrote.
Among participants who responded to placebo, MPII fell by 34.21% (95% CI, –46.88% to 28.29%) for A-tDCS treatment, compared with 18.13% (95% CI, –24.9% to 3.34%) for the sham tDCS. Meanwhile, for placebo non-responders, MPII decreased 35.49% (95% CI, –41.21% to –29.53%) for A-tDCS, vs. a decrease of 25.96% (95% CI, –34.31% to –20.42%) for the sham tDCS.
In all, 62.5% of patients in the A-tDCS group achieved an improvement of 50% or more, vs. 37.5% for the sham tDCS (RR = 0.6; 95% CI, 0.39-0.91).
“These findings are clinically significant because they demonstrate that home-based tDCS is an effective, feasible and safe strategy for managing fibromyalgia,” Caumo said. “Its combination with pain education and exercise reflects a real-world clinical approach.
“The study provides strong evidence to support the integration of home-based neuromodulation as a nonpharmacological treatment option for fibromyalgia, with the potential to improve access, reduce costs and overcome logistical barriers to in-clinic care,” he added. “It also enhances understanding of the neurobiological mechanisms involved and the modulatory role of placebo susceptibility.”
Wolnei Caumo, MD, PhD, can be reached at wcaumo@hcpa.edu.br.
Sources/Disclosures
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Disclosures:
Caumo reports holding a pending patent for BR 20 2015 016450 0 U2, receiving licensing royalties from Quark Medical, and receiving grants from the Foundation for the Support of Research at Rio Grande do Sul Ministry of Science and Technology.
