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A noninvasive, home-based brain treatment with transcranial direct current stimulation (tDCS) can reduce pain severity, improve pain-related disability, and enhance endogenous pain modulation in women with fibromyalgia, suggested the results of a clinical trial published in JAMA Network Open.

The study included 112 women between the ages of 18 years and 65 years with fibromyalgia. Half received anodal tDCS (A-tDCS), which applied 2 mA of electrical current through electrodes placed on the scalp over the left dorsolateral prefrontal cortex, for 20 minutes daily and 5 days per week. The other half used a lookalike sham device that did not deliver sustained stimulation. In addition, all participants completed exercise and pain neuroscience education. 

At the end of the 4-week treatment period, and after a 3-month follow-up, study participants rated their pain from 0 (none) to 10 (worst pain) for seven activities. Patients who used tDCS experienced an average 39% reduction in pain, and 62.5% of them had a 50% or more improvement in pain. In comparison, subjects who used the sham device experienced an average 16% reduction in pain. tDCS also reduced pain severity compared to sham treatment. 

“These results are consistent with evidence suggesting that stimulating the left dorsolateral prefrontal cortex enhances top-down control over pain, emotion, and cognitive processing,” said study author Wolnei Caumo, MD, PhD, professor of anesthesia and pain in the medical school at Federal University of Rio Grande do Sul, Porto Alegre, Brazil. “The moderate to large effect sizes observed reaffirm expectations about the clinical relevance of targeting the prefrontal cortex in fibromyalgia.”

How Does tDCS Reduce Fibromyalgia Pain? 

Prior research suggested that tDCS applies low-level electric currents to modulate neuronal excitability and neuroplasticity. Modulating activity in the brain’s dorsolateral prefrontal cortex in particular can enhance control over pain processing networks and reduce pain catastrophizing, Caumo said. “This region is implicated in both cognitive control and emotional regulation,” said E. Baron Short, MD, MSCR, a professor of psychiatry and medicine at the Medical University of South Carolina, Charleston, South Carolina. 

To understand how the placebo effect might influence the results, the patients had been randomly assigned to either treatment group and then stratified according to placebo test response; patients were evenly split between the A-tDCS and sham tDCS groups and between responders and nonresponders such that of the 56 placebo test nonresponders assigned to A-tDCS, 28 received sham treatment and 28 received active treatment, and of the 56 placebo test responders assigned to sham tDCS, 28 received sham treatment and 28 received active treatment. They found that placebo responses influenced pain intensity but not pain interference or psychosocial measures. 

“While a placebo can shape subjective pain perception, functional improvements require active neuromodulation,” Caumo said. “Moreover, placebo responders in the sham group regressed toward baseline at follow-up, while A-tDCS responders sustained their gains, highlighting the limited durability of placebo-only effects.”

In this study, tDCS didn’t act alone — the education and exercise that participants completed are also beneficial in fibromyalgia. 

“The evidence so far says that for chronic pain, the two therapeutic approaches that have the best evidence are pain science education and physical exercise,” said María Teresa Carrillo De La Peña, PhD, a professor of clinical psychology and psychobiology at the University of Santiago de Compostela, Santiago de Compostela, Spain, who studies novel treatments for chronic pain and cancer pain.

Exercise promotes the production of pain-relieving endorphins. And when patients learn about the brain’s role in pain perception and processing, they start paying more attention to the psychological and social factors that affect their pain, she said. 

“Sometimes patients think that their pain is in the knee or the back, and they are waiting for a solution for that,” she said. “Thanks to pain science education, we stress that we need to attend to the brain.”

How Could Patients Fit Home-Based tDCS Into Their Fibromyalgia Treatment Mix?

“Given the limited and often poorly tolerated options currently available for fibromyalgia, I do believe tDCS deserves serious consideration, particularly for patients who have not responded to conventional treatments or who struggle with medication side effects,” Baron said. “Its relative safety, ease of use, and the growing body of supportive evidence position it as a viable adjunctive treatment.”

The current study demonstrates that home-based tDCS is feasible, safe, and something patients stick with. The device used in the study was designed to be user-friendly with guidance from a healthcare professional who controls the electrode placement and timing settings. 

“It reduces transportation, cost, and time barriers, [which are] especially relevant for patients with chronic pain and mobility limitations,” Caumo said. “Additionally, the unsupervised model mimics real-world conditions and enhances scalability and autonomy, making it a cost-effective and patient-centered alternative to clinic-based sessions.”

Autonomy is powerful for patients with pain. “One of the most important things that we are seeing right now in the management of pain is that the patient takes this active role,” Carrillo De La Peña said.

This trial was supported by grants from the Brazilian National Council for Scientific and Technological Development, the Postgraduate Research Group at the 

Hospital de Clinicas de Porto Alegre, the Committee for the Development of Higher Education Personnel, and the US National Institutes of Health.  Caumo and a coauthor reported holding a pending patent for BR 20 2015 016450 0 U2 and receiving licensing royalties from Quark Medical. Carrillo De La Peña reported receiving research funding from the European Union. Short is a cofounder of Zendo Meditation and holder of patent 12257392.