High-definition transcranial direct current stimulation (HD-tDCS) has been found to provide pain relief in individuals with fibromyalgia, according to research published in The Journal of Pain.
The phase 2 study conducted by Laura Castillo Saavedra and colleagues from the Spaulding Rehabilitation Hospital in Cambridge, Massachusetts, aimed to establish the number of HD-tDCS sessions needed to achieve a 50% reduction in pain in patients with fibromyalgia. They estimated 15 as the mean number of sessions to achieve this goal, with benefits increasing in a cumulative effect with multiple sessions.
The researchers recruited 20 participants (17 female, 3 male; mean age 49.5 years) who were asked to remain in treatment until a clinically meaningful reduction in pain was achieved for a maximum of 6 weeks of treatment. A clinically meaningful reduction in pain was defined as a 50% reduction or more in Visual Analog Scale (VAS) pain scores compared to baseline.
All participants were scheduled to complete 10 HD-tDCS sessions in the first two weeks, after which their pain responses were assessed. Once participants met the criteria for clinical response, they were deemed responders, and follow-up HD-tDCS sessions were discontinued.
Those who did not meet the criteria of a 50% reduction in pain were deemed nonresponders and received 5 HD-tDCS sessions during the third week. They then received 5 additional HD-tDCS sessions during the fourth week, 3 during the fifth week, and up to 3 during the sixth week, following which the sessions ended regardless of response.
At the end of the sixth week of treatment, 7 participants were responders, with a median time to response of 15 visits; 6 participants dropped out of the study and 1 participant was a nonresponder.
“With these encouraging results, a future phase 3 study should aim to increase adherence to the 6 weeks of treatment, to rule out that the observed benefits were a result of selective attrition,” wrote Dr Saavedra.
“We did not exhaust the list of potential predictors that could be associated with response to HD-tDCS,” she added. “Further studies should address, for instance, the effects of HD-tDCS stimulation protocols on neuropsychological markers, including attention, in patients with fibromyalgia.”
Saavedra LC, Gebodh N, Bikson M, et al. Clinically effective treatment of fibromyalgia pain with HD-tDCS – phase II open-label dose-optimization. J Pain. 2015; doi:10.1016/j.jpain.2015.09.009.