Transcranial direct current stimulation (tDCS) to the primary motor cortex reduces pain intensity and fatigue and improves quality of life short-term in women with fibromyalgia, according to study findings published in Neuromodulation.
Researchers in Brazil conducted a triple-blind, randomized controlled trial with a 3-month follow-up period into which they enrolled 35 women diagnosed with fibromyalgia between the ages of 18 and 59 to analyze the effects of 10 sessions of tDCS on pain, fatigue, and quality of life in this patient population.
A blinded therapist randomly divided the 35 women into 2 groups: 17 into the treatment group receiving tDCS and 18 into the control group receiving a sham treatment. No significant differences between groups were detected regarding age or sociodemographics.
Treatment and placebo sessions took place on 5 consecutive days with 2 rest days followed by another 5 consecutive days. Active treatment with tDCS involved anodal electrical stimulation of the primary motor cortex with 2mA of direct current for 13 minutes followed by a 20-minute pause followed by a second round of stimulation at the same intensity for another 13 minutes (13:20:13). The sham treatment followed a similar 13:20:13 pattern; however, the device was programmed to shut off the current application 30 seconds after initiation.
To study how the active tDCS intervention affected different symptoms experienced by women with fibromyalgia compared with placebo, the researchers collected baseline data on:
- patient pain levels using the visual analog scale (VAS);
- patient attitudes toward chronic pain using the Portuguese version of the Survey of Pain Attitudes (SOPA-B);
- the impact of fibromyalgia on quality of life using the fibromyalgia Impact Questionnaire (FIQ);
- overall perceptions of quality of life using the World Health Organization’s Quality of Life Questionnaire (WHOQOL);
- anxiety using the Hamilton Anxiety Rating Scale (HAM-A);
- depression using the Hamilton Depression Rating Scale (HAM-D); and
- the impact of fibromyalgia on fatigue levels using the Fatigue Assessment Scale (FAS).
Researchers collected these measurements again on day 10 after the last intervention and during the follow-up period on day 30 and day 90. Pain intensity was also collected every day prior to intervention.
Women who received the active tDCS reported decreased pain levels compared with the placebo group after 10 sessions (difference between groups = -4.309; P <.001) with long lasting effects of the intervention reported on days 30 (difference: -5.614; P <.01) and 90 (difference: -5.599; P <.001). Pain intensity scores were also significantly reduced from baseline levels in the women who received active treatment with tDCS.
Not only did tDCS decrease pain due to fibromyalgia, it also improved the patients’ attitudes toward chronic pain in multiple domains, including perceptions on disability, medications, medical cures, and solicitude after 10 sessions compared with those in the placebo group. Prolonged impact of the treatment was maintained in several of these domains on days 30 and 90.
Additionally, women in the active treatment group reported decreased fatigue levels compared with the placebo group on days 10 (difference between groups: -4.426; P <.001) and 30 (difference: -4.216; P <.01). This effect did not carry over to day 90.
Quality of life improved for women in the active tDCS group according to better scores on both the FIQ and WHOQOL questionnaires. The women treated with active tDCS reported improved physical, psychological, and social functioning.
Researchers did not observe any statistical difference between the active and sham treatment groups in the reduction of anxiety and depression on days 10, 30, and 90.
“The results of this study suggest that active tDCS with an intensity of 2 mA for ten sessions was effective in decreasing pain and fatigue and improving QoL in patients with FM [fibromyalgia]” the researchers noted. “Patients did not experience serious adverse reactions, indicating that the proposed protocol was well tolerated,” they added.
Study limitations included lack of a standardized adverse event questionnaire, use of a uniform dose for all patients, which may not be the optimal treatment dosage for each patient, and potential confounding factors surrounding inclusion of only women in the study. Another limitation was the relatively short-term follow-up period of 3 months, leading to the question of whether treatment of fibromyalgia with tDCS has a longer carry-over of effects.
This article originally appeared on Neurology Advisor
Loreti EH, Freire AM, Alexandre da Silva A, Kakuta E, Martins Neto UR, Konkiewitz EC. Effects of anodal transcranial direct current stimulation on the primary motor cortex in women with fibromyalgia: a randomized, triple-blind clinical trial. Neuromodulation. S1094-7159(22)01370-8. doi:10.1016/j.neurom.2022.11.007