Effects of tDCS on improving pain and depressive symptoms in people with fibromyalgia: A systematic review with meta-analysis.

Eduardo Henrique Loreti 1; Elaine Kakuta 1; Alisson Alexandre da Silva 1; Francisca Jessica Lima dos Santos Costa 1; Elisabete Castelon Konkiewitz 1

1. Centro Universitário da Grande Dourados (UNIGRAN)

OBJECTIVE: To investigate the level of evidence of the effects of transcranial direct current stimulation (tDCS) on pain, anxiety and depressive symptoms in patients with fibromyalgia (FMG), as well as define the most effective areas for stimulation.

METHODS: two independent reviewers selected randomized clinical trials form the MEDLINE, Web of Science and PEDro databases published between 2010 and 2020 and extracted the following items: sample size, stimulated brain area, tDCS parameters, electrode size, duration of treatment, evaluation scale and scores for pain, anxiety and depression before and after treatment. Afterwards, meta-analysis was performed using the RevMan 5.3 program. PROSPERO: CRD42020189944.

RESULTS: six studies were included in the review, totaling 225 individuals. Significant pain improvement was observed with anodal stimulation of areas M1 and DLPFC. No significant improvement in anxiety (IC-2,0:-7,95 a 3,95; z=66; p=0,51) and depressive (IC-0,36:-4,89 a 3,62; z=0,29; p=0,77) symptoms was observed with anodal stimulation of the M1 area.

CONCLUSIONS: tDCS is an interesting treatment possibility for pain management in patients with FMG. The effects of tDCS on improving anxiety and depressive symptoms need to be further investigated

 FIGURE. Summary effect size for relieving pain

A: Pain scores for anodal tDCS over DLPFC and ONS compared with sham tDCS, as analyzed with the fixed-effects model. B: Pain scores for tDCS over DLPFC compared with tDCS over ONS, as analyzed with the fixed-effects model. C: Pain score for anodal tDCS over M1 compared with sham tDCS, as analyzed with the random-effects model. AxC: tDCS over DLPFC compared with sham tDCS. BxC: tDCS over ONS compared with sham tDCS

KEYWORDS: Transcranial direct current stimulation. Chronic pain. Rehabilitation

ACKNOWLEDGMENTS: None

FUNDING/FINANCIAL SUPPORT: None

DOI: https://doi.org/10.21801/ppcrj.2020.S1.37