Effect of tDCS in Intrinsic Functional Brain Connectivity Assessed by Functional Magnetic Resonance in Fibromyalgia

Considering the central component of fibromyalgia (FM), the focus of research on current therapeutic approaches has been techniques that may modify the dysfunctional neuroplasticity process, such as transcranial direct current (tDCS) stimulation in order to counteract the dysfunction responsible for triggering and maintain the symptoms of FM. Although this technique is gaining space in research and in the clinical scenario, many questions remain to be answered, such as time of treatment, place to be stimulated and neurophysiological clarification of the mechanisms involved. Based on the presented scenario, the present project was organized, being a double-blinded parallel randomized controlled trial with 20 female patients with FM diagnosed according to the criteria of the American Society of Rheumatology (2010 - reviewed in 2016) between 19 and 65 years of age, randomized to receive active or simulated anodic pole over the left dorsolateral prefrontal cortex (DLPFC) (10 patients in each group). Twenty 20-minute sessions, with a current intensity of 2 milliamperes, will be performed. In order to respond to the objectives of this study, the IFC will be evaluated before and after the intervention, through rs-fMRI using seed-based correlation analysis (SCA). The investigators have a secondary objective to correlate structural connectivity through the technique of diffusion tensors imaging (DTI) with measures of pain, functional capacity, depressive symptoms and catastrophism to pain. The hypothesis is that in FM there is a syndrome of dysfunction in basal intrinsic functional connectivity (IFC) and that the tDCS has a neuromodulatory effect capable of reducing connectivity between brain areas related to chronic pain and other neuropsychiatric components of FM, such as the ventrolateral thalamus, cortex motor, prefrontal cortex, insular cortex, hippocampus, periaqueductal gray matter, among others. The investigators believe that a higher cortico-thalamic IFC and betw