Functional Neuroimaging in Fibromyalgia Patients Receiving tDCS

Study of the Brain With Optic Functional Neuroimaging in Patients With Chronic Pain Using Transcranial Direct Current Stimulation

The purpose of this study is to evaluate effectiveness and cerebral neuronal ability to adaptation in patients with fibromyalgia who receive pregabalin and transcranial direct current stimulation.

Fibromyalgia syndrome occurs in around 2% of the population (predominantly women), and is characterized by its poor response to conventional therapies. Therapeutic approaches modulating inhibitory pathways, including pharmacologic options as pregabalin, and non pharmacological ones as transcranial direct current stimulation (tDCS) have been proven to be of limited utility independently. Aiming to evaluate a better understanding of the pathophysiogenic mechanisms and the effect of these treatments on neuroplasticity, this study was designed evaluating neurophysiologic, neurochemical and clinical parameters. Neurophysiologic parameters and functions to be assessed will include pain threshold, motor evoked potential, silent period, intracortical facilitation and inhibition assessed by Transcranial Magnetic Stimulation (TMS) and optic functional neuroimaging. Neurochemical measurements considered will be neurotrophins (BDNF) and inflammatory mediators (TNF, IL1, IL6, IL10 and cortisol). Clinical characteristics will be assessed using validated scales capable to detect functional capacity, quality of life (WHOCOHL), catastrophism, sleep disruptions (Pittsburgh) and depressive symptoms (Beck Depression Inventory). Considering the above described hypothesis, the present randomized clinical trial with blinded patients and evaluators is proposed. It pretends to analyze short-, mid- and long-term neurobiological mechanisms triggered by the selected interventions.

Inclusion Criteria:

• - Diagnosis of fibromyalgia according to the American College of Rheumatology criteria

Exclusion Criteria:

• Psychiatric or neurologic disorder that unable patient to consent and follow study protocol.
• De-compensated systemic disease.
• Chronic inflammatory disease (e.g. Systemic Lupus Erythematous, Rheumatoid Arthritis).