The purpose of this study is to assess the effects on fatigue and sleep of Unihemispheric Concurrent Dual-Site anodal Transcranial Direct Current Stimulation combined with therapeutic exercise in Fibromyalgia patients.

Fibromyalgia (FM) is one of the rheumatic diseases with the greatest impact on the quality of life, whose etiology and pathophysiology is not yet fully demonstrated.

Perhaps this is why its therapeutic approach is refractory to current treatments.

Apart from the widespread chronic pain characteristic of this syndrome, fatigue is a very disabling symptom in this pathology. It is a complicated, multifactorial, disconcerting and very persistent symptom that is highly frequent in FM. A vast majority of the published studies have focused the symptoms studied in FM on pain, while fatigue and sleep disturbances, despite not being minor symptoms, have not received the same attention.

Neuromodulation treatments with transcranial direct current stimulation (tDCS) have been shown to induce significant analgesia in FM through modification of sensory processing of pain by thalamic inhibitory circuits and improvement of sleep architecture. On the other hand, therapeutic exercise (TE) programs based on aerobic work and global muscle strengthening have been shown to have a beneficial effect in reducing the pain and severity of FM.

None of the four studies conducted so far combining tDCS and TE in fibromyalgia have evaluated the effect on fatigue or sleep. Currently, various studies conclude that Unihemispheric Concurrent Dual-Site anodal Transcranial Direct Current Stimulation (UHCDS a-tDCS) on the dorsolateral prefrontal cortex (DLPFC) and M1 produces a 50% greater modulation of corticospinal excitability. To date, no RCT has studied its effect in subjects with FM.

The present study aims to investigate the effect of UHCDS a-tDCS combined with TE on fatigue and sleep quality in subjects with FM.

Inclusion Criteria:

• Age between 18 and 65 years.
• Fulfilled the 2010 American Colleague of Rheumatology criteria for fibromyalgia.
• Able to participated in a therapeutic exercise program.
• Understanding of spoken and written Spanish.

Exclusion Criteria:

• Pregnancy or breastfeeding.
• Metallic implants in the head.
• Tumor, trauma or surgery in the brain.
• Epilepsy or stroke.
• History of substance abuse in the last 6 months.
• Use of carbamazepine in the last 6 months.
• Diagnosed psychiatric pathology.
• Rheumatic pathology not medically controlled.
• Coexisting autoimmune pathology.
• Chronic inflammatory disease (rheumatoid arthritis, erythematosus systemic lupus, inflammatory bowel disease).