Modified Non-invasive Brain Stimulation in Fibromyalgia

Fibromyalgia (FM) is one of the most difficult chronic pain syndromes to treat, affecting 3% to 5% of the world population [1,2]. It is characterized by musculoskeletal pain and muscle tenderness, accompanied by depression, sleep disorders, fatigue [3], cognitive and mood disturbances, and decreased physical function [4], which leads to a decreased quality of life. Although FM is well studied, little is known about its etiology. Recently, some studies have indicated that FM is a ‘‘dysfunctional pain syndrome’’, given the structural and neurochemical changes found in central pain pathways affecting pain modulatory systems [5-7]. Mhalla et al. [8] showed that FM is associated with impairment of intracortical modulation, which supports the hypothesis that FM is associated with changes in cortical excitability.