Transcranial direct current stimulation in patients with fibromyalgia syndrome

[eng] Fibromyalgia syndrome (FMS) is characterized by impaired sensory gating and deficient habituation. Despite advances in chronic pain management, current approaches remain limited in efficacy. The aim of this thesis is to examine the effects of tDCS on neurophysiological and clinical variables in patients with FMS with a specific focus on somatosensory gating. This research reveals critical gaps in the literature, including inconsistent findings on the efficacy of tDCS in FMS, variability in stimulation protocols, and limited understanding of its underlying mechanisms. It further demonstrates that tDCS over the somatosensory cortex modulates brain excitability, not only in healthy individuals - resulting in enhanced inhibitory mechanisms in response to repetitive somatosensory stimulation during later stages of information processing - but also in FMS patients, where it differentially enhances or reduces brain responses to repetitive touch. The significance of this research lies in demonstrating that tDCS can effectively alleviate FMS symptoms while targeting underlying neural mechanisms such as somatosensory gating. This highlights its potential as an adjunct therapy that addresses FMS symptoms on multiple levels, improving pain, mood, cognition, daily functioning, and overall quality of life.