Transcranial direct current stimulation (tDCS) is a non-invasive therapy increasingly used in facilities treating patients with chronic pain. This complementary therapy has the advantage of being non-pharmacological, with transient and mild side effects, an excellent safety profile, and good efficacy in the contexts where it has been the subject of dedicated research: neuropathic pain, fibromyalgia, and visceral pain. Few studies have focused on the application of tDCS in the context of complex regional pain syndrome (CRPS), which is a common condition.

This protocol aims to compare a group receiving a tDCS protocol with a sham control group. The hypothesis of this study is that tDCS is effective in treating CRPS in terms of reducing pain and the functional and emotional consequences of pain.

The primary objective of the study is to evaluate the effectiveness of tDCS on pain in patients with CRPS (complex regional pain syndrome), measured by the numerical pain scale (EN), after one month of treatment and one month after the end of treatment, compared to the sham arm.

The secondary objectives are:

• To assess anxiety and depression symptoms (HAD)
• To assess the functional impact of pain (Concise Pain Questionnaire - QCD)
• To assess central sensitization (Central Sensitization Inventory - CSI)
• To identify adverse effects related to tDCS

Inclusion Criteria:

• Major
• Clinically active or active complex regional pain syndrome (CRPS) with positive Budapest criteria
• Scintigraphy showing signs consistent with CRPS
• Being affiliated with or a beneficiary of a social security scheme

Exclusion Criteria:

• Algodystrophy no longer meeting the Budapest criteria
• Relative contraindication to tDCS: psychosis (including treated psychosis), uncontrolled epilepsy, large scalp scar, intracerebral/intracranial metallic body
• Pregnant or breastfeeding women
• Minors
• Persons under legal protection (guardianship, conservatorship, and protective supervision)
• Persons deprived of their liberty by judicial or administrative order
• Unwilling individuals who cannot give their consent or cannot return for scheduled visits according to the protocol