Complex Regional Pain Syndrome (CRPS)

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 study aims to evaluate the representation of action peripersonal space (PPS) in subjects suffering from unilateral segmental exclusion syndrome of the upper limb compared to healthy control subjects. Segmental exclusion is defined by non-use or under-use of a limb segment without central nervous system damage. The study hypothesizes that this syndrome leads to a modification (shrinkage) of the PPS representation. Participants will perform reachability judgments in a Virtual Reality (VR) environment.

This research study looks at the feasibility of using a new treatment, noninvasively activating the brain through repetitive transcranial magnetic stimulation (rTMS) to treat pain symptoms of complex regional pain syndrome (CRPS). This study will help us determine if this technique is feasible (able to recruit participants and if the research activities are feasible and can be used to treat CRPS patients with pain in a larger study. The investigators will also examine how TMS can be personalized to individuals using an individual's brain activity measured using EEG. The investigators will also study whether the effects of TMS are stronger if the TMS is delivered during a specific timing of the EEG activity.