Investigation of the Efficacy of tDCS in the Treatment of Complex Regional Pain Syndrome (CRPS) Type 1

TDCS was delivered according to the method described by Fregni et al. (2006) and the safety parameters related to tDCS application were respected (DaSilva et al., 2011). Direct current was delivered using a battery-driven constant current stimulator coupled to saline-soaked (0.9% NaCl) sponge electrodes (5 X 7 cm). Anodal stimulation was delivered over the M1; the anode was placed over C3 or C4 position in the 10/20 system for the EEG electrode position, contralateral to the affected limb, and the cathode over the opposite supraorbital area (i.e. ipsilateral to the affected limb). In the laboratory, a constant current of an intensity of 2 mA was applied for 20 min/day X 5 consecutive days during the first and the second weeks of GMI. To help maintain the potential effects of the neurostimulation, the tDCS was also applied simultaneously with GMI once a week during the 2 other phases until the end of the six weeks GMI program, for a total of 14 treatment sessions.

The treatment was performed using a software (Recognise™ online) provided by NOI group (http://www.noigroup.com/recognise). As an alternative to the software (for patients without an internet access), the patient could do the exercises with a Recognise™ Flash Cards set consists of 25 left and 25 right matching images (upper limb or lower limb). Using standardized procedures, inspired from the randomized controlled trial conducted by Moseley (2004, 2006), the participants performed the therapy at home, 10 minutes per session, 3x/day, 6 days/week, using the computer software and a mirror box (Lagueux et al., 2012).