Fig. 1

Study plan: the study will last 24 days (D-3 to D21) including a 3-day inclusion period (D-3-D0), a 5-day treatment period (D0-D4) and a 16-day follow-up period after stopping treatment (D8, D14, D21). Treatment consists of a daily tDCS session on 5 consecutive days. Patients will be randomized to 2 arms (1:1 ratio): active tDCS and sham tDCS. Patients and investigators will be blinded to the results of randomization (double-blind). The primary objective will be a significant reduction of pain evaluated by a numerical rating scale (NRS) from 0 to 10 between the baseline score recorded between D-3 and D0 and the score recorded 4 days after stopping treatment (D8)