General study methodology
drowsiness
This is a French bicentre (Clinique Bretéché and CHU/University Hospital Nantes), randomized, comparative, double-blind, sham-controlled trial conducted in two parallel arms: tDCS (35 patients) and sham tDCS (35 patients).Centralized randomization will be performed by software and will be specific to each of the 2 centres. Patients will not be informed about whether they have been allocated to the active tDCS arm or the sham tDCS arm. Physicians performing the tDCS technique and the evaluating physicians will also be blinded to the type of treatment delivered (see “Interventions: tDCS and follow-up intervention”).Doses of analgesic medications (opioids, antiepileptics and antidepressants) must be stable for at least 48 hours (D-3, D0) prior to inclusion in the study. The level of analgesic treatment will be assessed by MQS. Analgesic doses may be able to be decreased from the first day of tDCS depending on its analgesic effect. One of the objectives of tDCS is to decrease the doses of analgesics in order to avoid a state of drowsiness or torpor associated with impaired quality of life.