In this multicentric double-blind sham controlled study, the investigators plan to assess the effects of 20 sessions of tDCS on long-term behavioral recovery in patients with disorders of consciousness. Neurophysiological outcomes (EEG) will also be collected.

This research will 1) determine whether long-term behavioral recovery can be promoted with tDCS and 2) generate knowledge regarding the impact of tDCS on neurophysiological outcome (i.e., EEG) in severely brain injured patients. The investigators will compare the effects of active and sham tDCS on behavioral assessments and quantitative EEG in patients with severe brain injury and its potential application in rehabilitation.

Inclusion Criteria:

• CNS medication stable for at least a week
• Stable diagnosis (no diagnosis change based on 2 CRS-R performed within 1 week).
• Between 3 and 24 months post injury
• Structural MRI or CT-scan (to evidence focal lesions on the left DLPFC)

Exclusion Criteria:

• Craniotomies encompassing the frontal region (electrodes location)
• VPS under the stimulated area (prefrontal cortex)
• Pacemaker
• Metallic cerebral implant
• Severe medical conditions that might influence clinical diagnosis and EEG activity (e.g., severe hepatic insufficiency or renal failure, or sub-continuous or abundant epileptiform discharges on standard EEG recordings).