Clinical Research Directory

Inclusion Criteria: * Clinically stable * Diagnosis of UWS or MCS based on repeated "coma recovery scale-revised) (CRS-R) or SECONDs * More than 28 days post-insult * Informed consent from the legal representative of the patient Exclusion Criteria: * Neurological medications other than anti-spasticity drugs in the last 2 weeks or 4 half-lives * Previous neurological functional impairment other than related to their DoC * A history of psychotic disorders * Contraindication to MRI, EEG, PET or TMS * Use of nitrates or other vasodilators, central nervous system acting agents such as barbiturates, morphine and related drugs. * Use of drugs known to interact with ketamine (i.e., CYP3A4, diazepam, ...) * Coronary insufficiency * Other sympathomimetic drugs