Table 1.

Study inclusion and exclusion criteria.

Inclusion criteria	Exclusion criteria
•Age: > 18 years old •Diagnosed in UWS or MCS as defined by the two CRS-R assessments performed during the screening period •Acquired cerebral damage of known etiology •From 7 to 90 days since injury •Intact ear skin •Informed consent given by the substitute decision maker	•Anyone who is deemed medically too unstable for this study by a physician •Documented pregnancy •Active implant (e.g., pacemaker, cochlear implant…) •History of previous neurological disorder prior to the brain injury •Deep sedation such as one caused by general anaesthetics (e.g., propofol) or a combination of central acting sedatives (e.g., benzodiazepines, opioids)

UWS: unresponsive wakefulness syndrome; MCS: minimally conscious state; CRS-R: Coma Recovery Scale-Revised.