Table 1 Disorders of consciousness considered in the present paper (see [9, 10])

Vegetative state/Unresponsive wakefulness syndrome

Wakefulness accompanied by the absence of any sign of awareness

Minimally conscious state

Wakefulness accompanied by inconsistent but reproducible behavioural signs of awareness

Cognitive motor dissociation

Retained but unrecognized (covert) cognitive capacity for cerebral response to command in absence of purposeful behaviour