Transcranial direct current stimulation unveils covert consciousness

Thanks to modern neuroimaging techniques it appears that 30% of clinically unresponsive patients (i.e., unresponsive wakefulness syndrome – UWS [1]) retain cerebral functions that are similar to patients in a minimally conscious state – MCS [1], as assessed by fluorodeoxyglucose positron emission tomography (FDG-PET), functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). These patients are newly labeled as MCS* or with cognitive-motor dissociation [2,3]. Even if the majority of them will regain some signs of consciousness, techniques to promote their recovery are still lacking.