Bilateral M1 anodal transcranial direct current stimulation in post traumatic chronic minimally conscious state: a pilot EEG-tDCS study

ABSTRACTObjective: We tested the preliminary effects of bilateral anodal transcranial direct current stimulation (tDCS) in patients with disorders of consciousness.Design: Open label pilot study.Subjects: Ten chronic (greater than 12 months) patients in a minimally conscious state (MCS) following severe traumatic brain injury.Methods: The patients received 10 sessions of bilateral M1 anodal tDCS. Behavioural changes were assessed with the Coma Recovery Scale-Revised (CRS-R) before stimulation (T-1, T0), after five sessions (T1), at the end of the stimulation (T2), after two weeks (T3) and after three months (T4). Moreover, an EEG assessment was conducted.Results: Eight out of 10 patients showed new clinical signs of consciousness; specifically, a 2-point CRS-R improvement was detected in the last follow-up (p = 0.004). EEG upper α bandwidth was greater in the parietal site at T1 (p < 0.034). In addition, we found a significant correlation between behavioral and EEG indices at T1 (r =  0.89; p =  0.001).Co...