Transcranial Direct Current Stimulation in Patients With Disorders of Consciousness

Transcranial Direct Current Stimulation in Patients With Disorders of Consciousness: a Sham-controlled Randomised Double Blind Study

Previous studies showed that anodal transcranial direct current stimulation (tDCS) applied to the left dorsolateral prefrontal (DLPF) cortex transiently improves performance of memory and attention. Investigator assessed the effects of left DLPF-tDCS on Coma Recovery Scale-Revised (CRS-R) scores in severely brain damaged patients with disorders of consciousness in a double-blind sham-controlled experimental design.

Following severe brain damage and coma, some patients may remain in a vegetative state (VS) or minimally conscious state (MCS). At present, there are no evidence-based guidelines regarding the treatment of patients with disorders of consciousness (DOC).

Investigator aim to assess the effect of single session anodal (i.e., excitatory) transcranial direct current stimulation (tDCS) of the left dorsolateral prefrontal cortex (DLPF) on the level of consciousness in DOC patients in a double blind randomized sham controlled study.

tDCS is a form of safe non-invasive cortical stimulation, modulating cortical excitability at stimulation sites via weak polarizing currents, previously reported to transiently improve working memory and attention by stimulating the left DLPF in healthy subjects and patients with stroke, Parkinson's or Alzheimer's disease.

Inclusion Criteria:

• post-comatose patients
• patients in vegetative/unresponsive or minimally conscious state
• patients with stable cardiorespiratory parameters
• patients free of sedative drugs and Na+ or Ca++ channel blockers (e.g., carbamazepine) or NMDA receptor antagonists (e.g., dextromethorphan)

Exclusion Criteria:

• premorbit neurology antecedent
• patients in coma or <1week after the acute brain insult
• patients with a metallic cerebral implant or a pacemaker (in line with the safety criteria for tDCS in humans)