Transcranial Direct Current Stimulation in Patients With Disorders of Consciousness

Phase 2

Completed

Conditions: Disorders of Consciousness
Minimally Conscious State
Vegetative State

Brief Summary: 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.

Detailed Description: 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.

Recruitment & Eligibility

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)

Arm && Interventions

Group	Intervention	Description
Anodal tDCS	Anodal tDCS	Patients received anodal tDCS (on DLPF cortex) during 20 minutes preceded and followed by a clinical assessment (Coma Recovery Scale-Revised)
sham tDCS	sham tDCS	Patient received a sham tDCS (5sec of stimulation). The device runs during 20minutes and the anode was placed over the DLPF cortex. A behavioral assessment preceded and followed the stimulation.

Primary Outcome Measures

Name	Time	Method
Change in CRS-R Total Scores	Baseline and directly after the tDCS (20 minutes)	At the group level, assess the modification of CRS-R total scores in anodal tDCS as compared to sham stimulation in VS/UWS and MCS populations The Coma Recovery Scale Revised (CRS-R) is a behavioral scale performed at the patient's bedside. It consists of 23 hierarchically arranged items that comprise 6 subscales addressing auditory, visual, motor, verbal, communication, and arousal functions. Scoring is based on the presence or absence of specific behavioral responses to sensory stimuli administered in a standardized manner. Maximum scores of each subscale are summed to obtain the total score (from 0 to 23). The lowest item on each subscale represents reflexive activity, whereas the highest items represent cognitively mediated behaviors.

Secondary Outcome Measures

Name	Time	Method
Influence of Diagnosis on the Results	participants will be followed for the duration of 1 year
Influence of Etiology on the Results	participants will be followed for the duration of 1 year
Influence of Time Since Insult on the Results	participants will be followed for the duration of 1 year