Sub-study of the NEURODOC Project (Electrophysiological Evaluation of Consciousness in Patients With Disorders of Consciousness During Standard Care Procedures): Neurophysiological Evaluation of a Routine Care Open Label tDCS Session
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Disorder of Consciousness
- Sponsor
- Groupe Hospitalier Pitie-Salpetriere
- Enrollment
- 66
- Locations
- 1
- Primary Endpoint
- Support vector machine multivariate prediction of consciousness from resting state EEG markers
- Status
- Completed
- Last Updated
- 6 years ago
Overview
Brief Summary
Limited treatments are available to improve consciousness in severely brain injured patients. Transcranial Direct Current stimulation (tDCS) is one of the few therapeutics that showed evidence of efficacy to increase level of consciousness and functional communication in some Minimally Conscious State (MCS) patients, and in some Vegetative State (VS) patients.
However the mechanisms by which tDCS improves consciousness are poorly understood and the electrophysiological effects of such a stimulation have never been studied in disorders of consciousness patients.
In this study, the investigators will use detailed clinical examinations and electrophysiological assessments (quantitative high-density EEG and event-related potentials) to assess the effect of a open-label single session of left dorsolateral prefrontal cortex tDCS stimulation administered as routine care.
Detailed Description
Limited treatments are available to improve consciousness in severely brain injured patients. Transcranial Direct Current stimulation (tDCS) is one of the few therapeutics that showed evidence of efficacy to increase level of consciousness and functional communication in some Minimally Conscious State (MCS) patients, and in some Vegetative State (VS) patients (1, 2, 3, 4), with no side effects reported. However the mechanisms by which tDCS improves consciousness are poorly understood and the electrophysiological effects of the stimulation have never been studied in disorders of consciousness patients. In this study, the investigators will use detailed clinical examinations (Coma Recovery Scale - Revised (5)) and electrophysiological assessments (quantitative high-density EEG and event-related potentials) (6, 7) and event-related potentials (8, 9) together with a standard morphological MRI to assess the effect of a open-label single session of left dorsolateral prefrontal cortex tDCS stimulation administered as routine care. The primary goal is to investigate electrophysiological response to tDCS and its relation to behavioral response to better understand how tDCS affects consciousness in disorders of consciousness patients. References: 1. Angelakis, E. et al. Transcranial Direct Current Stimulation Effects in Disorders of Consciousness. Arch. Phys. Med. Rehabil. 95, 283-289 (2014). 2. Thibaut, A., Bruno, M.-A., Ledoux, D., Demertzi, A. \& Laureys, S. tDCS in patients with disorders of consciousness: sham-controlled randomized double-blind study. Neurology 82, 1112-1118 (2014). 3. Thibaut, A. et al. Controlled clinical trial of repeated prefrontal tDCS in patients with chronic minimally conscious state. Brain Inj. 1-9 (2017). doi:10.1080/02699052.2016.1274776 4. Martens, G. et al. Randomized controlled trial of home-based 4-week tDCS in chronic minimally conscious state. Brain Stimulat. (2018). doi:10.1016/j.brs.2018.04.021 5. Giacino, J. T. \& Kalmar, K. Diagnostic and prognostic guidelines for the vegetative and minimally conscious states. Neuropsychol. Rehabil. 15, 166-174 (2005). 6. Sitt, J. D. et al. Large scale screening of neural signatures of consciousness in patients in a vegetative or minimally conscious state. Brain 137, 2258-2270 (2014). 7. Engemann, D. A. et al. Robust EEG-based cross-site and cross-protocol classification of states of consciousness. Brain J. Neurol. 141, 3179-3192 (2018). 8. Bekinschtein, T. A. et al. Neural signature of the conscious processing of auditory regularities. Proc. Natl. Acad. Sci. 106, 1672-1677 (2009). 9. Faugeras, F. et al. Event related potentials elicited by violations of auditory regularities in patients with impaired consciousness. Neuropsychologia 50, 403-418 (2012).
Investigators
LIONEL NACCACHE
Professor
Groupe Hospitalier Pitie-Salpetriere
Eligibility Criteria
Inclusion Criteria
- •Age between 18 and 80 years
- •Disorder of consciousness assessed by CRS-R (VS, MCS, exitMCS)
- •Patients with stable clinical examination (even in intensive care unit)
- •Structural brain injury confirmed by cerebral imaging (MRI or TDM)
Exclusion Criteria
- •Refractory status epilepticus
- •Known preexisting severe neurodegenerative disease (ie: Alzheimer disease, Lewy body dementia, ...)
- •MRI contraindication: metallic intra-cranial implants, pacemaker or implantable cardioverter-defibrillator, cranial prosthesis
- •Pregnant, parturient or breastfeeding women
Outcomes
Primary Outcomes
Support vector machine multivariate prediction of consciousness from resting state EEG markers
Time Frame: Two time points: immediately before (baseline) and immediately after stimulation (post-stimulation)
Change from baseline of the predicted probability of conscious state, ie. to be classified a in a 'minimally conscious state' as opposed to be classified as in a 'vegetative state'. The prediction will be based on a set of markers extracted from the EEG (power spectra, information theory, complexity and connectivity markers) and will use a support vector machine classifier algorithm train on a validated database. See Sitt et al., Brain et al. 2014. for details on the EEG preprocessing, markers extraction, support vector machine algorithm and training database.
Evoked response potential during auditory oddball paradigm
Time Frame: Two time points: immediately before (baseline) and immediately after stimulation (post-stimulation)
Change of the Evoked Response Potentials recorded during the auditory oddball paradigm
Secondary Outcomes
- Resting state EEG individual markers(Two time points: immediately before (baseline) and immediately after stimulation (post-stimulation))
- State of consciousness(Two time points: immediately before (baseline) and immediately after stimulation (post-stimulation))