Open AccessEvoked and Event-Related Potentials as Biomarkers of Consciousness State and Recovery
Author(s) -
Estelle Pruvost-Robieux,
Angela Marchi,
Ilaria Martinelli,
Eléonore Bouchereau,
Martine Gavaret
Publication year - 2021
Publication title -
journal of clinical neurophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.657
H-Index - 99
eISSN - 1537-1603
pISSN - 0736-0258
DOI - 10.1097/wnp.0000000000000762
Subject(s) - persistent vegetative state , minimally conscious state , mismatch negativity , consciousness , coma (optics) , wakefulness , p3a , psychology , medicine , level of consciousness , etiology , neural correlates of consciousness , clinical neurophysiology , consciousness disorders , event related potential , neuroscience , electroencephalography , cognition , anesthesia , psychiatry , physics , optics
The definition of consciousness has been the subject of great interest for many scientists and philosophers. To better understand how evoked potentials may be identified as biomarkers of consciousness and recovery, the different theoretical models sustaining neural correlates of consciousness are reviewed. A multimodal approach can help to better predict clinical outcome in patients presenting with disorders of consciousness. Evoked potentials are inexpensive and easy-to-implement bedside examination techniques. Evoked potentials are an integral part of prognostic evaluation, particularly in cases of cognitive motor dissociation. Prognostic criteria are well established in postanoxic disorders of consciousness, especially postcardiac arrest but are less well determined in other etiologies. In the early examination, bilateral absence of N20 in disorder of consciousness patients is strongly associated with unfavorable outcome (i.e., death or unresponsive wakefulness syndrome) especially in postanoxic etiologies. This predictive value is lower in other etiologies and probably also in children. Both N20 and mismatch negativity are proven outcome predictors for acute coma. Many studies have shown that mismatch negativity and P3a are characterized by a high prognostic value for awakening, but some patients presenting unresponsive wakefulness syndrome also process a P3a. The presence of long-latency event-related potential components in response to stimuli is indicative of a better recovery. All neurophysiological data must be integrated within a multimodal approach combining repeated clinical evaluation, neuroimaging, functional imaging, biology, and neurophysiology combining passive and active paradigms.