TMS-EEG; anesthesia; anterior–posterior gradient; severe brain injury; spectral exponent; Cellular and Molecular Neuroscience; Cognitive Neuroscience
Abstract :
[en] Neurophysiological markers can overcome the limitations of behavioural assessments of Disorders of Consciousness (DoC). EEG alpha power emerged as a promising marker for DoC, although long-standing literature reported alpha power being sustained during anesthetic-induced unconsciousness, and reduced during dreaming and hallucinations. We hypothesized that EEG power suppression caused by severe anoxia could explain this conflict. Accordingly, we split DoC patients (n = 87) in postanoxic and non-postanoxic cohorts. Alpha power was suppressed only in severe postanoxia but failed to discriminate un/consciousness in other aetiologies. Furthermore, it did not generalize to an independent reference dataset (n = 65) of neurotypical, neurological, and anesthesia conditions. We then investigated EEG spatio-spectral gradients, reflecting anteriorization and slowing, as alternative markers. In non-postanoxic DoC, these features, combined in a bivariate model, reliably stratified patients and indexed consciousness, even in unresponsive patients identified as conscious by an independent neural marker (the Perturbational Complexity Index). Crucially, this model optimally generalized to the reference dataset. Overall, alpha power does not index consciousness; rather, its suppression entails diffuse cortical damage, in postanoxic patients. As an alternative, EEG spatio-spectral gradients, reflecting distinct pathophysiological mechanisms, jointly provide a robust, parsimonious, and generalizable marker of consciousness, whose clinical application may guide rehabilitation efforts.
Disciplines :
Neurology
Author, co-author :
Colombo, Michele Angelo ✱; Department of Biomedical and Clinical Sciences, University of Milan, Milan 20157, Italy
Comanducci, Angela ✱; IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy ; Department of Engineering, Università Campus Bio-Medico di Roma, Rome 00128, Italy
Casarotto, Silvia; Department of Biomedical and Clinical Sciences, University of Milan, Milan 20157, Italy ; IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
Derchi, Chiara-Camilla; IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
Annen, Jitka ; Université de Liège - ULiège > GIGA > GIGA Consciousness - Coma Science Group
Viganò, Alessandro; IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
Mazza, Alice; IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
Trimarchi, Pietro Davide; IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
Boly, Mélanie ; Université de Liège - ULiège > Département des sciences cliniques > Neurologie ; Department of Neurology and Department of Psychiatry, University of Wisconsin, Madison, WI 53705-2281, USA
Fecchio, Matteo; Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
Bodart, Olivier ; Centre Hospitalier Universitaire de Liège - CHU > > Service de neurologie
Navarro, Jorge; IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
Laureys, Steven ; Centre Hospitalier Universitaire de Liège - CHU > > Centre du Cerveau²
Gosseries, Olivia ; Université de Liège - ULiège > GIGA > GIGA Consciousness - Coma Science Group
Massimini, Marcello; Department of Biomedical and Clinical Sciences, University of Milan, Milan 20157, Italy ; IRCCS, Fondazione Don Carlo Gnocchi Onlus, Milan 20148, Italy
Sarasso, Simone; Department of Biomedical and Clinical Sciences, University of Milan, Milan 20157, Italy
Rosanova, Mario; Department of Biomedical and Clinical Sciences, University of Milan, Milan 20157, Italy
Fondazione Fratelli Giuseppe-Vitaliano, Tullio e Mario Confalonieri [IT] Italian Ministry of Health [IT] FRB - Fondation Roi Baudouin [BE] AstraZeneca [BE] FERB - Fondazione Europea Ricerca Biomedica [IT] F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE] Tiny Blue Dot Foundation [US-CA] [US-CA] EU - European Union [BE]
Funding text :
European Union’s Horizon 2020 Framework Program for Research and Innovation under the Specific Grant Agreement No.945539 (Human Brain Project SGA3) (to MM, MR, and SL); Fondazione Regionale per la Ricerca Biomedica (Regione Lombardia), Project Per Brain, call ERAPERMED2019–101, GA779282 (to MR and AC); Italian Ministry of Health (“Ricerca Corrente 2022”) to AC, CD, and AM; Tiny Blue Dot Foundation (toMM); Belgian National Funds for Scientific Research (F.R.S-FNRS; to SL and OG); Fondazione Europea di Ricerca Biomedica (to SL); BIAL Foundation (to SL and OG); AstraZeneca (to OG); Foundation Roi Baudouin (to SL); Italian Ministry of Health, GR−2016–02361494 (to SC); Fondazione Fratelli Giuseppe Vitaliano, Tullioe Mario Confalonieri (toMAC).
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