Title:
Consciousness and Complexity during Unresponsiveness Induced
by Propofol, Xenon, and Ketamine.
Authors:
Sarasso S; Boly M; Napolitani M; Gosseries O; Charland-Verville V;
Casarotto S; Rosanova M; Casali AG; Brichant JF; Boveroux P; Rex S;
Tononi G; Laureys S; Massimini M. Institution Sarasso,Simone. Dipartimento di Scienze Biomediche e Cliniche “L. Sacco”, Universita degli Studi di Milano, 20157 Milan, Italy. Boly,Melanie. Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA; Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA.
Napolitani,Martino. Dipartimento di Scienze Biomediche e Cliniche “L.
Sacco”, Universita degli Studi di Milano, 20157 Milan, Italy; Dipartimento di Scienze Clinico-chirurgiche, Diagnostiche e Pediatriche, Sezione di Anestesia Rianimazione e Terapia Antalgica, Universita degli Studi di Pavia, SC Anestesia e Rianimazione, Fondazione IRCCS Policlinico S. Matteo, 27100 Pavia, Italy. Gosseries,Olivia. Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA; Coma Science Group, University and University Hospital of Liege, GIGA-Research B34, 4000 Liege, Belgium. Charland-Verville,Vanessa. Coma Science Group, University and University Hospital of Liege, GIGA-Research B34, 4000 Liege, Belgium. Casarotto,Silvia. Dipartimento di Scienze Biomediche e Cliniche “L. Sacco”, Universita degli Studi di Milano, 20157 Milan, Italy. Rosanova,Mario. Dipartimento di Scienze Biomediche e Cliniche “L. Sacco”, Universita degli Studi di Milano, 20157 Milan, Italy.
Casali,Adenauer Girardi. Institute of Science and Technology, Federal
University of Sao Paulo, 12231-280 Sao Jose dos Campos, Brazil. Brichant,Jean-Francois. Department of Anesthesia and Intensive Care Medicine, CHU Sart Tilman University Hospital, University of Liege, 4000 Liege, Belgium. Boveroux,Pierre. Department of Anesthesia and Intensive Care Medicine, CHU Sart Tilman University Hospital, University of Liege, 4000 Liege, Belgium. Rex,Steffen. Department of Anaesthesiology, University Hospitals of the KU Leuven, KU Leuven, 3000 Leuven, Belgium; Department of Cardiovascular Sciences, University Hospitals of the KU Leuven, KU Leuven, 3000 Leuven, Belgium. Tononi, Giulio. Department of Psychiatry, University of Wisconsin-Madison,
Madison, WI 53719, USA. Laureys,Steven. Coma Science Group, University and University Hospit al of Liege, GIGA-Research B34, 4000 Liege, Belgium. Electronic address: steven.laureys@ulg.ac.be
Massimini,Marcello. Dipartimento di Scienze Biomediche e Cliniche “L.
Sacco”, Universita degli Studi di Milano, 20157 Milan, Italy; Istituto Di
Ricovero e Cura a Carattere Scientifico, Fondazione Don Carlo Gnocchi,
20148 Milan, Italy. Electronic address: marcello.massimini@unimi.it
.
Title:
Consciousness and Complexity during Unresponsiveness Induced
by Propofol, Xenon, and Ketamine.
Comments:
Comment in: Curr Biol. 2015 Dec 7;25(23):R1140-2; PMID: 26654376
Source:
Current Biology. 25(23):3099-105, 2015 Dec 7.
Abstract:
A common endpoint of general anesthetics is behavioral unrespon
siveness, which is commonly associated with loss of consciousness.
However, subjects can become disconnected from the environment while still having conscious experiences, as demonstrated by sleep states associated with dreaming. Among anesthetics, ketamine is remarkable in that it induces profound unresponsiveness, but subjects often report “ketamine dreams” upon emergence from anesthesia. Here, we aimed at assessing consciousness during anesthesia with propofol, xenon, and ketamine, independent of behavioral responsiveness. To do so, in 18 healthy volunteers, we measured the complexity of the cortical response to transcranial magnetic stimulation (TMS)–an approach that has proven helpful in assessing objectively the level of consciousness irrespective of sensory processing and motor responses. In addition, upon emergence from anesthesia, we collected reports about conscious experiences during unresponsiveness. Both frontal and parietal TMS elicited a low-amplitude
electroencephalographic (EEG) slow wave corresponding to a local pattern of cortical activation with low complexity during propofol anesthesia, a high-amplitude EEG slow wave corresponding to a global, stereotypical pattern of cortical activation with low complexity during
xenon anesthesia, and a wakefulness-like, complex spatiotemporal activation pattern during ketamine anesthesia. Crucially, participants reported no conscious experience after emergence from propofol and xenon anesthesia, whereas after ketamine they reported long, vivid dreams unrelated to the external environment. These results are relevant because they suggest that brain complexity may be sensitive to the presence of disconnected consciousness in subjects who are considered unconscious based on behavioral responses.
Copyright:
2015 Elsevier Ltd. All rights reserved.
Publication Type:
Journal Article. Research Support, Non-U.S. Gov’t.
