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Hansen E. Touching the unconscious in the unconscious - hypnotic communication with unconscious patients. Front Psychol 2024; 15:1389449. [PMID: 38966734 PMCID: PMC11223660 DOI: 10.3389/fpsyg.2024.1389449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 05/30/2024] [Indexed: 07/06/2024] Open
Abstract
If hypnosis means contact to the unconscious to modulate psychological and physiological functions by means of suggestions, and if this is facilitated by attenuation of the critical mind, then the question arises as to whether suggestions also have an effect when waking consciousness is otherwise eliminated, namely by coma or anesthesia. A prerequisite would be perception, which actually is evidenced by reports of patients after traumatic brain injury, artificial coma, resuscitation or general anesthesia. Moreover, posttraumatic stress disorder (PTSD) frequently observed after these medical situations is hardly explainable without some sort of awareness under such conditions. Even advanced neurophysiological diagnostic cannot yet rule out consciousness or sensory processing. Especially reference to perception during unconsciousness is given by the results of a recent multicenter study on the effects of hypnotic communication with patients under controlled adequate deep general anesthesia. The observed reductions in incidence and severity of postoperative pain, opioid use, nausea and vomiting cannot be explained by the reaction of a few but only by a considerable proportion of patients. This leads to a strong plea for a more careful treatment of unconscious patients in the emergency room, operating theater or intensive care unit, for the abandonment of the restriction of therapeutic communication to awake patients, and for new aspects of communication and hypnosis research. Obviously, loss of consciousness does not protect against psychological injury, and continuation of communication is needed. But how and what to talk to unconscious patients? Generally addressing the unconscious mind with suggestions that generally exert their effects unconsciously, hypnotic communication appears to be the adequate language. Especially addressing meaningful topics, as derived from the basic psychological needs and known stressors, appears essential. With respect to negative effects by negative or missing communication or to the proposed protective and supporting effects of therapeutic communication with patients clinically rated as unconscious, the role of consciousness is secondary. For the effects of perceived signals and suggestions it does not matter whether consciousness is absent, or partial, or unrecognized present.
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Affiliation(s)
- Ernil Hansen
- Department of Anesthesiology, University Hospital Regensburg, Regensburg, Germany
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Shumikhina SI, Kozhukhov SA, Bondar IV. Dose-dependent changes in orientation amplitude maps in the cat visual cortex after propofol bolus injections. IBRO Neurosci Rep 2024; 16:224-240. [PMID: 38352699 PMCID: PMC10862412 DOI: 10.1016/j.ibneur.2023.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/30/2023] [Indexed: 02/16/2024] Open
Abstract
A general intravenous anesthetic propofol (2,6-diisopropylphenol) is widely used in clinical, veterinary practice and animal experiments. It activates gamma- aminobutyric acid (GABAa) receptors. Though the cerebral cortex is one of the major targets of propofol action, no study of dose dependency of propofol action on cat visual cortex was performed yet. Also, no such investigation was done until now using intrinsic signal optical imaging. Here, we report for the first time on the dependency of optical signal in the visual cortex (area 17/area 18) on the propofol dose. Optical imaging of intrinsic responses to visual stimuli was performed in cats before and after propofol bolus injections at different doses on the background of continuous propofol infusion. Orientation amplitude maps were recorded. We found that amplitude of optical signal significantly decreased after a bolus dose of propofol. The effect was dose- and time-dependent producing stronger suppression of optical signal under the highest bolus propofol doses and short time interval after injection. In each hemisphere, amplitude at cardinal and oblique orientations decreased almost equally. However, surprisingly, amplitude at cardinal orientations in the ipsilateral hemisphere was depressed stronger than in contralateral cortex at most time intervals. As the magnitude of optical signal represents the strength of orientation tuned component, these our data give new insights on the mechanisms of generation of orientation selectivity. Our results also provide new data toward understanding brain dynamics under anesthesia and suggest a recommendation for conducting intrinsic signal optical imaging experiments on cortical functioning under propofol anesthesia.
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Affiliation(s)
- Svetlana I. Shumikhina
- Functional Neurocytology, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 5a Butlerova Street, 117485 Moscow, Russian Federation
| | - Sergei A. Kozhukhov
- Physiology of Sensory Systems, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 5a Butlerova Street, 117485 Moscow, Russian Federation
| | - Igor V. Bondar
- Physiology of Sensory Systems, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 5a Butlerova Street, 117485 Moscow, Russian Federation
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Mckilliam A. A mechanistic alternative to minimal sufficiency as the guiding principle for NCC research. Neurosci Conscious 2024; 2024:niae014. [PMID: 38618486 PMCID: PMC11013376 DOI: 10.1093/nc/niae014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 01/29/2024] [Accepted: 03/05/2024] [Indexed: 04/16/2024] Open
Abstract
A central project for the neuroscience of consciousness is to reveal the neural basis of consciousness. For the past 20-odd years, this project has been conceptualized in terms of minimal sufficiency. Recently, a number of authors have suggested that the project is better conceived in mechanistic terms as the search for difference-makers. In this paper, I (i) motivate this mechanistic alternative to minimal sufficiency, (ii) develop it further by clarifying debates about the prospects of leveraging mutual manipulability to distinguish constitutive difference-makers from those that are merely causal, and (iii) explore the implications this has for recent debates concerning the status of the prefrontal cortex. I argue that adopting a mechanistic approach to the neuroscience of consciousness suggests that the prefrontal cortex is part of the neural mechanisms underlying consciousness even if it is not strictly speaking a necessary part.
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Affiliation(s)
- Andy Mckilliam
- Cognition and Philosophy Lab, Monash Centre for Consciousness and Contemplative Studies, Department of Philosophy, Monash University, Room 429, 29 Ancora Imparo Way, Melbourne, VIC 3800, Australia
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Bardon AG, Ballesteros JJ, Brincat SL, Roy JE, Mahnke MK, Ishizawa Y, Brown EN, Miller EK. Convergent effects of different anesthetics are due to changes in phase alignment of cortical oscillations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.20.585943. [PMID: 38562734 PMCID: PMC10983946 DOI: 10.1101/2024.03.20.585943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Many different anesthetics cause loss of responsiveness despite having diverse underlying molecular and circuit actions. To explore the convergent effects of these drugs, we examined how ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, and dexmedetomidine, an α2 adrenergic receptor agonist, affected neural oscillations in the prefrontal cortex of nonhuman primates. Previous work has shown that anesthesia increases phase locking of low-frequency local field potential activity across cortex. We observed similar increases with anesthetic doses of ketamine and dexmedetomidine in the ventrolateral and dorsolateral prefrontal cortex, within and across hemispheres. However, the nature of the phase locking varied between regions. We found that oscillatory activity in different prefrontal subregions within each hemisphere became more anti-phase with both drugs. Local analyses within a region suggested that this finding could be explained by broad cortical distance-based effects, such as a large traveling wave. By contrast, homologous areas across hemispheres increased their phase alignment. Our results suggest that the drugs induce strong patterns of cortical phase alignment that are markedly different from those in the awake state, and that these patterns may be a common feature driving loss of responsiveness from different anesthetic drugs.
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Liang Z, Chang Y, Liu X, Cao S, Chen Y, Wang T, Xu J, Li D, Zhang J. Changes in information integration and brain networks during propofol-, dexmedetomidine-, and ketamine-induced unresponsiveness. Br J Anaesth 2024; 132:528-540. [PMID: 38105166 DOI: 10.1016/j.bja.2023.11.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/18/2023] [Accepted: 11/07/2023] [Indexed: 12/19/2023] Open
Abstract
BACKGROUND Information integration and network science are important theories for quantifying consciousness. However, whether these theories propose drug- or conscious state-related changes in EEG during anaesthesia-induced unresponsiveness remains unknown. METHODS A total of 72 participants were randomised to receive i.v. infusion of propofol, dexmedetomidine, or ketamine at a constant infusion rate until loss of responsiveness. High-density EEG was recorded during the consciousness transition from the eye-closed baseline to the unresponsiveness state and then to the recovery of the responsiveness state. Permutation cross mutual information (PCMI) and PCMI-based brain networks in broadband (0.1-45 Hz) and sub-band frequencies were used to analyse drug- and state-related EEG signature changes. RESULTS PCMI and brain networks exhibited state-related changes in certain brain regions and frequency bands. The within-area PCMI of the frontal, parietal, and occipital regions, and the between-area PCMI of the parietal-occipital region (median [inter-quartile ranges]), baseline vs unresponsive were as follows: 0.54 (0.46-0.58) vs 0.46 (0.40-0.50), 0.58 (0.52-0.60) vs 0.48 (0.44-0.53), 0.54 (0.49-0.59) vs 0.47 (0.42-0.52) decreased during anaesthesia for three drugs (P<0.05). Alpha PCMI in the frontal region, and gamma PCMI in the posterior area significantly decreased in the unresponsive state (P<0.05). The frontal, parietal, and occipital nodal clustering coefficients and parietal nodal efficiency decreased in the unresponsive state (P<0.05). The increased normalised path length in delta, theta, and gamma bands indicated impaired global integration (P<0.05). CONCLUSIONS The three anaesthetics caused changes in information integration patterns and network functions. Thus, it is possible to build a quantifying framework for anaesthesia-induced conscious state changes on the EEG scale using PCMI and network science.
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Affiliation(s)
- Zhenhu Liang
- Institute of Electrical Engineering, Yanshan University, Qinhuangdao, P.R. China; Key Laboratory of Intelligent Rehabilitation and Neuromodulation of Hebei Province, Qinhuangdao, P.R. China
| | - Yu Chang
- Institute of Electrical Engineering, Yanshan University, Qinhuangdao, P.R. China; Key Laboratory of Intelligent Rehabilitation and Neuromodulation of Hebei Province, Qinhuangdao, P.R. China
| | - Xiaoge Liu
- Department of Anaesthesiology, Fudan University Shanghai Cancer Center, Shanghai, P.R. China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Shumei Cao
- Department of Anaesthesiology, Fudan University Shanghai Cancer Center, Shanghai, P.R. China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Yali Chen
- Department of Anaesthesiology, Fudan University Shanghai Cancer Center, Shanghai, P.R. China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Tingting Wang
- Department of Anaesthesiology, Huashan Hospital, Fudan University, Shanghai, P.R. China
| | - Jianghui Xu
- Department of Anaesthesiology, Fudan University Shanghai Cancer Center, Shanghai, P.R. China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China
| | - Duan Li
- Center for Consciousness Science, Department of Anaesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jun Zhang
- Department of Anaesthesiology, Fudan University Shanghai Cancer Center, Shanghai, P.R. China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.
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Casey CP, Tanabe S, Farahbakhsh ZZ, Parker M, Bo A, White M, Ballweg T, Mcintosh A, Filbey W, Banks MI, Saalmann YB, Pearce RA, Sanders RD. Evaluation of putative signatures of consciousness using specific definitions of responsiveness, connectedness, and consciousness. Br J Anaesth 2024; 132:300-311. [PMID: 37914581 PMCID: PMC10808836 DOI: 10.1016/j.bja.2023.09.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 09/15/2023] [Accepted: 09/25/2023] [Indexed: 11/03/2023] Open
Abstract
BACKGROUND Understanding the neural correlates of consciousness has important ramifications for the theoretical understanding of consciousness and for clinical anaesthesia. A major limitation of prior studies is the use of responsiveness as an index of consciousness. We identified a collection of measures derived from unresponsive subjects and more specifically their association with consciousness (any subjective experience) or connectedness (specific experience of environmental stimuli). METHODS Using published data generated through the UNderstanding Consciousness Connectedness and Intra-Operative Unresponsiveness Study (NCT03284307), we evaluated 10 previously published resting-state EEG-based measures that were derived using unresponsiveness as a proxy for unconsciousness. Measures were tested across dexmedetomidine and propofol sedation and natural sleep. These markers represent the complexity, connectivity, cross-frequency coupling, graph theory, and power spectrum measures. RESULTS Although many of the proposed markers were associated with consciousness per se (reported subjective experience), none were specific to consciousness alone; rather, each was also associated with connectedness (i.e. awareness of the environment). In addition, multiple markers showed no association with consciousness and were associated only with connectedness. Of the markers tested, loss of normalised-symbolic transfer entropy (front to back) was associated with connectedness across all three experimental conditions, whereas the transition from disconnected consciousness to unconsciousness was associated with significant decreases in permutation entropy and spectral exponent (P<0.05 for all conditions). CONCLUSIONS None of the proposed EEG-based neural correlates of unresponsiveness corresponded solely to consciousness, highlighting the need for a more conservative use of the term (un)consciousness when assessing unresponsive participants. CLINICAL TRIAL REGISTRATION NCT03284307.
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Affiliation(s)
- Cameron P Casey
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA.
| | - Sean Tanabe
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Zahra Z Farahbakhsh
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Margaret Parker
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Amber Bo
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Marissa White
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Tyler Ballweg
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Andrew Mcintosh
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - William Filbey
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Matthew I Banks
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Yuri B Saalmann
- Department of Psychology, University of Wisconsin-Madison, Madison, WI, USA
| | - Robert A Pearce
- Department of Anesthesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Robert D Sanders
- Specialty of Anaesthetics & NHMRC Clinical Trials Centre, University of Sydney, Camperdown, NSW, Australia; Department of Anaesthetics, Royal Prince Alfred Hospital, Camperdown, NSW, Australia; Institute of Academic Surgery, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
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Montupil J, Cardone P, Staquet C, Bonhomme A, Defresne A, Martial C, Alnagger NL, Gosseries O, Bonhomme V. The nature of consciousness in anaesthesia. BJA OPEN 2023; 8:100224. [PMID: 37780201 PMCID: PMC10539891 DOI: 10.1016/j.bjao.2023.100224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 08/28/2023] [Indexed: 10/03/2023]
Abstract
Neuroscientists agree on the value of locating the source of consciousness within the brain. Anaesthesiologists are no exception, and have their own operational definition of consciousness based on phenomenological observations during anaesthesia. The full functional correlates of consciousness are yet to be precisely identified, however rapidly evolving progress in this scientific domain has yielded several theories that attempt to model the generation of consciousness. They have received variable support from experimental observations, including those involving anaesthesia and its ability to reversibly modulate different aspects of consciousness. Aside from the interest in a better understanding of the mechanisms of consciousness, exploring the functional tenets of the phenomenological consciousness states of general anaesthesia has the potential to ultimately improve patient management. It could facilitate the design of specific monitoring devices and approaches, aiming at reliably detecting each of the possible states of consciousness during an anaesthetic procedure, including total absence of mental content (unconsciousness), and internal awareness (sensation of self and internal thoughts) with or without conscious perception of the environment (connected or disconnected consciousness, respectively). Indeed, it must be noted that unresponsiveness is not sufficient to infer absence of connectedness or even absence of consciousness. This narrative review presents the current knowledge in this field from a system-level, underlining the contribution of anaesthesia studies in supporting theories of consciousness, and proposing directions for future research.
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Affiliation(s)
- Javier Montupil
- Anesthesia and Perioperative Neuroscience Laboratory, Liege, Belgium
- Department of Anesthesia and Intensive Care Medicine, Liege, Belgium
- University Department of Anesthesia and Intensive Care Medicine, Citadelle Regional Hospital, Liege, Belgium
| | - Paolo Cardone
- Coma Science Group, GIGA-Consciousness Thematic Unit, GIGA-Research, Liege University, Liege, Belgium
- Centre du Cerveau, Liege University Hospital, Liege, Belgium
| | - Cécile Staquet
- Anesthesia and Perioperative Neuroscience Laboratory, Liege, Belgium
- Department of Anesthesia and Intensive Care Medicine, Liege, Belgium
| | - Arthur Bonhomme
- Coma Science Group, GIGA-Consciousness Thematic Unit, GIGA-Research, Liege University, Liege, Belgium
| | - Aline Defresne
- Anesthesia and Perioperative Neuroscience Laboratory, Liege, Belgium
- Department of Anesthesia and Intensive Care Medicine, Liege, Belgium
- University Department of Anesthesia and Intensive Care Medicine, Citadelle Regional Hospital, Liege, Belgium
| | - Charlotte Martial
- Coma Science Group, GIGA-Consciousness Thematic Unit, GIGA-Research, Liege University, Liege, Belgium
- Centre du Cerveau, Liege University Hospital, Liege, Belgium
| | - Naji L.N. Alnagger
- Coma Science Group, GIGA-Consciousness Thematic Unit, GIGA-Research, Liege University, Liege, Belgium
- Centre du Cerveau, Liege University Hospital, Liege, Belgium
| | - Olivia Gosseries
- Coma Science Group, GIGA-Consciousness Thematic Unit, GIGA-Research, Liege University, Liege, Belgium
- Centre du Cerveau, Liege University Hospital, Liege, Belgium
| | - Vincent Bonhomme
- Anesthesia and Perioperative Neuroscience Laboratory, Liege, Belgium
- Department of Anesthesia and Intensive Care Medicine, Liege, Belgium
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Qin X, Chen X, Wang B, Zhao X, Tang Y, Yao L, Liang Z, He J, Li X. EEG Changes during Propofol Anesthesia Induction in Vegetative State Patients Undergoing Spinal Cord Stimulation Implantation Surgery. Brain Sci 2023; 13:1608. [PMID: 38002567 PMCID: PMC10669685 DOI: 10.3390/brainsci13111608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/07/2023] [Accepted: 11/17/2023] [Indexed: 11/26/2023] Open
Abstract
OBJECTIVE To compare the EEG changes in vegetative state (VS) patients and non-craniotomy, non-vegetative state (NVS) patients during general anesthesia with low-dose propofol and to find whether it affects the arousal rate of VS patients. METHODS Seven vegetative state patients (VS group: five with traumatic brain injury, two with ischemic-hypoxic VS) and five non-craniotomy, non-vegetative state patients (NVS group) treated in the Department of Neurosurgery, Peking University International Hospital from January to May 2022 were selected. All patients were induced with 0.5 mg/kg propofol, and the Bispectral Index (BIS) changes within 5 min after administration were observed. Raw EEG signals and perioperative EEG signals were collected and analyzed using EEGLAB in the MATLAB software environment, time-frequency spectrums were calculated, and EEG changes were analyzed using power spectrums. RESULTS There was no significant difference in the general data before surgery between the two groups (p > 0.05); the BIS reduction in the VS group was significantly greater than that in the NVS group at 1 min, 2 min, 3 min, 4 min, and 5 min after 0.5 mg/kg propofol induction (p < 0.05). Time-frequency spectrum analysis showed the following: prominent α band energy around 10 Hz and decreased high-frequency energy in the NVS group, decreased high-frequency energy and main energy concentrated below 10 Hz in traumatic brain injury VS patients, higher energy in the 10-20 Hz band in ischemic-hypoxic VS patients. The power spectrum showed that the brain electrical energy of the NVS group was weakened R5 min after anesthesia induction compared with 5 min before induction, mainly concentrated in the small wave peak after 10 Hz, i.e., the α band peak; the energy of traumatic brain injury VS patients was weakened after anesthesia induction, but no α band peak appeared; and in ischemic-hypoxic VS patients, there was no significant change in low-frequency energy after anesthesia induction, high-frequency energy was significantly weakened, and a clear α band peak appeared slightly after 10 Hz. Three months after the operation, follow-up visits were made to the VS group patients who had undergone SCS surgery. One patient with traumatic brain injury VS was diagnosed with MCS-, one patient with ischemic-hypoxic VS had increased their CRS-R score by 1 point, and the remaining five patients had no change in their CRS scores. CONCLUSIONS Low doses of propofol cause great differences in the EEG of different types of VS patients, which may be the unique response of damaged nerve cell residual function to propofol, and these weak responses may also be the basis of brain recovery.
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Affiliation(s)
- Xuewei Qin
- Department of Anesthesiology, Peking University International Hospital, Beijing 102206, China; (X.Q.); (X.Z.)
| | - Xuanling Chen
- Department of Anesthesiology, Peking University International Hospital, Beijing 102206, China; (X.Q.); (X.Z.)
| | - Bo Wang
- Department of Anesthesiology, Peking University International Hospital, Beijing 102206, China; (X.Q.); (X.Z.)
| | - Xin Zhao
- Department of Anesthesiology, Peking University International Hospital, Beijing 102206, China; (X.Q.); (X.Z.)
| | - Yi Tang
- Department of Anesthesiology, Peking University International Hospital, Beijing 102206, China; (X.Q.); (X.Z.)
| | - Lan Yao
- Department of Anesthesiology, Peking University International Hospital, Beijing 102206, China; (X.Q.); (X.Z.)
| | - Zhenhu Liang
- Institute of Electrical Engineering, Yanshan University, Qinhuangdao 066004, China;
| | - Jianghong He
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China;
| | - Xiaoli Li
- State Key Laboratory of Cognitive Neuroscience and Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China;
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China
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Zeng J, Fu Y, Wu Y, Wang S, Zhang W, Ma H. Absolute CO 2 /Xenon Separation in Ultramicropore MOF for Anesthetic Gases Regeneration. Angew Chem Int Ed Engl 2023; 62:e202310235. [PMID: 37658513 DOI: 10.1002/anie.202310235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/12/2023] [Accepted: 09/01/2023] [Indexed: 09/03/2023]
Abstract
Xe is an ideal anesthetic gas, but it has not been widely used in practice due to its high cost and low output. Closed-circuit Xe recovery and recycling is an economically viable method to ensure adequate supply in medical use. Herein, we design an innovative way to recover Xe by using a stable fluorinated metal-organic framework (MOF) NbOFFIVE-1-Ni to eliminate CO2 from moist exhaled anesthetic gases. Unlike other Xe recovery MOFs with low Xe/CO2 selectivity (less than 10), NbOFFIVE-1-Ni could achieve absolute molecular sieve separation of CO2 /Xe with excellent CO2 selectivity (825). Mixed-gas breakthrough experiments assert the potential of NbOFFIVE-1-Ni as a molecular sieve adsorbent for the effective and energy-efficient removal of carbon dioxide with 99.16 % Xe recovery. Absolute CO2 /Xe separation in NbOFFIVE-1-Ni makes closed-circuit Xe recovery and recycling can be easily realized, demonstrating the potential of NbOFFIVE-1-Ni for important anesthetic gas regeneration under ambient conditions.
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Affiliation(s)
- Jiahui Zeng
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, Shaanxi, 710049, P. R. China
| | - Yu Fu
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, Shaanxi, 710049, P. R. China
| | - Yue Wu
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, Shaanxi, 710049, P. R. China
| | - Shanshan Wang
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, Shaanxi, 710049, P. R. China
| | - Wenxiang Zhang
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, Shaanxi, 710049, P. R. China
| | - Heping Ma
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, Shaanxi, 710049, P. R. China
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10
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Cardone P, Bodart O, Kirsch M, Sanfilippo J, Virgillito A, Martial C, Simon J, Wannez S, Sanders RD, Laureys S, Massimini M, Vandewalle G, Bonhomme V, Gosseries O. Depth of sedation with dexmedetomidine increases transcranial magnetic stimulation-evoked potential amplitude non-linearly. Br J Anaesth 2023; 131:715-725. [PMID: 37596183 DOI: 10.1016/j.bja.2023.05.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 05/09/2023] [Accepted: 05/30/2023] [Indexed: 08/20/2023] Open
Abstract
BACKGROUND Cortical excitability is higher in unconsciousness than in wakefulness, but it is unclear how this relates to anaesthesia. We investigated cortical excitability in response to dexmedetomidine, the effects of which are not fully known. METHODS We recorded transcranial magnetic stimulation (TMS) and EEG in frontal and parietal cortex of 20 healthy subjects undergoing dexmedetomidine sedation in four conditions (baseline, light sedation, deep sedation, recovery). We used the first component (0-30 ms) of the TMS-evoked potential (TEP) to measure cortical excitability (amplitude), slope, and positive and negative peak latencies (collectively, TEP indices). We used generalised linear mixed models to test the effect of condition, brain region, and responsiveness on TEP indices. RESULTS Compared with baseline, amplitude in the frontal cortex increased by 6.52 μV (P<0.001) in light sedation, 4.55 μV (P=0.003) in deep sedation, and 5.03 μV (P<0.001) in recovery. Amplitude did not change in the parietal cortex. Compared with baseline, slope increased in all conditions (P<0.02) in the frontal but not parietal cortex. The frontal cortex showed 5.73 μV higher amplitude (P<0.001), 0.63 μV ms-1 higher slope (P<0.001), and 2.2 ms shorter negative peak latency (P=0.001) than parietal areas. Interactions between dexmedetomidine and region had effects over amplitude (P=0.004) and slope (P=0.009), with both being higher in light sedation, deep sedation, and recovery compared with baseline. CONCLUSIONS Transcranial magnetic stimulation-evoked potential amplitude changes non-linearly as a function of depth of sedation by dexmedetomidine, with a region-specific paradoxical increase. Future research should investigate other anaesthetics to elucidate the link between cortical excitability and depth of sedation.
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Affiliation(s)
- Paolo Cardone
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium; Centre du Cerveau, University of Liège, Liège, Belgium
| | - Olivier Bodart
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium; Centre du Cerveau, University of Liège, Liège, Belgium; Department of Neurology, University of Liège, Liège, Belgium
| | - Murielle Kirsch
- Anesthesia and Perioperative Neuroscience Laboratory, GIGA-Consciousness, University of Liège, Liège, Belgium; Department of Anaesthesia and Intensive Care Medicine, University of Liège, Liège, Belgium
| | - Julien Sanfilippo
- Anesthesia and Perioperative Neuroscience Laboratory, GIGA-Consciousness, University of Liège, Liège, Belgium
| | | | - Charlotte Martial
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium; Centre du Cerveau, University of Liège, Liège, Belgium
| | - Jessica Simon
- Psychology and Neuroscience of Cognition, University of Liège, Liège, Belgium
| | - Sarah Wannez
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium
| | - Robert D Sanders
- Specialty of Anaesthetics, University of Sydney, Camperdown, Australia; Department of Anaesthetics & Institute of Academic Surgery, Royal Prince Alfred Hospital, Camperdown, Australia
| | - Steven Laureys
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium; Centre du Cerveau, University of Liège, Liège, Belgium; Joint International Research Unit on Consciousness, CERVO Brain Research Centre, CIUSS, University Laval, Québec City, QC, Canada
| | - Marcello Massimini
- Department of Biomedical and Clinical Sciences "L. Sacco", Università degli Studi di Milano, Milan, Italy; IRCCS Fondazione Don Gnocchi, Milan, Italy
| | - Gilles Vandewalle
- Sleep and Chronobiology Lab, GIGA-Cyclotron Research Centre-In Vivo Imaging, University of Liège, Liège, Belgium
| | - Vincent Bonhomme
- Anesthesia and Perioperative Neuroscience Laboratory, GIGA-Consciousness, University of Liège, Liège, Belgium; Department of Anaesthesia and Intensive Care Medicine, University of Liège, Liège, Belgium; University Department of Anaesthesia and Intensive Care Medicine, Centre Hospitalier Régional de la Citadelle (CHR Citadelle), Liège, Belgium.
| | - Olivia Gosseries
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium; Centre du Cerveau, University of Liège, Liège, Belgium.
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Sepúlveda PO, Vera R, Fernández MS, Lobo FA. Linear thinking does not reflect the newer 21st-century anesthesia concepts. A narrative review. J Clin Monit Comput 2023; 37:1133-1144. [PMID: 37129792 DOI: 10.1007/s10877-023-01021-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 04/17/2023] [Indexed: 05/03/2023]
Abstract
The brain constitutes a good example of a chaotic, nonlinear biological system where large neuronal networks operate chaotically with random connectivity. This critical state is significantly affected by the anesthetic loss of consciousness induced by drugs whose pharmacological behavior has been classically based on linear kinetics and dynamics. Recent developments in pharmacology and brain monitoring during anesthesia suggest a different view that we tried to explore in this article. The concepts of effect-site for hypnotic drugs modeling a maximum effect, electroencephalographic dynamics during induction, maintenance, and recovery from anesthesia are discussed, integrated into this alternative view, and how it may be applied in daily clinical practice.
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Affiliation(s)
- Pablo O Sepúlveda
- Hospital Base San José de Osorno, Chile, Universidad Austral de Chile, Osorno, Chile.
| | - Rodrigo Vera
- Ing. Civil Industrial, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - M Silvia Fernández
- Anesthesiology Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Francisco A Lobo
- Anesthesiology Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates
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12
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Venkatraghavan L, Bhardwaj S, Banik S, Chowdhury T, McAndrews MP, Valiante T. Emergence Patterns from General Anesthesia after Epilepsy Surgery: An Observational Pilot Study. Asian J Neurosurg 2023; 18:516-521. [PMID: 38152514 PMCID: PMC10749865 DOI: 10.1055/s-0043-1771365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023] Open
Abstract
Objective Emergence from anesthesia starts from the limbic structures and then spreads outwards to brainstem, reticular activating systems, and then to the cortex. Epilepsy surgery often involves resection of limbic structures and hence may disrupt the pattern of emergence. The aim of this study was to explore the pattern of emergence from anesthesia following epilepsy surgery and to determine associated variables affecting the emergence pattern. Setting and Design Tertiary care center, prospective observational study. Materials and Methods We conducted a prospective observation pilot study on adult patients undergoing anterior temporal lobectomy and amygdalohippocampectomy for epilepsy. Anesthesia management was standardized in all patients, and they were allowed to wake up with "no touch" technique. Primary outcome of the study was the pattern of emergence (normal emergence, agitated emergence, or slow emergence) from anesthesia. Secondary outcomes were to explore the differences in preoperative neuropsychological profile and limbic structure volumes between the different patterns of emergence. Quantitative variables were analyzed using Student's t -test. Qualitative variables were analyzed using chi-square test. Results Twenty-nine patients completed the study: 9 patients (31%) had agitated emergence, and 20 patients had normal emergence. Among the agitated emergence, 2 patients had Riker scale of 7 indicating violent emergence. Patient demographics, anesthetic used, neuropsychological profile, and limbic structure volumes were similar between normal emergence and agitated emergence groups. However, two patients who had severe agitation (Riker scale of 7) had the lowest intelligence quotient. Conclusion Our pilot study showed that emergence agitation is not uncommon in patients undergoing epilepsy surgery. However, due to smaller sample size, the role of preoperative neuropsychologic profile and hippocampal volumes in predicting the pattern of emergence is inconclusive.
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Affiliation(s)
- Lashmi Venkatraghavan
- Department of Anesthesia and Pain Management, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Suparna Bhardwaj
- Department of Neuro Anaesthesia & Neurocritical Care, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India
| | - Sujoy Banik
- Department of Anesthesia and Perioperative medicine, Western University, London, Canada
| | - Tumul Chowdhury
- Department of Anesthesia and Pain Management, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Mary Pat McAndrews
- Department of Neuropsychology, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Taufik Valiante
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
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13
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Luppi AI, Cabral J, Cofre R, Mediano PAM, Rosas FE, Qureshi AY, Kuceyeski A, Tagliazucchi E, Raimondo F, Deco G, Shine JM, Kringelbach ML, Orio P, Ching S, Sanz Perl Y, Diringer MN, Stevens RD, Sitt JD. Computational modelling in disorders of consciousness: Closing the gap towards personalised models for restoring consciousness. Neuroimage 2023; 275:120162. [PMID: 37196986 PMCID: PMC10262065 DOI: 10.1016/j.neuroimage.2023.120162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 04/16/2023] [Accepted: 05/09/2023] [Indexed: 05/19/2023] Open
Abstract
Disorders of consciousness are complex conditions characterised by persistent loss of responsiveness due to brain injury. They present diagnostic challenges and limited options for treatment, and highlight the urgent need for a more thorough understanding of how human consciousness arises from coordinated neural activity. The increasing availability of multimodal neuroimaging data has given rise to a wide range of clinically- and scientifically-motivated modelling efforts, seeking to improve data-driven stratification of patients, to identify causal mechanisms for patient pathophysiology and loss of consciousness more broadly, and to develop simulations as a means of testing in silico potential treatment avenues to restore consciousness. As a dedicated Working Group of clinicians and neuroscientists of the international Curing Coma Campaign, here we provide our framework and vision to understand the diverse statistical and generative computational modelling approaches that are being employed in this fast-growing field. We identify the gaps that exist between the current state-of-the-art in statistical and biophysical computational modelling in human neuroscience, and the aspirational goal of a mature field of modelling disorders of consciousness; which might drive improved treatments and outcomes in the clinic. Finally, we make several recommendations for how the field as a whole can work together to address these challenges.
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Affiliation(s)
- Andrea I Luppi
- Division of Anaesthesia and Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
| | - Joana Cabral
- Life and Health Sciences Research Institute, University of Minho, Portugal
| | - Rodrigo Cofre
- CIMFAV-Ingemat, Facultad de Ingeniería, Universidad de Valparaíso, Valparaíso, Chile; Centre National de la Recherche Scientifique (CNRS), Institute of Neuroscience (NeuroPSI), Paris-Saclay University, Gif-sur-Yvette, France
| | - Pedro A M Mediano
- Department of Computing, Imperial College London, London, UK; Department of Psychology, University of Cambridge, Cambridge, UK
| | - Fernando E Rosas
- Department of Informatics, University of Sussex, Brighton, UK; Centre for Psychedelic Research, Department of Brain Sciences, Imperial College London, London, UK; Centre for Complexity Science, Imperial College London, London, UK; Centre for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford, UK
| | - Abid Y Qureshi
- University of Kansas Medical Center, Kansas City, MO, USA
| | - Amy Kuceyeski
- Department of Radiology, Weill Cornell Medicine, New York, USA
| | - Enzo Tagliazucchi
- Departamento de Física (UBA) e Instituto de Fisica de Buenos Aires (CONICET), Buenos Aires, Argentina; Latin American Brain Health Institute (BrainLat), Universidad Adolfo Ibáñez, Santiago, Chile
| | - Federico Raimondo
- Institute of Neuroscience and Medicine (INM-7: Brain and Behaviour), Research Centre Jülich, Germany; Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Gustavo Deco
- Center for Brain and Cognition, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain; Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain; Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC, Australia
| | - James M Shine
- Brain and Mind Center, The University of Sydney, Sydney, Australia
| | - Morten L Kringelbach
- Centre for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford, UK; Department of Psychiatry, University of Oxford, Oxford, UK; Center for Music in the Brain, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Patricio Orio
- Centro Interdisciplinario de Neurociencia de Valparaíso and Instituto de Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - ShiNung Ching
- Electrical and Systems Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Yonatan Sanz Perl
- Center for Brain and Cognition, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain; Institut du Cerveau et de la Moelle épinière - Paris Brain Institute, ICM, Paris, France; National Scientific and Technical Research Council (CONICET), Godoy Cruz, CABA 2290, Argentina
| | - Michael N Diringer
- Department of Neurology and Neurosurgery, Washington University in St. Louis, St. Louis, MO, USA
| | - Robert D Stevens
- Departments of Anesthesiology and Critical Care Medicine, Neurology, and Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Jacobo Diego Sitt
- Institut du Cerveau et de la Moelle épinière - Paris Brain Institute, ICM, Paris, France; Sorbonne Université, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, Paris, France.
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14
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Becerra D, Calixto A, Orio P. The Conscious Nematode: Exploring Hallmarks of Minimal Phenomenal Consciousness in Caenorhabditis Elegans. Int J Psychol Res (Medellin) 2023; 16:87-104. [PMID: 38106963 PMCID: PMC10723751 DOI: 10.21500/20112084.6487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 10/21/2022] [Accepted: 03/13/2023] [Indexed: 12/19/2023] Open
Abstract
While subcellular components of cognition and affectivity that involve the interaction between experience, environment, and physiology -such as learning, trauma, or emotion- are being identified, the physical mechanisms of phenomenal consciousness remain more elusive. We are interested in exploring whether ancient, simpler organisms such as nematodes have minimal consciousness. Is there something that feels like to be a worm? Or are worms blind machines? 'Simpler' models allow us to simultaneously extract data from multiple levels such as slow and fast neural dynamics, structural connectivity, molecular dynamics, behavior, decision making, etc., and thus, to test predictions of the current frameworks in dispute. In the present critical review, we summarize the current models of consciousness in order to reassess in light of the new evidence whether Caenorhabditis elegans, a nematode with a nervous system composed of 302 neurons, has minimal consciousness. We also suggest empirical paths to further advance consciousness research using C. elegans.
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Affiliation(s)
- Diego Becerra
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
- Doctorado en Ciencias, mención Biofísica y Biología Computacional, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
| | - Andrea Calixto
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
- Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
| | - Patricio Orio
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
- Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.Universidad de ValparaísoUniversidad de ValparaísoValparaísoChile
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15
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Bong CL, Balanza GA, Khoo CEH, Tan JSK, Desel T, Purdon PL. A Narrative Review Illustrating the Clinical Utility of Electroencephalogram-Guided Anesthesia Care in Children. Anesth Analg 2023; 137:108-123. [PMID: 36729437 DOI: 10.1213/ane.0000000000006267] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The major therapeutic end points of general anesthesia include hypnosis, amnesia, and immobility. There is a complex relationship between general anesthesia, responsiveness, hemodynamic stability, and reaction to noxious stimuli. This complexity is compounded in pediatric anesthesia, where clinicians manage children from a wide range of ages, developmental stages, and body sizes, with their concomitant differences in physiology and pharmacology. This renders anesthetic requirements difficult to predict based solely on a child's age, body weight, and vital signs. Electroencephalogram (EEG) monitoring provides a window into children's brain states and may be useful in guiding clinical anesthesia management. However, many clinicians are unfamiliar with EEG monitoring in children. Young children's EEGs differ substantially from those of older children and adults, and there is a lack of evidence-based guidance on how and when to use the EEG for anesthesia care in children. This narrative review begins by summarizing what is known about EEG monitoring in pediatric anesthesia care. A key knowledge gap in the literature relates to a lack of practical information illustrating the utility of the EEG in clinical management. To address this gap, this narrative review illustrates how the EEG spectrogram can be used to visualize, in real time, brain responses to anesthetic drugs in relation to hemodynamic stability, surgical stimulation, and other interventions such as cardiopulmonary bypass. This review discusses anesthetic management principles in a variety of clinical scenarios, including infants, children with altered conscious levels, children with atypical neurodevelopment, children with hemodynamic instability, children undergoing total intravenous anesthesia, and those undergoing cardiopulmonary bypass. Each scenario is accompanied by practical illustrations of how the EEG can be visualized to help titrate anesthetic dosage to avoid undersedation or oversedation when patients experience hypotension or other physiological challenges, when surgical stimulation increases, and when a child's anesthetic requirements are otherwise less predictable. Overall, this review illustrates how well-established clinical management principles in children can be significantly complemented by the addition of EEG monitoring, thus enabling personalized anesthesia care to enhance patient safety and experience.
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Affiliation(s)
- Choon Looi Bong
- From the Department of Pediatric Anesthesia, KK Women's and Children's Hospital, Duke-NUS Medical School, Singapore
| | - Gustavo A Balanza
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Charis Ern-Hui Khoo
- From the Department of Pediatric Anesthesia, KK Women's and Children's Hospital, Duke-NUS Medical School, Singapore
| | - Josephine Swee-Kim Tan
- From the Department of Pediatric Anesthesia, KK Women's and Children's Hospital, Duke-NUS Medical School, Singapore
| | - Tenzin Desel
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Patrick Lee Purdon
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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16
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Feng T, Zhao C, Rao JS, Guo XJ, Bao SS, He LW, Zhao W, Liu Z, Yang ZY, Li XG. Different macaque brain network remodeling after spinal cord injury and NT3 treatment. iScience 2023; 26:106784. [PMID: 37378337 PMCID: PMC10291247 DOI: 10.1016/j.isci.2023.106784] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 03/08/2023] [Accepted: 04/26/2023] [Indexed: 06/29/2023] Open
Abstract
Graph theory-based analysis describes the brain as a complex network. Only a few studies have examined modular composition and functional connectivity (FC) between modules in patients with spinal cord injury (SCI). Little is known about the longitudinal changes in hubs and topological properties at the modular level after SCI and treatment. We analyzed differences in FC and nodal metrics reflecting modular interaction to investigate brain reorganization after SCI-induced compensation and neurotrophin-3 (NT3)-chitosan-induced regeneration. Mean inter-modular FC and participation coefficient of areas related to motor coordination were significantly higher in the treatment animals than in the SCI-only ones at the late stage. The magnocellular part of the red nucleus may reflect the best difference in brain reorganization after SCI and therapy. Treatment can enhance information flows between regions and promote the integration of motor functions to return to normal. These findings may reveal the information processing of disrupted network modules.
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Affiliation(s)
- Ting Feng
- School of Biological Science and Medical Engineering, Beijing Key Laboratory for Biomaterials and Neural Regeneration, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, PR China
| | - Can Zhao
- Institute of Rehabilitation Engineering, China Rehabilitation Science Institute, Beijing, PR China
| | - Jia-Sheng Rao
- School of Biological Science and Medical Engineering, Beijing Key Laboratory for Biomaterials and Neural Regeneration, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, PR China
| | - Xiao-Jun Guo
- School of Biological Science and Medical Engineering, Beijing Key Laboratory for Biomaterials and Neural Regeneration, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, PR China
| | - Shu-Sheng Bao
- School of Biological Science and Medical Engineering, Beijing Key Laboratory for Biomaterials and Neural Regeneration, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, PR China
| | - Le-Wei He
- School of Biological Science and Medical Engineering, Beijing Key Laboratory for Biomaterials and Neural Regeneration, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, PR China
| | - Wen Zhao
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China
| | - Zuxiang Liu
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, PR China
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, PR China
- Department of Biology, College of Life Sciences, University of Chinese Academy of Sciences, Beijing, PR China
| | - Zhao-Yang Yang
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China
| | - Xiao-Guang Li
- School of Biological Science and Medical Engineering, Beijing Key Laboratory for Biomaterials and Neural Regeneration, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, PR China
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17
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Sodré ME, Wießner I, Irfan M, Schenck CH, Mota-Rolim SA. Awake or Sleeping? Maybe Both… A Review of Sleep-Related Dissociative States. J Clin Med 2023; 12:3876. [PMID: 37373570 DOI: 10.3390/jcm12123876] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 06/29/2023] Open
Abstract
Recent studies have begun to understand sleep not only as a whole-brain process but also as a complex local phenomenon controlled by specific neurotransmitters that act in different neural networks, which is called "local sleep". Moreover, the basic states of human consciousness-wakefulness, sleep onset (N1), light sleep (N2), deep sleep (N3), and rapid eye movement (REM) sleep-can concurrently appear, which may result in different sleep-related dissociative states. In this article, we classify these sleep-related dissociative states into physiological, pathological, and altered states of consciousness. Physiological states are daydreaming, lucid dreaming, and false awakenings. Pathological states include sleep paralysis, sleepwalking, and REM sleep behavior disorder. Altered states are hypnosis, anesthesia, and psychedelics. We review the neurophysiology and phenomenology of these sleep-related dissociative states of consciousness and update them with recent studies. We conclude that these sleep-related dissociative states have a significant basic and clinical impact since their study contributes to the understanding of consciousness and the proper treatment of neuropsychiatric diseases.
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Affiliation(s)
| | - Isabel Wießner
- Brain Institute, Federal University of Rio Grande do Norte, Natal 59078-970, RN, Brazil
| | - Muna Irfan
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Carlos H Schenck
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sergio A Mota-Rolim
- Brain Institute, Federal University of Rio Grande do Norte, Natal 59078-970, RN, Brazil
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18
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Deverett B. Anesthesia for non-traditional consciousness. Front Hum Neurosci 2023; 17:1146242. [PMID: 37228852 PMCID: PMC10203240 DOI: 10.3389/fnhum.2023.1146242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 04/17/2023] [Indexed: 05/27/2023] Open
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19
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Wang X, Wang T, Fan X, Zhang Z, Wang Y, Li Z. A Molecular Toolbox of Positron Emission Tomography Tracers for General Anesthesia Mechanism Research. J Med Chem 2023; 66:6463-6497. [PMID: 37145921 DOI: 10.1021/acs.jmedchem.2c01965] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
With appropriate radiotracers, positron emission tomography (PET) allows direct or indirect monitoring of the spatial and temporal distribution of anesthetics, neurotransmitters, and biomarkers, making it an indispensable tool for studying the general anesthesia mechanism. In this Perspective, PET tracers that have been recruited in general anesthesia research are introduced in the following order: 1) 11C/18F-labeled anesthetics, i.e., PET tracers made from inhaled and intravenous anesthetics; 2) PET tracers targeting anesthesia-related receptors, e.g., neurotransmitters and voltage-gated ion channels; and 3) PET tracers for studying anesthesia-related neurophysiological effects and neurotoxicity. The radiosynthesis, pharmacodynamics, and pharmacokinetics of the above PET tracers are mainly discussed to provide a practical molecular toolbox for radiochemists, anesthesiologists, and those who are interested in general anesthesia.
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Affiliation(s)
- Xiaoxiao Wang
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Tao Wang
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiaowei Fan
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Zhao Zhang
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Yingwei Wang
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Zijing Li
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
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20
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Lawn T, Martins D, O'Daly O, Williams S, Howard M, Dipasquale O. The effects of propofol anaesthesia on molecular-enriched networks during resting-state and naturalistic listening. Neuroimage 2023; 271:120018. [PMID: 36935083 PMCID: PMC10410200 DOI: 10.1016/j.neuroimage.2023.120018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/09/2023] [Indexed: 03/19/2023] Open
Abstract
Placing a patient in a state of anaesthesia is crucial for modern surgical practice. However, the mechanisms by which anaesthetic drugs, such as propofol, impart their effects on consciousness remain poorly understood. Propofol potentiates GABAergic transmission, which purportedly has direct actions on cortex as well as indirect actions via ascending neuromodulatory systems. Functional imaging studies to date have been limited in their ability to unravel how these effects on neurotransmission impact the system-level dynamics of the brain. Here, we leveraged advances in multi-modal imaging, Receptor-Enriched Analysis of functional Connectivity by Targets (REACT), to investigate how different levels of propofol-induced sedation alter neurotransmission-related functional connectivity (FC), both at rest and when individuals are exposed to naturalistic auditory stimulation. Propofol increased GABA-A- and noradrenaline transporter-enriched FC within occipital and somatosensory regions respectively. Additionally, during auditory stimulation, the network related to the dopamine transporter showed reduced FC within bilateral regions of temporal and mid/posterior cingulate cortices, with the right temporal cluster showing an interaction between auditory stimulation and level of consciousness. In bringing together these micro- and macro-scale systems, we provide support for both direct GABAergic and indirect noradrenergic and dopaminergic-related network changes under propofol sedation. Further, we delineate a cognition-related reconfiguration of the dopaminergic network, highlighting the utility of REACT to explore the molecular substrates of consciousness and cognition.
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Affiliation(s)
- Timothy Lawn
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's college London, London, UK.
| | - Daniel Martins
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's college London, London, UK
| | - Owen O'Daly
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's college London, London, UK
| | - Steve Williams
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's college London, London, UK
| | - Matthew Howard
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's college London, London, UK
| | - Ottavia Dipasquale
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's college London, London, UK
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21
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Choe M, Jin SH, Kim JS, Chung CK. Propofol anesthesia-induced spatiotemporal changes in cortical activity with loss of external and internal awareness: An electrocorticography study. Clin Neurophysiol 2023; 149:51-60. [PMID: 36898318 DOI: 10.1016/j.clinph.2023.01.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 01/12/2023] [Accepted: 01/29/2023] [Indexed: 02/17/2023]
Abstract
OBJECTIVE To understand the underlying mechanism of consciousness, investigating spatiotemporal changes in the cortical activity during the induction phase of unconsciousness is important. Loss of consciousness induced by general anesthesia is not necessarily accompanied by a uniform inhibition of all cortical activities. We hypothesized that cortical regions involved in internal awareness would be suppressed after disruption of cortical regions involved in external awareness. Thus, we investigated temporal changes in cortex during induction of unconsciousness. METHODS We recorded electrocorticography data of 16 epilepsy patients and investigated power spectral changes during induction phase from awake state to unconsciousness. Temporal changes were assessed at 1) the start point and 2) the interval of normalized time between start and end of power change (Δ tnormalized). RESULTS We found that the power increased at frequencies < 46 Hz, and decreased in range of 62-150 Hz, in global channels. In temporal changes of power change, superior parietal lobule and dorsolateral prefrontal cortex started to change early, but the changes were completed over a prolonged interval, whereas angular gyrus and associative visual cortex showed a delayed change and rapid completion. CONCLUSIONS Loss of consciousness induced by general anesthesia results first from disrupted communication between self and external world, followed by disrupted communication within self, with decreased activities of superior parietal lobule and dorsolateral prefrontal cortex, and later, attenuated activities of angular gyrus. SIGNIFICANCE Our findings provided neurophysiological evidence for the temporal changes in consciousness components induced by general anesthesia.
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Affiliation(s)
- Mikyung Choe
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Seung-Hyun Jin
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - June Sic Kim
- The Research Institute of Basic Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Chun Kee Chung
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea; Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Neurosurgery, Seoul National University Hospital, Seoul, Republic of Korea.
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22
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Layton R, Layton D, Beggs D, Fisher A, Mansell P, Stanger KJ. The impact of stress and anesthesia on animal models of infectious disease. Front Vet Sci 2023; 10:1086003. [PMID: 36816193 PMCID: PMC9933909 DOI: 10.3389/fvets.2023.1086003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/09/2023] [Indexed: 02/05/2023] Open
Abstract
Stress and general anesthesia have an impact on the functional response of the organism due to the detrimental effects on cardiovascular, immunological, and metabolic function, which could limit the organism's response to an infectious event. Animal studies have formed an essential step in understanding and mitigating infectious diseases, as the complexities of physiology and immunity cannot yet be replicated in vivo. Using animals in research continues to come under increasing societal scrutiny, and it is therefore crucial that the welfare of animals used in disease research is optimized to meet both societal expectations and improve scientific outcomes. Everyday management and procedures in animal studies are known to cause stress, which can not only cause poorer welfare outcomes, but also introduces variables in disease studies. Whilst general anesthesia is necessary at times to reduce stress and enhance animal welfare in disease research, evidence of physiological and immunological disruption caused by general anesthesia is increasing. To better understand and quantify the effects of stress and anesthesia on disease study and welfare outcomes, utilizing the most appropriate animal monitoring strategies is imperative. This article aims to analyze recent scientific evidence about the impact of stress and anesthesia as uncontrolled variables, as well as reviewing monitoring strategies and technologies in animal models during infectious diseases.
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Affiliation(s)
- Rachel Layton
- Australian Centre for Disease Preparedness, CSIRO, Geelong, VIC, Australia,*Correspondence: Rachel Layton ✉
| | - Daniel Layton
- Australian Centre for Disease Preparedness, CSIRO, Geelong, VIC, Australia
| | - David Beggs
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, University of Melbourne, Melbourne, VIC, Australia
| | - Andrew Fisher
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, University of Melbourne, Melbourne, VIC, Australia
| | - Peter Mansell
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, University of Melbourne, Melbourne, VIC, Australia
| | - Kelly J. Stanger
- Australian Centre for Disease Preparedness, CSIRO, Geelong, VIC, Australia
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23
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Mélotte E, Maudoux A, Panda R, Kaux JF, Lagier A, Herr R, Belorgeot M, Laureys S, Gosseries O. Links Between Swallowing and Consciousness: A Narrative Review. Dysphagia 2023; 38:42-64. [PMID: 35773497 DOI: 10.1007/s00455-022-10452-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 12/06/2021] [Indexed: 01/27/2023]
Abstract
This literature review explores a wide range of themes addressing the links between swallowing and consciousness. Signs of consciousness are historically based on the principle of differentiating reflexive from volitional behaviors. We show that the sequencing of the components of swallowing falls on a continuum of voluntary to reflex behaviors and we describe several types of volitional and non-volitional swallowing tasks. The frequency, speed of initiation of the swallowing reflex, efficacy of the pharyngeal phase of swallowing and coordination between respiration and swallowing are influenced by the level of consciousness during non-pathological modifications of consciousness such as sleep and general anesthesia. In patients with severe brain injury, the level of consciousness is associated with several components related to swallowing, such as the possibility of extubation, risk of pneumonia, type of feeding or components directly related to swallowing such as oral or pharyngeal abnormalities. Based on our theoretical and empirical analysis, the efficacy of the oral phase and the ability to receive exclusive oral feeding seem to be the most robust signs of consciousness related to swallowing in patients with disorders of consciousness. Components of the pharyngeal phase (in terms of abilities of saliva management) and evoked cough may be influenced by consciousness, but further studies are necessary to determine if they constitute signs of consciousness as such or only cortically mediated behaviors. This review also highlights the critical lack of tools and techniques to assess and treat dysphagia in patients with disorders of consciousness.
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Affiliation(s)
- Evelyne Mélotte
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium.
- Physical and Rehabilitation Medicine Department, University and University Hospital of Liège, Avenue de l'Hopital 1, 4000, Liège, Belgium.
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium.
| | - Audrey Maudoux
- Sensation and Perception Research Group, GIGA, University and University Hospital of Liège, Liège, Belgium
- Otorhinolaryngology Head and Neck Surgery Department, Robert Debré University Hospital, APHP, Paris, France
| | - Rajanikant Panda
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium
| | - Jean-François Kaux
- Physical and Rehabilitation Medicine Department, University and University Hospital of Liège, Avenue de l'Hopital 1, 4000, Liège, Belgium
| | - Aude Lagier
- Otorhinolaryngology Head and Neck Surgery Department, University Hospital of Liège, Liège, Belgium
| | - Roxanne Herr
- Department of Speech and Language Pathology, Faculty of Medicine, University of Strasbourg, Strasbourg, France
| | - Marion Belorgeot
- Physical and Rehabilitation Medicine Department, University Hospital of Nîmes, Nîmes, France
| | - Steven Laureys
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
| | - Olivia Gosseries
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
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24
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Romand R, Ehret G. Neuro-functional modeling of near-death experiences in contexts of altered states of consciousness. Front Psychol 2023; 13:846159. [PMID: 36743633 PMCID: PMC9891231 DOI: 10.3389/fpsyg.2022.846159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 11/23/2022] [Indexed: 01/19/2023] Open
Abstract
Near-death experiences (NDEs) including out-of-body experiences (OBEs) have been fascinating phenomena of perception both for affected persons and for communities in science and medicine. Modern progress in the recording of changing brain functions during the time between clinical death and brain death opened the perspective to address and understand the generation of NDEs in brain states of altered consciousness. Changes of consciousness can experimentally be induced in well-controlled clinical or laboratory settings. Reports of the persons having experienced the changes can inform about the similarity of the experiences with those from original NDEs. Thus, we collected neuro-functional models of NDEs including OBEs with experimental backgrounds of drug consumption, epilepsy, brain stimulation, and ischemic stress, and included so far largely unappreciated data from fighter pilot tests under gravitational stress generating cephalic nervous system ischemia. Since we found a large overlap of NDE themes or topics from original NDE reports with those from neuro-functional NDE models, we can state that, collectively, the models offer scientifically appropriate causal explanations for the occurrence of NDEs. The generation of OBEs, one of the NDE themes, can be localized in the temporo-parietal junction (TPJ) of the brain, a multimodal association area. The evaluated literature suggests that NDEs may emerge as hallucination-like phenomena from a brain in altered states of consciousness (ASCs).
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Affiliation(s)
- Raymond Romand
- Faculty of Medicine, University of Strasbourg, Strasbourg, France,*Correspondence: Raymond Romand,
| | - Günter Ehret
- Institute of Neurobiology, University of Ulm, Ulm, Germany,Günter Ehret,
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25
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Sevenius Nilsen A, Juel BE, Thürer B, Aamodt A, Storm JF. Are we really unconscious in “unconscious” states? Common assumptions revisited. Front Hum Neurosci 2022; 16:987051. [PMID: 36277049 PMCID: PMC9581328 DOI: 10.3389/fnhum.2022.987051] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 09/08/2022] [Indexed: 12/05/2022] Open
Abstract
In the field of consciousness science, there is a tradition to categorize certain states such as slow-wave non-REM sleep and deep general anesthesia as “unconscious”. While this categorization seems reasonable at first glance, careful investigations have revealed that it is not so simple. Given that (1) behavioral signs of (un-)consciousness can be unreliable, (2) subjective reports of (un-)consciousness can be unreliable, and, (3) states presumed to be unconscious are not always devoid of reported experience, there are reasons to reexamine our traditional assumptions about “states of unconsciousness”. While these issues are not novel, and may be partly semantic, they have implications both for scientific progress and clinical practice. We suggest that focusing on approaches that provide a more pragmatic and nuanced characterization of different experimental conditions may promote clarity in the field going forward, and help us build stronger foundations for future studies.
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Affiliation(s)
- Andre Sevenius Nilsen
- Department of Physiology, Institute of Basic Medicine, University of Oslo, Oslo, Norway
- *Correspondence: Andre Sevenius Nilsen,
| | - Bjørn E. Juel
- Department of Physiology, Institute of Basic Medicine, University of Oslo, Oslo, Norway
- School of Medicine and Public Health, Wisconsin Institute for Sleep and Consciousness, University of Wisconsin-Madison, Madison, WI, United States
- Bjørn E. Juel,
| | - Benjamin Thürer
- Department of Physiology, Institute of Basic Medicine, University of Oslo, Oslo, Norway
| | - Arnfinn Aamodt
- Department of Physiology, Institute of Basic Medicine, University of Oslo, Oslo, Norway
| | - Johan F. Storm
- Department of Physiology, Institute of Basic Medicine, University of Oslo, Oslo, Norway
- Johan F. Storm,
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26
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Chen K, Xie T, Ma L, Hudson AE, Ai Q, Liu Q. A Two-Stream Graph Convolutional Network Based on Brain Connectivity for Anesthetized States Analysis. IEEE Trans Neural Syst Rehabil Eng 2022; 30:2077-2087. [PMID: 35862321 DOI: 10.1109/tnsre.2022.3193103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Investigating neural mechanisms of anesthesia process and developing efficient anesthetized state detection methods are especially on high demand for clinical consciousness monitoring. Traditional anesthesia monitoring methods are not involved with the topological changes between electrodes covering the prefrontal-parietal cortices, by investigating electrocorticography (ECoG). To fill this gap, a framework based on the two-stream graph convolutional network (GCN) was proposed, i.e., one stream for extracting topological structure features, and the other one for extracting node features. The two-stream graph convolutional network includes GCN Model 1 and GCN Model 2. For GCN Model 1, brain connectivity networks were constructed by using phase lag index (PLI), representing different structure features. A common adjacency matrix was founded through the dual-graph method, the structure features were expressed on nodes. Therefore, the traditional spectral graph convolutional network can be directly applied on the graphs with changing topological structures. On the other hand, the average of the absolute signal amplitudes was calculated as node features, then a fully connected matrix was constructed as the adjacency matrix of these node features, as the input of GCN Model 2. This method learns features of both topological structure and nodes of the graph, and uses a dual-graph approach to enhance the focus on topological structure features. Based on the ECoG signals of monkeys, results show that this method which can distinguish awake state, moderate sedation and deep sedation achieved an accuracy of 92.75% in group-level experiments and mean accuracy of 93.50% in subject-level experiments. Our work verifies the excellence of the graph convolutional network in anesthesia monitoring, the high recognition accuracy also shows that the brain network may carry neurological markers associated with anesthesia.
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27
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Klimek M, Gravesteijn BY, Costa AM, Lobo FA. How to Study the Brain While Anesthetizing It?! A Scoping Review on Running Neuroanesthesiologic Studies and Trials That Include Neurosurgical Patients. World Neurosurg 2022; 161:376-381. [PMID: 35505557 DOI: 10.1016/j.wneu.2021.08.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/13/2021] [Indexed: 11/26/2022]
Abstract
This scoping review addresses the challenges of neuroanesthesiologic research: the population, the methods/treatment/exposure, and the outcome/results. These challenges are put into the context of a future research agenda for peri-/intraoperative anesthetic management, neurocritical care, and applied neurosciences. Finally, the opportunities of adaptive trial design in neuroanesthesiologic research are discussed.
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Affiliation(s)
- Markus Klimek
- Department of Anesthesiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Benjamin Y Gravesteijn
- Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Andreia M Costa
- Department of Anesthesiology, Centro Hospitalar Lisboa Norte, Lisbon, Portugal
| | - Francisco A Lobo
- Institute of Anesthesiology, Cleveland Clinic, Abu Dhabi, United Arabic Emirates
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28
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Ward-Flanagan R, Lo AS, Clement EA, Dickson CT. A Comparison of Brain-State Dynamics across Common Anesthetic Agents in Male Sprague-Dawley Rats. Int J Mol Sci 2022; 23:ijms23073608. [PMID: 35408973 PMCID: PMC8998244 DOI: 10.3390/ijms23073608] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/11/2022] [Accepted: 03/21/2022] [Indexed: 02/04/2023] Open
Abstract
Anesthesia is a powerful tool in neuroscientific research, especially in sleep research where it has the experimental advantage of allowing surgical interventions that are ethically problematic in natural sleep. Yet, while it is well documented that different anesthetic agents produce a variety of brain states, and consequently have differential effects on a multitude of neurophysiological factors, these outcomes vary based on dosages, the animal species used, and the pharmacological mechanisms specific to each anesthetic agent. Thus, our aim was to conduct a controlled comparison of spontaneous electrophysiological dynamics at a surgical plane of anesthesia under six common research anesthetics using a ubiquitous animal model, the Sprague-Dawley rat. From this direct comparison, we also evaluated which anesthetic agents may serve as pharmacological proxies for the electrophysiological features and dynamics of unconscious states such as sleep and coma. We found that at a surgical plane, pentobarbital, isoflurane and propofol all produced a continuous pattern of burst-suppression activity, which is a neurophysiological state characteristically observed during coma. In contrast, ketamine-xylazine produced synchronized, slow-oscillatory activity, similar to that observed during slow-wave sleep. Notably, both urethane and chloral hydrate produced the spontaneous, cyclical alternations between forebrain activation (REM-like) and deactivation (non-REM-like) that are similar to those observed during natural sleep. Thus, choice of anesthesia, in conjunction with continuous brain state monitoring, are critical considerations in order to avoid brain-state confounds when conducting neurophysiological experiments.
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Affiliation(s)
- Rachel Ward-Flanagan
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada; (R.W.-F.); (E.A.C.)
| | - Alto S. Lo
- Department of Psychology, University of Alberta, Edmonton, AB T6G 2R3, Canada;
| | - Elizabeth A. Clement
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada; (R.W.-F.); (E.A.C.)
| | - Clayton T. Dickson
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada; (R.W.-F.); (E.A.C.)
- Department of Psychology, University of Alberta, Edmonton, AB T6G 2R3, Canada;
- Department of Physiology, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, AB T6G 2G3, Canada
- Correspondence: ; Tel.: +1-(780)-492-7860
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29
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A call for comparing theories of consciousness and data sharing. Behav Brain Sci 2022; 45:e47. [PMID: 35319418 DOI: 10.1017/s0140525x21001941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Merker, Williford, and Rudrauf make several arguments against the integrated information theory of consciousness; whereas some have merit, their conclusion that the theory should be discarded is premature. Coming years promise advances in the empirical study of consciousness, and only after theories are independently tested with shared data can they be ruled in or out. We propose future research directions.
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30
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A Response to: Letter to the Editor Regarding "Neurophysiological Assessments During Continuous Sedation Until Death Put Validity of Observational Assessments Into Question: A Prospective Observational Study". Pain Ther 2022; 11:743-746. [PMID: 35286600 PMCID: PMC9098768 DOI: 10.1007/s40122-022-00369-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 02/16/2022] [Indexed: 11/02/2022] Open
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31
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Lee M, Sanz LRD, Barra A, Wolff A, Nieminen JO, Boly M, Rosanova M, Casarotto S, Bodart O, Annen J, Thibaut A, Panda R, Bonhomme V, Massimini M, Tononi G, Laureys S, Gosseries O, Lee SW. Quantifying arousal and awareness in altered states of consciousness using interpretable deep learning. Nat Commun 2022; 13:1064. [PMID: 35217645 PMCID: PMC8881479 DOI: 10.1038/s41467-022-28451-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 01/25/2022] [Indexed: 12/16/2022] Open
Abstract
Consciousness can be defined by two components: arousal (wakefulness) and awareness (subjective experience). However, neurophysiological consciousness metrics able to disentangle between these components have not been reported. Here, we propose an explainable consciousness indicator (ECI) using deep learning to disentangle the components of consciousness. We employ electroencephalographic (EEG) responses to transcranial magnetic stimulation under various conditions, including sleep (n = 6), general anesthesia (n = 16), and severe brain injury (n = 34). We also test our framework using resting-state EEG under general anesthesia (n = 15) and severe brain injury (n = 34). ECI simultaneously quantifies arousal and awareness under physiological, pharmacological, and pathological conditions. Particularly, ketamine-induced anesthesia and rapid eye movement sleep with low arousal and high awareness are clearly distinguished from other states. In addition, parietal regions appear most relevant for quantifying arousal and awareness. This indicator provides insights into the neural correlates of altered states of consciousness.
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Affiliation(s)
- Minji Lee
- Department of Brain and Cognitive Engineering, Korea University, Seoul, Republic of Korea
| | - Leandro R D Sanz
- Coma Science Group, GIGA-Consciousness, GIGA Research Center, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
| | - Alice Barra
- Coma Science Group, GIGA-Consciousness, GIGA Research Center, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
| | - Audrey Wolff
- Coma Science Group, GIGA-Consciousness, GIGA Research Center, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
| | - Jaakko O Nieminen
- Wisconsin Institute for Sleep and Consciousness, Department of Psychiatry, University of Wisconsin, Madison, USA
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Melanie Boly
- Wisconsin Institute for Sleep and Consciousness, Department of Psychiatry, University of Wisconsin, Madison, USA
- Department of Neurology, University of Wisconsin, Madison, WI, USA
| | - Mario Rosanova
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
- Fondazione Europea di Ricerca Biomedica, FERB Onlus, Milan, Italy
| | - Silvia Casarotto
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, Milan, Italy
| | - Olivier Bodart
- Coma Science Group, GIGA-Consciousness, GIGA Research Center, University of Liège, Liège, Belgium
| | - Jitka Annen
- Coma Science Group, GIGA-Consciousness, GIGA Research Center, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
| | - Aurore Thibaut
- Coma Science Group, GIGA-Consciousness, GIGA Research Center, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
| | - Rajanikant Panda
- Coma Science Group, GIGA-Consciousness, GIGA Research Center, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
| | - Vincent Bonhomme
- Department of Anesthesia and Intensive Care Medicine, University Hospital of Liège, Liège, Belgium
- University Department of Anesthesia and Intensive Care Medicine, CHR Citadelle, Liège, Belgium
- Anesthesia and Intensive Care Laboratory, GIGA-Consciousness, GIGA Research Center, University of Liège, Liège, Belgium
| | - Marcello Massimini
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, Milan, Italy
| | - Giulio Tononi
- Wisconsin Institute for Sleep and Consciousness, Department of Psychiatry, University of Wisconsin, Madison, USA
| | - Steven Laureys
- Coma Science Group, GIGA-Consciousness, GIGA Research Center, University of Liège, Liège, Belgium
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium
| | - Olivia Gosseries
- Coma Science Group, GIGA-Consciousness, GIGA Research Center, University of Liège, Liège, Belgium.
- Centre du Cerveau², University Hospital of Liège, Liège, Belgium.
- Wisconsin Institute for Sleep and Consciousness, Department of Psychiatry, University of Wisconsin, Madison, USA.
- Department of Psychology, University of Wisconsin, Madison, WI, USA.
| | - Seong-Whan Lee
- Department of Artificial Intelligence, Korea University, Seoul, Republic of Korea.
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32
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You L, Zhao Q, Yan J, Li W, Yang Y, Qin C. Effect of Thiopental on Ischemic Stroke in Rat Brain in Spontaneously Hypertensive Rats. Appl Bionics Biomech 2022; 2022:8063965. [PMID: 35103077 PMCID: PMC8800597 DOI: 10.1155/2022/8063965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 12/21/2021] [Accepted: 12/27/2021] [Indexed: 11/29/2022] Open
Abstract
Motivation and Problem Statement. Thiopental is an anesthetic drug related to the condition of controlling the area of neurological contexts. This study is related to the analysis of effectiveness for the condition of thiopental application on spontaneously hypertensive rats. Methodology. We have evaluated the thiopental induction as the anesthetic agent. The hypertensive rats were selected to administer thiopental in the form of anesthesia. The selection and application of hypertensive strokes are related to the derivation of an inducible model to assess the efficacy for analyzing the ischemic stroke parameters which relate to the human body. We used middle cerebral artery occlusion (MCAO) models related to spontaneous hypertension with the area of examining the complications in ischemic stroke. Results and Conclusion. The study focused on the experimental analysis based on the selection of spontaneously hypertensive rats associated with the incidence of ischemic stroke. Application of thiopental has reported the weak functionality and mechanism on the relaxation of neuronal activity in the case of rat brain. The considered population of the spontaneously hypertensive rats is evaluated based on the condition of effectiveness as well as the duration of the medication effects within the rat brain. Involvement of thiopental in the case of ischemic stroke has provided the area of risk development for high rate of death incidences after occurrence of acute ischemic stroke. A complication in the area of defining neuroprotective actions provides difficulty in drawing an appropriate conclusion of the study.
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Affiliation(s)
- Lu You
- Department of Anesthesiology, Guizhou Provincial People's Hospital, China
| | - Qian Zhao
- Department of Anesthesiology, Guizhou Provincial People's Hospital, China
| | - JianYong Yan
- Department of Anesthesiology, Guizhou Provincial People's Hospital, China
| | - Wen Li
- Department of Anesthesiology, Guizhou Provincial People's Hospital, China
| | - Ye Yang
- Department of Anesthesiology, Guizhou Provincial Orthopaedic Hospital, China
| | - Chenguang Qin
- Department of Anesthesiology, Guizhou Provincial People's Hospital, China
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Abstract
Fetal pain perception has important implications for fetal surgery, as well as for abortion. Current neuroscientific evidence indicates the possibility of fetal pain perception during the first trimester (<14 weeks gestation). Evidence for this conclusion is based on the following findings: (1) the neural pathways for pain perception via the cortical subplate are present as early as 12 weeks gestation, and via the thalamus as early as 7–8 weeks gestation; (2) the cortex is not necessary for pain to be experienced; (3) consciousness is mediated by subcortical structures, such as the thalamus and brainstem, which begin to develop during the first trimester; (4) the neurochemicals in utero do not cause fetal unconsciousness; and (5) the use of fetal analgesia suppresses the hormonal, physiologic, and behavioral responses to pain, avoiding the potential for both short- and long-term sequelae. As the medical evidence has shifted in acknowledging fetal pain perception prior to viability, there has been a gradual change in the fetal pain debate, from disputing the existence of fetal pain to debating the significance of fetal pain. The presence of fetal pain creates tension in the practice of medicine with respect to beneficence and nonmaleficence.
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Wang J, Xu Y, Deshpande G, Li K, Sun P, Liang P. The Effect of Light Sedation with Midazolam on Functional Connectivity of the Dorsal Attention Network. Brain Sci 2021; 11:brainsci11081107. [PMID: 34439725 PMCID: PMC8392174 DOI: 10.3390/brainsci11081107] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 11/19/2022] Open
Abstract
Altered connectivity within and between the resting-state networks (RSNs) brought about by anesthetics that induce altered consciousness remains incompletely understood. It is known that the dorsal attention network (DAN) and its anticorrelations with other RSNs have been implicated in consciousness. However, the role of DAN-related functional patterns in drug-induced sedative effects is less clear. In the current study, we investigated altered functional connectivity of the DAN during midazolam-induced light sedation. In a placebo-controlled and within-subjects experimental study, fourteen healthy volunteers received midazolam or saline with a 1-week interval. Resting-state fMRI data were acquired before and after intravenous drug administration. A multiple region of interest-driven analysis was employed to investigate connectivity within and between RSNs. It was found that functional connectivity was significantly decreased by midazolam injection in two regions located in the left inferior parietal lobule and the left middle temporal area within the DAN as compared with the saline condition. We also identified three clusters in anticorrelation between the DAN and other RSNs for the interaction effect, which included the left medial prefrontal cortex, the right superior temporal gyrus, and the right superior frontal gyrus. Connectivity between all regions and DAN was significantly decreased by midazolam injection. The sensorimotor network was minimally affected. Midazolam decreased functional connectivity of the dorsal attention network. These findings advance the understanding of the neural mechanism of sedation, and such functional patterns might have clinical implications in other medical conditions related to patients with cognitive impairment.
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Affiliation(s)
- Junkai Wang
- Department of Psychology, Tsinghua University, Haidian District, Beijing 100084, China;
| | - Yachao Xu
- Department of Anesthesiology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China;
| | - Gopikrishna Deshpande
- School of Psychology, Capital Normal University, Haidian District, Beijing 100048, China;
- Beijing Key Laboratory of Learning and Cognition, Capital Normal University, Beijing 100048, China
- AU MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849, USA
- Department of Psychological Sciences, Auburn University, Auburn, AL 36849, USA
- Alabama Advanced Imaging Consortium, Birmingham, AL 35233, USA
- Center for Neuroscience, Auburn University, Auburn, AL 36849, USA
- Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560030, India
- Center for Brain Research, Indian Institute of Science, Bangalore 560012, India
| | - Kuncheng Li
- Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China;
- Beijing Key Laboratory of Magnetic Resonance Imaging and Brain Informatics, Capital Medical University, Beijing 100053, China
| | - Pei Sun
- Department of Psychology, Tsinghua University, Haidian District, Beijing 100084, China;
- Correspondence: (P.S.); (P.L.)
| | - Peipeng Liang
- School of Psychology, Capital Normal University, Haidian District, Beijing 100048, China;
- Beijing Key Laboratory of Learning and Cognition, Capital Normal University, Beijing 100048, China
- Correspondence: (P.S.); (P.L.)
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Dopaminergic brainstem disconnection is common to pharmacological and pathological consciousness perturbation. Proc Natl Acad Sci U S A 2021; 118:2026289118. [PMID: 34301891 PMCID: PMC8325270 DOI: 10.1073/pnas.2026289118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Understanding the neural bases of consciousness is of basic scientific and clinical importance. Human neuroimaging has established that a network of interconnected brain regions known as the default mode network disintegrates in anesthesia and after brain damage that causes disorders of consciousness. However, the neurochemical underpinnings of this network change remain largely unknown. Motivated by preclinical animal work and clinical observations, we found that across pharmacological (sedation) and pathological (disorders of consciousness) consciousness perturbation, the dopaminergic source nucleus, the ventral tegmental area, disconnects from the main nodes of the default mode network. As the severity of this dopaminergic disconnection was associated with default mode network disintegration, we propose that dopaminergic modulation may be a central mechanism for consciousness maintenance. Clinical research into consciousness has long focused on cortical macroscopic networks and their disruption in pathological or pharmacological consciousness perturbation. Despite demonstrating diagnostic utility in disorders of consciousness (DoC) and monitoring anesthetic depth, these cortico-centric approaches have been unable to characterize which neurochemical systems may underpin consciousness alterations. Instead, preclinical experiments have long implicated the dopaminergic ventral tegmental area (VTA) in the brainstem. Despite dopaminergic agonist efficacy in DoC patients equally pointing to dopamine, the VTA has not been studied in human perturbed consciousness. To bridge this translational gap between preclinical subcortical and clinical cortico-centric perspectives, we assessed functional connectivity changes of a histologically characterized VTA using functional MRI recordings of pharmacologically (propofol sedation) and pathologically perturbed consciousness (DoC patients). Both cohorts demonstrated VTA disconnection from the precuneus and posterior cingulate (PCu/PCC), a main default mode network node widely implicated in consciousness. Strikingly, the stronger VTA–PCu/PCC connectivity was, the more the PCu/PCC functional connectome resembled its awake configuration, suggesting a possible neuromodulatory relationship. VTA-PCu/PCC connectivity increased toward healthy control levels only in DoC patients who behaviorally improved at follow-up assessment. To test whether VTA–PCu/PCC connectivity can be affected by a dopaminergic agonist, we demonstrated in a separate set of traumatic brain injury patients without DoC that methylphenidate significantly increased this connectivity. Together, our results characterize an in vivo dopaminergic connectivity deficit common to reversible and chronic consciousness perturbation. This noninvasive assessment of the dopaminergic system bridges preclinical and clinical work, associating dopaminergic VTA function with macroscopic network alterations, thereby elucidating a critical aspect of brainstem–cortical interplay for consciousness.
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Nourski KV, Steinschneider M, Rhone AE, Krause BM, Mueller RN, Kawasaki H, Banks MI. Cortical Responses to Vowel Sequences in Awake and Anesthetized States: A Human Intracranial Electrophysiology Study. Cereb Cortex 2021; 31:5435-5448. [PMID: 34117741 PMCID: PMC8568007 DOI: 10.1093/cercor/bhab168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/22/2021] [Accepted: 05/22/2021] [Indexed: 02/07/2023] Open
Abstract
Elucidating neural signatures of sensory processing across consciousness states is a major focus in neuroscience. Noninvasive human studies using the general anesthetic propofol reveal differential effects on auditory cortical activity, with a greater impact on nonprimary and auditory-related areas than primary auditory cortex. This study used intracranial electroencephalography to examine cortical responses to vowel sequences during induction of general anesthesia with propofol. Subjects were adult neurosurgical patients with intracranial electrodes placed to identify epileptic foci. Data were collected before electrode removal surgery. Stimuli were vowel sequences presented in a target detection task during awake, sedated, and unresponsive states. Averaged evoked potentials (AEPs) and high gamma (70-150 Hz) power were measured in auditory, auditory-related, and prefrontal cortex. In the awake state, AEPs were found throughout studied brain areas; high gamma activity was limited to canonical auditory cortex. Sedation led to a decrease in AEP magnitude. Upon LOC, there was a decrease in the superior temporal gyrus and adjacent auditory-related cortex and a further decrease in AEP magnitude in core auditory cortex, changes in the temporal structure and increased trial-to-trial variability of responses. The findings identify putative biomarkers of LOC and serve as a foundation for future investigations of altered sensory processing.
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Affiliation(s)
- Kirill V Nourski
- Address correspondence to Kirill V. Nourski, MD, PhD, Department of Neurosurgery, The University of Iowa, 200 Hawkins Dr. 1815 JCP, Iowa City, IA 52242, USA.
| | - Mitchell Steinschneider
- Department of Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ariane E Rhone
- Department of Neurosurgery, The University of Iowa, Iowa City, IA 52242, USA
| | - Bryan M Krause
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Rashmi N Mueller
- Department of Neurosurgery, The University of Iowa, Iowa City, IA 52242, USA,Department of Anesthesia, The University of Iowa, Iowa City, IA 52242, USA
| | - Hiroto Kawasaki
- Department of Neurosurgery, The University of Iowa, Iowa City, IA 52242, USA
| | - Matthew I Banks
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA,Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
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Sattin D, Duran D, Visintini S, Schiaffi E, Panzica F, Carozzi C, Rossi Sebastiano D, Visani E, Tobaldini E, Carandina A, Citterio V, Magnani FG, Cacciatore M, Orena E, Montano N, Caldiroli D, Franceschetti S, Picozzi M, Matilde L. Analyzing the Loss and the Recovery of Consciousness: Functional Connectivity Patterns and Changes in Heart Rate Variability During Propofol-Induced Anesthesia. Front Syst Neurosci 2021; 15:652080. [PMID: 33889078 PMCID: PMC8055941 DOI: 10.3389/fnsys.2021.652080] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/15/2021] [Indexed: 11/13/2022] Open
Abstract
The analysis of the central and the autonomic nervous systems (CNS, ANS) activities during general anesthesia (GA) provides fundamental information for the study of neural processes that support alterations of the consciousness level. In the present pilot study, we analyzed EEG signals and the heart rate (HR) variability (HRV) in a sample of 11 patients undergoing spinal surgery to investigate their CNS and ANS activities during GA obtained with propofol administration. Data were analyzed during different stages of GA: baseline, the first period of anesthetic induction, the period before the loss of consciousness, the first period after propofol discontinuation, and the period before the recovery of consciousness (ROC). In EEG spectral analysis, we found a decrease in posterior alpha and beta power in all cortical areas observed, except the occipital ones, and an increase in delta power, mainly during the induction phase. In EEG connectivity analysis, we found a significant increase of local efficiency index in alpha and delta bands between baseline and loss of consciousness as well as between baseline and ROC in delta band only and a significant reduction of the characteristic path length in alpha band between the baseline and ROC. Moreover, connectivity results showed that in the alpha band there was mainly a progressive increase in the number and in the strength of incoming connections in the frontal region, while in the beta band the parietal region showed mainly a significant increase in the number and in the strength of outcoming connections values. The HRV analysis showed that the induction of anesthesia with propofol was associated with a progressive decrease in complexity and a consequent increase in the regularity indexes and that the anesthetic procedure determined bradycardia which was accompanied by an increase in cardiac sympathetic modulation and a decrease in cardiac parasympathetic modulation during the induction. Overall, the results of this pilot study showed as propofol-induced anesthesia caused modifications on EEG signal, leading to a "rebalance" between long and short-range cortical connections, and had a direct effect on the cardiac system. Our data suggest interesting perspectives for the interactions between the central and autonomic nervous systems for the modulation of the consciousness level.
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Affiliation(s)
- Davide Sattin
- Neurology, Public Health, Disability Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
- Clinical and Experimental Medicine and Medical Humanities-PhD Program, Insubria University, Varese, Italy
| | - Dunja Duran
- Clinical and Experimental Epileptology Division, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Sergio Visintini
- Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Elena Schiaffi
- Neurophysiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Ferruccio Panzica
- Clinical Engineering Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Carla Carozzi
- Department of Anaesthesia, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | | | - Elisa Visani
- Clinical and Experimental Epileptology Division, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Eleonora Tobaldini
- Department of Internal Medicine, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Angelica Carandina
- Department of Internal Medicine, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Valeria Citterio
- Department of Internal Medicine, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Francesca Giulia Magnani
- Neurology, Public Health, Disability Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Martina Cacciatore
- Neurology, Public Health, Disability Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Eleonora Orena
- Department of Anaesthesia, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Nicola Montano
- Department of Internal Medicine, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Dario Caldiroli
- Department of Anaesthesia, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Silvana Franceschetti
- Neurophysiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Mario Picozzi
- Center for Clinical Ethics, Biotechnology and Life Sciences Department, Insubria University, Varese, Italy
| | - Leonardi Matilde
- Neurology, Public Health, Disability Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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Draguhn A, Mallatt JM, Robinson DG. Anesthetics and plants: no pain, no brain, and therefore no consciousness. PROTOPLASMA 2021; 258:239-248. [PMID: 32880005 PMCID: PMC7907021 DOI: 10.1007/s00709-020-01550-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 08/26/2020] [Indexed: 05/05/2023]
Abstract
Plants have a rich variety of interactions with their environment, including adaptive responses mediated by electrical signaling. This has prompted claims that information processing in plants is similar to that in animals and, hence, that plants are conscious, intelligent organisms. In several recent reports, the facts that general anesthetics cause plants to lose their sensory responses and behaviors have been taken as support for such beliefs. These lipophilic substances, however, alter multiple molecular, cellular, and systemic functions in almost every organism. In humans and other animals with complex brains, they eliminate the experience of pain and disrupt consciousness. The question therefore arises: do plants feel pain and have consciousness? In this review, we discuss what can be learned from the effects of anesthetics in plants. For this, we describe the mechanisms and structural prerequisites for pain sensations in animals and show that plants lack the neural anatomy and all behaviors that would indicate pain. By explaining the ubiquitous and diverse effects of anesthetics, we discuss whether these substances provide any empirical or logical evidence for "plant consciousness" and whether it makes sense to study the effects of anesthetics on plants for this purpose. In both cases, the answer is a resounding no.
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Affiliation(s)
- Andreas Draguhn
- Institute for Physiology and Pathophysiology, Medical Faculty, University of Heidelberg, 69120, Heidelberg, Germany
| | - Jon M Mallatt
- The University of Washington WWAMI Medical Education Program, The University of Idaho, Moscow, ID, 83844, USA
| | - David G Robinson
- Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120, Heidelberg, Germany.
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Foundations of Human Consciousness: Imaging the Twilight Zone. J Neurosci 2020; 41:1769-1778. [PMID: 33372062 PMCID: PMC8115882 DOI: 10.1523/jneurosci.0775-20.2020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 09/07/2020] [Accepted: 11/03/2020] [Indexed: 11/30/2022] Open
Abstract
What happens in the brain when conscious awareness of the surrounding world fades? We manipulated consciousness in two experiments in a group of healthy males and measured brain activity with positron emission tomography. Measurements were made during wakefulness, escalating and constant levels of two anesthetic agents (experiment 1, n = 39), and during sleep-deprived wakefulness and non-rapid eye movement sleep (experiment 2, n = 37). In experiment 1, the subjects were randomized to receive either propofol or dexmedetomidine until unresponsiveness. In both experiments, forced awakenings were applied to achieve rapid recovery from an unresponsive to a responsive state, followed by immediate and detailed interviews of subjective experiences during the preceding unresponsive condition. Unresponsiveness rarely denoted unconsciousness, as the majority of the subjects had internally generated experiences. Unresponsive anesthetic states and verified sleep stages, where a subsequent report of mental content included no signs of awareness of the surrounding world, indicated a disconnected state. Functional brain imaging comparing responsive and connected versus unresponsive and disconnected states of consciousness during constant anesthetic exposure revealed that activity of the thalamus, cingulate cortices, and angular gyri are fundamental for human consciousness. These brain structures were affected independent from the pharmacologic agent, drug concentration, and direction of change in the state of consciousness. Analogous findings were obtained when consciousness was regulated by physiological sleep. State-specific findings were distinct and separable from the overall effects of the interventions, which included widespread depression of brain activity across cortical areas. These findings identify a central core brain network critical for human consciousness. SIGNIFICANCE STATEMENT Trying to understand the biological basis of human consciousness is currently one of the greatest challenges of neuroscience. While the loss and return of consciousness regulated by anesthetic drugs and physiological sleep are used as model systems in experimental studies on consciousness, previous research results have been confounded by drug effects, by confusing behavioral “unresponsiveness” and internally generated consciousness, and by comparing brain activity levels across states that differ in several other respects than only consciousness. Here, we present carefully designed studies that overcome many previous confounders and for the first time reveal the neural mechanisms underlying human consciousness and its disconnection from behavioral responsiveness, both during anesthesia and during normal sleep, and in the same study subjects.
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Farnes N, Juel BE, Nilsen AS, Romundstad LG, Storm JF. Increased signal diversity/complexity of spontaneous EEG, but not evoked EEG responses, in ketamine-induced psychedelic state in humans. PLoS One 2020; 15:e0242056. [PMID: 33226992 PMCID: PMC7682856 DOI: 10.1371/journal.pone.0242056] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/27/2020] [Indexed: 01/21/2023] Open
Abstract
How and to what extent electrical brain activity reflects pharmacologically altered states and contents of consciousness, is not well understood. Therefore, we investigated whether measures of evoked and spontaneous electroencephalographic (EEG) signal diversity are altered by sub-anaesthetic levels of ketamine compared to normal wakefulness, and how these measures relate to subjective experience. High-density 62-channel EEG was used to record spontaneous brain activity and responses evoked by transcranial magnetic stimulation (TMS) in 10 healthy volunteers before and during administration of sub-anaesthetic doses of ketamine in an open-label within-subject design. Evoked signal diversity was assessed using the perturbational complexity index (PCI), calculated from EEG responses to TMS perturbations. Signal diversity of spontaneous EEG, with eyes open and eyes closed, was assessed by Lempel Ziv complexity (LZc), amplitude coalition entropy (ACE), and synchrony coalition entropy (SCE). Although no significant difference was found in TMS-evoked complexity (PCI) between the sub-anaesthetic ketamine condition and normal wakefulness, all measures of spontaneous EEG signal diversity (LZc, ACE, SCE) showed significantly increased values in the sub-anaesthetic ketamine condition. This increase in signal diversity correlated with subjective assessment of altered states of consciousness. Moreover, spontaneous signal diversity was significantly higher when participants had eyes open compared to eyes closed, both during normal wakefulness and during influence of sub-anaesthetic ketamine. The results suggest that PCI and spontaneous signal diversity may reflect distinct, complementary aspects of changes in brain properties related to altered states of consciousness: the brain’s capacity for information integration, assessed by PCI, might be indicative of the brain’s ability to sustain consciousness, while spontaneous complexity, as measured by EEG signal diversity, may be indicative of the complexity of conscious content. Thus, sub-anaesthetic ketamine may increase the complexity of the conscious content and the brain activity underlying it, while the level or general capacity for consciousness remains largely unaffected.
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Affiliation(s)
- Nadine Farnes
- Brain Signaling Group, Department of Molecular Medicine, University of Oslo, Oslo, Norway
| | - Bjørn E Juel
- Brain Signaling Group, Department of Molecular Medicine, University of Oslo, Oslo, Norway
| | - André S Nilsen
- Brain Signaling Group, Department of Molecular Medicine, University of Oslo, Oslo, Norway
| | - Luis G Romundstad
- Department of Anaesthesia, and Intervention Centre, Oslo University Hospital, Oslo, Norway
| | - Johan F Storm
- Brain Signaling Group, Department of Molecular Medicine, University of Oslo, Oslo, Norway
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Halder S, Juel BE, Nilsen AS, Raghavan LV, Storm JF. Changes in measures of consciousness during anaesthesia of one hemisphere (Wada test). Neuroimage 2020; 226:117566. [PMID: 33221442 DOI: 10.1016/j.neuroimage.2020.117566] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/25/2020] [Accepted: 11/16/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND In the Wada test, one hemisphere is selectively anaesthetised by unilateral intracarotid injection of a fast-acting anaesthetic agent. This gives a unique opportunity to observe the functions and physiological activity of one hemisphere while anaesthetising the other, allowing direct comparisons between brain states and hemispheres that are not possible in any other setting. AIM To test whether potential measures of consciousness would be affected by selective anaesthesia of one hemisphere, and reliably distinguish the states of the anesthetised and non-anesthetised hemispheres. METHODS We analysed EEG data from 7 patients undergoing Wada-tests in preparation for neurosurgery and computed several measures reported to correlate with the state of consciousness: power spectral density, functional connectivity, and measures of signal diversity. These measures were compared between conditions (normal rest vs. unilateral anaesthesia) and hemispheres (injected vs. non-injected), and used with a support vector machine to classify the state and site of injection objectively from individual patient's recordings. RESULTS Although brain function, assessed behaviourally, appeared to be substantially altered only on the injected side, we found large bilateral changes in power spectral density for all frequency bands tested, and functional connectivity changed significantly both between and within both hemispheres. Surprisingly, we found no statistically significant differences in the measures of signal diversity between hemispheres or states, for the group of 7 patients, although 4 of the individual patients showed a significant decrease in signal diversity on the injected side. Nevertheless, including signal diversity measures improved the classification results, indicating that these measures carry at least some non-redundant information about the condition and injection site. We propose that several of these results may be explained by conduction of activity, via the corpus callosum, from the injected to the contralateral hemisphere and vice versa, without substantially affecting the function of the receiving hemisphere, thus reflecting what we call "cross-state unreceptiveness".
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Affiliation(s)
- Sebastian Halder
- Brain Signalling Group, Section for Physiology, Department of Molecular Medicine, IMB, University of Oslo, 0317 Oslo, Norway; School of Computer Science and Electronic Engineering, University of Essex, CO4 3SQ Colchester, United Kingdom.
| | - Bjørn E Juel
- Brain Signalling Group, Section for Physiology, Department of Molecular Medicine, IMB, University of Oslo, 0317 Oslo, Norway; Department of Psychiatry, Center for Sleep and Consciousness, University of Wisconsin, Madison, WI, USA
| | - André S Nilsen
- Brain Signalling Group, Section for Physiology, Department of Molecular Medicine, IMB, University of Oslo, 0317 Oslo, Norway
| | - Lashmi Venkat Raghavan
- Department of Anesthesia and Pain Medicine, Toronto Western Hospital, University of Toronto, Canada
| | - Johan F Storm
- Brain Signalling Group, Section for Physiology, Department of Molecular Medicine, IMB, University of Oslo, 0317 Oslo, Norway.
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Volatile Anesthetics Activate a Leak Sodium Conductance in Retrotrapezoid Nucleus Neurons to Maintain Breathing during Anesthesia in Mice. Anesthesiology 2020; 133:824-838. [PMID: 32773689 DOI: 10.1097/aln.0000000000003493] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Volatile anesthetics moderately depress respiratory function at clinically relevant concentrations. Phox2b-expressing chemosensitive neurons in the retrotrapezoid nucleus, a respiratory control center, are activated by isoflurane, but the underlying mechanisms remain unclear. The hypothesis of this study was that the sodium leak channel contributes to the volatile anesthetics-induced modulation of retrotrapezoid nucleus neurons and to respiratory output. METHODS The contribution of sodium leak channels to isoflurane-, sevoflurane-, and propofol-evoked activity of Phox2b-expressing retrotrapezoid nucleus neurons and respiratory output were evaluated in wild-type and genetically modified mice lacking sodium leak channels (both sexes). Patch-clamp recordings were performed in acute brain slices. Whole-body plethysmography was used to measure the respiratory activity. RESULTS Isoflurane at 0.42 to 0.50 mM (~1.5 minimum alveolar concentration) increased the sodium leak channel-mediated holding currents and conductance from -75.0 ± 12.9 to -130.1 ± 34.9 pA (mean ± SD, P = 0.002, n = 6) and 1.8 ± 0.5 to 3.6 ± 1.0 nS (P = 0.001, n = 6), respectively. At these concentrations, isoflurane increased activity of Phox2b-expressing retrotrapezoid nucleus neurons from 1.1 ± 0.2 to 2.8 ± 0.2 Hz (P < 0.001, n = 5), which was eliminated by bath application of gadolinium or genetic silencing of sodium leak channel. Genetic silencing of sodium leak channel in the retrotrapezoid nucleus resulted in a diminished ventilatory response to carbon dioxide in mice under control conditions and during isoflurane anesthesia. Sevoflurane produced an effect comparable to that of isoflurane, whereas propofol did not activate sodium leak channel-mediated holding conductance. CONCLUSIONS Isoflurane and sevoflurane increase neuronal excitability of chemosensitive retrotrapezoid nucleus neurons partly by enhancing sodium leak channel conductance. Sodium leak channel expression in the retrotrapezoid nucleus is required for the ventilatory response to carbon dioxide during anesthesia by isoflurane and sevoflurane, thus identifying sodium leak channel as a requisite determinant of respiratory output during anesthesia of volatile anesthetics. EDITOR’S PERSPECTIVE
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Wang J, Sun P, Liang P. Neuropsychopharmacological effects of midazolam on the human brain. Brain Inform 2020; 7:15. [PMID: 33170396 PMCID: PMC7655878 DOI: 10.1186/s40708-020-00116-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 10/26/2020] [Indexed: 12/17/2022] Open
Abstract
As a commonly used anesthetic agent, midazolam has the properties of water-soluble, rapid onset, and short duration of action. With the rapid development in the field of neuroimaging, numerous studies have investigated how midazolam acts on the human brain to induce the alteration of consciousness. However, the neural bases of midazolam-induced sedation or anesthesia remain beginning to be understood in detail. In this review, we summarize findings from neuroimaging studies that have used midazolam to study altered consciousness at different levels and content. We also compare the results to those of neuroimaging studies using diverse anesthetic agents and describe the common neural correlates of anesthetic-induced alteration of consciousness.
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Affiliation(s)
- Junkai Wang
- School of Psychology, Capital Normal University, Haidian District, Beijing, 100048, China.,Beijing Key Laboratory of Learning and Cognition, Beijing, China.,Department of Psychology, Tsinghua University, Haidian District, Beijing, 100084, China
| | - Pei Sun
- Department of Psychology, Tsinghua University, Haidian District, Beijing, 100084, China.
| | - Peipeng Liang
- School of Psychology, Capital Normal University, Haidian District, Beijing, 100048, China. .,Beijing Key Laboratory of Learning and Cognition, Beijing, China.
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Patlatzoglou K, Chennu S, Gosseries O, Bonhomme V, Wolff A, Laureys S. Generalized Prediction of Unconsciousness during Propofol Anesthesia using 3D Convolutional Neural Networks. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:134-137. [PMID: 33017948 DOI: 10.1109/embc44109.2020.9175324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Neuroscience has generated a number of recent advances in the search for the neural correlates of consciousness, but these have yet to find valuable real-world applications. Electroencephalography under anesthesia provides a powerful experimental setup to identify electrophysiological signatures of altered states of consciousness, as well as a testbed for developing systems for automatic diagnosis and prognosis of awareness in clinical settings. In this work, we use deep convolutional neural networks to automatically differentiate sub-anesthetic states and depths of anesthesia, solely from one second of raw EEG signal. Our results with leave-one-participant-out-cross-validation show that behavioral measures, such as the Ramsay score, can be used to learn generalizable neural networks that reliably predict levels of unconsciousness in unseen transitional anesthetic states, as well as in unseen experimental setups and behaviors. Our findings highlight the potential of deep learning to detect progressive changes in anesthetic-induced unconsciousness with higher granularity than behavioral or pharmacological markers. This work has broader significance for identifying generalized patterns of brain activity that index states of consciousness.Clinical Relevance- In the United States alone, over 100,000 people receive general anesthesia every day, from which up to 1% is affected by unintended intraoperative awareness [1]. Despite this, brain-based monitoring of consciousness is not common in the clinic, and has had mixed success [2]. Given this context, our aim is to develop and explore an automated deep learning model that accurately predicts and interprets the depth and quality of anesthesia from the raw EEG signal.
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Aru J, Suzuki M, Larkum ME. Cellular Mechanisms of Conscious Processing. Trends Cogn Sci 2020; 24:814-825. [PMID: 32855048 DOI: 10.1016/j.tics.2020.07.006] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/16/2020] [Accepted: 07/21/2020] [Indexed: 01/08/2023]
Abstract
Recent breakthroughs in neurobiology indicate that the time is ripe to understand how cellular-level mechanisms are related to conscious experience. Here, we highlight the biophysical properties of pyramidal cells, which allow them to act as gates that control the evolution of global activation patterns. In conscious states, this cellular mechanism enables complex sustained dynamics within the thalamocortical system, whereas during unconscious states, such signal propagation is prohibited. We suggest that the hallmark of conscious processing is the flexible integration of bottom-up and top-down data streams at the cellular level. This cellular integration mechanism provides the foundation for Dendritic Information Theory, a novel neurobiological theory of consciousness.
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Affiliation(s)
- Jaan Aru
- Institute of Biology, Humboldt University of Berlin, Berlin, Germany; Institute of Computer Science, University of Tartu, Tartu, Estonia.
| | - Mototaka Suzuki
- Institute of Biology, Humboldt University of Berlin, Berlin, Germany
| | - Matthew E Larkum
- Institute of Biology, Humboldt University of Berlin, Berlin, Germany; Neurocure Center for Excellence, Charité Universitätsmedizin, Berlin, Germany.
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Luo M, Song B, Zhu J. Sleep Disturbances After General Anesthesia: Current Perspectives. Front Neurol 2020; 11:629. [PMID: 32733363 PMCID: PMC7360680 DOI: 10.3389/fneur.2020.00629] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/28/2020] [Indexed: 12/18/2022] Open
Abstract
The purpose of this article is to review (1) sleep mechanism under general anesthesia, harmful effects of postoperative sleep disturbances; (2) risk factors associated with postoperative sleep disturbances; (3) measures to prevent and improve postoperative sleep disturbances. General anesthesia changes the postoperative sleep structure especially in elderly patients after major surgery and results in a high incidence rate of sleep disturbances. Sleep disturbances produce harmful effects on postoperative patients and lead to a higher risk of delirium, more cardiovascular events, and poorer recovery. Some researchers do propose non-pharmacological treatments such as attention to environmental and psychological factors, application of electroacupuncture (EA) technology and pharmacological treatments are helpful, but larger high-quality clinical trials with longer following-up are needed to further investigate the efficacy and safety.
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Affiliation(s)
- Man Luo
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Bijia Song
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang, China.,Department of Anesthesiology, Friendship Hospital of Capital Medical University, Beijing, China
| | - Junchao Zhu
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang, China
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Reimann HM, Niendorf T. The (Un)Conscious Mouse as a Model for Human Brain Functions: Key Principles of Anesthesia and Their Impact on Translational Neuroimaging. Front Syst Neurosci 2020; 14:8. [PMID: 32508601 PMCID: PMC7248373 DOI: 10.3389/fnsys.2020.00008] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 01/27/2020] [Indexed: 12/11/2022] Open
Abstract
In recent years, technical and procedural advances have brought functional magnetic resonance imaging (fMRI) to the field of murine neuroscience. Due to its unique capacity to measure functional activity non-invasively, across the entire brain, fMRI allows for the direct comparison of large-scale murine and human brain functions. This opens an avenue for bidirectional translational strategies to address fundamental questions ranging from neurological disorders to the nature of consciousness. The key challenges of murine fMRI are: (1) to generate and maintain functional brain states that approximate those of calm and relaxed human volunteers, while (2) preserving neurovascular coupling and physiological baseline conditions. Low-dose anesthetic protocols are commonly applied in murine functional brain studies to prevent stress and facilitate a calm and relaxed condition among animals. Yet, current mono-anesthesia has been shown to impair neural transmission and hemodynamic integrity. By linking the current state of murine electrophysiology, Ca2+ imaging and fMRI of anesthetic effects to findings from human studies, this systematic review proposes general principles to design, apply and monitor anesthetic protocols in a more sophisticated way. The further development of balanced multimodal anesthesia, combining two or more drugs with complementary modes of action helps to shape and maintain specific brain states and relevant aspects of murine physiology. Functional connectivity and its dynamic repertoire as assessed by fMRI can be used to make inferences about cortical states and provide additional information about whole-brain functional dynamics. Based on this, a simple and comprehensive functional neurosignature pattern can be determined for use in defining brain states and anesthetic depth in rest and in response to stimuli. Such a signature can be evaluated and shared between labs to indicate the brain state of a mouse during experiments, an important step toward translating findings across species.
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Affiliation(s)
- Henning M. Reimann
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers (HZ), Berlin, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers (HZ), Berlin, Germany
- Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany
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Kamimura HAS, Conti A, Toschi N, Konofagou EE. Ultrasound neuromodulation: mechanisms and the potential of multimodal stimulation for neuronal function assessment. FRONTIERS IN PHYSICS 2020; 8:150. [PMID: 32509757 PMCID: PMC7274478 DOI: 10.3389/fphy.2020.00150] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Focused ultrasound (FUS) neuromodulation has shown that mechanical waves can interact with cell membranes and mechanosensitive ion channels, causing changes in neuronal activity. However, the thorough understanding of the mechanisms involved in these interactions are hindered by different experimental conditions for a variety of animal scales and models. While the lack of complete understanding of FUS neuromodulation mechanisms does not impede benefiting from the current known advantages and potential of this technique, a precise characterization of its mechanisms of action and their dependence on experimental setup (e.g., tuning acoustic parameters and characterizing safety ranges) has the potential to exponentially improve its efficacy as well as spatial and functional selectivity. This could potentially reach the cell type specificity typical of other, more invasive techniques e.g., opto- and chemogenetics or at least orientation-specific selectivity afforded by transcranial magnetic stimulation. Here, the mechanisms and their potential overlap are reviewed along with discussions on the potential insights into mechanisms that magnetic resonance imaging sequences along with a multimodal stimulation approach involving electrical, magnetic, chemical, light, and mechanical stimuli can provide.
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Affiliation(s)
- Hermes A. S. Kamimura
- Ultrasound Elasticity Imaging Laboratory, Department of Biomedical Engineering, Columbia University, New Yor, NY, USA
| | - Allegra Conti
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Nicola Toschi
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
- Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Charlestown, MA, USA
| | - Elisa E. Konofagou
- Ultrasound Elasticity Imaging Laboratory, Department of Biomedical Engineering, Columbia University, New Yor, NY, USA
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Baron Shahaf D, Hare GMT, Shahaf G. The Effects of Anesthetics on the Cortex-Lessons From Event-Related Potentials. Front Syst Neurosci 2020; 14:2. [PMID: 32116577 PMCID: PMC7026482 DOI: 10.3389/fnsys.2020.00002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/06/2020] [Indexed: 12/14/2022] Open
Abstract
Consciousness while under general anesthesia is a dreadful condition. Various electroencephalogram (EEG)-based technologies have been developed, on the basis of empirical evidence, in order to identify this condition. However, certain electrophysiological phenomena, which seem strongly related with depth of anesthesia in some drugs, appear less consistent with those of other anesthetic drugs. There is a gap between the complexity of the phenomenon of consciousness and its behavioral manifestations, on the one hand, and the empirical nature of the reported electrophysiological markers, which are associated with it, on the other hand. In fact, such a gap might prevent us from progressing toward unified electrophysiological markers of consciousness while under anesthesia, which are applicable to all anesthetic drugs. We believe that there is a need to bridge this conceptual gap. Therefore, in this work, we will try to present a theoretical framework for such bridging. First, we suggest focusing on neuropsychological processes, which seem to have a clear role in the behavioral manifestations of consciousness while under anesthesia but seem, nevertheless, better defined than consciousness itself-such as perception and attention. Then, we suggest analyzing the effects of anesthesia upon these neuropsychological processes, as they are manifested in the EEG signal. Specifically, we will focus on the effects of anesthesia on event-related potentials (ERPs), which seem more easily associable with neuropsychological modeling.
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Affiliation(s)
| | - Gregory M T Hare
- Department of Anesthesia, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada.,St. Michael's Hospital Center of Excellence for Patient Blood Management, St. Michael's Hospital, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Research, in the Li Ka Shing Knowledge Institute, Toronto, ON, Canada
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Martial C, Cassol H, Laureys S, Gosseries O. Near-Death Experience as a Probe to Explore (Disconnected) Consciousness. Trends Cogn Sci 2020; 24:173-183. [PMID: 31982302 DOI: 10.1016/j.tics.2019.12.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/17/2019] [Accepted: 12/17/2019] [Indexed: 12/15/2022]
Abstract
Forty-five years ago, the first evidence of near-death experience (NDE) during comatose state was provided, setting the stage for a new paradigm for studying the neural basis of consciousness in unresponsive states. At present, the state of consciousness associated with NDEs remains an open question. In the common view, consciousness is said to disappear in a coma with the brain shutting down, but this is an oversimplification. We argue that a novel framework distinguishing awareness, wakefulness, and connectedness is needed to comprehend the phenomenon. Classical NDEs correspond to internal awareness experienced in unresponsive conditions, thereby corresponding to an episode of disconnected consciousness. Our proposal suggests new directions for NDE research, and more broadly, consciousness science.
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Affiliation(s)
- Charlotte Martial
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium; Centre du Cerveau (Centre intégré pluridisciplinaire de l'étude du cerveau, de la cognition et de la conscience), University Hospital of Liège, Liège, Belgium.
| | - Héléna Cassol
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium; Centre du Cerveau (Centre intégré pluridisciplinaire de l'étude du cerveau, de la cognition et de la conscience), University Hospital of Liège, Liège, Belgium
| | - Steven Laureys
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium; Centre du Cerveau (Centre intégré pluridisciplinaire de l'étude du cerveau, de la cognition et de la conscience), University Hospital of Liège, Liège, Belgium
| | - Olivia Gosseries
- Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium; Centre du Cerveau (Centre intégré pluridisciplinaire de l'étude du cerveau, de la cognition et de la conscience), University Hospital of Liège, Liège, Belgium
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