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Pâslaru AC, Călin A, Morozan VP, Stancu M, Tofan L, Panaitescu AM, Zăgrean AM, Zăgrean L, Moldovan M. Burst-Suppression EEG Reactivity to Photic Stimulation-A Translational Biomarker in Hypoxic-Ischemic Brain Injury. Biomolecules 2024; 14:953. [PMID: 39199341 PMCID: PMC11352952 DOI: 10.3390/biom14080953] [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: 06/30/2024] [Revised: 07/28/2024] [Accepted: 08/02/2024] [Indexed: 09/01/2024] Open
Abstract
The reactivity of an electroencephalogram (EEG) to external stimuli is impaired in comatose patients showing burst-suppression (BS) patterns following hypoxic-ischemic brain injury (HIBI). We explored the reactivity of BS induced by isoflurane in rat models of HIBI and controls using intermittent photic stimulation (IPS) delivered to one eye. The relative time spent in suppression referred to as the suppression ratio (SR) was measured on the contralateral fronto-occipital cortical EEG channel. The BS reactivity (BSR) was defined as the decrease in the SR during IPS from the baseline before stimulation (SRPRE). We found that BSR increased with SRPRE. To standardize by anesthetic depth, we derived the BSR index (BSRi) as BSR divided by SRPRE. We found that the BSRi was decreased at 3 days after transient global cerebral ischemia in rats, which is a model of brain injury after cardiac arrest. The BSRi was also reduced 2 months after experimental perinatal asphyxia in rats, a model of birth asphyxia, which is a frequent neonatal complication in humans. Furthermore, Oxytocin attenuated BSRi impairment, consistent with a neuroprotective effect in this model. Our data suggest that the BSRi is a promising translational marker in HIBI which should be considered in future neuroprotection studies.
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Affiliation(s)
- Alexandru-Cătălin Pâslaru
- Division of Physiology—Neuroscience, Department of Functional Sciences, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania; (A.-C.P.); (V.-P.M.); (M.S.); (L.T.); (A.M.P.); (A.-M.Z.); (L.Z.)
| | - Alexandru Călin
- Department of Clinical Neurophysiology, King’s College Hospital NHS Foundation Trust, London SE59RS, UK;
| | - Vlad-Petru Morozan
- Division of Physiology—Neuroscience, Department of Functional Sciences, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania; (A.-C.P.); (V.-P.M.); (M.S.); (L.T.); (A.M.P.); (A.-M.Z.); (L.Z.)
| | - Mihai Stancu
- Division of Physiology—Neuroscience, Department of Functional Sciences, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania; (A.-C.P.); (V.-P.M.); (M.S.); (L.T.); (A.M.P.); (A.-M.Z.); (L.Z.)
- Division of Neurobiology, Ludwig-Maximilian University, 80539 Munich, Germany
| | - Laurențiu Tofan
- Division of Physiology—Neuroscience, Department of Functional Sciences, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania; (A.-C.P.); (V.-P.M.); (M.S.); (L.T.); (A.M.P.); (A.-M.Z.); (L.Z.)
| | - Anca Maria Panaitescu
- Division of Physiology—Neuroscience, Department of Functional Sciences, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania; (A.-C.P.); (V.-P.M.); (M.S.); (L.T.); (A.M.P.); (A.-M.Z.); (L.Z.)
- Clinical Hospital of Obstetrics and Gynaecology Filantropia, 011132 Bucharest, Romania
- Obstetrics and Gynaecology Department, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Ana-Maria Zăgrean
- Division of Physiology—Neuroscience, Department of Functional Sciences, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania; (A.-C.P.); (V.-P.M.); (M.S.); (L.T.); (A.M.P.); (A.-M.Z.); (L.Z.)
| | - Leon Zăgrean
- Division of Physiology—Neuroscience, Department of Functional Sciences, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania; (A.-C.P.); (V.-P.M.); (M.S.); (L.T.); (A.M.P.); (A.-M.Z.); (L.Z.)
| | - Mihai Moldovan
- Division of Physiology—Neuroscience, Department of Functional Sciences, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania; (A.-C.P.); (V.-P.M.); (M.S.); (L.T.); (A.M.P.); (A.-M.Z.); (L.Z.)
- Department of Neuroscience, University of Copenhagen, 2200 Copenhagen, Denmark
- Department of Neurology, Rigshospitalet, 2600 Glostrup, Denmark
- Department of Clinical Neurophysiology, Rigshospitalet, 2100 Copenhagen, Denmark
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Sarma AK, Popli G, Anzalone A, Contillo N, Cornell C, Nunn AM, Rowland JA, Godwin DW, Flashman LA, Couture D, Stapleton-Kotloski JR. Use of magnetic source imaging to assess recovery after severe traumatic brain injury-an MEG pilot study. Front Neurol 2023; 14:1257886. [PMID: 38020602 PMCID: PMC10656620 DOI: 10.3389/fneur.2023.1257886] [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: 07/14/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023] Open
Abstract
Rationale Severe TBI (sTBI) is a devastating neurological injury that comprises a significant global trauma burden. Early comprehensive neurocritical care and rehabilitation improve outcomes for such patients, although better diagnostic and prognostic tools are necessary to guide personalized treatment plans. Methods In this study, we explored the feasibility of conducting resting state magnetoencephalography (MEG) in a case series of sTBI patients acutely after injury (~7 days), and then about 1.5 and 8 months after injury. Synthetic aperture magnetometry (SAM) was utilized to localize source power in the canonical frequency bands of delta, theta, alpha, beta, and gamma, as well as DC-80 Hz. Results At the first scan, SAM source maps revealed zones of hypofunction, islands of preserved activity, and hemispheric asymmetry across bandwidths, with markedly reduced power on the side of injury for each patient. GCS scores improved at scan 2 and by scan 3 the patients were ambulatory. The SAM maps for scans 2 and 3 varied, with most patients showing increasing power over time, especially in gamma, but a continued reduction in power in damaged areas and hemispheric asymmetry and/or relative diminishment in power at the site of injury. At the group level for scan 1, there was a large excess of neural generators operating within the delta band relative to control participants, while the number of neural generators for beta and gamma were significantly reduced. At scan 2 there was increased beta power relative to controls. At scan 3 there was increased group-wise delta power in comparison to controls. Conclusion In summary, this pilot study shows that MEG can be safely used to monitor and track the recovery of brain function in patients with severe TBI as well as to identify patient-specific regions of decreased or altered brain function. Such MEG maps of brain function may be used in the future to tailor patient-specific rehabilitation plans to target regions of altered spectral power with neurostimulation and other treatments.
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Affiliation(s)
- Anand Karthik Sarma
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
- Neurocritical Care, Piedmont Atlanta Hospital, Atlanta, GA, United States
| | - Gautam Popli
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Anthony Anzalone
- Wake Forest University School of Medicine, Winston-Salem, NC, United States
- Department of Neurosurgery, Henry Ford Health System, Detroit, MI, United States
| | - Nicholas Contillo
- Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Cassandra Cornell
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Andrew M. Nunn
- Department of Surgery, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Jared A. Rowland
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, NC, United States
- Research and Education Department, W.G. (Bill) Hefner VA Healthcare System, Salisbury, NC, United States
| | - Dwayne W. Godwin
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, NC, United States
- Research and Education Department, W.G. (Bill) Hefner VA Healthcare System, Salisbury, NC, United States
| | - Laura A. Flashman
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Daniel Couture
- Department of Neurosurgery, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Jennifer R. Stapleton-Kotloski
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, NC, United States
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Tyulmenkova A, Zwick A, Dillon T, Isgor C. Progressive generalized tonic-clonic seizures in a transgenic mouse model of adult-onset epilepsy: Implications for morphological changes in cortico-limbic and brainstem structures. Epilepsy Res 2023; 194:107178. [PMID: 37295319 PMCID: PMC10527249 DOI: 10.1016/j.eplepsyres.2023.107178] [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: 03/17/2023] [Revised: 05/21/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023]
Abstract
Video/cortical electroencephalography (EEG) is monitored to assess progressive severity of generalized tonic clonic seizures (GTCSs) in a transgenic mouse model of adult-onset epilepsy with increased death risk. The mice overexpress the brain derived neurotrophic factor (BDNF) in the forebrain under the calcium/calmodulin dependent protein kinase 2a (termed TgBDNF) and develop GTCSs in response to tail suspension/cage agitation stimulation at 3-4 months of age. With successive GTCSs (a total of 16 across 10 weeks of assessment), seizures became more severe as evidenced by increased duration of postictal generalized EEG suppression (PGES) associated with loss of posture/consciousness. Mice also developed spike wave discharges with behavioral arrest during the seizure recovery that increased in duration as a function of number of GTCSs. Overall seizure duration (from preictal spike to offset of PGES) and ictal spectral power (full spectra) were also increased. Half of the TgBDNF mice expired following a long period of PGES at the last recorded GTCS. Seizure-evoked general arousal impairment was associated with a striking decrease in total number of gigantocellular neurons of the brainstem nucleus pontis oralis along with increase in volumes of the anterior cingulate cortex and dorsal dentate gyrus in severely convulsive TgBDNF mice compared to litter-matched WT controls and non-convulsive TgBDNF mice. The latter effect was accompanied with an increase in total number of hippocampal granule neurons. These results provide structure-function associations in an animal model of adult-onset GTCSs that progressively increase in severity with clinical relevance for sudden unexpected death following generalized seizures.
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Affiliation(s)
- Anastasia Tyulmenkova
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Amanda Zwick
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Tashi Dillon
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Ceylan Isgor
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA.
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Charpier S. Between life and death: the brain twilight zones. Front Neurosci 2023; 17:1156368. [PMID: 37260843 PMCID: PMC10227869 DOI: 10.3389/fnins.2023.1156368] [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: 02/01/2023] [Accepted: 04/24/2023] [Indexed: 06/02/2023] Open
Abstract
Clinically, and legally, death is considered a well-defined state of the organism characterized, at least, by a complete and irreversible cessation of brain activities and functions. According to this pragmatic approach, the moment of death is implicitly represented by a discrete event from which all cerebral processes abruptly cease. However, a growing body of experimental and clinical evidence has demonstrated that cardiorespiratory failure, the leading cause of death, causes complex time-dependent changes in neuronal activity that can lead to death but also be reversed with successful resuscitation. This review synthesizes our current knowledge of the succeeding alterations in brain activities that accompany the dying and resuscitation processes. The anoxia-dependent brain defects that usher in a process of potential death successively include: (1) a set of changes in electroencephalographic (EEG) and neuronal activities, (2) a cessation of brain spontaneous electrical activity (isoelectric state), (3) a loss of consciousness whose timing in relation to EEG changes remains unclear, (4) an increase in brain resistivity, caused by neuronal swelling, concomitant with the occurrence of an EEG deviation reflecting the neuronal anoxic insult (the so-called "wave of death," or "terminal spreading depolarization"), followed by, (5) a terminal isoelectric brain state leading to death. However, a timely restoration of brain oxygen supply-or cerebral blood flow-can initiate a mirrored sequence of events: a repolarization of neurons followed by a re-emergence of neuronal, synaptic, and EEG activities from the electrocerebral silence. Accordingly, a recent study has revealed a new death-related brain wave: the "wave of resuscitation," which is a marker of the collective recovery of electrical properties of neurons at the beginning of the brain's reoxygenation phase. The slow process of dying still represents a terra incognita, during which neurons and neural networks evolve in uncertain states that remain to be fully understood. As current event-based models of death have become neurophysiologically inadequate, I propose a new mixed (event-process) model of death and resuscitation. It is based on a detailed description of the different phases that succeed each other in a dying brain, which are generally described separately and without mechanistic linkage, in order to integrate them into a continuum of declining brain activity. The model incorporates cerebral twilight zones (with still unknown neuronal and synaptic processes) punctuated by two characteristic cortical waves providing real-time biomarkers of death- and resuscitation.
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Affiliation(s)
- Stéphane Charpier
- Sorbonne Université, Institut du Cerveau – Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié-Salpêtriére, Paris, France
- Sorbonne University, UPMC Université Paris, Paris, France
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5
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Fisch U, Jünger AL, Hert L, Rüegg S, Sutter R. Therapeutically induced EEG burst-suppression pattern to treat refractory status epilepticus—what is the evidence? ZEITSCHRIFT FÜR EPILEPTOLOGIE 2022. [DOI: 10.1007/s10309-022-00539-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractCurrent guidelines advocate to treat refractory status epilepticus (RSE) with continuously administered anesthetics to induce an artificial coma if first- and second-line antiseizure drugs have failed to stop seizure activity. A common surrogate for monitoring the depth of the artificial coma is the appearance of a burst-suppression pattern (BS) in the EEG. This review summarizes the current knowledge on the origin and neurophysiology of the BS phenomenon as well as the evidence from the literature for the presumed benefit of BS as therapy in adult patients with RSE.
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Portnova G, Nekrashevich M, Morozova M, Martynova O, Sharaev M. New approaches to Clinical Electroencephalography analysis in typically developing children and children with autism. COGN SYST RES 2022. [DOI: 10.1016/j.cogsys.2022.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Sirmpilatze N, Mylius J, Ortiz-Rios M, Baudewig J, Paasonen J, Golkowski D, Ranft A, Ilg R, Gröhn O, Boretius S. Spatial signatures of anesthesia-induced burst-suppression differ between primates and rodents. eLife 2022; 11:e74813. [PMID: 35607889 PMCID: PMC9129882 DOI: 10.7554/elife.74813] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 05/01/2022] [Indexed: 01/19/2023] Open
Abstract
During deep anesthesia, the electroencephalographic (EEG) signal of the brain alternates between bursts of activity and periods of relative silence (suppressions). The origin of burst-suppression and its distribution across the brain remain matters of debate. In this work, we used functional magnetic resonance imaging (fMRI) to map the brain areas involved in anesthesia-induced burst-suppression across four mammalian species: humans, long-tailed macaques, common marmosets, and rats. At first, we determined the fMRI signatures of burst-suppression in human EEG-fMRI data. Applying this method to animal fMRI datasets, we found distinct burst-suppression signatures in all species. The burst-suppression maps revealed a marked inter-species difference: in rats, the entire neocortex engaged in burst-suppression, while in primates most sensory areas were excluded-predominantly the primary visual cortex. We anticipate that the identified species-specific fMRI signatures and whole-brain maps will guide future targeted studies investigating the cellular and molecular mechanisms of burst-suppression in unconscious states.
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Affiliation(s)
- Nikoloz Sirmpilatze
- Functional Imaging Laboratory, German Primate Center – Leibniz Institute for Primate ResearchGöttingenGermany
- Georg-August University of GöttingenGöttingenGermany
- International Max Planck Research School for NeurosciencesGöttingenGermany
| | - Judith Mylius
- Functional Imaging Laboratory, German Primate Center – Leibniz Institute for Primate ResearchGöttingenGermany
| | - Michael Ortiz-Rios
- Functional Imaging Laboratory, German Primate Center – Leibniz Institute for Primate ResearchGöttingenGermany
| | - Jürgen Baudewig
- Functional Imaging Laboratory, German Primate Center – Leibniz Institute for Primate ResearchGöttingenGermany
| | - Jaakko Paasonen
- A.I.V. Institute for Molecular Sciences, University of Eastern FinlandKuopioFinland
| | - Daniel Golkowski
- Department of Neurology, Klinikum Rechts der Isar der Technischen Universität MünchenMunichGermany
- Department of Neurology, Heidelberg University HospitalHeidelbergGermany
| | - Andreas Ranft
- Department of Anesthesiology and Intensive Care Medicine, Klinikum Rechts der Isar der Technischen Universität MünchenMunichGermany
| | - Rüdiger Ilg
- Department of Neurology, Klinikum Rechts der Isar der Technischen Universität MünchenMunichGermany
- Department of Neurology, Asklepios Stadtklinik Bad TölzBad TölzGermany
| | - Olli Gröhn
- A.I.V. Institute for Molecular Sciences, University of Eastern FinlandKuopioFinland
| | - Susann Boretius
- Functional Imaging Laboratory, German Primate Center – Leibniz Institute for Primate ResearchGöttingenGermany
- Georg-August University of GöttingenGöttingenGermany
- International Max Planck Research School for NeurosciencesGöttingenGermany
- Leibniz Science Campus Primate CognitionGöttingenGermany
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Salami P, Borzello M, Kramer MA, Westover MB, Cash SS. Quantifying seizure termination patterns reveals limited pathways to seizure end. Neurobiol Dis 2022; 165:105645. [PMID: 35104646 PMCID: PMC8860887 DOI: 10.1016/j.nbd.2022.105645] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 01/06/2022] [Accepted: 01/26/2022] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE Despite their possible importance in the design of novel neuromodulatory approaches and in understanding status epilepticus, the dynamics and mechanisms of seizure termination are not well studied. We examined intracranial recordings from patients with epilepsy to differentiate seizure termination patterns and investigated whether these patterns are indicative of different underlying mechanisms. METHODS Seizures were classified into one of two termination patterns: (a) those that end simultaneously across the brain (synchronous), and (b) those whose termination is piecemeal across the cortex (asynchronous). Both types ended with either a burst suppression pattern, or continuous seizure activity. These patterns were quantified and compared using burst suppression ratio, absolute energy, and network connectivity. RESULTS Seizures with electrographic generalization showed burst suppression patterns in 90% of cases, compared with only 60% of seizures which remained focal. Interestingly, we found similar absolute energy and burst suppression ratios in seizures with synchronous and asynchronous termination, while seizures with continuous seizure activity were found to be different from seizures with burst suppression, showing lower energy during seizure and lower burst suppression ratio at the start and end of seizure. Finally, network density was observed to increase with seizure progression, with significantly lower densities in seizures with continuous seizure activity compared to seizures with burst suppression. SIGNIFICANCE Based on this spatiotemporal classification scheme, we suggest that there are a limited number of seizure termination patterns and dynamics. If this bears out, it would imply that the number of mechanisms underlying seizure termination is also constrained. Seizures with different termination patterns exhibit different dynamics even before their start. This may provide useful clues about how seizures may be managed, which in turn may lead to more targeted modes of therapy for seizure control.
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Affiliation(s)
- Pariya Salami
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Mia Borzello
- Department of Cognitive Science, University of California, San Diego, CA, USA; Computational Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | - M Brandon Westover
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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Ma K, Bebawy JF. Electroencephalographic Burst-Suppression, Perioperative Neuroprotection, Postoperative Cognitive Function, and Mortality: A Focused Narrative Review of the Literature. Anesth Analg 2021; 135:79-90. [PMID: 34871183 DOI: 10.1213/ane.0000000000005806] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Burst-suppression is an electroencephalographic pattern that results from a diverse array of pathophysiological causes and/or metabolic neuronal suppression secondary to the administration of anesthetic medications. The purpose of this review is to provide an overview of the physiological mechanisms that underlie the burst-suppression pattern and to present in a comprehensive way the available evidence both supporting and in opposition to the clinical use of this electroencephalographic pattern as a therapeutic measure in various perioperative settings.
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Affiliation(s)
- Kan Ma
- From the *Department of Anesthesiology and Pain Medicine, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
| | - John F Bebawy
- Department of Anesthesiology & Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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González-Trujano ME, Urbina-Trejo E, Santos-Valencia F, Villasana-Salazar B, Carmona-Aparicio L, Martínez-Vargas D. Pharmacological and toxicological effects of Ruta chalepensis L. on experimentally induced seizures and electroencephalographic spectral power in mice. JOURNAL OF ETHNOPHARMACOLOGY 2021; 271:113866. [PMID: 33485978 DOI: 10.1016/j.jep.2021.113866] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 12/22/2020] [Accepted: 01/18/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Ruta chalepensis L. (Rutaceae) is used in traditional medicine to treat a wide variety of disorders such as rheumatism, fever, mental disorders, dropsy, neuralgia, menstrual problems, anxiety, and epilepsy. AIM OF THE STUDY To evaluate and compare the anticonvulsant properties of an aqueous extract and ethyl acetate (AcOEt) fraction of R. chalepensis on pentylenetetrazole (PTZ)-induced seizures and maximal electroshock (MES) test in mice, by analyzing behavior and electroencephalogram (EEG), as well as GABAA receptors involvement. METHODS The effect of an acute administration of different dosage of the aqueous extract (300 or 500 mg/kg) or AcOEt fraction (100, 300, 500 or 1000 mg/kg) of R. chalepensis was explored on two different models of acute seizure induction in mice, the PTZ and maximal electroshock (MES) tests. Behavioral and electrographic effects were quantified. Additionally, the possible involvement of the GABAA receptors was explored in the presence of picrotoxin (a non-competitive antagonist of the GABAA receptor). RESULTS AcOEt fraction of R. chalepensis was more efficient than aqueous extract to reduce the incidence of tonic-clonic seizures and mortality in a significant and dose-dependent manner in both the PTZ and MES tests. This anticonvulsant effect was not abolished in the presence of picrotoxin. The EEG spectral power analysis revealed that aqueous extract decreased alpha and beta power, while AcOEt fraction decreased alpha and gamma power confirming previous findings of its depressant effect in the central nervous system. It is important to mention that the highest dosage of the AcOEt (1000 mg/kg) produced a severe suppression or isoelectric EEG activity (EEG flattening), recognized as a comatose state, suggesting a neurotoxic effect at this dosage. CONCLUSION Our data reinforce that depressant and anticonvulsant effects of R. chalepensis depend in part on the presence of constituents from medium polarity. We also found that anticonvulsant effect is not mediated by GABAA receptors. In addition, cautious is emphasized when high doses of this natural product are used in traditional medicine since it might produce neurotoxic effects.
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Affiliation(s)
- M E González-Trujano
- Laboratorio de Neurofarmacología de Productos Naturales, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría "Ramón de La Fuente Muñiz", Calz. México-Xochimilco 101, Col. San Lorenzo Huipulco, 14370, Ciudad de México, Mexico.
| | - E Urbina-Trejo
- Laboratorio de Neurofisiología Del Control y La Regulación, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría "Ramón de La Fuente Muñiz", Calz. México-Xochimilco 101, Col. San Lorenzo Huipulco, 14370, Ciudad de México, Mexico.
| | - F Santos-Valencia
- Laboratorio de Neurofisiología Del Control y La Regulación, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría "Ramón de La Fuente Muñiz", Calz. México-Xochimilco 101, Col. San Lorenzo Huipulco, 14370, Ciudad de México, Mexico.
| | - B Villasana-Salazar
- Laboratorio de Neurofisiología Del Control y La Regulación, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría "Ramón de La Fuente Muñiz", Calz. México-Xochimilco 101, Col. San Lorenzo Huipulco, 14370, Ciudad de México, Mexico.
| | - L Carmona-Aparicio
- Laboratorio de Neurociencias, Instituto Nacional de Pediatría, 04530, Ciudad de México, Mexico.
| | - D Martínez-Vargas
- Laboratorio de Neurofisiología Del Control y La Regulación, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría "Ramón de La Fuente Muñiz", Calz. México-Xochimilco 101, Col. San Lorenzo Huipulco, 14370, Ciudad de México, Mexico.
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Lott DT, Yeshi T, Norchung N, Dolma S, Tsering N, Jinpa N, Woser T, Dorjee K, Desel T, Fitch D, Finley AJ, Goldman R, Bernal AMO, Ragazzi R, Aroor K, Koger J, Francis A, Perlman DM, Wielgosz J, Bachhuber DRW, Tamdin T, Sadutshang TD, Dunne JD, Lutz A, Davidson RJ. No Detectable Electroencephalographic Activity After Clinical Declaration of Death Among Tibetan Buddhist Meditators in Apparent Tukdam, a Putative Postmortem Meditation State. Front Psychol 2021; 11:599190. [PMID: 33584435 PMCID: PMC7876463 DOI: 10.3389/fpsyg.2020.599190] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/14/2020] [Indexed: 11/13/2022] Open
Abstract
Recent EEG studies on the early postmortem interval that suggest the persistence of electrophysiological coherence and connectivity in the brain of animals and humans reinforce the need for further investigation of the relationship between the brain's activity and the dying process. Neuroscience is now in a position to empirically evaluate the extended process of dying and, more specifically, to investigate the possibility of brain activity following the cessation of cardiac and respiratory function. Under the direction of the Center for Healthy Minds at the University of Wisconsin-Madison, research was conducted in India on a postmortem meditative state cultivated by some Tibetan Buddhist practitioners in which decomposition is putatively delayed. For all healthy baseline (HB) and postmortem (PM) subjects presented here, we collected resting state electroencephalographic data, mismatch negativity (MMN), and auditory brainstem response (ABR). In this study, we present HB data to demonstrate the feasibility of a sparse electrode EEG configuration to capture well-defined ERP waveforms from living subjects under very challenging field conditions. While living subjects displayed well-defined MMN and ABR responses, no recognizable EEG waveforms were discernable in any of the tukdam cases.
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Affiliation(s)
- Dylan T. Lott
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | - Tenzin Yeshi
- Men-Tsee-Khang/TMAI, Upmuhal, Dharamshala, Himachal Pradesh, India
| | - N. Norchung
- Men-Tsee-Khang/TMAI, Upmuhal, Dharamshala, Himachal Pradesh, India
| | - Sonam Dolma
- Men-Tsee-Khang/TMAI, Upmuhal, Dharamshala, Himachal Pradesh, India
| | - Nyima Tsering
- Men-Tsee-Khang/TMAI, Upmuhal, Dharamshala, Himachal Pradesh, India
| | - Ngawang Jinpa
- Men-Tsee-Khang/TMAI, Upmuhal, Dharamshala, Himachal Pradesh, India
| | - Tenzin Woser
- Men-Tsee-Khang/TMAI, Upmuhal, Dharamshala, Himachal Pradesh, India
| | - Kunsang Dorjee
- Men-Tsee-Khang/TMAI, Upmuhal, Dharamshala, Himachal Pradesh, India
| | - Tenzin Desel
- Men-Tsee-Khang/TMAI, Upmuhal, Dharamshala, Himachal Pradesh, India
| | - Dan Fitch
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | - Anna J. Finley
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | - Robin Goldman
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | | | - Rachele Ragazzi
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | - Karthik Aroor
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | - John Koger
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | - Andy Francis
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | - David M. Perlman
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | - Joseph Wielgosz
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | - David R. W. Bachhuber
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
| | - Tsewang Tamdin
- Men-Tsee-Khang/TMAI, Upmuhal, Dharamshala, Himachal Pradesh, India
| | | | - John D. Dunne
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
- Department of East Asian Languages and Literature, University of Wisconsin-Madison, Madison, WI, United States
| | - Antoine Lutz
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
- Lyon Neuroscience Research Centre, INSERM U1028, CNRS UMR5292, Lyon 1 University, Lyon, France
| | - Richard J. Davidson
- Center for Health Minds, University of Wisconsin-Madison, Madison, WI, United States
- Departments of Psychology and Psychiatry, University of Wisconsin-Madison, Madison, WI, United States
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12
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Carton-Leclercq A, Lecas S, Chavez M, Charpier S, Mahon S. Neuronal excitability and sensory responsiveness in the thalamo-cortical network in a novel rat model of isoelectric brain state. J Physiol 2020; 599:609-629. [PMID: 33095909 DOI: 10.1113/jp280266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 10/21/2020] [Indexed: 01/04/2023] Open
Abstract
KEY POINTS The neuronal and network properties that persist during an isoelectric coma remain largely unknown. We developed a new in vivo rat model to assess cell excitability and sensory responsiveness in the thalamo-cortical pathway during an isoflurane-induced isoelectric brain state. The isoelectric electrocorticogram reflected a complete interruption of spontaneous synaptic and firing activities in cortical and thalamic neurons. Cell excitability and sensory responses in the thalamo-cortical network persisted at a reduced level in the isoelectric condition and returned to control values after resumption of background brain activity. These findings could lead to a reassessment of the functional status of the drug-induced isoelectric state: a latent state in which individual neurons and networks retain to some extent the ability of being activated by external inputs. ABSTRACT The neuronal and network properties that persist in an isoelectric brain completely deprived of spontaneous electrical activity remain largely unexplored. Here, we developed a new in vivo rat model to examine cell excitability and sensory responsiveness in somatosensory thalamo-cortical networks during the interruption of endogenous brain activity induced by high doses of isoflurane. Electrocorticograms (ECoGs) from the barrel cortex were captured simultaneously with either intracellular recordings of subjacent cortical pyramidal neurons or extracellular records of the related thalamo-cortical neurons. Isoelectric ECoG periods reflected the disappearance of spontaneous synaptic and firing activities in cortical and thalamic neurons. This was associated with a sustained membrane hyperpolarization and a reduced intrinsic excitability in deep-layer cortical neurons, without significant changes in their membrane input resistance. Concomitantly, we found that whisker-evoked potentials in the ECoG and synaptic responses in cortical neurons were attenuated in amplitude and increased in latency. Impaired responsiveness in the barrel cortex paralleled with a lowering of the sensory-induced firing in thalamic cells. The return of endogenous brain electrical activities, after reinstatement of a control isoflurane concentration, led to the recovery of cortical neurons excitability and sensory responsiveness. These findings demonstrate the persistence of a certain level of cell excitability and sensory integration in the isoelectric state and the full recovery of cortico-thalamic functions after restoration of internal cerebral activities.
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Affiliation(s)
- Antoine Carton-Leclercq
- Institut du Cerveau, ICM, INSERM UMRS 1127, CNRS UMR 7225, Pitié-Salpêtrière Hospital, Paris, France
| | - Sarah Lecas
- Institut du Cerveau, ICM, INSERM UMRS 1127, CNRS UMR 7225, Pitié-Salpêtrière Hospital, Paris, France.,Sorbonne University, UPMC Université Paris, Paris, France
| | - Mario Chavez
- Institut du Cerveau, ICM, INSERM UMRS 1127, CNRS UMR 7225, Pitié-Salpêtrière Hospital, Paris, France
| | - Stéphane Charpier
- Institut du Cerveau, ICM, INSERM UMRS 1127, CNRS UMR 7225, Pitié-Salpêtrière Hospital, Paris, France.,Sorbonne University, UPMC Université Paris, Paris, France
| | - Séverine Mahon
- Institut du Cerveau, ICM, INSERM UMRS 1127, CNRS UMR 7225, Pitié-Salpêtrière Hospital, Paris, France
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13
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Suhre W, Van Norman GA. Ethical Issues in Organ Transplantation at End of Life: Defining Death. Anesthesiol Clin 2020; 38:231-246. [PMID: 32008655 DOI: 10.1016/j.anclin.2019.10.009] [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] [Indexed: 06/10/2023]
Abstract
End-of-life vital organ transplantation involves singular ethical issues, because survival of the donor is impossible, and organ retrieval is ideally as close to the death of the donor as possible to minimize organ ischemic time. Historical efforts to define death have been met with confusion and discord. Fifty years on, the Harvard criteria for brain death continue to be problematic and now face significant legislative efforts to limit their authority.
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Affiliation(s)
- Wendy Suhre
- Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Box 356540, 1959 Northeast Pacific Street, Seattle, WA 98195, USA
| | - Gail A Van Norman
- Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA; Bioethics, University of Washington, Seattle, WA, USA.
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14
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Tanaka M, Kidokoro H, Kubota T, Fukasawa T, Okai Y, Sakaguchi Y, Ito Y, Yamamoto H, Ohno A, Nakata T, Negoro T, Okumura A, Kato T, Watanabe K, Takahashi Y, Natsume J. Pseudo-sawtooth pattern on amplitude-integrated electroencephalography in neonatal hypoxic-ischemic encephalopathy. Pediatr Res 2020; 87:529-535. [PMID: 31493771 DOI: 10.1038/s41390-019-0567-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 08/08/2019] [Accepted: 08/16/2019] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The objective of this study was to describe a novel amplitude-integrated electroencephalography (aEEG) pattern in infants with hypoxic-ischemic encephalopathy (HIE) and to assess the clinical significance. METHODS The aEEG traces of infants with HIE who were treated with therapeutic hypothermia (TH) from 2012 to 2017 were analyzed. A pseudo-sawtooth (PST) pattern was defined as a periodic increase of the upper and/or lower margin of the trace on aEEG without showing seizure activities on conventional EEG (CEEG). RESULTS Of the 46 infants, 6 (13%) had the PST pattern. The PST pattern appeared following a flat trace or a continuous low-voltage pattern and was followed by a burst-suppression pattern. On CEEG, the PST pattern consists of alternating cycles of low-voltage irregular activities and almost flat tracing. The PST pattern was associated with neuroimaging abnormalities and with various degrees of neurodevelopmental outcomes. Positive predictive values of the PST or worse pattern for adverse outcomes were high at 12 h after birth. CONCLUSION A novel aEEG background pattern in infants with HIE was reported. The PST pattern likely indicates a suppressed background pattern and may be linked to unfavorable outcomes. Further multicenter validation study is needed to clarify its clinical significance.
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Affiliation(s)
- Masaharu Tanaka
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroyuki Kidokoro
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan.
| | - Tetsuo Kubota
- Department of Pediatrics, Anjo Kosei Hospital, Anjo, Japan
| | | | - Yu Okai
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoko Sakaguchi
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yuji Ito
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroyuki Yamamoto
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Atsuko Ohno
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tomohiko Nakata
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tamiko Negoro
- Department of Pediatrics, Anjo Kosei Hospital, Anjo, Japan
| | - Akihisa Okumura
- Department of Pediatrics, Aichi Medical University, Nagakute, Japan
| | - Toru Kato
- Department of Pediatrics, Okazaki City Hospital, Okazaki, Japan
| | - Kazuyoshi Watanabe
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshiyuki Takahashi
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Jun Natsume
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Developmental Disability Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
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15
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Traub RD, Moeller F, Rosch R, Baldeweg T, Whittington MA, Hall SP. Seizure initiation in infantile spasms vs. focal seizures: proposed common cellular mechanisms. Rev Neurosci 2020; 31:181-200. [PMID: 31525161 DOI: 10.1515/revneuro-2019-0030] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 06/01/2019] [Indexed: 11/15/2022]
Abstract
Infantile spasms (IS) and seizures with focal onset have different clinical expressions, even when electroencephalography (EEG) associated with IS has some degree of focality. Oddly, identical pathology (with, however, age-dependent expression) can lead to IS in one patient vs. focal seizures in another or even in the same, albeit older, patient. We therefore investigated whether the cellular mechanisms underlying seizure initiation are similar in the two instances: spasms vs. focal. We noted that in-common EEG features can include (i) a background of waves at alpha to delta frequencies; (ii) a period of flattening, lasting about a second or more - the electrodecrement (ED); and (iii) often an interval of very fast oscillations (VFO; ~70 Hz or faster) preceding, or at the beginning of, the ED. With IS, VFO temporally coincides with the motor spasm. What is different between the two conditions is this: with IS, the ED reverts to recurring slow waves, as occurring before the ED, whereas with focal seizures the ED instead evolves into an electrographic seizure, containing high-amplitude synchronized bursts, having superimposed VFO. We used in vitro data to help understand these patterns, as such data suggest cellular mechanisms for delta waves, for VFO, for seizure-related burst complexes containing VFO, and, more recently, for the ED. We propose a unifying mechanistic hypothesis - emphasizing the importance of brain pH - to explain the commonalities and differences of EEG signals in IS versus focal seizures.
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Affiliation(s)
- Roger D Traub
- IBM Thomas J. Watson Research Center, Yorktown Heights, NY 10598, USA
- Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Friederike Moeller
- Department of Clinical Neurophysiology, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Richard Rosch
- MRC Centre for Neurodevelopmental Disorders, King's College London, New Hunt's House, London SE1 1UL, UK
| | - Torsten Baldeweg
- Institute of Child Health, University College London, 30 Guildford Street, London WC1N 1EH, UK
| | | | - Stephen P Hall
- Hull York Medical School, University of York, Heslington YO10 5DD, UK
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16
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Gao S, Proekt A, Renier N, Calderon DP, Pfaff DW. Activating an anterior nucleus gigantocellularis subpopulation triggers emergence from pharmacologically-induced coma in rodents. Nat Commun 2019; 10:2897. [PMID: 31263107 PMCID: PMC6603023 DOI: 10.1038/s41467-019-10797-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/01/2019] [Indexed: 02/08/2023] Open
Abstract
Multiple areas within the reticular activating system (RAS) can hasten awakening from sleep or light planes of anesthesia. However, stimulation in individual sites has shown limited recovery from deep global suppression of brain activity, such as coma. Here we identify a subset of RAS neurons within the anterior portion of nucleus gigantocellularis (aNGC) capable of producing a high degree of awakening represented by a broad high frequency cortical reactivation associated with organized movements and behavioral reactivity to the environment from two different models of deep pharmacologically-induced coma (PIC): isoflurane (1.25%-1.5%) and induced hypoglycemic coma. Activating aNGC neurons triggered awakening by recruiting cholinergic, noradrenergic, and glutamatergic arousal pathways. In summary, we identify an evolutionarily conserved population of RAS neurons, which broadly restore cerebral cortical activation and motor behavior in rodents through the coordinated activation of multiple arousal-promoting circuits.
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Affiliation(s)
- S Gao
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, 10065, USA
| | - A Proekt
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, 10065, USA
- Laboratory of Neurobiology and Behavior, the Rockefeller University, New York, NY, 10065, USA
| | - N Renier
- ICM, Brain and Spine Institute, Hopital de la Pitie-Salpetriere, Sorbonne Universite, Inserm, CNRS, Paris, 75013, France
| | - D P Calderon
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, 10065, USA.
- Laboratory of Neurobiology and Behavior, the Rockefeller University, New York, NY, 10065, USA.
| | - D W Pfaff
- Laboratory of Neurobiology and Behavior, the Rockefeller University, New York, NY, 10065, USA
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17
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Abstract
Companion animal euthanasia is of great emotional, social, ethical, and medical significance because of the strong bond between pets and their owners. Few studies exist quantifying adverse events during and after euthanasia. Such events have profound effects on pet owners, veterinary professionals and veterinary patients. Best practices or standards of care have yet to be established. Companion animal euthanasia warrants further rigorous investigation regarding current veterinary medical practices due to its significant, complex, and far-reaching effects. Literature evaluating human euthanasia and assisted death in countries where such practices are legal can be a useful area of investigation and collaborative inquiry.
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Affiliation(s)
- Beth Marchitelli
- 4 Paws Farewell, Mobile Pet Hospice, Palliative Care and Home Euthanasia, Asheville, NC 28806, USA.
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18
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Sinmyee S, Pandit VJ, Pascual JM, Dahan A, Heidegger T, Kreienbühl G, Lubarsky DA, Pandit JJ. Legal and ethical implications of defining an optimum means of achieving unconsciousness in assisted dying. Anaesthesia 2019; 74:630-637. [PMID: 30786320 DOI: 10.1111/anae.14532] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2018] [Indexed: 01/15/2023]
Abstract
A decision by a society to sanction assisted dying in any form should logically go hand-in-hand with defining the acceptable method(s). Assisted dying is legal in several countries and we have reviewed the methods commonly used, contrasting these with an analysis of capital punishment in the USA. We expected that, since a common humane aim is to achieve unconsciousness at the point of death, which then occurs rapidly without pain or distress, there might be a single technique being used. However, the considerable heterogeneity in methods suggests that an optimum method of achieving unconsciousness remains undefined. In voluntary assisted dying (in some US states and European countries), the common method to induce unconsciousness appears to be self-administered barbiturate ingestion, with death resulting slowly from asphyxia due to cardiorespiratory depression. Physician-administered injections (a combination of general anaesthetic and neuromuscular blockade) are an option in Dutch guidelines. Hypoxic methods involving helium rebreathing have also been reported. The method of capital punishment (USA) resembles the Dutch injection technique, but specific drugs, doses and monitoring employed vary. However, for all these forms of assisted dying, there appears to be a relatively high incidence of vomiting (up to 10%), prolongation of death (up to 7 days), and re-awakening from coma (up to 4%), constituting failure of unconsciousness. This raises a concern that some deaths may be inhumane, and we have used lessons from the most recent studies of accidental awareness during anaesthesia to describe an optimal means that could better achieve unconsciousness. We found that the very act of defining an 'optimum' itself has important implications for ethics and the law.
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Affiliation(s)
- S Sinmyee
- Department of Anaesthesia, Northwick Park Hospital, London North West Healthcare NHS Trust, London, UK
| | - V J Pandit
- University of Kent, UK.,l'Aix-Marseille Université, Marseille, France
| | - J M Pascual
- Department of Neurology and Neurotherapeutics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - A Dahan
- Department of Anesthesiology, Leiden University Medical Center, Leiden, the Netherlands
| | - T Heidegger
- Department of Anaesthesia, Intensive Care and Resuscitation Spitalregion Rheintal Werdenberg Sarganserland, Grabs, Switzerland.,University of Bern, Bern, Switzerland
| | - G Kreienbühl
- Kantonsspital St. Gallen and Former Head of Research Ethics Committee, Kanton St Gallen, Switzerland
| | - D A Lubarsky
- Human Health Sciences and Chief Executive Officer, University of California, UC Davis Health, USA
| | - J J Pandit
- Nuffield Department of Anaesthetics, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
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19
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Pais-Roldán P, Edlow BL, Jiang Y, Stelzer J, Zou M, Yu X. Multimodal assessment of recovery from coma in a rat model of diffuse brainstem tegmentum injury. Neuroimage 2019; 189:615-630. [PMID: 30708105 DOI: 10.1016/j.neuroimage.2019.01.060] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/07/2019] [Accepted: 01/22/2019] [Indexed: 01/03/2023] Open
Abstract
Despite the association between brainstem lesions and coma, a mechanistic understanding of coma pathogenesis and recovery is lacking. We developed a coma model in the rat mimicking human brainstem coma, which allowed multimodal analysis of a brainstem tegmentum lesion's effects on behavior, cortical electrophysiology, and global brain functional connectivity. After coma induction, we observed a transient period (∼1h) of unresponsiveness accompanied by cortical burst-suppression. Comatose rats then gradually regained behavioral responsiveness concurrent with emergence of delta/theta-predominant cortical rhythms in primary somatosensory cortex. During the acute stage of coma recovery (∼1-8h), longitudinal resting-state functional MRI revealed an increase in functional connectivity between subcortical arousal nuclei in the thalamus, basal forebrain, and basal ganglia and cortical regions implicated in awareness. This rat coma model provides an experimental platform to systematically study network-based mechanisms of coma pathogenesis and recovery, as well as to test targeted therapies aimed at promoting recovery of consciousness after coma.
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Affiliation(s)
- Patricia Pais-Roldán
- High-Field Magnetic Resonance Department, Max Planck Institute for Biological Cybernetics, Tuebingen, 72076, Germany; Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tuebingen, Tuebingen, 72074, Germany
| | - Brian L Edlow
- Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, Boston, MA, 02114, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Yuanyuan Jiang
- High-Field Magnetic Resonance Department, Max Planck Institute for Biological Cybernetics, Tuebingen, 72076, Germany
| | - Johannes Stelzer
- High-Field Magnetic Resonance Department, Max Planck Institute for Biological Cybernetics, Tuebingen, 72076, Germany
| | - Ming Zou
- Department of Geriatrics & Neurology, The 2nd Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
| | - Xin Yu
- High-Field Magnetic Resonance Department, Max Planck Institute for Biological Cybernetics, Tuebingen, 72076, Germany; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA.
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20
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Gent TC, Detotto C, Vyssotski AL, Bettschart-Wolfensberger R. Epileptiform activity during inert gas euthanasia of mice. PLoS One 2018; 13:e0195872. [PMID: 29672545 PMCID: PMC5908136 DOI: 10.1371/journal.pone.0195872] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 03/30/2018] [Indexed: 02/04/2023] Open
Abstract
Carbon dioxide (CO2) is one of the most commonly used euthanasia agents for mice, yet it is highly aversive and nociceptive. Inert gases are a possible alternative, however there are qualitative reports of seizures resulting from exposure. Here we evaluate epileptiform activity caused by inert gases (N2, He, Ar and Xe) and CO2 in mice chronically instrumented for EEG/EMG undergoing single-gas euthanasia. We found that N2, He and Ar caused epileptiform activity in all animals, CO2 in half of animals and no epileptiform activity produced by Xe. Atmospheric O2 concentrations at epileptiform activity onset were significantly higher for CO2 than for all other gases and occurred soon after loss of motion, whereas N2 and Ar epileptiform activity occurred at cessation of neocortical activity. Helium caused the longest epileptiform activity and these commenced significantly before isoelectric EEG. We did not detect any epileptiform activity during active behaviour. Taken together, these results demonstrate that whilst epileptiform activity from inert gases and particularly Ar and N2 are more prevalent than for CO2, their occurrence at the onset of an isoelectric EEG is unlikely to impact on the welfare of the animal. Epileptiform activity from these gases should not preclude them from further investigation as euthanasia agents. The genesis of epileptiform activity from CO2 is unlikely to result from hypoxia as with the inert gases. Helium caused epileptiform activity before cessation of neocortical activity and for a longer duration and is therefore less suitable as an alternative to CO2.
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Affiliation(s)
- Thomas C. Gent
- Anaesthesiology Section, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
- * E-mail:
| | - Carlotta Detotto
- Anaesthesiology Section, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
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21
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Altwegg-Boussac T, Schramm AE, Ballestero J, Grosselin F, Chavez M, Lecas S, Baulac M, Naccache L, Demeret S, Navarro V, Mahon S, Charpier S. Cortical neurons and networks are dormant but fully responsive during isoelectric brain state. Brain 2017; 140:2381-2398. [PMID: 29050394 DOI: 10.1093/brain/awx175] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 05/29/2017] [Indexed: 01/30/2023] Open
Abstract
A continuous isoelectric electroencephalogram reflects an interruption of endogenously-generated activity in cortical networks and systematically results in a complete dissolution of conscious processes. This electro-cerebral inactivity occurs during various brain disorders, including hypothermia, drug intoxication, long-lasting anoxia and brain trauma. It can also be induced in a therapeutic context, following the administration of high doses of barbiturate-derived compounds, to interrupt a hyper-refractory status epilepticus. Although altered sensory responses can be occasionally observed on an isoelectric electroencephalogram, the electrical membrane properties and synaptic responses of individual neurons during this cerebral state remain largely unknown. The aim of the present study was to characterize the intracellular correlates of a barbiturate-induced isoelectric electroencephalogram and to analyse the sensory-evoked synaptic responses that can emerge from a brain deprived of spontaneous electrical activity. We first examined the sensory responsiveness from patients suffering from intractable status epilepticus and treated by administration of thiopental. Multimodal sensory responses could be evoked on the flat electroencephalogram, including visually-evoked potentials that were significantly amplified and delayed, with a high trial-to-trial reproducibility compared to awake healthy subjects. Using an analogous pharmacological procedure to induce prolonged electro-cerebral inactivity in the rat, we could describe its cortical and subcortical intracellular counterparts. Neocortical, hippocampal and thalamo-cortical neurons were all silent during the isoelectric state and displayed a flat membrane potential significantly hyperpolarized compared with spontaneously active control states. Nonetheless, all recorded neurons could fire action potentials in response to intracellularly injected depolarizing current pulses and their specific intrinsic electrophysiological features were preserved. Manipulations of the membrane potential and intracellular injection of chloride in neocortical neurons failed to reveal an augmented synaptic inhibition during the isoelectric condition. Consistent with the sensory responses recorded from comatose patients, large and highly reproducible somatosensory-evoked potentials could be generated on the inactive electrocorticogram in rats. Intracellular recordings revealed that the underlying neocortical pyramidal cells responded to sensory stimuli by complex synaptic potentials able to trigger action potentials. As in patients, sensory responses in the isoelectric state were delayed compared to control responses and exhibited an elevated reliability during repeated stimuli. Our findings demonstrate that during prolonged isoelectric brain state neurons and synaptic networks are dormant rather than excessively inhibited, conserving their intrinsic properties and their ability to integrate and propagate environmental stimuli.
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Affiliation(s)
- Tristan Altwegg-Boussac
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Adrien E Schramm
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Jimena Ballestero
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Fanny Grosselin
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Mario Chavez
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Sarah Lecas
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France.,UPMC Univ Paris 06, F-75005, Paris, France
| | - Michel Baulac
- Epilepsy Unit, Clinical Neurophysiology Department, AP-HP, Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Lionel Naccache
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France.,Evoked Potential Unit, Neurophysiology Department, AP-HP, Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Sophie Demeret
- Intensive Care Unit of Neurology, Neurology Department, AP-HP, Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Vincent Navarro
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France.,Epilepsy Unit, Clinical Neurophysiology Department, AP-HP, Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Séverine Mahon
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Stéphane Charpier
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France.,UPMC Univ Paris 06, F-75005, Paris, France
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22
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Demianenko LE, Poddubnaya EP, Makedonsky IA, Kulagina IB, Korogod SM. Hypothermic Suppression of Epileptiform Bursting Activity of a Hyppocampal Granule Neuron Possessing Thermosensitive TRP Channels (a Model Study: Biophysical and Clinical Aspects). NEUROPHYSIOLOGY+ 2017. [DOI: 10.1007/s11062-017-9624-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Abstract
The heart and brain are constantly interacting under normal physiological conditions. This interaction is under the control of the autonomic nervous system with parasympathetic and sympathetic nerve fibers including the participating brain structures. Pathological conditions, such as epilepsy and ischemic cerebral stroke influence heart function, especially the frequency and may result in severe arrhythmia. An asymmetric influence of the left and right brain hemispheres on the heart rate is still under debate. Conversely, the influence of the heart in cases of acute cardiac arrest on brain function is equally relevant and a common clinical problem after resuscitation. We review the damaging cascade of global cerebral hypoxia and the value of different diagnostic procedures as well as the ethical problem of the point in time of termination of consciousness and the instruments for estimating the prognosis.
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24
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Şerban CA, Barborică A, Roceanu AM, Mîndruță IR, Ciurea J, Zăgrean AM, Zăgrean L, Moldovan M. EEG Assessment of Consciousness Rebooting from Coma. THE PHYSICS OF THE MIND AND BRAIN DISORDERS 2017. [DOI: 10.1007/978-3-319-29674-6_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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25
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Chalia M, Lee CW, Dempsey LA, Edwards AD, Singh H, Michell AW, Everdell NL, Hill RW, Hebden JC, Austin T, Cooper RJ. Hemodynamic response to burst-suppressed and discontinuous electroencephalography activity in infants with hypoxic ischemic encephalopathy. NEUROPHOTONICS 2016; 3:031408. [PMID: 27446969 PMCID: PMC4945004 DOI: 10.1117/1.nph.3.3.031408] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 03/23/2016] [Indexed: 05/24/2023]
Abstract
Burst suppression (BS) is an electroencephalographic state associated with a profound inactivation of the brain. BS and pathological discontinuous electroencephalography (EEG) are often observed in term-age infants with neurological injury and can be indicative of a poor outcome and lifelong disability. Little is known about the neurophysiological mechanisms of BS or how the condition relates to the functional state of the neonatal brain. We used simultaneous EEG and diffuse optical tomography (DOT) to investigate whether bursts of EEG activity in infants with hypoxic ischemic encephalopathy are associated with an observable cerebral hemodynamic response. We were able to identify significant changes in concentration of both oxy and deoxyhemoglobin that are temporally correlated with EEG bursts and present a relatively consistent morphology across six infants. Furthermore, DOT reveals patient-specific spatial distributions of this hemodynamic response that may be indicative of a complex pattern of cortical activation underlying discontinuous EEG activity that is not readily apparent in scalp EEG.
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Affiliation(s)
- Maria Chalia
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, The Evelyn Perinatal Imaging Centre, neoLAB, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, Department of Neonatology, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Chuen Wai Lee
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, The Evelyn Perinatal Imaging Centre, neoLAB, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, Department of Neonatology, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Laura A. Dempsey
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, The Evelyn Perinatal Imaging Centre, neoLAB, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
- University College London, Department of Medical Physics and Biomedical Engineering, Malet Place Engineering Building, Gower Street, London WC1E 6BT, United Kingdom
| | - Andrea D. Edwards
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, The Evelyn Perinatal Imaging Centre, neoLAB, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, Department of Neonatology, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Harsimrat Singh
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, The Evelyn Perinatal Imaging Centre, neoLAB, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
- University College London, Department of Medical Physics and Biomedical Engineering, Malet Place Engineering Building, Gower Street, London WC1E 6BT, United Kingdom
| | - Andrew W. Michell
- Cambridge University Hospitals NHS Foundation Trust, Department of Clinical Neurophysiology, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Nicholas L. Everdell
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, The Evelyn Perinatal Imaging Centre, neoLAB, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
- University College London, Department of Medical Physics and Biomedical Engineering, Malet Place Engineering Building, Gower Street, London WC1E 6BT, United Kingdom
| | - Reuben W. Hill
- University College London, Department of Medical Physics and Biomedical Engineering, Malet Place Engineering Building, Gower Street, London WC1E 6BT, United Kingdom
| | - Jeremy C. Hebden
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, The Evelyn Perinatal Imaging Centre, neoLAB, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
- University College London, Department of Medical Physics and Biomedical Engineering, Malet Place Engineering Building, Gower Street, London WC1E 6BT, United Kingdom
| | - Topun Austin
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, The Evelyn Perinatal Imaging Centre, neoLAB, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, Department of Neonatology, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
| | - Robert J. Cooper
- Cambridge University Hospitals NHS Foundation Trust, The Rosie Hospital, The Evelyn Perinatal Imaging Centre, neoLAB, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0QQ, United Kingdom
- University College London, Department of Medical Physics and Biomedical Engineering, Malet Place Engineering Building, Gower Street, London WC1E 6BT, United Kingdom
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Rady MY, Verheijde JL. Neuroscience and awareness in the dying human brain: Implications for organ donation practices. J Crit Care 2016; 34:121-3. [PMID: 27288623 DOI: 10.1016/j.jcrc.2016.04.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 04/17/2016] [Indexed: 02/05/2023]
Abstract
Consciousness has 2 components: wakefulness (arousal) and awareness (perception of the self and the external environment). Functional neuroimaging has identified 2 distinctive functional networks that mediate external awareness of the surrounding environment and internal awareness of the self. Recent studies suggest that awareness is not always associated with wakefulness. There is little clinical research that has specifically focused on determining awareness in the dying phase, after the cessation of systemic circulation. Pana et al (J Crit Care, http://dx.doi.org/10.1016/j.jcrc.2016.04.001) concluded from a retrospective analysis of published human and animal studies that the cessation of clinical brain function and spontaneous electroencephalography activity occurred within 30 seconds of circulatory arrest. They inferred from this that a 5-minute period of cessation of circulation constitutes a valid indicator that awareness has ceased. This aligns with the 5-minute no-touch time after the loss of arterial pulse, the current circulatory standard of death determination in non-heart-beating organ donation. We argue that the capacity for awareness may not be irreversibly lost after a relatively brief period of cessation of systemic circulation, and outline empirical data in support of the claim that awareness without wakefulness may be present. Obviously, if correct, this will have practical and ethical implications on organ donation practices.
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Affiliation(s)
- Mohamed Y Rady
- Department of Critical Care, Mayo Clinic Hospital, Phoenix, AZ.
| | - Joseph L Verheijde
- Department of Physical Medicine & Rehabilitation, Mayo Clinic, Scottsdale, AZ.
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27
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Altwegg-Boussac T, Mahon S, Chavez M, Charpier S, Schramm AE. Induction of an Isoelectric Brain State to Investigate the Impact of Endogenous Synaptic Activity on Neuronal Excitability In Vivo. J Vis Exp 2016:e53576. [PMID: 27078163 PMCID: PMC4841322 DOI: 10.3791/53576] [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] [Indexed: 10/31/2022] Open
Abstract
The way neurons process information depends both on their intrinsic membrane properties and on the dynamics of the afferent synaptic network. In particular, endogenously-generated network activity, which strongly varies as a function of the state of vigilance, significantly modulates neuronal computation. To investigate how different spontaneous cerebral dynamics impact single neurons' integrative properties, we developed a new experimental strategy in the rat consisting in suppressing in vivo all cerebral activity by means of a systemic injection of a high dose of sodium pentobarbital. Cortical activities, continuously monitored by combined electrocorticogram (ECoG) and intracellular recordings are progressively slowed down, leading to a steady isoelectric profile. This extreme brain state, putting the rat into a deep comatose, was carefully monitored by measuring the physiological constants of the animal throughout the experiments. Intracellular recordings allowed us to characterize and compare the integrative properties of the same neuron embedded into physiologically relevant cortical dynamics, such as those encountered in the sleep-wake cycle, and when the brain was fully silent.
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Affiliation(s)
- Tristan Altwegg-Boussac
- Inserm U1127; CNRS UMR 7225; UPMC Univ Paris 06, UMR S 1127, Sorbonne Universités; Institut du Cerveau et de la Moelle épinière (ICM)
| | - Séverine Mahon
- Inserm U1127; CNRS UMR 7225; UPMC Univ Paris 06, UMR S 1127, Sorbonne Universités; Institut du Cerveau et de la Moelle épinière (ICM)
| | - Mario Chavez
- Inserm U1127; CNRS UMR 7225; UPMC Univ Paris 06, UMR S 1127, Sorbonne Universités; Institut du Cerveau et de la Moelle épinière (ICM)
| | - Stéphane Charpier
- Inserm U1127; CNRS UMR 7225; UPMC Univ Paris 06, UMR S 1127, Sorbonne Universités; Institut du Cerveau et de la Moelle épinière (ICM)
| | - Adrien E Schramm
- Inserm U1127; CNRS UMR 7225; UPMC Univ Paris 06, UMR S 1127, Sorbonne Universités; Institut du Cerveau et de la Moelle épinière (ICM);
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28
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Fernández-Torre JL, Kaplan PW, Hernández-Hernández MA. New understanding of nonconvulsive status epilepticus in adults: treatments and challenges. Expert Rev Neurother 2015; 15:1455-73. [DOI: 10.1586/14737175.2015.1115719] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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29
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Pavel B, Acatrinei CA, Menardy F, Zahiu CMD, Popa D, Zagrean AM, Zagrean L. Changes of cortical connectivity during deep anaesthesia. Rom J Anaesth Intensive Care 2015; 22:83-88. [PMID: 28913462 PMCID: PMC5505379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023] Open
Abstract
BACKGROUND AND AIMS The aim of this study was to evaluate the frontal intracortical connectivity during deep anaesthesia (burst-suppression). METHODS Experiments were carried out on 5 adult Sprague Dawley rats. The anaesthesia was induced and maintained with isoflurane. Following the induction of anaesthesia, rats were placed in a stereotactic instrument. A hole was drilled in the skull over the frontal cortex and electrodes were inserted in order to record the local field potentials. Rats were maintained in deep level anaesthesia (burst-suppression). The cortical connectivity was assessed by computing the coherence spectra. The frontal intracortical connectivity was calculated during burst, suppression (non-burst) and slow wave anaesthesia periods. RESULTS The global cortical connectivity (0.5-100 Hz) was 0.61 ± 0.078 during the burst periods compared to 0.55 ± 0.032 (p < 0.05) during the suppression periods and 0.55 ± 0.015 (p < 0.05) during slow wave anaesthesia. CONCLUSIONS The global cortical connectivity increased during the burst periods compared to the suppression periods and slow wave anaesthesia. This increase in the cortical synchronization might be due to the subcortical origin of the bursts.
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Affiliation(s)
- Bogdan Pavel
- “Carol Davila” University of Medicine and Pharmacy, Division of Physiology and Fundamental Neurosciences, Bucharest, Romania
| | - Camelia Alexandra Acatrinei
- “Carol Davila” University of Medicine and Pharmacy, Division of Physiology and Fundamental Neurosciences, Bucharest, Romania
| | - Fabien Menardy
- Institut de Biologie de l’Ecole Normale Supérieure, Paris, France
| | - Carmen Mihaela Denise Zahiu
- “Carol Davila” University of Medicine and Pharmacy, Division of Physiology and Fundamental Neurosciences, Bucharest, Romania
| | - Daniela Popa
- Institut de Biologie de l’Ecole Normale Supérieure, Paris, France
| | - Ana-Maria Zagrean
- “Carol Davila” University of Medicine and Pharmacy, Division of Physiology and Fundamental Neurosciences, Bucharest, Romania
| | - Leon Zagrean
- “Carol Davila” University of Medicine and Pharmacy, Division of Physiology and Fundamental Neurosciences, Bucharest, Romania
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30
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Abstract
This paper describes the various electroencephalographic (EEG) patterns expressed by the comatose brain, starting with the sleep-like oscillations associated with light coma. Deeper coma generally displays a burst-suppression pattern characterized by alternating episodes of isoelectric (flat) EEG and bursting slow waves. The latter are the result of cortical hyperexcitability, as demonstrated by intracellular recordings in anesthetized animals. Further deepening of the coma yields to continuous isoelectric electroencephalogram and eventually results in a newly discovered type of spiky waves that have been termed Nu-complexes. The paper discusses the structures participating in the genesis of burst suppression, the afferent mechanisms, and the reasons for which this activity should or should not be regarded as an epileptic disorder. This article is part of a Special Issue entitled "Status Epilepticus".
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Affiliation(s)
- Florin Amzica
- Department of Stomatology, School of Dentistry, Université de Montreal, Montreal, Canada; Department of Neurosciences, School of Medicine, Université de Montreal, Montreal, Canada.
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31
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Nelson K. Near-death experiences--Neuroscience perspectives on near-death experiences. MISSOURI MEDICINE 2015; 112:92-98. [PMID: 25958650 PMCID: PMC6170042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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32
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Nathaniel TI, Williams-Hernandez A, Hunter AL, Liddy C, Peffley DM, Umesiri FE, Imeh-Nathaniel A. Tissue hypoxia during ischemic stroke: adaptive clues from hypoxia-tolerant animal models. Brain Res Bull 2015; 114:1-12. [PMID: 25738761 DOI: 10.1016/j.brainresbull.2015.02.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 02/12/2015] [Accepted: 02/19/2015] [Indexed: 10/23/2022]
Abstract
The treatment and prevention of hypoxic/ischemic brain injury in stroke patients remain a severe and global medical issue. Numerous clinical studies have resulted in a failure to develop chemical neuroprotection for acute, ischemic stroke. Over 150 estimated clinical trials of ischemic stroke treatments have been done, and more than 200 drugs and combinations of drugs for ischemic and hemorrhagic strokes have been developed. Billions of dollars have been invested for new scientific breakthroughs with only limited success. The revascularization of occluded cerebral arteries such as anti-clot treatments of thrombolysis has proven effective, but it can only be used in a 3-4.5h time frame after the onset of a stroke, and not for every patient. This review is about novel insights on how to resist tissue hypoxia from unconventional animal models. Ability to resist tissue hypoxia is an extraordinary ability that is not common in many laboratory animals such as rat and mouse models. For example, we can learn from a naked mole-rat, Chrysemys picta, how to actively regulate brain metabolic activity to defend the brain against fluctuating oxygen tension and acute bouts of oxidative stress following the onset of a stroke. Additionally, a euthermic arctic ground squirrel can teach us how the brain of a stroke patient can remain well oxygenated during tissue hypoxia with no evidence of cellular stress. In this review, we discuss how these animals provide us with a system to gain insight into the possible mechanisms of tissue hypoxia/ischemia. This issue is of clinical significance to stroke patients. We describe specific physiological and molecular adaptations employed by different animals' models of hypoxia tolerance in aquatic and terrestrial environments. We highlight how these adaptations might provide potential clues on strategies to adapt for the clinical management of tissue hypoxia during conditions such as stroke where oxygen demand fails to match the supply.
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Affiliation(s)
- Thomas I Nathaniel
- University of South Carolina School of Medicine-Greenville, 701 Grove Road, Greenville, SC 29605, United States.
| | - Ashley Williams-Hernandez
- University of South Carolina School of Medicine-Greenville, 701 Grove Road, Greenville, SC 29605, United States
| | - Anan L Hunter
- University of South Carolina School of Medicine-Greenville, 701 Grove Road, Greenville, SC 29605, United States
| | - Caroline Liddy
- University of South Carolina School of Medicine-Greenville, 701 Grove Road, Greenville, SC 29605, United States
| | - Dennis M Peffley
- University of South Carolina School of Medicine-Greenville, 701 Grove Road, Greenville, SC 29605, United States
| | - Francis E Umesiri
- Chemistry department, John Brown University, 2000 W. University Street, Siloam Springs, AR 72761, United States
| | - Adebobola Imeh-Nathaniel
- Department of Biology, North Greenville University, 7801 North Tigerville Road, Tigerville, SC 29688, United States
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33
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Persistent activity on electrocardiography and electroencephalography after acute circulatory arrest: implications for non-heart-beating organ donation. Crit Care Med 2014; 42:e681-2. [PMID: 25226145 DOI: 10.1097/ccm.0000000000000493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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34
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Parnia S, Spearpoint K, de Vos G, Fenwick P, Goldberg D, Yang J, Zhu J, Baker K, Killingback H, McLean P, Wood M, Zafari AM, Dickert N, Beisteiner R, Sterz F, Berger M, Warlow C, Bullock S, Lovett S, McPara RMS, Marti-Navarette S, Cushing P, Wills P, Harris K, Sutton J, Walmsley A, Deakin CD, Little P, Farber M, Greyson B, Schoenfeld ER. AWARE—AWAreness during REsuscitation—A prospective study. Resuscitation 2014; 85:1799-805. [DOI: 10.1016/j.resuscitation.2014.09.004] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 09/02/2014] [Accepted: 09/07/2014] [Indexed: 11/25/2022]
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35
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Parnia S. Death and consciousness--an overview of the mental and cognitive experience of death. Ann N Y Acad Sci 2014; 1330:75-93. [DOI: 10.1111/nyas.12582] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Sam Parnia
- The State University of New York at Stony Brook; Stony Brook New York
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36
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Rady MY, Verheijde JL. The moral code in Islam and organ donation in Western countries: reinterpreting religious scriptures to meet utilitarian medical objectives. Philos Ethics Humanit Med 2014; 9:11. [PMID: 24888748 PMCID: PMC4047256 DOI: 10.1186/1747-5341-9-11] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 05/13/2014] [Indexed: 06/02/2023] Open
Abstract
End-of-life organ donation is controversial in Islam. The controversy stems from: (1) scientifically flawed medical criteria of death determination; (2) invasive perimortem procedures for preserving transplantable organs; and (3) incomplete disclosure of information to consenting donors and families. Data from a survey of Muslims residing in Western countries have shown that the interpretation of religious scriptures and advice of faith leaders were major barriers to willingness for organ donation. Transplant advocates have proposed corrective interventions: (1) reinterpreting religious scriptures, (2) reeducating faith leaders, and (3) utilizing media campaigns to overcome religious barriers in Muslim communities. This proposal disregards the intensifying scientific, legal, and ethical controversies in Western societies about the medical criteria of death determination in donors. It would also violate the dignity and inviolability of human life which are pertinent values incorporated in the Islamic moral code. Reinterpreting religious scriptures to serve the utilitarian objectives of a controversial end-of-life practice, perceived to be socially desirable, transgresses the Islamic moral code. It may also have deleterious practical consequences, as donors can suffer harm before death. The negative normative consequences of utilitarian secular moral reasoning reset the Islamic moral code upholding the sanctity and dignity of human life.
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Affiliation(s)
- Mohamed Y Rady
- Department of Critical Care Medicine, Mayo Clinic Hospital, Mayo Clinic, Phoenix, Arizona, USA
| | - Joseph L Verheijde
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Phoenix, Arizona, USA
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37
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Radin D. Getting comfortable with near death experiences. Out of one's mind or beyond the brain? The challenge of interpreting near-death experiences. MISSOURI MEDICINE 2014; 111:24-8. [PMID: 24645294 PMCID: PMC6179515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
With one exception, near-death experiences (NDEs) may be interpreted as unusual forms of hallucinations associated with the injured or dying brain. The exception involves perceptions described from vantage points outside the body that are later confirmed to be correct and could not have been inferred. Over a century of laboratory studies have investigated whether it is possible in principle for the mind to transcend the physical boundaries of the brain. The cumulative experimental database strongly indicates that it can. It is not clear that this implies the mind is separate from the brain, but it does suggest that a comprehensive explanation for NDEs will require revisions to present scientific assumptions about the brain-mind relationship.
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