1
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Young MJ, Kazazian K, Fischer D, Lissak IA, Bodien YG, Edlow BL. Disclosing Results of Tests for Covert Consciousness: A Framework for Ethical Translation. Neurocrit Care 2024; 40:865-878. [PMID: 38243150 PMCID: PMC11147696 DOI: 10.1007/s12028-023-01899-8] [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: 09/25/2023] [Accepted: 11/22/2023] [Indexed: 01/21/2024]
Abstract
The advent of neurotechnologies including advanced functional magnetic resonance imaging and electroencephalography to detect states of awareness not detectable by traditional bedside neurobehavioral techniques (i.e., covert consciousness) promises to transform neuroscience research and clinical practice for patients with brain injury. As these interventions progress from research tools into actionable, guideline-endorsed clinical tests, ethical guidance for clinicians on how to responsibly communicate the sensitive results they yield is crucial yet remains underdeveloped. Drawing on insights from empirical and theoretical neuroethics research and our clinical experience with advanced neurotechnologies to detect consciousness in behaviorally unresponsive patients, we critically evaluate ethical promises and perils associated with disclosing the results of clinical covert consciousness assessments and describe a semistructured approach to responsible data sharing to mitigate potential risks.
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Affiliation(s)
- Michael J Young
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 101 Merrimac Street, Suite 310, Boston, MA, 02114, USA.
| | - Karnig Kazazian
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 101 Merrimac Street, Suite 310, Boston, MA, 02114, USA
- Western Institute of Neuroscience, Western University, London, ON, Canada
| | - David Fischer
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - India A Lissak
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 101 Merrimac Street, Suite 310, Boston, MA, 02114, USA
| | - Yelena G Bodien
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 101 Merrimac Street, Suite 310, Boston, MA, 02114, USA
| | - Brian L Edlow
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 101 Merrimac Street, Suite 310, Boston, MA, 02114, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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2
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Kalkach Aparicio M, Lazaridis C. Conceptualizing Consciousness: a Change in Perspective: The Elephant Still Surprises Those only Touching Its Trunk. Phys Med Rehabil Clin N Am 2024; 35:1-13. [PMID: 37993181 DOI: 10.1016/j.pmr.2023.06.021] [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: 11/24/2023]
Abstract
Providers of patients with disorders of consciousness (DoC) face clinical and ethical challenges that could be lessened by becoming acquainted with the subjective and objective aspects of consciousness. A first step to improving DoC taxonomies, management, and outcomes might be to recognize the shortcomings of the medical concept of consciousness and to improve the terminology used for the clinical parameters assessed. The authors critically review the medical perspective of consciousness represented by three sub-concepts that do not necessarily correlate with one another and discuss how none of them reflects fully the personal subjective nature of consciousness.
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Affiliation(s)
- Mariel Kalkach Aparicio
- Department of Neurology, University of Wisconsin, 1685 Highland Avenue, 7th Floor, Madison, WI 53705-2281, USA; Centro Anahuac de Desarrollo Estrategico en Bioetica (CADEBI), Universidad Anahuac Mexico, Edo. Mex. MEX; UNESCO Chair of Bioethics and Human Rights, Rome, ITA.
| | - Christos Lazaridis
- Department of Neurology, The University of Chicago, 5841 South Maryland Avenue, MC 2030, Chicago, IL 60637, USA
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3
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Birch J. Medical AI, inductive risk and the communication of uncertainty: the case of disorders of consciousness. JOURNAL OF MEDICAL ETHICS 2023:jme-2023-109424. [PMID: 37979975 DOI: 10.1136/jme-2023-109424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 10/28/2023] [Indexed: 11/20/2023]
Abstract
Some patients, following brain injury, do not outwardly respond to spoken commands, yet show patterns of brain activity that indicate responsiveness. This is 'cognitive-motor dissociation' (CMD). Recent research has used machine learning to diagnose CMD from electroencephalogram recordings. These techniques have high false discovery rates, raising a serious problem of inductive risk. It is no solution to communicate the false discovery rates directly to the patient's family, because this information may confuse, alarm and mislead. Instead, we need a procedure for generating case-specific probabilistic assessments that can be communicated clearly. This article constructs a possible procedure with three key elements: (1) A shift from categorical 'responding or not' assessments to degrees of evidence; (2) The use of patient-centred priors to convert degrees of evidence to probabilistic assessments; and (3) The use of standardised probability yardsticks to convey those assessments as clearly as possible.
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Affiliation(s)
- Jonathan Birch
- Centre for Philosophy of Natural and Social Science, LSE, London, UK
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4
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Huntley J, Bor D, Deng F, Mancuso M, Mediano PAM, Naci L, Owen AM, Rocchi L, Sternin A, Howard R. Assessing awareness in severe Alzheimer's disease. Front Hum Neurosci 2023; 16:1035195. [PMID: 36819296 PMCID: PMC9930987 DOI: 10.3389/fnhum.2022.1035195] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 12/30/2022] [Indexed: 02/04/2023] Open
Abstract
There is an urgent need to understand the nature of awareness in people with severe Alzheimer's disease (AD) to ensure effective person-centered care. Objective biomarkers of awareness validated in other clinical groups (e.g., anesthesia, minimally conscious states) offer an opportunity to investigate awareness in people with severe AD. In this article we demonstrate the feasibility of using Transcranial magnetic stimulation (TMS) combined with EEG, event related potentials (ERPs) and fMRI to assess awareness in severe AD. TMS-EEG was performed in six healthy older controls and three people with severe AD. The perturbational complexity index (PCIST) was calculated as a measure of capacity for conscious awareness. People with severe AD demonstrated a PCIST around or below the threshold for consciousness, suggesting reduced capacity for consciousness. ERPs were recorded during a visual perception paradigm. In response to viewing faces, two patients with severe AD provisionally demonstrated similar visual awareness negativity to healthy controls. Using a validated fMRI movie-viewing task, independent component analysis in two healthy controls and one patient with severe AD revealed activation in auditory, visual and fronto-parietal networks. Activation patterns in fronto-parietal networks did not significantly correlate between the patient and controls, suggesting potential differences in conscious awareness and engagement with the movie. Although methodological issues remain, these results demonstrate the feasibility of using objective measures of awareness in severe AD. We raise a number of challenges and research questions that should be addressed using these biomarkers of awareness in future studies to improve understanding and care for people with severe AD.
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Affiliation(s)
- Jonathan Huntley
- Division of Psychiatry, University College London, London, United Kingdom
| | - Daniel Bor
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Feng Deng
- School of Psychology, Trinity College Dublin, Global Brain Health Institute, Dublin, Ireland
| | - Marco Mancuso
- Human Neuroscience Department, Sapienza University of Rome, Rome, Italy
| | - Pedro A. M. Mediano
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Lorina Naci
- School of Psychology, Trinity College Dublin, Global Brain Health Institute, Dublin, Ireland
| | - Adrian M. Owen
- Department of Physiology and Pharmacology, Brain and Mind Institute, University of Western Ontario, London, ON, Canada
- Department of Psychology, Brain and Mind Institute, University of Western Ontario, London, ON, Canada
| | - Lorenzo Rocchi
- Institute of Neurology, University College London, London, United Kingdom
| | - Avital Sternin
- Department of Physiology and Pharmacology, Brain and Mind Institute, University of Western Ontario, London, ON, Canada
- Department of Psychology, Brain and Mind Institute, University of Western Ontario, London, ON, Canada
| | - Robert Howard
- Division of Psychiatry, University College London, London, United Kingdom
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5
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Willacker L, Raiser TM, Bassi M, Bender A, Comanducci A, Rosanova M, Sobel N, Arzi A, Belloli L, Casarotto S, Colombo M, Derchi CC, Fló Rama E, Grill E, Hohl M, Kuehlmeyer K, Manasova D, Rosenfelder MJ, Valota C, Sitt JD. PerBrain: a multimodal approach to personalized tracking of evolving state-of-consciousness in brain-injured patients: protocol of an international, multicentric, observational study. BMC Neurol 2022; 22:468. [PMID: 36494776 PMCID: PMC9733076 DOI: 10.1186/s12883-022-02958-x] [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: 09/07/2022] [Accepted: 11/01/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Disorders of consciousness (DoC) are severe neurological conditions in which consciousness is impaired to various degrees. They are caused by injury or malfunction of neural systems regulating arousal and awareness. Over the last decades, major efforts in improving and individualizing diagnostic and prognostic accuracy for patients affected by DoC have been made, mainly focusing on introducing multimodal assessments to complement behavioral examination. The present EU-funded multicentric research project "PerBrain" is aimed at developing an individualized diagnostic hierarchical pathway guided by both behavior and multimodal neurodiagnostics for DoC patients. METHODS In this project, each enrolled patient undergoes repetitive behavioral, clinical, and neurodiagnostic assessments according to a patient-tailored multi-layer workflow. Multimodal diagnostic acquisitions using state-of-the-art techniques at different stages of the patients' clinical evolution are performed. The techniques applied comprise well-established behavioral scales, innovative neurophysiological techniques (such as quantitative electroencephalography and transcranial magnetic stimulation combined with electroencephalography), structural and resting-state functional magnetic resonance imaging, and measurements of physiological activity (i.e. nasal airflow respiration). In addition, the well-being and treatment decision attitudes of patients' informal caregivers (primarily family members) are investigated. Patient and caregiver assessments are performed at multiple time points within one year after acquired brain injury, starting at the acute disease phase. DISCUSSION Accurate classification and outcome prediction of DoC are of crucial importance for affected patients as well as their caregivers, as individual rehabilitation strategies and treatment decisions are critically dependent on the latter. The PerBrain project aims at optimizing individual DoC diagnosis and accuracy of outcome prediction by integrating data from the suggested multimodal examination methods into a personalized hierarchical diagnosis and prognosis procedure. Using the parallel tracking of both patients' neurological status and their caregivers' mental situation, well-being, and treatment decision attitudes from the acute to the chronic phase of the disease and across different countries, this project aims at significantly contributing to the current clinical routine of DoC patients and their family members. TRIAL REGISTRATION ClinicalTrials.gov, NCT04798456 . Registered 15 March 2021 - Retrospectively registered.
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Affiliation(s)
- L. Willacker
- grid.5252.00000 0004 1936 973XDepartment of Neurology, University Hospital of the Ludwig-Maximilians-Universität München, Marchioninistr. 15, Munich, Germany
| | - T. M. Raiser
- grid.5252.00000 0004 1936 973XDepartment of Neurology, University Hospital of the Ludwig-Maximilians-Universität München, Marchioninistr. 15, Munich, Germany
| | - M. Bassi
- grid.4708.b0000 0004 1757 2822Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
| | - A. Bender
- grid.5252.00000 0004 1936 973XDepartment of Neurology, University Hospital of the Ludwig-Maximilians-Universität München, Marchioninistr. 15, Munich, Germany ,grid.478057.90000 0004 0381 347XTherapiezentrum Burgau, Hospital for Neurological Rehabilitation, Burgau, Germany
| | - A. Comanducci
- grid.418563.d0000 0001 1090 9021IRCCS Fondazione Don Carlo Gnocchi ONLUS, Milan, Italy
| | - M. Rosanova
- grid.4708.b0000 0004 1757 2822Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
| | - N. Sobel
- grid.13992.300000 0004 0604 7563Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - A. Arzi
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, 75013 Paris, France ,grid.9619.70000 0004 1937 0538Department of Medical Neurobiology and Department of Cognitive and Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - L. Belloli
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, 75013 Paris, France ,grid.7345.50000 0001 0056 1981Laboratorio de Inteligencia Artificial Aplicada, Instituto de Ciencias de la Computación, Universidad de Buenos Aires, Buenos Aires, Argentina ,grid.423606.50000 0001 1945 2152Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ministry of Science, Technology and Innovation, Buenos Aires, Argentina
| | - S. Casarotto
- grid.4708.b0000 0004 1757 2822Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy ,grid.418563.d0000 0001 1090 9021IRCCS Fondazione Don Carlo Gnocchi ONLUS, Milan, Italy
| | - M. Colombo
- grid.4708.b0000 0004 1757 2822Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy
| | - C. C. Derchi
- grid.418563.d0000 0001 1090 9021IRCCS Fondazione Don Carlo Gnocchi ONLUS, Milan, Italy
| | - E. Fló Rama
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, 75013 Paris, France
| | - E. Grill
- grid.5252.00000 0004 1936 973XInstitute for Medical Information Processing, Biometry and Epidemiology, Ludwig-Maximilians-Universität München, Munich, Germany ,grid.411095.80000 0004 0477 2585German Center for Vertigo and Balance Disorders, Klinikum der Universität München, Munich, Germany
| | - M. Hohl
- grid.5252.00000 0004 1936 973XDepartment of Neurology, University Hospital of the Ludwig-Maximilians-Universität München, Marchioninistr. 15, Munich, Germany
| | - K. Kuehlmeyer
- grid.5252.00000 0004 1936 973XInstitute of Ethics, History and Theory of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - D. Manasova
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, 75013 Paris, France ,grid.508487.60000 0004 7885 7602Université Paris Cité, Paris, France
| | - M. J. Rosenfelder
- grid.478057.90000 0004 0381 347XTherapiezentrum Burgau, Hospital for Neurological Rehabilitation, Burgau, Germany ,grid.6582.90000 0004 1936 9748Clinical and Biological Psychology, Institute of Psychology and Education, Ulm University, Ulm, Germany
| | - C. Valota
- grid.4708.b0000 0004 1757 2822Department of Biomedical and Clinical Sciences, University of Milano, Milan, Italy ,grid.418563.d0000 0001 1090 9021IRCCS Fondazione Don Carlo Gnocchi ONLUS, Milan, Italy
| | - J. D. Sitt
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, 75013 Paris, France
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6
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Naci L, Owen AM. Uncovering consciousness and revealing the preservation of mental life in unresponsive brain-injured patients. Semin Neurol 2022; 42:299-308. [PMID: 35790202 DOI: 10.1055/a-1892-1715] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Lorina Naci
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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7
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Electrophysiological evidence of sustained attention to music among conscious participants and unresponsive hospice patients at the end of life. Clin Neurophysiol 2022; 139:9-22. [DOI: 10.1016/j.clinph.2022.03.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 02/28/2022] [Accepted: 03/24/2022] [Indexed: 11/18/2022]
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8
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Young MJ, Bodien YG, Edlow BL. Ethical Considerations in Clinical Trials for Disorders of Consciousness. Brain Sci 2022; 12:211. [PMID: 35203974 PMCID: PMC8870384 DOI: 10.3390/brainsci12020211] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 01/28/2022] [Accepted: 01/28/2022] [Indexed: 11/30/2022] Open
Abstract
As the clinical trial landscape for patients with disorders of consciousness (DoC) expands, consideration of associated ethical challenges and opportunities is of ever-increasing importance. Responsible conduct of research in the vulnerable population of persons with DoC, including those with coma, vegetative state/unresponsive wakefulness syndrome (VS/UWS), minimally conscious state (MCS), covert cortical processing (CCP), and cognitive motor dissociation (CMD), demands proactive deliberation of unique ethical issues that may arise and the adoption of robust protections to safeguard patients, surrogates, and other key stakeholders. Here we identify and critically evaluate four central categories of ethical considerations in clinical trials involving participants with DoC: (1) autonomy, respect for persons and informed consent of individuals with liminal consciousness; (2) balancing unknown benefits and risks, especially considering the epistemological gap between behavior and consciousness that complicates ordinary ascription of subjective states; (3) disclosure to surrogates and clinical teams of investigational results pertaining to consciousness; and (4) justice considerations, including equitable access to clinical trial enrollment across communities and geographies. We outline guiding principles and research opportunities for clinicians, neuroethicists, and researchers engaged in DoC clinical trials to advance ethical study design and deployment in this complex yet crucial area of investigation.
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Affiliation(s)
- Michael J. Young
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA; (Y.G.B.); (B.L.E.)
| | - Yelena G. Bodien
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA; (Y.G.B.); (B.L.E.)
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Charlestown, MA 02114, USA
| | - Brian L. Edlow
- Center for Neurotechnology and Neurorecovery, Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA; (Y.G.B.); (B.L.E.)
- Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02114, USA
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9
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Abdalmalak A, Milej D, Norton L, Debicki DB, Owen AM, Lawrence KS. The Potential Role of fNIRS in Evaluating Levels of Consciousness. Front Hum Neurosci 2021; 15:703405. [PMID: 34305558 PMCID: PMC8296905 DOI: 10.3389/fnhum.2021.703405] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 05/31/2021] [Indexed: 12/13/2022] Open
Abstract
Over the last few decades, neuroimaging techniques have transformed our understanding of the brain and the effect of neurological conditions on brain function. More recently, light-based modalities such as functional near-infrared spectroscopy have gained popularity as tools to study brain function at the bedside. A recent application is to assess residual awareness in patients with disorders of consciousness, as some patients retain awareness albeit lacking all behavioural response to commands. Functional near-infrared spectroscopy can play a vital role in identifying these patients by assessing command-driven brain activity. The goal of this review is to summarise the studies reported on this topic, to discuss the technical and ethical challenges of working with patients with disorders of consciousness, and to outline promising future directions in this field.
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Affiliation(s)
- Androu Abdalmalak
- Department of Physiology and Pharmacology, Western University, London, ON, Canada.,Brain and Mind Institute, Western University, London, ON, Canada
| | - Daniel Milej
- Imaging Program, Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
| | - Loretta Norton
- Department of Psychology, King's College, Western University, London, ON, Canada
| | - Derek B Debicki
- Brain and Mind Institute, Western University, London, ON, Canada.,Clinical Neurological Sciences, Western University, London, ON, Canada
| | - Adrian M Owen
- Department of Physiology and Pharmacology, Western University, London, ON, Canada.,Brain and Mind Institute, Western University, London, ON, Canada.,Department of Psychology, Western University, London, ON, Canada
| | - Keith St Lawrence
- Imaging Program, Lawson Health Research Institute, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
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10
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Riganello F, Vatrano M, Carozzo S, Russo M, Lucca LF, Ursino M, Ruggiero V, Cerasa A, Porcaro C. The Timecourse of Electrophysiological Brain-Heart Interaction in DoC Patients. Brain Sci 2021; 11:750. [PMID: 34198911 PMCID: PMC8228557 DOI: 10.3390/brainsci11060750] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/31/2021] [Accepted: 06/03/2021] [Indexed: 01/09/2023] Open
Abstract
Disorders of Consciousness (DOC) are a spectrum of pathologies affecting one's ability to interact with the external world. Two possible conditions of patients with DOC are Unresponsive Wakefulness Syndrome/Vegetative State (UWS/VS) and Minimally Conscious State (MCS). Analysis of spontaneous EEG activity and the Heart Rate Variability (HRV) are effective techniques in exploring and evaluating patients with DOC. This study aims to observe fluctuations in EEG and HRV parameters in the morning/afternoon resting-state recording. The study enrolled 13 voluntary Healthy Control (HC) subjects and 12 DOC patients (7 MCS, 5 UWS/VS). EEG and EKG were recorded. PSDalpha, PSDtheta powerband, alpha-blocking, alpha/theta of the EEG, Complexity Index (CI) and SDNN of EKG were analyzed. Higher values of PSDalpha, alpha-blocking, alpha/theta and CI values and lower values of PSD theta characterized HC individuals in the morning with respect to DOC patients. In the afternoon, we detected a significant difference between groups in the CI, PSDalpha, PSDtheta, alpha/theta and SDNN, with lower PSDtheta value for HC. CRS-R scores showed a strong correlation with recorded parameters mainly during evaluations in the morning. Our finding put in evidence the importance of the assessment, as the stimulation of DOC patients in research for behavioural response, in the morning.
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Affiliation(s)
- Francesco Riganello
- S.Anna Institute—Research in Advanced Neurorehabilitation, 88900 Crotone, Italy; (M.V.); (S.C.); (M.R.); (L.F.L.); (M.U.); (V.R.); (A.C.); (C.P.)
| | - Martina Vatrano
- S.Anna Institute—Research in Advanced Neurorehabilitation, 88900 Crotone, Italy; (M.V.); (S.C.); (M.R.); (L.F.L.); (M.U.); (V.R.); (A.C.); (C.P.)
| | - Simone Carozzo
- S.Anna Institute—Research in Advanced Neurorehabilitation, 88900 Crotone, Italy; (M.V.); (S.C.); (M.R.); (L.F.L.); (M.U.); (V.R.); (A.C.); (C.P.)
| | - Miriam Russo
- S.Anna Institute—Research in Advanced Neurorehabilitation, 88900 Crotone, Italy; (M.V.); (S.C.); (M.R.); (L.F.L.); (M.U.); (V.R.); (A.C.); (C.P.)
| | - Lucia Francesca Lucca
- S.Anna Institute—Research in Advanced Neurorehabilitation, 88900 Crotone, Italy; (M.V.); (S.C.); (M.R.); (L.F.L.); (M.U.); (V.R.); (A.C.); (C.P.)
| | - Maria Ursino
- S.Anna Institute—Research in Advanced Neurorehabilitation, 88900 Crotone, Italy; (M.V.); (S.C.); (M.R.); (L.F.L.); (M.U.); (V.R.); (A.C.); (C.P.)
| | - Valentina Ruggiero
- S.Anna Institute—Research in Advanced Neurorehabilitation, 88900 Crotone, Italy; (M.V.); (S.C.); (M.R.); (L.F.L.); (M.U.); (V.R.); (A.C.); (C.P.)
| | - Antonio Cerasa
- S.Anna Institute—Research in Advanced Neurorehabilitation, 88900 Crotone, Italy; (M.V.); (S.C.); (M.R.); (L.F.L.); (M.U.); (V.R.); (A.C.); (C.P.)
- Institute for Biomedical Research and Innovation (IRIB)—National Research Council of Italy (CNR), 87050 Mangone, Italy
| | - Camillo Porcaro
- S.Anna Institute—Research in Advanced Neurorehabilitation, 88900 Crotone, Italy; (M.V.); (S.C.); (M.R.); (L.F.L.); (M.U.); (V.R.); (A.C.); (C.P.)
- Department of Information Engineering, Università Politecnica delle Marche, 60131 Ancona, Italy
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham B15 2TT, UK
- Institute of Cognitive Sciences and Technologies (ISTC) - National Research Council (CNR), 00185 Rome, Italy
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11
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Pain Perception in Disorder of Consciousness: A Scoping Review on Current Knowledge, Clinical Applications, and Future Perspective. Brain Sci 2021; 11:brainsci11050665. [PMID: 34065349 PMCID: PMC8161058 DOI: 10.3390/brainsci11050665] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 05/05/2021] [Accepted: 05/19/2021] [Indexed: 01/18/2023] Open
Abstract
Pain perception in individuals with prolonged disorders of consciousness (PDOC) is still a matter of debate. Advanced neuroimaging studies suggest some cortical activations even in patients with unresponsive wakefulness syndrome (UWS) compared to those with a minimally conscious state (MCS). Therefore, pain perception has to be considered even in individuals with UWS. However, advanced neuroimaging assessment can be challenging to conduct, and its findings are sometimes difficult to be interpreted. Conversely, multichannel electroencephalography (EEG) and laser-evoked potentials (LEPs) can be carried out quickly and are more adaptable to the clinical needs. In this scoping review, we dealt with the neurophysiological basis underpinning pain in PDOC, pointing out how pain perception assessment in these individuals might help in reducing the misdiagnosis rate. The available literature data suggest that patients with UWS show a more severe functional connectivity breakdown among the pain-related brain areas compared to individuals in MCS, pointing out that pain perception increases with the level of consciousness. However, there are noteworthy exceptions, because some UWS patients show pain-related cortical activations that partially overlap those observed in MCS individuals. This suggests that some patients with UWS may have residual brain functional connectivity supporting the somatosensory, affective, and cognitive aspects of pain processing (i.e., a conscious experience of the unpleasantness of pain), rather than only being able to show autonomic responses to potentially harmful stimuli. Therefore, the significance of the neurophysiological approach to pain perception in PDOC seems to be clear, and despite some methodological caveats (including intensity of stimulation, multimodal paradigms, and active vs. passive stimulation protocols), remain to be solved. To summarize, an accurate clinical and neurophysiological assessment should always be performed for a better understanding of pain perception neurophysiological underpinnings, a more precise differential diagnosis at the level of individual cases as well as group comparisons, and patient-tailored management.
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12
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Peterson A, Aas S, Wasserman D. What Justifies the Allocation of Health Care Resources to Patients with Disorders of Consciousness? AJOB Neurosci 2021; 12:127-139. [PMID: 33787458 DOI: 10.1080/21507740.2021.1896594] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This paper critically engages ethical issues in the allocation of novel, and potentially costly, health care resources to patients with disorders of consciousness. First, we review potential benefits of novel health care resources for patients and their families and outline preliminary considerations to address concerns about cost. We then address two problems regarding the allocation of health care resources to patients with disorders of consciousness: (1) the problem of uncertain moral status; and (2) the problem of accurately measuring the welfare burdens these resources would relieve. We conclude by suggesting that opportunity-based frameworks might complement standard approaches for justifying resources allocation to patients with disorders of consciousness.
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Affiliation(s)
- Andrew Peterson
- Institute for Philosophy and Public Policy, George Mason University
| | - Sean Aas
- Kennedy Institute of Ethics, Georgetown University
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13
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Confronting the grey zone after severe brain injury. Emerg Top Life Sci 2020; 3:707-711. [PMID: 32915226 DOI: 10.1042/etls20190115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/21/2019] [Accepted: 10/28/2019] [Indexed: 11/17/2022]
Abstract
In recent years, rapid technological developments in the field of neuroimaging have provided several new methods for revealing thoughts, actions and intentions based solely on the pattern of activity that is observed in the brain. In specialized centres, these methods are now being employed routinely to assess residual cognition, detect consciousness and even communicate with some behaviorally non-responsive patients who clinically appear to be comatose or in a vegetative state. In this article, we consider some of the ethical issues raised by these developments and the profound implications they have for clinical care, diagnosis, prognosis and medical-legal decision-making after severe brain injury.
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14
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Nadin D, Duclos C, Mahdid Y, Rokos A, Badawy M, Létourneau J, Arbour C, Plourde G, Blain-Moraes S. Brain network motif topography may predict emergence from disorders of consciousness: a case series. Neurosci Conscious 2020; 2020:niaa017. [PMID: 33376599 PMCID: PMC7751128 DOI: 10.1093/nc/niaa017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 03/18/2020] [Accepted: 06/03/2020] [Indexed: 11/16/2022] Open
Abstract
Neuroimaging methods have improved the accuracy of diagnosis in patients with disorders of consciousness (DOC), but novel, clinically translatable methods for prognosticating this population are still needed. In this case series, we explored the association between topographic and global brain network properties and prognosis in patients with DOC. We recorded high-density electroencephalograms in three patients with acute or chronic DOC, two of whom also underwent an anesthetic protocol. In these two cases, we compared functional network motifs, network hubs and power topography (i.e. topographic network properties), as well as relative power and graph theoretical measures (i.e. global network properties), at baseline, during exposure to anesthesia and after recovery from anesthesia. We also compared these properties to a group of healthy, conscious controls. At baseline, the topographic distribution of nodes participating in alpha motifs resembled conscious controls in patients who later recovered consciousness and high relative power in the delta band was associated with a negative outcome. Strikingly, the reorganization of network motifs, network hubs and power topography under anesthesia followed by their return to a baseline patterns upon recovery from anesthesia, was associated with recovery of consciousness. Our findings suggest that topographic network properties measured at the single-electrode level might provide more prognostic information than global network properties that are averaged across the brain network. In addition, we propose that the brain network's capacity to reorganize in response to a perturbation is a precursor to the recovery of consciousness in DOC patients.
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Affiliation(s)
- Danielle Nadin
- Montreal General Hospital, McGill University Health Center Research Institute, Montreal, QC, Canada
- Integrated Program in Neuroscience, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Catherine Duclos
- Montreal General Hospital, McGill University Health Center Research Institute, Montreal, QC, Canada
- School of Physical and Occupational Therapy, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Yacine Mahdid
- Montreal General Hospital, McGill University Health Center Research Institute, Montreal, QC, Canada
- Integrated Program in Neuroscience, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Alexander Rokos
- Montreal General Hospital, McGill University Health Center Research Institute, Montreal, QC, Canada
- Integrated Program in Neuroscience, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Mohamed Badawy
- Montreal Neurological Hospital and Institute, McGill University Health Center, Montreal, QC, Canada
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Justin Létourneau
- Montreal Neurological Hospital and Institute, McGill University Health Center, Montreal, QC, Canada
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Caroline Arbour
- Centre de recherche, CIUSSS du-Nord-de-l’Île-de-Montréal, Montreal, QC, Canada
- Faculty of Nursing, Université de Montréal, Montreal, QC, Canada
| | - Gilles Plourde
- Montreal Neurological Hospital and Institute, McGill University Health Center, Montreal, QC, Canada
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Stefanie Blain-Moraes
- Montreal General Hospital, McGill University Health Center Research Institute, Montreal, QC, Canada
- School of Physical and Occupational Therapy, Faculty of Medicine, McGill University, Montreal, QC, Canada
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15
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Comanducci A, Boly M, Claassen J, De Lucia M, Gibson RM, Juan E, Laureys S, Naccache L, Owen AM, Rosanova M, Rossetti AO, Schnakers C, Sitt JD, Schiff ND, Massimini M. Clinical and advanced neurophysiology in the prognostic and diagnostic evaluation of disorders of consciousness: review of an IFCN-endorsed expert group. Clin Neurophysiol 2020; 131:2736-2765. [PMID: 32917521 DOI: 10.1016/j.clinph.2020.07.015] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 07/06/2020] [Accepted: 07/26/2020] [Indexed: 12/13/2022]
Abstract
The analysis of spontaneous EEG activity and evoked potentialsis a cornerstone of the instrumental evaluation of patients with disorders of consciousness (DoC). Thepast few years have witnessed an unprecedented surge in EEG-related research applied to the prediction and detection of recovery of consciousness after severe brain injury,opening up the prospect that new concepts and tools may be available at the bedside. This paper provides a comprehensive, critical overview of bothconsolidated and investigational electrophysiological techniquesfor the prognostic and diagnostic assessment of DoC.We describe conventional clinical EEG approaches, then focus on evoked and event-related potentials, and finally we analyze the potential of novel research findings. In doing so, we (i) draw a distinction between acute, prolonged and chronic phases of DoC, (ii) attempt to relate both clinical and research findings to the underlying neuronal processes and (iii) discuss technical and conceptual caveats.The primary aim of this narrative review is to bridge the gap between standard and emerging electrophysiological measures for the detection and prediction of recovery of consciousness. The ultimate scope is to provide a reference and common ground for academic researchers active in the field of neurophysiology and clinicians engaged in intensive care unit and rehabilitation.
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Affiliation(s)
- A Comanducci
- IRCCS Fondazione Don Carlo Gnocchi, Milan, Italy
| | - M Boly
- Department of Neurology and Department of Psychiatry, University of Wisconsin, Madison, USA; Wisconsin Institute for Sleep and Consciousness, Department of Psychiatry, University of Wisconsin-Madison, Madison, USA
| | - J Claassen
- Department of Neurology, Columbia University Medical Center, New York Presbyterian Hospital, New York, NY, USA
| | - M De Lucia
- Laboratoire de Recherche en Neuroimagerie, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - R M Gibson
- The Brain and Mind Institute and the Department of Physiology and Pharmacology, Western Interdisciplinary Research Building, N6A 5B7 University of Western Ontario, London, Ontario, Canada
| | - E Juan
- Wisconsin Institute for Sleep and Consciousness, Department of Psychiatry, University of Wisconsin-Madison, Madison, USA; Amsterdam Brain and Cognition, Department of Psychology, University of Amsterdam, Amsterdam, the Netherlands
| | - S Laureys
- Coma Science Group, Centre du Cerveau, GIGA-Consciousness, University and University Hospital of Liège, 4000 Liège, Belgium; Fondazione Europea per la Ricerca Biomedica Onlus, Milan 20063, Italy
| | - L Naccache
- Inserm U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France; Sorbonne Université, UPMC Université Paris 06, Faculté de Médecine Pitié-Salpêtrière, Paris, France
| | - A M Owen
- The Brain and Mind Institute and the Department of Physiology and Pharmacology, Western Interdisciplinary Research Building, N6A 5B7 University of Western Ontario, London, Ontario, Canada
| | - M Rosanova
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy; Fondazione Europea per la Ricerca Biomedica Onlus, Milan 20063, Italy
| | - A O Rossetti
- Neurology Service, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - C Schnakers
- Research Institute, Casa Colina Hospital and Centers for Healthcare, Pomona, CA, USA
| | - J D Sitt
- Inserm U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - N D Schiff
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA
| | - M Massimini
- IRCCS Fondazione Don Carlo Gnocchi, Milan, Italy; Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
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16
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From Awareness to Prognosis: Ethical Implications of Uncovering Hidden Awareness in Behaviorally Nonresponsive Patients. Camb Q Healthc Ethics 2020; 28:616-631. [PMID: 31526429 DOI: 10.1017/s0963180119000550] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Long-term patient outcomes after severe brain injury are highly variable, and reliable prognostic indicators are urgently needed to guide treatment decisions. Functional neuroimaging is a highly sensitive method of uncovering covert cognition and awareness in patients with prolonged disorders of consciousness, and there has been increased interest in using it as a research tool in acutely brain injured patients. When covert awareness is detected in a research context, this may impact surrogate decisionmaking-including decisions about life-sustaining treatment-even though the prognostic value of covert consciousness is currently unknown. This paper provides guidance to clinicians and families in incorporating individual research results of unknown prognostic value into surrogate decisionmaking, focusing on three potential issues: (1) Surrogate decisionmakers may misinterpret results; (2) Results may create false hope about the prospects of recovery; (3) There may be disagreement about the meaningfulness or relevance of results, and appropriateness of continued care.
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17
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Cortese D, Riganello F, Arcuri F, Lucca L, Tonin P, Schnakers C, Laureys S. The Trace Conditional Learning of the Noxious Stimulus in UWS Patients and Its Prognostic Value in a GSR and HRV Entropy Study. Front Hum Neurosci 2020; 14:97. [PMID: 32327985 PMCID: PMC7161674 DOI: 10.3389/fnhum.2020.00097] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 03/02/2020] [Indexed: 01/18/2023] Open
Abstract
The assessment of the consciousness level of Unresponsive Wakefulness Syndrome (UWS) patients often depends on a subjective interpretation of the observed spontaneous and volitional behavior. To date, the misdiagnosis level is around 30%. The aim of this study was to observe the behavior of UWS patients, during the administration of noxious stimulation by a Trace Conditioning protocol, assessed by the Galvanic Skin Response (GSR) and Heart Rate Variability (HRV) entropy. We recruited 13 Healthy Control (HC) and 30 UWS patients at 31 ± 9 days from the acute event evaluated by Coma Recovery Scale–Revised (CRS-R) and Nociception Coma Scale (NCS). Two different stimuli [musical stimulus (MUS) and nociceptive stimulus (NOC)], preceded, respectively by two different tones, were administered following the sequences (A) MUS1 – NOC1 – MUS2 – MUS3 – NOC2 – MUS4 – NOC3 – NOC*, and (B) MUS1*, NOC1*, NOC2*, MUS2*, NOC3*, MUS3*, NOC4*, MUS4*. All the (*) indicate the only tones administration. CRS-R and NCS assessments were repeated for three consecutive weeks. MUS4, NOC3, and NOC* were compared for GSR wave peak magnitude, time to reach the peak, and time of wave's decay by Wilcoxon's test to assess the Conditioned Response (CR). The Sample Entropy (SampEn) was recorded in baseline and both sequences. Machine Learning approach was used to identify a rule to discriminate the CR. The GSR magnitude of CR was higher comparing music stimulus (p < 0.0001) and CR extinction (p < 0.002) in nine patients and in HC. Patients with CR showed a higher SampEn in sequence A compared to patients without CR. Within the third and fourth weeks from protocol administration, eight of the nine patients (88.9%) evolved into MCS. The Machine-learning showed a high performance to differentiate presence/absence of CR (≥95%). The possibility to observe the CR to the noxious stimulus, by means of the GSR and SampEn, can represent a potential method to reduce the misdiagnosis in UWS patients.
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Affiliation(s)
- Daniela Cortese
- Research in Advanced NeuroRehabilitation, Istituto Sant'Anna, Crotone, Italy
| | - Francesco Riganello
- Research in Advanced NeuroRehabilitation, Istituto Sant'Anna, Crotone, Italy.,Coma Science Group, GIGA-Consciousness, University & Hospital of Liege, Liege, Belgium
| | - Francesco Arcuri
- Research in Advanced NeuroRehabilitation, Istituto Sant'Anna, Crotone, Italy
| | - Lucia Lucca
- Research in Advanced NeuroRehabilitation, Istituto Sant'Anna, Crotone, Italy
| | - Paolo Tonin
- Research in Advanced NeuroRehabilitation, Istituto Sant'Anna, Crotone, Italy
| | - Caroline Schnakers
- Neurosurgery Department, University of California, Los Angeles, Los Angeles, CA, United States.,Research Institute, Casa Colina Hospital and Centers of Healthcare, Pomona, CA, United States
| | - Steven Laureys
- Coma Science Group, GIGA-Consciousness, University & Hospital of Liege, Liege, Belgium
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18
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Molteni E, Colombo K, Pastore V, Galbiati S, Recla M, Locatelli F, Galbiati S, Fedeli C, Strazzer S. Joint Neuropsychological Assessment through Coma/Near Coma and Level of Cognitive Functioning Assessment Scales Reduces Negative Findings in Pediatric Disorders of Consciousness. Brain Sci 2020; 10:E162. [PMID: 32178348 PMCID: PMC7140001 DOI: 10.3390/brainsci10030162] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 02/28/2020] [Accepted: 03/10/2020] [Indexed: 01/26/2023] Open
Abstract
The present study aimed to: (a) characterize the emergence to a conscious state (CS) in a sample of children and adolescents with severe brain injury during the post-acute rehabilitation and through two different neuropsychological assessment tools: the Rappaport Coma/Near Coma Scale (CNCS) and Level of Cognitive Functioning Assessment Scale (LOCFAS); (b) compare the evolution in patients with brain lesions due to traumatic and non-traumatic etiologies; and (c) describe the relationship between the emergence to a CS and some relevant clinical variables. In this observational prospective longitudinal study, 92 consecutive patients were recruited. Inclusion criteria were severe disorders of consciousness (DOC), Glasgow Coma Scale (GCS) score ≤8 at insult, age 0 to 18 years, and direct admission to inpatient rehabilitation from acute care. The main outcome measures were CNCS and LOCFAS, both administered three and six months after injury. The cohort globally shifted towards milder DOC over time, moving from overall 'moderate/near coma' at three months to 'near/no coma' at six months post-injury. The shift was captured by both CNCS and LOCFAS. CNCS differentiated levels of coma at best, while LOCFAS was superior in characterizing the emergence from coma. Agreement between scales was fair, and reduced negative findings at less than 10%. Patients with traumatic brain injury (TBI) vs. non-traumatic brain injury (NTBI) were older and had neurosurgical intervention more frequently. No relation between age and the level of consciousness was found overall. Concurrent administration of CNCS and LOCFAS reduced the rate of false negatives and better detected signs of arousal and awareness. This provides indication to administer both tools to increase measurement precision.
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Affiliation(s)
- Erika Molteni
- School of Biomedical Engineering & Imaging Sciences, and Centre for Medical Engineering, King’s College, London SE1 7EU, UK
| | - Katia Colombo
- Neuropsychological and Cognitive-behavioral Service, Neurophysiatric Department, Scientific Institute, I.R.C.C.S. Eugenio Medea, 23842 Bosisio Parini, Italy; (V.P.); (S.G.); (M.R.); (C.F.)
| | - Valentina Pastore
- Neuropsychological and Cognitive-behavioral Service, Neurophysiatric Department, Scientific Institute, I.R.C.C.S. Eugenio Medea, 23842 Bosisio Parini, Italy; (V.P.); (S.G.); (M.R.); (C.F.)
| | - Susanna Galbiati
- Neuropsychological and Cognitive-behavioral Service, Neurophysiatric Department, Scientific Institute, I.R.C.C.S. Eugenio Medea, 23842 Bosisio Parini, Italy; (V.P.); (S.G.); (M.R.); (C.F.)
| | - Monica Recla
- Neuropsychological and Cognitive-behavioral Service, Neurophysiatric Department, Scientific Institute, I.R.C.C.S. Eugenio Medea, 23842 Bosisio Parini, Italy; (V.P.); (S.G.); (M.R.); (C.F.)
| | - Federica Locatelli
- Neurophysiatric Department, Scientific Institute, I.R.C.C.S. Eugenio Medea, 23842 Bosisio Parini, Italy; (F.L.); (S.G.); (S.S.)
| | - Sara Galbiati
- Neurophysiatric Department, Scientific Institute, I.R.C.C.S. Eugenio Medea, 23842 Bosisio Parini, Italy; (F.L.); (S.G.); (S.S.)
| | - Claudia Fedeli
- Neuropsychological and Cognitive-behavioral Service, Neurophysiatric Department, Scientific Institute, I.R.C.C.S. Eugenio Medea, 23842 Bosisio Parini, Italy; (V.P.); (S.G.); (M.R.); (C.F.)
| | - Sandra Strazzer
- Neurophysiatric Department, Scientific Institute, I.R.C.C.S. Eugenio Medea, 23842 Bosisio Parini, Italy; (F.L.); (S.G.); (S.S.)
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19
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Abdalmalak A, Milej D, Yip LCM, Khan AR, Diop M, Owen AM, St Lawrence K. Assessing Time-Resolved fNIRS for Brain-Computer Interface Applications of Mental Communication. Front Neurosci 2020; 14:105. [PMID: 32132894 PMCID: PMC7040089 DOI: 10.3389/fnins.2020.00105] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 01/27/2020] [Indexed: 12/13/2022] Open
Abstract
Brain-computer interfaces (BCIs) are becoming increasingly popular as a tool to improve the quality of life of patients with disabilities. Recently, time-resolved functional near-infrared spectroscopy (TR-fNIRS) based BCIs are gaining traction because of their enhanced depth sensitivity leading to lower signal contamination from the extracerebral layers. This study presents the first account of TR-fNIRS based BCI for “mental communication” on healthy participants. Twenty-one (21) participants were recruited and were repeatedly asked a series of questions where they were instructed to imagine playing tennis for “yes” and to stay relaxed for “no.” The change in the mean time-of-flight of photons was used to calculate the change in concentrations of oxy- and deoxyhemoglobin since it provides a good compromise between depth sensitivity and signal-to-noise ratio. Features were extracted from the average oxyhemoglobin signals to classify them as “yes” or “no” responses. Linear-discriminant analysis (LDA) and support vector machine (SVM) classifiers were used to classify the responses using the leave-one-out cross-validation method. The overall accuracies achieved for all participants were 75% and 76%, using LDA and SVM, respectively. The results also reveal that there is no significant difference in accuracy between questions. In addition, physiological parameters [heart rate (HR) and mean arterial pressure (MAP)] were recorded on seven of the 21 participants during motor imagery (MI) and rest to investigate changes in these parameters between conditions. No significant difference in these parameters was found between conditions. These findings suggest that TR-fNIRS could be suitable as a BCI for patients with brain injuries.
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Affiliation(s)
- Androu Abdalmalak
- Department of Medical Biophysics, Western University, London, ON, Canada.,Imaging Program, Lawson Health Research Institute, London, ON, Canada
| | - Daniel Milej
- Department of Medical Biophysics, Western University, London, ON, Canada.,Imaging Program, Lawson Health Research Institute, London, ON, Canada
| | - Lawrence C M Yip
- Department of Medical Biophysics, Western University, London, ON, Canada.,Imaging Program, Lawson Health Research Institute, London, ON, Canada
| | - Ali R Khan
- Department of Medical Biophysics, Western University, London, ON, Canada.,Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada
| | - Mamadou Diop
- Department of Medical Biophysics, Western University, London, ON, Canada.,Imaging Program, Lawson Health Research Institute, London, ON, Canada
| | - Adrian M Owen
- Brain and Mind Institute, Western University, London, ON, Canada
| | - Keith St Lawrence
- Department of Medical Biophysics, Western University, London, ON, Canada.,Imaging Program, Lawson Health Research Institute, London, ON, Canada
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20
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Calabrò RS, Chillura A, Billeri L, Cannavò A, Buda A, Molonia F, Manuli A, Bramanti P, Naro A. Peri-Personal Space Tracing by Hand-Blink Reflex Modulation in Patients with Chronic Disorders of Consciousness. Sci Rep 2020; 10:1712. [PMID: 32015445 PMCID: PMC6997168 DOI: 10.1038/s41598-020-58625-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 01/17/2020] [Indexed: 12/14/2022] Open
Abstract
The assessment of awareness in patients with chronic Disorders of Consciousness (DoC), including Unresponsive Wakefulness Syndrome (UWS) and Minimally Conscious State (MCS), is challenging. The level of awareness impairment may depend on the degree of deterioration of the large-scale cortical-thalamo-cortical networks induced by brain injury. Electrophysiological approaches may shed light on awareness presence in patients with DoC by estimating cortical functions related to the cortical-thalamo-cortical networks including, for example, the cortico-subcortical processes generating motor responses to the perturbation of the peri-personal space (PPS). We measured the amplitude, latency, and duration of the hand-blink reflex (HBR) responses by recording electromyography (EMG) signals from both the orbicularis oculi muscles while electrically stimulating the median nerve at the wrist. Such a BR is thought to be mediated by a neural circuit at the brainstem level. Despite its defensive-response nature, HBR can be modulated by the distance between the stimulated hand and the face. This suggests a functional top-down control of HBR as reflected by HBR features changes (latency, amplitude, and magnitude). We therefore estimated HBR responses in a sample of patients with DoC (8 MCS and 12 UWS, compared to 15 healthy controls -HC) while performing a motor task targeting the PPS. This consisted of passive movements in which the hand of the subject was positioned at different distances from the participant's face. We aimed at demonstrating a residual top-down modulation of HBR properties, which could be useful to differentiate patients with DoC and, potentially, demonstrate awareness preservation. We found a decrease in latency, and an increase in duration and magnitude of HBR responses, which were all inversely related to the hand-to-face distance in HC and patients with MCS, but not in individuals with UWS. Our data suggest that only patients with MCS have preserved, residual, top-down modulation of the processes related to the PPS from higher-order cortical areas to sensory-motor integration network. Although the sample size was relatively small, being thus our data preliminary, HBR assessment seems a rapid, easy, and first-level tool to differentiate patients with MCS from those with UWS. We may also hypothesize that such a HBR modulation suggests awareness preservation.
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Affiliation(s)
| | | | - Luana Billeri
- IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | | | - Antonio Buda
- IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | | | | | | | - Antonino Naro
- IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
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21
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Molteni E, Colombo K, Beretta E, Galbiati S, Santos Canas LD, Modat M, Strazzer S. Comparison of Multi-class Machine Learning Methods for the Identification of Factors Most Predictive of Prognosis in Neurobehavioral assessment of Pediatric Severe Disorder of Consciousness through LOCFAS scale. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:269-272. [PMID: 31945893 DOI: 10.1109/embc.2019.8856880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Severe Disorders of Consciousness (DoC) are generally caused by brain trauma, anoxia or stroke, and result in conditions ranging from coma to the confused-agitated state. Prognostic decision is difficult to achieve during the first year after injury, especially in the pediatric cases. Nevertheless, prognosis crucially informs rehabilitation decision and family expectations. We compared four multi-class machine learning classification approaches for the prognostic decision in pediatric DoC. We identified domains of a neurobehavioral assessment tool, Level of Cognitive Functioning Assessment Scale, mostly contributing to decision in a cohort of 124 cases. We showed the possibility to generalize to new admitted pediatric cases, thus paving the way for real employment of machine learning classifiers as an assistive tool to prognostic decision in clinics.
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22
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How Does Functional Neurodiagnostics Inform Surrogate Decision-Making for Patients with Disorders of Consciousness? A Qualitative Interview Study with Patients’ Next of Kin. NEUROETHICS-NETH 2020. [DOI: 10.1007/s12152-019-09425-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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23
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Peterson A. How Will Families React to Evidence of Covert Consciousness in Brain-Injured Patients? NEUROETHICS-NETH 2020. [DOI: 10.1007/s12152-019-09428-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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24
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Kostick KM, Halm A, O'Brien K, Kothari S, Blumenthal-Barby JS. Conceptualizations of consciousness and continuation of care among family members and health professionals caring for patients in a minimally conscious state. Disabil Rehabil 2019; 43:2285-2294. [PMID: 34315308 DOI: 10.1080/09638288.2019.1697383] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND The American Academy of Neurology recently emphasized the importance of communicating with patients' families to better reflect patient values in clinical care. However, little is known about how decisions about continuing rehabilitative care made by family caregivers and healthcare providers working with minimally conscious patients are informed by conceptualizations of consciousness and moral status. METHODS We explored these issues in interviews with 18 family caregivers and 20 healthcare professionals caring for minimally conscious patients. Data were analyzed using thematic content analysis. RESULTS Results suggest that family members and healthcare professionals share similar views of what consciousness is ("being there") and what it is indicated by ("a look in the eyes," and/or an "ability to do"/agency). They also share a belief that the presence (or "level") of consciousness does not determine whether rehabilitative care should be discontinued. Rather, it should be determined by considerations of suffering and well-being. Providers were more likely to view suffering as rationale for discontinuation of care, while family members viewed suffering as an indicator of and motivator for potential recovery. CONCLUSION Findings can help optimize family-provider communications about minimally conscious patients by acknowledging shared assumptions and interpretations of consciousness, as well as key areas where perspectives diverge.Implications for rehabilitationFamily and professional caregivers' interpretations of consciousness and suffering are implicated in decisions about continuing rehabilitation for minimally conscious patients.Family members and healthcare providers both rely to some extent on non-observable evidence to evaluate consciousness, which may be an adaptive and philanthropic response to clinical uncertainty.Acknowledging shared assumptions and interpretations of consciousness, as well as diverging perspectives, can help to optimize family-provider communications.
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Affiliation(s)
- Kristin M Kostick
- Center for Medical Ethics and Health Policy, Baylor College of Medicine, Houston, TX, USA
| | - Abby Halm
- Center for Medical Ethics and Health Policy, Baylor College of Medicine, Houston, TX, USA
| | - Katherine O'Brien
- Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, TX, USA.,TIRR Memorial Hermann Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Sunil Kothari
- TIRR Memorial Hermann Research Institute, Baylor College of Medicine, Houston, TX, USA
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25
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A Critical Analysis of Joseph Fins' Mosaic Decisionmaking: A Response to "Mosaic Decisionmaking and Reemergent Agency after Severe Brain Injury" (CQ 27 (1)). Camb Q Healthc Ethics 2019; 28:725-736. [PMID: 31526420 DOI: 10.1017/s0963180119000665] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this paper, the author argues that Joseph Fins' mosaic decisionmaking model for brain-injured patients is untenable. He supports this claim by identifying three problems with mosaic decisionmaking. First, that it is unclear whether a mosaic is a conceptually adequate metaphor for a decisionmaking process that is intended to promote patient autonomy. Second, that the proposed legal framework for mosaic decisionmaking is inappropriate. Third, that it is unclear how we ought to select patients for participation in mosaic decisionmaking.
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Structural Neuroimaging and Early Neuroprognostication of Hypoxic-Ischemic Brain Injury in Cardiac Arrest Survivors. Crit Care Med 2019; 45:e875. [PMID: 28708694 DOI: 10.1097/ccm.0000000000002482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Verheijde JL, Rady MY, Potts M. Neuroscience and Brain Death Controversies: The Elephant in the Room. JOURNAL OF RELIGION AND HEALTH 2018; 57:1745-1763. [PMID: 29931477 PMCID: PMC6132575 DOI: 10.1007/s10943-018-0654-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The conception and the determination of brain death continue to raise scientific, legal, philosophical, and religious controversies. While both the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research in 1981 and the President's Council on Bioethics in 2008 committed to a biological definition of death as the basis for the whole-brain death criteria, contemporary neuroscientific findings augment the concerns about the validity of this biological definition. Neuroscientific evidentiary findings, however, have not yet permeated discussions about brain death. These findings have critical relevance (scientifically, medically, legally, morally, and religiously) because they indicate that some core assumptions about brain death are demonstrably incorrect, while others lack sufficient evidential support. If behavioral unresponsiveness does not equate to unconsciousness, then the philosophical underpinning of the definition based on loss of capacity for consciousness as well as the criteria, and tests in brain death determination are incongruent with empirical evidence. Thus, the primary claim that brain death equates to biological death has then been de facto falsified. This conclusion has profound philosophical, religious, and legal implications that should compel respective authorities to (1) reassess the philosophical rationale for the definition of death, (2) initiate a critical reappraisal of the presumed alignment of brain death with the theological definition of death in Abrahamic faith traditions, and (3) enact new legislation ratifying religious exemption to death determination by neurologic criteria.
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Affiliation(s)
- Joseph L. Verheijde
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, 13400 E Shea Blvd, Scottsdale, AZ 85259 USA
| | - Mohamed Y. Rady
- Department of Critical Care Medicine, Mayo Clinic Hospital, 5777 E Mayo Blvd, Phoenix, AZ 85054 USA
| | - Michael Potts
- Department of Philosophy and Religion, Methodist University, 5400 Ramsey Street, Fayetteville, NC 28311-1498 USA
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Huang Z, Vlisides PE, Tarnal VC, Janke EL, Keefe KM, Collins MM, McKinney AM, Picton P, Harris RE, Mashour GA, Hudetz AG. Brain imaging reveals covert consciousness during behavioral unresponsiveness induced by propofol. Sci Rep 2018; 8:13195. [PMID: 30181567 PMCID: PMC6123455 DOI: 10.1038/s41598-018-31436-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/17/2018] [Indexed: 12/11/2022] Open
Abstract
Detecting covert consciousness in behaviorally unresponsive patients by brain imaging is of great interest, but a reproducible model and evidence from independent sources is still lacking. Here we demonstrate the possibility of using general anesthetics in a within-subjects study design to test methods or statistical paradigms of assessing covert consciousness. Using noninvasive neuroimaging in healthy volunteers, we identified a healthy study participant who was able to exhibit the specific fMRI signatures of volitional mental imagery while behaviorally unresponsive due to sedation with propofol. Our findings reveal a novel model that may accelerate the development of new approaches to reproducibly detect covert consciousness, which is difficult to achieve in patients with heterogeneous and sometimes clinically unstable neuropathology.
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Affiliation(s)
- Zirui Huang
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA.
- Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Phillip E Vlisides
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
- Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Vijaykumar C Tarnal
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
- Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Ellen L Janke
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
- Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kelley M Keefe
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Margaret M Collins
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Amy M McKinney
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Paul Picton
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Richard E Harris
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
- Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - George A Mashour
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA
- Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - Anthony G Hudetz
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, USA.
- Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, USA.
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA.
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Rady MY, Verheijde JL. Legislative Enforcement of Nonconsensual Determination of Neurological (Brain) Death in Muslim Patients: A Violation of Religious Rights. JOURNAL OF RELIGION AND HEALTH 2018; 57:649-661. [PMID: 29067599 PMCID: PMC5854742 DOI: 10.1007/s10943-017-0512-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Death is defined in the Quran with a single criterion of irreversible separation of the ruh (soul) from the body. The Quran is a revelation from God to man, and the primary source of Islamic knowledge. The secular concept of death by neurological criteria, or brain death, is at odds with the Quranic definition of death. The validity of this secular concept has been contested scientifically and philosophically. To legitimize brain death for the purpose of organ donation and transplantation in Muslim communities, Chamsi-Pasha and Albar (concurring with the US President's Council on Bioethics) have argued that irreversible loss of capacity for consciousness and breathing (apneic coma) in brain death defines true death in accordance with Islamic sources. They have postulated that the absence of nafs (personhood) and nafas (breath) in apneic coma constitutes true death because of departure of the soul (ruh) from the body. They have also asserted that general anesthesia is routine in brain death before surgical procurement. Their argument is open to criticism because: (1) the ruh is described as the essence of life, whereas the nafs and nafas are merely human attributes; (2) unlike true death, the ruh is still present even with absent nafs and nafas in apneic coma; and (3) the routine use of general anesthesia indicates the potential harm to brain-dead donors from surgical procurement. Postmortem general anesthesia is not required for autopsy. Therefore, the conclusion must be that legislative enforcement of nonconsensual determination of neurological (brain) death and termination of life-support and medical treatment violates the religious rights of observant Muslims.
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Affiliation(s)
- Mohamed Y. Rady
- Mayo Clinic College of Medicine and Science and Department of Critical Care Medicine, Mayo Clinic Hospital, 5777 East Mayo Blvd, Phoenix, AZ 85054 USA
| | - Joseph L. Verheijde
- Mayo Clinic College of Medicine and Science and Department of Physical Medicine and Rehabilitation, Mayo Clinic, 13400 E Shea Blvd, Scottsdale, AZ 85259 USA
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Kameda N, Suzuki M. Caregivers' lived experience in trying to read slight movements in a child with severe brain injury: A phenomenological study. J Clin Nurs 2018; 27:e1202-e1213. [PMID: 29314400 DOI: 10.1111/jocn.14255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2017] [Indexed: 11/28/2022]
Abstract
AIMS AND OBJECTIVES To explore caregivers' lived experience of reading slight movements of a child with severe brain injury. BACKGROUND Despite increased need, the development of individual care for children with severe brain injuries has been prevented by their severe physical state and the poor reproducibility of their movements. In addition to a lack of evidence on the motor characteristics of patients with severe brain injury with multiple disabilities, their own development contributes to increasing variability in their states. Thus, caregivers are compelled to rely on their experiences, which have not been academically explored. DESIGN A qualitative study based on van Manen's method of hermeneutic phenomenology. METHODS Data were obtained through twenty-one 3-hr observation sessions and five 15- to 45-min group interviews. We observed a child (called AK) with severe brain injury and his 61 caregivers, and conducted group interviews with 28 caregivers. We focused on caregivers' experiences of reading AK's slight movements. The data were interpreted based on van Manen's hermeneutic phenomenological approach. RESULTS Four themes emerged as caregivers' experience in trying to read AK's slight movements. By considering "AK's physical state and his slight movements" and discovering "caregivers' 'sense of uncertainty' about AK's slight movements," caregivers could decipher "AK's multiple slight movements." "Sharing" was found as a necessary aspect of these other three themes of reading AK's slight movements. CONCLUSIONS We presented caregivers' experiences as related to these four themes in their efforts to read the slight movements of AK. Due to AK's slight movements with poor reproducibility, "sharing" was necessary to read AK's slight movements, as it exposes caregivers' lived experience to the interpretation of multiple caregivers. RELEVANCE TO CLINICAL PRACTICE These four themes may be useful for assessing, guiding and promoting caregivers' use of sharing when reading the slight movements of children with severe brain injury.
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Affiliation(s)
- Naoko Kameda
- Setsunan University, Hirakata City, Osaka, Japan
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31
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Absent Cerebellar Circulation With Intact Cerebral Blood Flow on a 99mTc Bicisate "Brain Death" Study. Clin Nucl Med 2017; 42:983-984. [PMID: 29076900 DOI: 10.1097/rlu.0000000000001866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A 55-year old woman presented in an obtunded state and was found to have a subarachnoid hemorrhage. After endovascular repair, her condition deteriorated, and brain death was suspected. A Tc bicisate brain blood flow study was performed, which showed a complete absence of blood flow to the cerebellum despite intact circulation to the cerebral hemispheres. These atypical findings are likely a result of a transient intracranial pressure differential and the timing of the study. A timely and accurate declaration of brain death has important psychosocial and ethical implications, particularly when organ donation is being considered.
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Ragazzoni A, Cincotta M, Giovannelli F, Cruse D, Young GB, Miniussi C, Rossi S. Clinical neurophysiology of prolonged disorders of consciousness: From diagnostic stimulation to therapeutic neuromodulation. Clin Neurophysiol 2017; 128:1629-1646. [DOI: 10.1016/j.clinph.2017.06.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 05/17/2017] [Accepted: 06/15/2017] [Indexed: 10/19/2022]
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Rady MY, Verheijde JL. Judicial oversight of life-ending withdrawal of assisted nutrition and hydration in disorders of consciousness in the United Kingdom: A matter of life and death. Med Leg J 2017; 85:148-154. [PMID: 28368210 PMCID: PMC5580785 DOI: 10.1177/0025817217702289] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mr Justice Baker delivered the Oxford Shrieval Lecture 'A Matter of Life and Death' on 11 October 2016. The lecture created public controversies about who can authorise withdrawal of assisted nutrition and hydration (ANH) in disorders of consciousness (DOC). The law requires court permission in 'best interests' decisions before ANH withdrawal only in permanent vegetative state and minimally conscious state. Some clinicians favour abandoning the need for court approval on the basis that clinicians are already empowered to withdraw ANH in other common conditions of DOC (e.g. coma, neurological disorders, etc.) based on their best interests assessment without court oversight. We set out a rationale in support of court oversight of best interests decisions in ANH withdrawal intended to end life in any person with DOC (who will lack relevant decision-making capacity). This ensures the safety of the general public and the protection of vulnerable disabled persons in society.
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Affiliation(s)
- Mohamed Y Rady
- Mayo Clinic College of Medicine and Science and Department of Critical Care Medicine, Mayo Clinic Hospital, Phoenix, AZ, USA
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34
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Morlet D, Ruby P, André-Obadia N, Fischer C. The auditory oddball paradigm revised to improve bedside detection of consciousness in behaviorally unresponsive patients. Psychophysiology 2017; 54:1644-1662. [DOI: 10.1111/psyp.12954] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 06/09/2017] [Accepted: 06/12/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Dominique Morlet
- Lyon Neuroscience Research Center (CRNL), Brain Dynamics and Cognition Team, INSERM U 1028, CNRS UMR 5292, University Lyon 1; Lyon France
| | - Perrine Ruby
- Lyon Neuroscience Research Center (CRNL), Brain Dynamics and Cognition Team, INSERM U 1028, CNRS UMR 5292, University Lyon 1; Lyon France
| | - Nathalie André-Obadia
- Functional Neurology and Epileptology Department; Neurological Hospital, Hospices Civils de Lyon; Lyon France
- Lyon Neuroscience Research Center (CRNL), Neuropain Team, INSERM U 1028, CNRS UMR 5292, University Lyon 1; Lyon France
| | - Catherine Fischer
- Lyon Neuroscience Research Center (CRNL), Brain Dynamics and Cognition Team, INSERM U 1028, CNRS UMR 5292, University Lyon 1; Lyon France
- Functional Neurology and Epileptology Department; Neurological Hospital, Hospices Civils de Lyon; Lyon France
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35
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Chennu S, Annen J, Wannez S, Thibaut A, Chatelle C, Cassol H, Martens G, Schnakers C, Gosseries O, Menon D, Laureys S. Brain networks predict metabolism, diagnosis and prognosis at the bedside in disorders of consciousness. Brain 2017; 140:2120-2132. [PMID: 28666351 DOI: 10.1093/brain/awx163] [Citation(s) in RCA: 175] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 05/25/2017] [Indexed: 01/28/2023] Open
Affiliation(s)
- Srivas Chennu
- School of Computing, University of Kent, UK
- Department of Clinical Neurosciences, University of Cambridge, UK
| | - Jitka Annen
- Coma Science Group, GIGA Consciousness, University and University Hospital of Liège, Liège, Belgium
| | - Sarah Wannez
- Coma Science Group, GIGA Consciousness, University and University Hospital of Liège, Liège, Belgium
| | - Aurore Thibaut
- Coma Science Group, GIGA Consciousness, University and University Hospital of Liège, Liège, Belgium
- Spaulding-Labuschagne Neuromodulation Center, Spaulding Rehabilitation Hospital, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, USA
| | - Camille Chatelle
- Coma Science Group, GIGA Consciousness, University and University Hospital of Liège, Liège, Belgium
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital and Harvard Medical School, Boston, MA, USA
- Laboratory for NeuroImaging of Coma and Consciousness, Massachusetts General Hospital, Boston, MA, USA
| | - Helena Cassol
- Coma Science Group, GIGA Consciousness, University and University Hospital of Liège, Liège, Belgium
| | - Géraldine Martens
- Coma Science Group, GIGA Consciousness, University and University Hospital of Liège, Liège, Belgium
| | - Caroline Schnakers
- Neurosurgery Department, University of California, Los Angeles, CA, USA
- Research Institute, Casa Colina Hospital and Centers of Healthcare, Pomona, CA, USA
| | - Olivia Gosseries
- Coma Science Group, GIGA Consciousness, University and University Hospital of Liège, Liège, Belgium
| | - David Menon
- Division of Anaesthetics, University of Cambridge, UK
| | - Steven Laureys
- Coma Science Group, GIGA Consciousness, University and University Hospital of Liège, Liège, Belgium
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36
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Demertzi A, Sitt JD, Sarasso S, Pinxten W. Measuring states of pathological (un)consciousness: research dimensions, clinical applications, and ethics. Neurosci Conscious 2017; 2017:nix010. [PMID: 30042843 PMCID: PMC6007135 DOI: 10.1093/nc/nix010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 02/02/2017] [Accepted: 04/18/2017] [Indexed: 12/26/2022] Open
Abstract
Consciousness is a multidimensional construct with no widely accepted definition. Especially in pathological conditions, it is less clear what exactly is meant by (un)consciousness, how it can be reliably observed or measured. Here, we aim at (i) bringing together state of the art approaches to classification of single patients suffering from disorders of consciousness by means of motor-independent assessment of consciousness states with electrophysiology and functional neuroimaging, (ii) showing how each proposed metric translates into clinical practice and (iii) raising a discussion on the ethical aspects of consciousness measurements. We realize that when dealing with patients some issues commonly pertain to each methodology discussed here, such as the overall clinical condition, clinical heterogeneity, and diagnostic uncertainty. When predicting patients' diagnosis, though, each method adopts a different approach to determine (a) a "gold standard" of the benchmark population upon which the metric is computed and (b) the generalization and replicability in the attempt to avoid overfitting. From an applied ethics perspective, the focus is, hence, on knowing what one is measuring and on the validity of measurements. We conclude that, when searching for consciousness in pathological conditions, confident diagnosis can be based on the use of probabilistic predictions as well as on accumulative evidence stemming from multiple non-overlapping assessments with different modalities. A framework which will regulate the application order of these techniques (balancing their availability, sensitivity, and specificity, based on underlying clinical assumptions about a patient's conscious state), is expected to ameliorate clinical management and further inform on the critical patterns of (un)consciousness.
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Affiliation(s)
- Athena Demertzi
- Brain and Spine Institute- Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, 47, bd de l'Hôpital - 75013 Paris, France
- Coma Science Group, GIGA Research, CHU Sart Tilman B34-Quartier Hôpital, Avenue de l'Hôpital, 11 4000 Liège, Belgium
| | - Jacobo Diego Sitt
- Brain and Spine Institute- Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, 47, bd de l'Hôpital - 75013 Paris, France
- INSERM, U 1127, F-75013, Paris, France
| | - Simone Sarasso
- Department of Biomedical and Clinical Sciences “L. Sacco”, University of Milan, Via G.B. Grassi, 74. 20157, Milano, Italy
| | - Wim Pinxten
- Faculty of Medicine and Life Sciences, Hasselt University, Martelarenlaan 42, 3500 Hasselt, Belgium
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37
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Naci L, Graham M, Owen AM, Weijer C. Covert narrative capacity: Mental life in patients thought to lack consciousness. Ann Clin Transl Neurol 2016; 4:61-70. [PMID: 28078316 PMCID: PMC5221458 DOI: 10.1002/acn3.376] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/20/2016] [Accepted: 10/31/2016] [Indexed: 01/22/2023] Open
Abstract
Despite the apparent absence of external signs of consciousness, a significant proportion of behaviorally nonresponsive patients can respond to commands by willfully modulating their brain activity. However, little is known about the mental life of these patients. We discuss a recent innovative approach, which sheds light on the preserved cognitive capacities of these patients, including executive function, theory of mind, and the experience of affective states. This research represents a fundamental shift in our understanding of these patients, and has important implications for both their continued treatment and care. Moreover, this research marks out avenues for future inquiry into the residual cognitive capacities of these patients.
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Affiliation(s)
- Lorina Naci
- Brain and Mind Institute Western University London Ontario N6A 5B7 Canada
| | - Mackenzie Graham
- Rotman Institute of Philosophy Western University London Ontario N6A 5B8 Canada
| | - Adrian M Owen
- Brain and Mind Institute Western University London Ontario N6A 5B7 Canada
| | - Charles Weijer
- Rotman Institute of Philosophy Western University London Ontario N6A 5B8 Canada
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38
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Casarotto S, Comanducci A, Rosanova M, Sarasso S, Fecchio M, Napolitani M, Pigorini A, G Casali A, Trimarchi PD, Boly M, Gosseries O, Bodart O, Curto F, Landi C, Mariotti M, Devalle G, Laureys S, Tononi G, Massimini M. Stratification of unresponsive patients by an independently validated index of brain complexity. Ann Neurol 2016; 80:718-729. [PMID: 27717082 PMCID: PMC5132045 DOI: 10.1002/ana.24779] [Citation(s) in RCA: 228] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 09/12/2016] [Accepted: 09/13/2016] [Indexed: 12/19/2022]
Abstract
Objective Validating objective, brain‐based indices of consciousness in behaviorally unresponsive patients represents a challenge due to the impossibility of obtaining independent evidence through subjective reports. Here we address this problem by first validating a promising metric of consciousness—the Perturbational Complexity Index (PCI)—in a benchmark population who could confirm the presence or absence of consciousness through subjective reports, and then applying the same index to patients with disorders of consciousness (DOCs). Methods The benchmark population encompassed 150 healthy controls and communicative brain‐injured subjects in various states of conscious wakefulness, disconnected consciousness, and unconsciousness. Receiver operating characteristic curve analysis was performed to define an optimal cutoff for discriminating between the conscious and unconscious conditions. This cutoff was then applied to a cohort of noncommunicative DOC patients (38 in a minimally conscious state [MCS] and 43 in a vegetative state [VS]). Results We found an empirical cutoff that discriminated with 100% sensitivity and specificity between the conscious and the unconscious conditions in the benchmark population. This cutoff resulted in a sensitivity of 94.7% in detecting MCS and allowed the identification of a number of unresponsive VS patients (9 of 43) with high values of PCI, overlapping with the distribution of the benchmark conscious condition. Interpretation Given its high sensitivity and specificity in the benchmark and MCS population, PCI offers a reliable, independently validated stratification of unresponsive patients that has important physiopathological and therapeutic implications. In particular, the high‐PCI subgroup of VS patients may retain a capacity for consciousness that is not expressed in behavior. Ann Neurol 2016;80:718–729
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Affiliation(s)
- Silvia Casarotto
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
| | - Angela Comanducci
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
| | - Mario Rosanova
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy.,Fondazione Europea per la Ricerca Biomedica, Milan, Italy
| | - Simone Sarasso
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
| | - Matteo Fecchio
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
| | - Martino Napolitani
- Department of Health Science, School of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy
| | - Andrea Pigorini
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
| | - Adenauer G Casali
- Institute of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil
| | - Pietro D Trimarchi
- Istituto di Ricovero e Cura a Carattere Scientifico, Fondazione Don Gnocchi Onlus, Milan, Italy
| | - Melanie Boly
- Department of Psychiatry, University of Wisconsin, Madison, WI, USA.,Department of Neurology, University of Wisconsin, Madison, WI, USA
| | - Olivia Gosseries
- Department of Psychiatry, University of Wisconsin, Madison, WI, USA.,Coma Science Group, GIGA, University of Liège, Liège, Belgium
| | - Olivier Bodart
- Coma Science Group, GIGA, University of Liège, Liège, Belgium.,Department of Neurology, University of Liège and University Hospital of Liège, Liège, Belgium
| | - Francesco Curto
- Neurocritical Care Unit, Department of Neuroscience, Azienda Socio-Sanitaria Territoriale, Grande Ospedale Metropolitano Niguarda Cà Granda, Milan, Italy
| | - Cristina Landi
- Fondazione Europea per la Ricerca Biomedica, Milan, Italy
| | - Maurizio Mariotti
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy
| | - Guya Devalle
- Istituto di Ricovero e Cura a Carattere Scientifico, Fondazione Don Gnocchi Onlus, Milan, Italy
| | - Steven Laureys
- Coma Science Group, GIGA, University of Liège, Liège, Belgium
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin, Madison, WI, USA
| | - Marcello Massimini
- Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico, Fondazione Don Gnocchi Onlus, Milan, Italy
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Toppi J, Mattia D, Risetti M, Formisano R, Babiloni F, Astolfi L. Testing the Significance of Connectivity Networks: Comparison of Different Assessing Procedures. IEEE Trans Biomed Eng 2016; 63:2461-2473. [PMID: 27810793 DOI: 10.1109/tbme.2016.2621668] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Despite the well-established use of partial directed coherence (PDC) to estimate interactions between brain signals, the assessment of its statistical significance still remains controversial. Commonly used approaches are based on the generation of empirical distributions of the null case, implying a considerable computational time, which may become a serious limitation in practical applications. Recently, rigorous asymptotic distributions for PDC were proposed. The aim of this work is to compare the performances of the asymptotic statistics with those of an empirical approach, in terms of both accuracy and computational time. METHODS Indices of performance were derived for the two approaches by a simulation study implementing different ground-truth networks under different levels of signal-to-noise ratio and amount of data available for the estimate. The two approaches were then applied to the resting-state EEG data acquired in a group of minimally conscious state and vegetative state/unresponsive wakefulness syndrome patients. RESULTS The performances of the asymptotic statistics in simulations matched those obtained by the empirical approach, with a considerable reduction of the computational time. Results of the application to real data showed that the asymptotic statistics led to the extraction of connectivity-based indices able to discriminate patients in different disorders of consciousness conditions and to correlate significantly with clinical scales. Such results were similar to those obtained by the empirical assessment, but with a considerable time economy. SIGNIFICANCE Asymptotic statistics provide an approach to the assessment of PDC significance with comparable performances with respect to the previously used empirical approaches but with a substantial advantage in terms of computational time.
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Gibson RM, Owen AM, Cruse D. Brain-computer interfaces for patients with disorders of consciousness. PROGRESS IN BRAIN RESEARCH 2016; 228:241-91. [PMID: 27590972 DOI: 10.1016/bs.pbr.2016.04.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The disorders of consciousness refer to clinical conditions that follow a severe head injury. Patients diagnosed as in a vegetative state lack awareness, while patients diagnosed as in a minimally conscious state retain fluctuating awareness. However, it is a challenge to accurately diagnose these disorders with clinical assessments of behavior. To improve diagnostic accuracy, neuroimaging-based approaches have been developed to detect the presence or absence of awareness in patients who lack overt responsiveness. For the small subset of patients who retain awareness, brain-computer interfaces could serve as tools for communication and environmental control. Here we review the existing literature concerning the sensory and cognitive abilities of patients with disorders of consciousness with respect to existing brain-computer interface designs. We highlight the challenges of device development for this special population and address some of the most promising approaches for future investigations.
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Affiliation(s)
- R M Gibson
- The Brain and Mind Institute, University of Western Ontario, London, ON, Canada; University of Western Ontario, London, ON, Canada.
| | - A M Owen
- The Brain and Mind Institute, University of Western Ontario, London, ON, Canada; University of Western Ontario, London, ON, Canada
| | - D Cruse
- School of Psychology, University of Birmingham, Birmingham, 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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End-Of-Life Decisions in Chronic Disorders of Consciousness: Sacrality and Dignity as Factors. NEUROETHICS-NETH 2016. [DOI: 10.1007/s12152-016-9257-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Robles del Olmo B, García Collado D. Retos éticos del hallazgo de consciencia encubierta con neuroimagen en estados vegetativos. Med Clin (Barc) 2016; 146:218-22. [DOI: 10.1016/j.medcli.2015.07.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 07/22/2015] [Indexed: 11/26/2022]
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Peterson A. Consilience, clinical validation, and global disorders of consciousness. Neurosci Conscious 2016; 2016:niw011. [PMID: 30356913 PMCID: PMC6192376 DOI: 10.1093/nc/niw011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 06/08/2016] [Accepted: 07/09/2016] [Indexed: 11/14/2022] Open
Abstract
Behavioral diagnosis of global disorders of consciousness is difficult and errors in diagnosis occur often. Recent advances in neuroimaging may resolve this problem. However, clinical translation of neuroimaging requires clinical validation. Applying the orthodox approach of clinical validation to neuroimaging raises two critical questions: (i) What exactly is being validated? and (ii) what counts as a gold standard? I argue that confusion over these questions leads to systematic errors in the empirical literature. I propose an alternative approach to clinical validation motivated by reasoning by consilience. Consilience is a mode of reasoning that assigns a degree of plausibility to a hypothesis based on its fit with multiple pieces of evidence from independent sources. I argue that this approach resolves the questions raised by the orthodox approach and may be a useful framework for optimizing future clinical validation studies in the science of consciousness.
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Affiliation(s)
- Andrew Peterson
- Rotman Institute of Philosophy and The Brain and Mind Institute,
University of Western Ontario, London, ON, Canada
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Noirhomme Q, Brecheisen R, Lesenfants D, Antonopoulos G, Laureys S. "Look at my classifier's result": Disentangling unresponsive from (minimally) conscious patients. Neuroimage 2015; 145:288-303. [PMID: 26690804 DOI: 10.1016/j.neuroimage.2015.12.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 11/12/2015] [Accepted: 12/04/2015] [Indexed: 12/22/2022] Open
Abstract
Given the fact that clinical bedside examinations can have a high rate of misdiagnosis, machine learning techniques based on neuroimaging and electrophysiological measurements are increasingly being considered for comatose patients and patients with unresponsive wakefulness syndrome, a minimally conscious state or locked-in syndrome. Machine learning techniques have the potential to move from group-level statistical results to personalized predictions in a clinical setting. They have been applied for the purpose of (1) detecting changes in brain activation during functional tasks, equivalent to a behavioral command-following test and (2) estimating signs of consciousness by analyzing measurement data obtained from multiple subjects in resting state. In this review, we provide a comprehensive overview of the literature on both approaches and discuss the translation of present findings to clinical practice. We found that most studies struggle with the difficulty of establishing a reliable behavioral assessment and fluctuations in the patient's levels of arousal. Both these factors affect the training and validation of machine learning methods to a considerable degree. In studies involving more than 50 patients, small to moderate evidence was found for the presence of signs of consciousness or good outcome, where one study even showed strong evidence for good outcome.
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Affiliation(s)
- Quentin Noirhomme
- Brain Innovation BV, Maastricht, Netherlands; Department of Cognitive Neuroscience, Faculty Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands; Cyclotron Research Centre, University of Liege, Liege, Belgium.
| | - Ralph Brecheisen
- Brain Innovation BV, Maastricht, Netherlands; Department of Cognitive Neuroscience, Faculty Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Damien Lesenfants
- School of Engineering and Institute for Brain Science, Brown University, Providence, Rhode Island, USA
| | | | - Steven Laureys
- Coma Science Group, University Hospital of Liege, Liege, Belgium
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Neurophysiological Indicators of Residual Cognitive Capacity in the Minimally Conscious State. Behav Neurol 2015; 2015:145913. [PMID: 26504351 PMCID: PMC4609423 DOI: 10.1155/2015/145913] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/07/2015] [Accepted: 09/09/2015] [Indexed: 11/18/2022] Open
Abstract
Background. The diagnostic usefulness of electrophysiological methods in assessing disorders of consciousness (DoC) remains to be established on an individual patient level, and there is need to determine what constitutes robust experimental paradigm to elicit electrophysiological indices of covert cognitive capacity. Objectives. Two tasks encompassing active and passive conditions were explored in an event-related potentials (ERP) study. The task robustness was studied in healthy controls, and their utility to detect covert signs of command-following on an individual patient level was investigated in patients in a minimally conscious state (MCS). Methods. Twenty healthy controls and 20 MCS patients participated. The active tasks included (1) listening for a change of pitch in the subject's own name (SON) and (2) counting SON, both contrasted to passive conditions. Midline ERPs are reported. Results. A larger P3 response was detected in the counting task compared to active listening to pitch change in the healthy controls. On an individual level, the counting task revealed a higher rate of responders among both healthy subjects and MCS patients. Conclusion. ERP paradigms involving actively counting SON represent a robust paradigm in probing for volitional cognition in minimally conscious patients and add important diagnostic information in some patients.
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Osborne NR, Owen AM, Fernández-Espejo D. The dissociation between command following and communication in disorders of consciousness: an fMRI study in healthy subjects. Front Hum Neurosci 2015; 9:493. [PMID: 26441593 PMCID: PMC4569885 DOI: 10.3389/fnhum.2015.00493] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 08/24/2015] [Indexed: 01/18/2023] Open
Abstract
Neuroimaging studies have identified a subgroup of patients with a Disorder of Consciousness (DOC) who, while being behaviorally non-responsive, are nevertheless able to follow commands by modulating their brain activity in motor imagery (MI) tasks. These techniques have even allowed for binary communication in a small number of DOC patients. However, the majority of patients who can follow commands are unable to use their responses to communicate. A similar dissociation between present command following (CF) and absent communication abilities has been reported in overt behavioral assessments. However, the neural correlates of this dissociation in both overt and covert modalities are unknown. Here, we used functional magnetic resonance imaging (fMRI) to explore the neural mechanisms underlying CF and selection of responses for binary communication using either executed or imagined movements. Fifteen healthy participants executed or imagined two different types of arm movements that were either pre-determined by the experimenters (CF) or decided by them (action selection, AS). Action selection involved greater activity in high-level associative areas in frontal and parietal regions than CF. Additionally, motor execution (ME), as compared to MI, activated contralateral motor cortex, while the opposite contrast revealed activation in the ipsilateral sensorimotor cortex and the left inferior frontal gyrus. Importantly, there was no interaction between the task (CF/AS) and modality (MI/ME). Our results suggest that the neural processes involved in following a motor command or selecting between two motor actions are not dependent on how the response is expressed (via ME/MI). They also suggest a potential neural basis for the distinction in cognitive abilities seen in DOC patients.
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Affiliation(s)
- Natalie R Osborne
- The Brain and Mind Institute, University of Western Ontario London, ON, Canada ; Department of Psychology, University of Western Ontario London, ON, Canada
| | - Adrian M Owen
- The Brain and Mind Institute, University of Western Ontario London, ON, Canada ; Department of Psychology, University of Western Ontario London, ON, Canada
| | - Davinia Fernández-Espejo
- The Brain and Mind Institute, University of Western Ontario London, ON, Canada ; Department of Psychology, University of Western Ontario London, ON, Canada
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