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Șerban CA, Barborică A, Roceanu AM, Mîndruță IR, Ciurea J, Stancu M, Pâslaru AC, Zăgrean AM, Zăgrean L, Moldovan M. Towards an electroencephalographic measure of awareness based on the reactivity of oscillatory macrostates to hearing a subject's own name. Eur J Neurosci 2024; 59:771-785. [PMID: 37675619 DOI: 10.1111/ejn.16138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 08/09/2023] [Accepted: 08/16/2023] [Indexed: 09/08/2023]
Abstract
We proposed that the brain's electrical activity is composed of a sequence of alternating states with repeating topographic spectral distributions on scalp electroencephalogram (EEG), referred to as oscillatory macrostates. The macrostate showing the largest decrease in the probability of occurrence, measured as a percentage (reactivity), during sensory stimulation was labelled as the default EEG macrostate (DEM). This study aimed to assess the influence of awareness on DEM reactivity (DER). We included 11 middle cerebral artery ischaemic stroke patients with impaired awareness having a median Glasgow Coma Scale (GCS) of 6/15 and a group of 11 matched healthy controls. EEG recordings were carried out during auditory 1 min stimulation epochs repeating either the subject's own name (SON) or the SON in reverse (rSON). The DEM was identified across three SON epochs alternating with three rSON epochs. Compared with the patients, the DEM of controls contained more posterior theta activity reflecting source dipoles that could be mapped in the posterior cingulate cortex. The DER was measured from the 1 min quiet baseline preceding each stimulation epoch. The difference in mean DER between the SON and rSON epochs was measured by the salient EEG reactivity (SER) theoretically ranging from -100% to 100%. The SER was 12.4 ± 2.7% (Mean ± standard error of the mean) in controls and only 1.3 ± 1.9% in the patient group (P < 0.01). The patient SER decreased with the Glasgow Coma Scale. Our data suggest that awareness increases DER to SON as measured by SER.
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Affiliation(s)
- Cosmin-Andrei Șerban
- Physics Department, University of Bucharest, Bucharest, Romania
- Termobit Prod SRL, Bucharest, Romania
- FHC Inc, Bowdoin, Maine, USA
| | - Andrei Barborică
- Physics Department, University of Bucharest, Bucharest, Romania
- Termobit Prod SRL, Bucharest, Romania
- FHC Inc, Bowdoin, Maine, USA
| | | | | | - Jan Ciurea
- Department of Neurosurgery, Bagdasar-Arseni Emergency Hospital, Bucharest, Romania
| | - Mihai Stancu
- Division of Physiology and Neuroscience, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
- Division of Neurobiology, Faculty of Biology, Ludwig Maximilian University, Munich, Germany
| | - Alexandru C Pâslaru
- Division of Physiology and Neuroscience, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Ana-Maria Zăgrean
- Division of Physiology and Neuroscience, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Leon Zăgrean
- Division of Physiology and Neuroscience, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Mihai Moldovan
- Termobit Prod SRL, Bucharest, Romania
- Division of Physiology and Neuroscience, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
- Clinical Neurophysiology and Neurology, Rigshospitalet, Copenhagen, Denmark
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Carroll EE, Der-Nigoghossian C, Alkhachroum A, Appavu B, Gilmore E, Kromm J, Rohaut B, Rosanova M, Sitt JD, Claassen J. Common Data Elements for Disorders of Consciousness: Recommendations from the Electrophysiology Working Group. Neurocrit Care 2023; 39:578-585. [PMID: 37606737 DOI: 10.1007/s12028-023-01795-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 06/22/2023] [Indexed: 08/23/2023]
Abstract
BACKGROUND Electroencephalography (EEG) has long been recognized as an important tool in the investigation of disorders of consciousness (DoC). From inspection of the raw EEG to the implementation of quantitative EEG, and more recently in the use of perturbed EEG, it is paramount to providing accurate diagnostic and prognostic information in the care of patients with DoC. However, a nomenclature for variables that establishes a convention for naming, defining, and structuring data for clinical research variables currently is lacking. As such, the Neurocritical Care Society's Curing Coma Campaign convened nine working groups composed of experts in the field to construct common data elements (CDEs) to provide recommendations for DoC, with the main goal of facilitating data collection and standardization of reporting. This article summarizes the recommendations of the electrophysiology DoC working group. METHODS After assessing previously published pertinent CDEs, we developed new CDEs and categorized them into "disease core," "basic," "supplemental," and "exploratory." Key EEG design elements, defined as concepts that pertained to a methodological parameter relevant to the acquisition, processing, or analysis of data, were also included but were not classified as CDEs. RESULTS After identifying existing pertinent CDEs and developing novel CDEs for electrophysiology in DoC, variables were organized into a framework based on the two primary categories of resting state EEG and perturbed EEG. Using this categorical framework, two case report forms were generated by the working group. CONCLUSIONS Adherence to the recommendations outlined by the electrophysiology working group in the resting state EEG and perturbed EEG case report forms will facilitate data collection and sharing in DoC research on an international level. In turn, this will allow for more informed and reliable comparison of results across studies, facilitating further advancement in the realm of DoC research.
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Affiliation(s)
- Elizabeth E Carroll
- Department of Neurology, Columbia University Medical Center, 177 Fort Washington Avenue, MHB 8 Center, Room 300, New York, NY, 10032, USA
- NewYork-Presbyterian Hospital, New York, NY, USA
| | | | | | - Brian Appavu
- Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA
- University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA
| | - Emily Gilmore
- Divisions of Neurocritical Care and Emergency Neurology and Epilepsy, Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Yale New Haven Hospital, New Haven, CT, USA
| | - Julie Kromm
- Departments of Critical Care Medicine and Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Benjamin Rohaut
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, Centre national de la recherche scientifique, Assistance Publique-Hôpitaux de Paris, Neurosciences, Hôpital de La Pitié Salpêtrière, Paris, France
| | - Mario Rosanova
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Jacobo Diego Sitt
- Paris Brain Institute (ICM), Centre national de la recherche scientifique, Paris, France
| | - Jan Claassen
- Department of Neurology, Columbia University Medical Center, 177 Fort Washington Avenue, MHB 8 Center, Room 300, New York, NY, 10032, USA.
- NewYork-Presbyterian Hospital, New York, NY, USA.
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3
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Zouaoui I, Zellag M, Hernout J, Dumais A, Potvin S, Lavoie ME. Alpha and theta oscillations during the cognitive reappraisal of aversive pictures: A spatio-temporal qEEG investigation. Int J Psychophysiol 2023; 192:13-25. [PMID: 37490956 DOI: 10.1016/j.ijpsycho.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/27/2023]
Abstract
CONTEXT Emotion regulation is a set of processes responsible for controlling, evaluating and adjusting reactions to achieve a goal. Results derived from magnetic resonance imaging agreed on the involvement of frontal and limbic structures in this process. Findings using cognition and physiology interactions are still scarce but suggest a role of alpha rhythm in emotional induction and for theta in regulation. OBJECTIVES AND HYPOTHESES Our goal was to investigate alpha and theta rhythm during the reappraisal of aversive stimuli. We hypothesized that an implication of alpha rhythm in emotional induction only and an increase in prefrontal theta rhythm positively correlated with successful regulation. METHOD Twenty-four healthy participants were recorded with 64 EEG electrodes while asked to watch or reappraise negative pictures passively. Theta and alpha rhythms were compared across maintain, decrease and increase regulation conditions, and a source localization estimated the generators. RESULTS Theta activity was consistently higher in the upregulation than in the maintenance condition (p = .04) for the entire control period, but mainly at the beginning of regulation (1-3 s) for low-theta and later (5-7 s) for high-theta. Moreover, our results confirm that a low-theta generator correlated with mainly the middle frontal gyrus and the anterior dorsal cingulate cortex during upregulation. Theta was sensitive to emotion upregulation, whereas the alpha oscillation was non-sensitive to emotion induction and regulation. CONCLUSION Theta rhythm was involved explicitly in emotion upregulation processes that occur at a definite time during reappraisal, whereas the alpha rhythm was not altered by emotion induction and regulation.
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Affiliation(s)
- Inès Zouaoui
- Laboratoire de Psychophysiologie Cognitive et Sociale, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Canada; Département de Psychiatrie et Addictologie, Université de Montréal, Canada.
| | - Meryem Zellag
- Laboratoire de Psychophysiologie Cognitive et Sociale, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Canada; Département de Psychiatrie et Addictologie, Université de Montréal, Canada
| | - Julien Hernout
- Laboratoire de Psychophysiologie Cognitive et Sociale, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Canada; Département de Psychiatrie et Addictologie, Université de Montréal, Canada
| | - Alexandre Dumais
- Laboratoire de Psychophysiologie Cognitive et Sociale, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Canada; Département de Psychiatrie et Addictologie, Université de Montréal, Canada
| | - Stéphane Potvin
- Laboratoire de Psychophysiologie Cognitive et Sociale, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Canada; Département de Psychiatrie et Addictologie, Université de Montréal, Canada
| | - Marc E Lavoie
- Laboratoire de Psychophysiologie Cognitive et Sociale, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Canada; Département de Psychiatrie et Addictologie, Université de Montréal, Canada.
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Lindenbaum L, Steppacher I, Mehlmann A, Kissler JM. The effect of neural pre-stimulus oscillations on post-stimulus somatosensory event-related potentials in disorders of consciousness. Front Neurosci 2023; 17:1179228. [PMID: 37360157 PMCID: PMC10287968 DOI: 10.3389/fnins.2023.1179228] [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: 03/03/2023] [Accepted: 05/22/2023] [Indexed: 06/28/2023] Open
Abstract
Brain activity of people in a disorder of consciousness (DoC) is diffuse and different from healthy people. In order to get a better understanding of their cognitive processes and functions, electroencephalographic activity has often been examined in patients with DoC, including detection of event-related potentials (ERPs) and spectral power analysis. However, the relationship between pre-stimulus oscillations and post-stimulus ERPs has rarely been explored in DoC, although it is known from healthy participants that pre-stimulus oscillations predispose subsequent stimulus detection. Here, we examine to what extent pre-stimulus electroencephalography band power in DoC relates to post-stimulus ERPs in a similar way as previously documented in healthy people. 14 DoC patients in an unresponsive wakefulness syndrome (UWS, N = 2) or a minimally conscious state (MCS, N = 12) participated in this study. In an active oddball paradigm patients received vibrotactile stimuli. Significant post-stimulus differences between brain responses to deviant and standard stimulation could be found in six MCS patients (42.86%). Regarding relative pre-stimulus frequency bands, delta oscillations predominated in most patients, followed by theta and alpha, although two patients showed a relatively normal power spectrum. The statistical analysis of the relationship between pre-stimulus power and post-stimulus event-related brain response showed multiple significant correlations in five out of the six patients. Individual results sometimes showed similar correlation patterns as in healthy subjects primarily between the relative pre-stimulus alpha power and post-stimulus variables in later time-intervals. However, opposite effects were also found, indicating high inter-individual variability in DoC patients´ functional brain activity. Future studies should determine on an individual level to what extent the relationship between pre- and post-stimulus brain activity could relate to the course of the disorder.
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Affiliation(s)
- Laura Lindenbaum
- Department of Psychology, Bielefeld University, Bielefeld, Germany
- Center for Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
| | - Inga Steppacher
- Department of Psychology, Bielefeld University, Bielefeld, Germany
| | | | - Johanna Maria Kissler
- Department of Psychology, Bielefeld University, Bielefeld, Germany
- Center for Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
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5
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Ballanti S, Campagnini S, Liuzzi P, Hakiki B, Scarpino M, Macchi C, Oddo CM, Carrozza MC, Grippo A, Mannini A. EEG-based methods for recovery prognosis of patients with disorders of consciousness: A systematic review. Clin Neurophysiol 2022; 144:98-114. [PMID: 36335795 DOI: 10.1016/j.clinph.2022.09.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 09/15/2022] [Accepted: 09/19/2022] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Disorders of consciousness (DoC) are acquired conditions of severely altered consciousness. Electroencephalography (EEG)-derived biomarkers have been studied as clinical predictors of consciousness recovery. Therefore, this study aimed to systematically review the methods, features, and models used to derive prognostic EEG markers in patients with DoC in a rehabilitation setting. METHODS We conducted a systematic literature search of EEG-based strategies for consciousness recovery prognosis in five electronic databases. RESULTS The search resulted in 2964 papers. After screening, 15 studies were included in the review. Our analyses revealed that simpler experimental settings and similar filtering cut-off frequencies are preferred. The results of studies were categorised by extracting qualitative and quantitative features. The quantitative features were further classified into evoked/event-related potentials, spectral measures, entropy measures, and graph-theory measures. Despite the variety of methods, features from all categories, including qualitative ones, exhibited significant correlations with DoC prognosis. Moreover, no agreement was found on the optimal set of EEG-based features for the multivariate prognosis of patients with DoC, which limits the computational methods applied for outcome prediction and correlation analysis to classical ones. Nevertheless, alpha power, reactivity, and higher complexity metrics were often found to be predictive of consciousness recovery. CONCLUSIONS This study's findings confirm the essential role of qualitative EEG and suggest an important role for quantitative EEG. Their joint use could compensate for their reciprocal limitations. SIGNIFICANCE This study emphasises the need for further efforts toward guidelines on standardised EEG analysis pipeline, given the already proven role of EEG markers in the recovery prognosis of patients with DoC.
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Affiliation(s)
- Sara Ballanti
- IRCCS Fondazione Don Carlo Gnocchi, Firenze 50143, Italy; The Biorobotics Institute, Scuola Superiore Sant'Anna, Pontedera 56025, Pisa, Italy; Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa 56127, Italy.
| | - Silvia Campagnini
- IRCCS Fondazione Don Carlo Gnocchi, Firenze 50143, Italy; The Biorobotics Institute, Scuola Superiore Sant'Anna, Pontedera 56025, Pisa, Italy; Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa 56127, Italy.
| | - Piergiuseppe Liuzzi
- IRCCS Fondazione Don Carlo Gnocchi, Firenze 50143, Italy; The Biorobotics Institute, Scuola Superiore Sant'Anna, Pontedera 56025, Pisa, Italy; Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa 56127, Italy.
| | - Bahia Hakiki
- IRCCS Fondazione Don Carlo Gnocchi, Firenze 50143, Italy.
| | | | - Claudio Macchi
- IRCCS Fondazione Don Carlo Gnocchi, Firenze 50143, Italy; Department of Experimental and Clinical Medicine, University of Florence, Firenze 50143, Italy.
| | - Calogero Maria Oddo
- The Biorobotics Institute, Scuola Superiore Sant'Anna, Pontedera 56025, Pisa, Italy; Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa 56127, Italy.
| | - Maria Chiara Carrozza
- The Biorobotics Institute, Scuola Superiore Sant'Anna, Pontedera 56025, Pisa, Italy; Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa 56127, Italy.
| | | | - Andrea Mannini
- IRCCS Fondazione Don Carlo Gnocchi, Firenze 50143, Italy.
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6
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Zhao J, Yang Y, An X, Liu S, Du H, Ming D. Auditory event-related potentials based on name stimuli: A pilot study. Front Neurosci 2022; 16:808897. [PMID: 36117639 PMCID: PMC9477379 DOI: 10.3389/fnins.2022.808897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Abstract
In recent years, diagnostic studies of brain disorders based on auditory event-related potentials (AERP) have become a hot topic. Research showed that AERP might help to detect patient consciousness, especially using the subjects' own name (SON). In this study, we conducted a preliminary analysis of the brain response to Chinese name stimuli. Twelve subjects participated in this study. SONs were used as target stimuli for each trial. The names used for non-target stimuli were divided into three Chinese character names condition (3CC) and two Chinese characters names condition (2CC). Thus, each subject was required to be in active (silent counting) and passive mode (without counting) with four conditions [(passive, active) × (3CC, 2CC)]. We analyzed the spatio-temporal features for each condition, and we used SVM for target vs. non-target classification. The results showed that the passive mode under 3CC conditions showed a similar brain response to the active mode, and when 3CC was used as a non-target stimulus, the brain response induced by the target stimulus would have a better interaction than 2CC. We believe that the passive mode 3CC may be a good paradigm to replace the active mode which might need more attention from subjects. The results of this study can provide certain guidelines for the selection and optimization of the paradigm of auditory event-related potentials based on name stimulation.
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Affiliation(s)
- Jindi Zhao
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Yuancheng Yang
- College of Precision Instruments & Optoelectronics Engineering, Tianjin University, Tianjin, China
| | - Xingwei An
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
- *Correspondence: Xingwei An
| | - Shuang Liu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Hongyin Du
- Department of Anesthesiology, Tianjin First Central Hospital, Tianjin, China
| | - Dong Ming
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
- Dong Ming
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7
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Williams A, Zeng Y, Li Z, Thakor N, Geocadin RG, Bronder J, Martinez NC, Ritzl EK, Cho SM. Quantitative Assessment of Electroencephalogram Reactivity in Comatose Patients on Extracorporeal Membrane Oxygenation. Int J Neural Syst 2022; 32:2250025. [PMID: 35443895 DOI: 10.1142/s0129065722500253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Objective assessment of the brain's responsiveness in comatose patients on Extracorporeal Membrane Oxygenation (ECMO) support is essential to clinical care, but current approaches are limited by subjective methodology and inter-rater disagreement. Quantitative electroencephalogram (EEG) algorithms could potentially assist clinicians, improving diagnostic accuracy. We developed a quantitative, stimulus-based algorithm to assess EEG reactivity features in comatose patients on ECMO support. Patients underwent a stimulation protocol of increasing intensity (auditory, peripheral, and nostril stimulation). A total of 129 20-s EEG epochs were collected from 24 patients (age [Formula: see text], 10 females, 14 males) on ECMO support with a Glasgow Coma Scale[Formula: see text]8. EEG reactivity scores ([Formula: see text]-scores) were calculated using aggregated spectral power and permutation entropy for each of five frequency bands ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]. Parameter estimation techniques were applied to [Formula: see text]-scores to identify properties that replicate the decision process of experienced clinicians performing visual analysis. Spectral power changes from audio stimulation were concentrated in the [Formula: see text] band, whereas peripheral stimulation elicited an increase in spectral power across multiple bands, and nostril stimulation changed the entropy of the [Formula: see text] band. The findings of this pilot study on [Formula: see text]-score lay a foundation for a future prediction tool with clinical applications.
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Affiliation(s)
- Autumn Williams
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Yinuo Zeng
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Ziwei Li
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Nitish Thakor
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Romergryko G Geocadin
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jay Bronder
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Eva K Ritzl
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sung-Min Cho
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Phipps 455, Baltimore, MD, USA
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Osińska A, Rynkiewicz A, Binder M, Komendziński T, Borowicz A, Leszczyński A. Non-invasive Vagus Nerve Stimulation in Treatment of Disorders of Consciousness – Longitudinal Case Study. Front Neurosci 2022; 16:834507. [PMID: 35600632 PMCID: PMC9120963 DOI: 10.3389/fnins.2022.834507] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 03/29/2022] [Indexed: 11/16/2022] Open
Abstract
Neuromodulatory electroceuticals such as vagus nerve stimulation have been recently gaining traction as potential rehabilitation tools for disorders of consciousness (DoC). We present a longitudinal case study of non-invasive auricular vagus nerve stimulation (taVNS) in a patient diagnosed with chronic unresponsive wakefulness syndrome (previously known as vegetative state). Over a period of 6 months we applied taVNS daily and regularly evaluated the patient’s behavioral outcomes using Coma Recovery Scale – Revised. We also took electrophysiological measures: resting state electroencephalography (EEG), heart rate (HR) and heart rate variability (HRV). All these methods revealed signs of improvement in the patient’s condition. The total CRS-R scores fluctuated but rose from 4 and 6 at initial stages to the heights of 12 and 13 in the 3rd and 5th month, which would warrant a change in diagnosis to a Minimally Conscious State. Scores obtained in a 2 months follow-up period, though, suggest this may not have been a lasting improvement. Behavioral signs of recovery are triangulated by EEG frequency spectrum profiles with re-emergence of a second oscillatory peak in the alpha range, which has been shown to characterize aware people. However, sustained spontaneous theta oscillations did not predictably diminish, which most likely reflects structural brain damage. ECG measures revealed a steady decrease in pre-stimulation HR combined with an increase in HRV-HR. This suggests a gradual withdrawal of sympathetic and an increase in parasympathetic control of the heart, which the previous literature has also linked with DoC improvements. Together, this study suggests that taVNS stimulation holds promise as a DoC treatment.
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Affiliation(s)
- Albertyna Osińska
- Faculty of Psychology, University of Warsaw, Warsaw, Poland
- *Correspondence: Albertyna Osińska,
| | - Andrzej Rynkiewicz
- Faculty of Psychology, University of Warsaw, Warsaw, Poland
- Andrzej Rynkiewicz,
| | - Marek Binder
- Institute of Psychology, Jagiellonian University, Kraków, Poland
| | - Tomasz Komendziński
- Department of Cognitive Science, Faculty of Humanities, Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Anna Borowicz
- Department of Cognitive Science, Faculty of Humanities, Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Antoni Leszczyński
- Department of Cognitive Science, Faculty of Humanities, Nicolaus Copernicus University in Toruń, Toruń, Poland
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9
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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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10
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Lei L, Liu K, Yang Y, Doubliez A, Hu X, Xu Y, Zhou Y. Spatio-temporal analysis of EEG features during consciousness recovery in patients with disorders of consciousness. Clin Neurophysiol 2021; 133:135-144. [PMID: 34864400 DOI: 10.1016/j.clinph.2021.08.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/10/2021] [Accepted: 08/29/2021] [Indexed: 12/17/2022]
Abstract
OBJECTIVE As consciousness recovery is not only dynamic but also involves interactions between various brain regions, elucidating the mechanism of recovery requires tracking cortical activity in spatio-temporal dimensions. METHODS We tracked the cortical activities of 40 patients (mean age: 54.38 years; 28 males; 21 patients with minimally conscious states) with disorders of consciousness, and collected a total of 156 electroencephalographic signals. We investigated the longitudinal changes in EEG nonlinear dynamic features (i.e., approximate entropy, sample entropy, and Lempel-Ziv complexity) and relative wavelet energy along with consciousness recovery. RESULTS Global EEG features showed a non-monotonic trend during consciousness recovery (P < 0.05). When the level of consciousness of patients was transferred to a minimally conscious state from an unresponsive wakefulness syndrome/ vegetative state, an inflection point appeared in the EEG features. The EEG feature change trends between the injured and uninjured areas were dissimilar (P < 0.05). Importantly, the degree of dissimilarity increased non-monotonically across the levels of consciousness (P < 0.05). CONCLUSIONS EEG recovery was non-monotonic and dissimilar in spatio-temporal dimensions, with an inflection point. SIGNIFICANCE These findings further clarify the process of consciousness recovery and provide assistance in exploring the mechanism of consciousness recovery.
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Affiliation(s)
- Ling Lei
- College of Automation, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China
| | - Kehong Liu
- Wu Jing Hospital, Rehabilitation Center, Hangzhou, Zhejiang 310051, China
| | - Yong Yang
- College of Automation, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China.
| | - Alice Doubliez
- Paris Descartes University, 45 rue des Saints-Peres, Paris 75006, France
| | - Xiaohua Hu
- Wu Jing Hospital, Rehabilitation Center, Hangzhou, Zhejiang 310051, China
| | - Ying Xu
- College of Automation, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China
| | - Yixing Zhou
- First People's Hospital of Zhaoqing City, No. 9 Donggang East Road, Duanzhou District, Zhaoqing 526060, China.
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11
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Rivera-Lillo G, Stamatakis EA, Bekinschtein TA, Menon DK, Chennu S. Delta band activity contributes to the identification of command following in disorder of consciousness. Sci Rep 2021; 11:16267. [PMID: 34381123 PMCID: PMC8357781 DOI: 10.1038/s41598-021-95818-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 07/30/2021] [Indexed: 11/09/2022] Open
Abstract
The overt or covert ability to follow commands in patients with disorders of consciousness is considered a sign of awareness and has recently been defined as cortically mediated behaviour. Despite its clinical relevance, the brain signatures of the perceptual processing supporting command following have been elusive. This multimodal study investigates the temporal spectral pattern of electrical brain activity to identify features that differentiated healthy controls from patients both able and unable to follow commands. We combined evidence from behavioural assessment, functional neuroimaging during mental imagery and high-density electroencephalography collected during auditory prediction, from 21 patients and 10 controls. We used a penalised regression model to identify command following using features from electroencephalography. We identified seven well-defined spatiotemporal signatures in the delta, theta and alpha bands that together contribute to identify DoC subjects with and without the ability to follow command, and further distinguished these groups of patients from controls. A fine-grained analysis of these seven signatures enabled us to determine that increased delta modulation at the frontal sensors was the main feature in command following patients. In contrast, higher frequency theta and alpha modulations differentiated controls from both groups of patients. Our findings highlight a key role of spatiotemporally specific delta modulation in supporting cortically mediated behaviour including the ability to follow command. However, patients able to follow commands nevertheless have marked differences in brain activity in comparison with healthy volunteers.
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Affiliation(s)
- Gonzalo Rivera-Lillo
- Neuroscience Department, Faculty of Medicine, Universidad de Chile, Santiago, Chile. .,Physical Therapy Department, Faculty of Medicine, Universidad de Chile, Santiago, Chile. .,Research and Develop Unit, Los Coihues Clinic, Santiago, Chile.
| | - Emmanuel A Stamatakis
- Division of Anaesthesia, Department of Medicine, School of Clinical Medicine, University of Cambridge, Cambridge, UK.,Department of Clinical Neurosciences, Wolfson Brain Imaging Centre, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Tristan A Bekinschtein
- Cambridge Consciousness and Cognition Lab, Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
| | - David K Menon
- Division of Anaesthesia, Department of Medicine, School of Clinical Medicine, University of Cambridge, Cambridge, UK.,Department of Clinical Neurosciences, Wolfson Brain Imaging Centre, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Srivas Chennu
- School of Computing, University of Kent, Medway, UK.,Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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12
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Naro A, Pignolo L, Lucca LF, Calabrò RS. An action-observation/motor-imagery based approach to differentiate disorders of consciousness: what is beneath the tip of the iceberg? Restor Neurol Neurosci 2021; 39:181-197. [PMID: 33998559 DOI: 10.3233/rnn-201130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The evaluation of motor imagery in persons with prolonged Disorders of Consciousness (pDOC) is a practical approach to differentiate between patients with Minimally Conscious State (MCS) and Unresponsive Wakefulness Syndrome (UWS) and to identify residual awareness even in individuals with UWS. Investigating the influence of motor observation on motor imagery could be helpful in this regard. OBJECTIVE In order to corroborate the clinical diagnosis and identify misdiagnosed individuals, we used EEG recordings, to assess the influence of the low-level perceptual and motoric mechanisms on motor observation on motor imagery, taking into account the role of the high-level cognitive mechanisms in patients with pDOC. METHODS We assessed the influence of motor observation of walking in first-person or third-person view (by a video provision) on motor imagery of walking in the first-person view on the visual N190 (expression of motor observation processing), the readiness potential (RP) (expressing motor preparation), and the P3 component (high-level cognitive processes) in a sample of 10 persons with MCS, 10 with UWS, and 10 healthy controls (CG). Specifically, the video showed a first-view or third-view walk down the street while the participants were asked to imagine a first-view walking down the street. RESULTS CG showed greater N190 response (low-level sensorimotor processing) in the non-matching than in the matching condition. Conversely, the P3 and RP responses (high-level sensorimotor processing) were greater in the matching than in the non-matching condition. Remarkably, 6 out of 10 patients with MCS showed the preservation of both high- and low-level sensorimotor processing. One UWS patient showed responses similar to those six patients, suggesting a preservation of cognitively-mediated sensorimotor processing despite a detrimental motor preparation process. The remaining patients with MCS did not show diversified EEG responses, suggesting limited cognitive functioning. CONCLUSIONS Our study suggests that identifying the low-level visual and high-level motor preparation processes in response to a simple influence of motor observation of motor imagery tasks potentially supports the clinical differential diagnosis of with MCS and UWS. This might help identify UWS patients which were misdiagnosed and who deserve more sophisticated diagnoses.
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Affiliation(s)
- Antonino Naro
- IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
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13
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Meiron O, Barron J, David J, Jaul E. Neural reactivity parameters of awareness predetermine one-year survival in patients with disorders of consciousness. Brain Inj 2021; 35:453-459. [PMID: 33599140 DOI: 10.1080/02699052.2021.1879398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Objective: The current investigation evaluated the sensitivity of neural-reactivity markers of awareness versus standard clinical assessments in predicting 1-year survival in nonresponsive-awake patients with disorders of consciousness (DOC).Methods: Pre-attentive auditory mismatch-negativity (MMN) event-related potentials (ERP's), globally induced electroencephalography (EEG) spectral power following verbal command, and clinical parameters were assessed. The study included 10 patients with DOC with mixed etiology and 10 healthy controls (HC) at baseline. The clinical status of patients with DOC was reassessed after 1 year.Results: Unlike baseline clinical assessment scores, baseline MMN amplitudes of non-survivors and induced theta-power following verbal-command clearly distinguished the non-surviving patients versus surviving patients. Baseline MMN peak-amplitude latencies in survivors with DOC were significantly related to clinical outcome over a 1-year period.Conclusion: Current findings underscore the increased sensitivity of EEG-reactivity markers of awareness versus standard clinical scores in predicting 1-year clinical outcome and survival in patients with DOC. Further longitudinal research in larger DOC samples is needed to confirm the prognostic-reliability, and validity of neural reactivity parameters of awareness in patients with DOC. Current finding may have implications for clinical care and medical-legal decisions in unresponsive-awake patients, and could assist clinicians to predict their survival up to 1 year from admission.
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Affiliation(s)
- Oded Meiron
- Electrophysiology and Neurocognition Lab, Clinical Research Center for Brain Sciences, Herzog Medical Center, Jerusalem, Israel
| | - Jeremy Barron
- Electrophysiology and Neurocognition Lab, Clinical Research Center for Brain Sciences, Herzog Medical Center, Jerusalem, Israel.,Herzog Medical Center, Ventilator Care Department, Jerusalem, Israel.,Johns Hopkins University, Division of Geriatric Medicine, Baltimore, MD, USA
| | - Jonathan David
- Electrophysiology and Neurocognition Lab, Clinical Research Center for Brain Sciences, Herzog Medical Center, Jerusalem, Israel
| | - Efraim Jaul
- Johns Hopkins University, Division of Geriatric Medicine, Baltimore, MD, USA.,Herzog Medical Center, Geriatric Skilled Nursing Department, Jerusalem, Israel.,School of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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14
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Karakaş S. A review of theta oscillation and its functional correlates. Int J Psychophysiol 2020; 157:82-99. [DOI: 10.1016/j.ijpsycho.2020.04.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 04/06/2020] [Accepted: 04/09/2020] [Indexed: 12/29/2022]
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15
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Naro A, Calabrò RS. Towards New Diagnostic Approaches in Disorders of Consciousness: A Proof of Concept Study on the Promising Use of Imagery Visuomotor Task. Brain Sci 2020; 10:brainsci10100746. [PMID: 33080823 PMCID: PMC7603054 DOI: 10.3390/brainsci10100746] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/08/2020] [Accepted: 10/14/2020] [Indexed: 12/16/2022] Open
Abstract
Background: advanced paraclinical approaches using functional neuroimaging and electroencephalography (EEG) allow identifying patients who are covertly aware despite being diagnosed as unresponsive wakefulness syndrome (UWS). Bedside detection of covert awareness employing motor imagery tasks (MI), which is a universally accepted clinical indicator of awareness in the absence of overt behavior, may miss some of these patients, as they could still have a certain level of awareness. We aimed at assessing covert awareness in patients with UWS using a visuomotor-guided motor imagery task (VMI) during EEG recording. Methods: nine patients in a minimally conscious state (MCS), 11 patients in a UWS, and 15 healthy individuals (control group—CG) were provided with an VMI (imagine dancing while watching a group dance video to command), a simple-MI (imagine squeezing their right hand to command), and an advanced-MI (imagine dancing without watching a group dance video to command) to detect command-following. We analyzed the command-specific EEG responses (event-related synchronization/desynchronization—ERS/ERD) of each patient, assessing whether these responses were appropriate, consistent, and statistically similar to those elicited in the CG, as reliable markers of motor imagery. Results: All patients in MCS, all healthy individuals and one patient in UWS repeatedly and reliably generated appropriate EEG responses to distinct commands of motor imagery with a classification accuracy of 60–80%. Conclusions: VMI outperformed significantly MI tasks. Therefore, patients in UWS may be still misdiagnosed despite a rigorous clinical assessment and an appropriate MI assessment. It is thus possible to suggest that motor imagery tasks should be delivered to patients with chronic disorders of consciousness in visuomotor-aided modality (also in the rehabilitation setting) to greatly entrain patient’s participation. In this regard, the EEG approach we described has the clear advantage of being cheap, portable, widely available, and objective. It may be thus considered as, at least, a screening tool to identify the patients who deserve further, advanced paraclinical approaches.
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16
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Jain R, Ramakrishnan AG. Electrophysiological and Neuroimaging Studies - During Resting State and Sensory Stimulation in Disorders of Consciousness: A Review. Front Neurosci 2020; 14:555093. [PMID: 33041757 PMCID: PMC7522478 DOI: 10.3389/fnins.2020.555093] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/25/2020] [Indexed: 12/17/2022] Open
Abstract
A severe brain injury may lead to a disorder of consciousness (DOC) such as coma, vegetative state (VS), minimally conscious state (MCS) or locked-in syndrome (LIS). Till date, the diagnosis of DOC relies only on clinical evaluation or subjective scoring systems such as Glasgow coma scale, which fails to detect subtle changes and thereby results in diagnostic errors. The high rate of misdiagnosis and inability to predict the recovery of consciousness for DOC patients have created a huge research interest in the assessment of consciousness. Researchers have explored the use of various stimulation and neuroimaging techniques to improve the diagnosis. In this article, we present the important findings of resting-state as well as sensory stimulation methods and highlight the stimuli proven to be successful in the assessment of consciousness. Primarily, we review the literature based on (a) application/non-use of stimuli (i.e., sensory stimulation/resting state-based), (b) type of stimulation used (i.e., auditory, visual, tactile, olfactory, or mental-imagery), (c) electrophysiological signal used (EEG/ERP, fMRI, PET, EMG, SCL, or ECG). Among the sensory stimulation methods, auditory stimulation has been extensively used, since it is easier to conduct for these patients. Olfactory and tactile stimulation have been less explored and need further research. Emotionally charged stimuli such as subject’s own name or narratives in a familiar voice or subject’s own face/family pictures or music result in stronger responses than neutral stimuli. Studies based on resting state analysis have employed measures like complexity, power spectral features, entropy and functional connectivity patterns to distinguish between the VS and MCS patients. Resting-state EEG and fMRI are the state-of-the-art techniques and have a huge potential in predicting the recovery of coma patients. Further, EMG and mental-imagery based studies attempt to obtain volitional responses from the VS patients and thus could detect their command-following capability. This may provide an effective means to communicate with these patients. Recent studies have employed fMRI and PET to understand the brain-activation patterns corresponding to the mental imagery. This review promotes our knowledge about the techniques used for the diagnosis of patients with DOC and attempts to provide ideas for future research.
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Affiliation(s)
- Ritika Jain
- Medical Intelligence and Language Engineering Laboratory, Department of Electrical Engineering, Indian Institute of Science, Bengaluru, India
| | - Angarai Ganesan Ramakrishnan
- Medical Intelligence and Language Engineering Laboratory, Department of Electrical Engineering, Indian Institute of Science, Bengaluru, India
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17
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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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18
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Cao R, Hao Y, Wang X, Gao Y, Shi H, Huo S, Wang B, Guo H, Xiang J. EEG Functional Connectivity Underlying Emotional Valance and Arousal Using Minimum Spanning Trees. Front Neurosci 2020; 14:355. [PMID: 32457566 PMCID: PMC7222391 DOI: 10.3389/fnins.2020.00355] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/24/2020] [Indexed: 11/20/2022] Open
Abstract
In recent years, traditional methods such as power spectrum and amplitude analysis have been used to research the emotional electroencephalogram (EEG). The brain network method is also used in emotional EEG research, which can better reflect the activity of brains. A minimum spanning tree (MST) represents the key information flow in the weighted brain network, and it provides a sensitive method to capture subtle information in network organization while effectively avoiding the shortcomings of traditional brain networks. The DEAP dataset provides electroencephalogram (EEG) data for four categories of emotions: high arousal and high valence (HAHV), high arousal and low valence (HALV), low arousal and high valence (LAHV), and low arousal and low valence (LALV). Phase lag index (PLI) weighted matrices were calculated in five frequency bands. On this basis, the minimum spanning trees were constructed. At the same valence level in the gamma (γ) band, HAHV and HALV showed significant higher mean PLI (MPLI), maximum degree (Degreemax) and leaf fraction and significant lower diameter and eccentricity than LAHV and LALV. At the same arousal level in the γ band, HALV showed significant higher MPLI, Degreemax and leaf fraction and significant lower diameter and eccentricity than HAHV. These results indicate that the low-arousal showed more line-shaped configurations than the high-arousal. Additionally, in the high-arousal condition, a shift toward more star-shaped trees from high-valence to low-valence supports the trend toward randomness of the brain network with negative emotions and that the brain is more activated when faced with negative emotions. From a brain network perspective, this phenomenon provides a theoretical basis for negative bias.
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Affiliation(s)
- Rui Cao
- College of Software Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Yan Hao
- College of Software Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Xin Wang
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Yuan Gao
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Huiyu Shi
- College of Software Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Shoujun Huo
- College of Software Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Bin Wang
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Hao Guo
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
| | - Jie Xiang
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan, China
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19
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Jaiswal S, Tsai SY, Juan CH, Muggleton NG, Liang WK. Low delta and high alpha power are associated with better conflict control and working memory in high mindfulness, low anxiety individuals. Soc Cogn Affect Neurosci 2020; 14:645-655. [PMID: 31119291 PMCID: PMC6688451 DOI: 10.1093/scan/nsz038] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 03/11/2019] [Accepted: 05/15/2019] [Indexed: 01/13/2023] Open
Abstract
Working memory capacity (WMC) can predict conflict control ability. Measures of both abilities are impaired by anxiety, which is often inversely linked with mindfulness. It has been shown that a combination of high mindfulness and low anxiety is associated with better conflict control and WMC. The current study explored the electrophysiology related to such behavioral differences. Two experimental groups, one with high mindfulness and low anxiety (HMLA) and one with low mindfulness and high anxiety (LMHA), performed a color Stroop task and a change detection task, both with simultaneous electroencephalogram (EEG) recording. An advanced EEG analytical approach, Hilbert–Huang transform (HHT) analysis, was employed. This is regarded as a robust method to analyze non-linear and non-stationary signals. Lower delta activity at posterior temporal and occipital regions was seen in the HMLA group for the Stroop conflict conditions and might be generally associated with higher accuracy in this group and indicative of higher attentiveness. Higher accuracy rates and WMC were seen in the HMLA group and might be specifically associated with the higher alpha activity observed in prefrontal cortex, fronto-central and centro-parietal regions in this group. Future studies should explore how mindfulness and anxiety can independently affect these cognitive functions and their associated neurophysiology.
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Affiliation(s)
- Satish Jaiswal
- Institute of Cognitive Neuroscience, National Central University, Taoyuan, Taiwan
| | - Shao-Yang Tsai
- Institute of Cognitive Neuroscience, National Central University, Taoyuan, Taiwan
| | - Chi-Hung Juan
- Institute of Cognitive Neuroscience, National Central University, Taoyuan, Taiwan.,Brain Research Center, National Central University, Taoyuan, Taiwan
| | - Neil G Muggleton
- Institute of Cognitive Neuroscience, National Central University, Taoyuan, Taiwan.,Brain Research Center, National Central University, Taoyuan, Taiwan.,Institute of Cognitive Neuroscience, University College London, London, UK.,Department of Psychology, Goldsmiths, University of London, London, UK
| | - Wei-Kuang Liang
- Institute of Cognitive Neuroscience, National Central University, Taoyuan, Taiwan.,Brain Research Center, National Central University, Taoyuan, Taiwan
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20
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Billeri L, Filoni S, Russo EF, Portaro S, Militi D, Calabrò RS, Naro A. Toward Improving Diagnostic Strategies in Chronic Disorders of Consciousness: An Overview on the (Re-)Emergent Role of Neurophysiology. Brain Sci 2020; 10:brainsci10010042. [PMID: 31936844 PMCID: PMC7016627 DOI: 10.3390/brainsci10010042] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/03/2020] [Accepted: 01/08/2020] [Indexed: 12/13/2022] Open
Abstract
The differential diagnosis of patients with Disorder of Consciousness (DoC), in particular in the chronic phase, is significantly difficult. Actually, about 40% of patients with unresponsive wakefulness syndrome (UWS) and the minimally conscious state (MCS) are misdiagnosed. Indeed, only advanced paraclinical approaches, including advanced EEG analyses, can allow achieving a more reliable diagnosis, that is, discovering residual traces of awareness in patients with UWS (namely, functional Locked-In Syndrome (fLIS)). These approaches aim at capturing the residual brain network models, at rest or that may be activated in response to relevant stimuli, which may be appropriate for awareness to emerge (despite their insufficiency to generate purposeful motor behaviors). For this, different brain network models have been studied in patients with DoC by using sensory stimuli (i.e., passive tasks), probing response to commands (i.e., active tasks), and during resting-state. Since it can be difficult for patients with DoC to perform even simple active tasks, this scoping review aims at summarizing the current, innovative neurophysiological examination methods in resting state/passive modality to differentiate and prognosticate patients with DoC. We conclude that the electrophysiologically-based diagnostic procedures represent an important resource for diagnosis, prognosis, and, therefore, management of patients with DoC, using advance passive and resting state paradigm analyses for the patients who lie in the “greyzones” between MCS, UWS, and fLIS.
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Affiliation(s)
- Luana Billeri
- IRCCS Centro Neurolesi Bonino Pulejo, 98124 Messina, Italy; (L.B.); (S.P.); (A.N.)
| | - Serena Filoni
- Padre Pio Foundation and Rehabilitation Centers, San Giovanni Rotondo, 71013 Foggia, Italy;
- Correspondence: (S.F.); (R.S.C.); Tel.: +39-090-6012-8166 (R.S.C.)
| | | | - Simona Portaro
- IRCCS Centro Neurolesi Bonino Pulejo, 98124 Messina, Italy; (L.B.); (S.P.); (A.N.)
| | | | - Rocco Salvatore Calabrò
- IRCCS Centro Neurolesi Bonino Pulejo, 98124 Messina, Italy; (L.B.); (S.P.); (A.N.)
- Correspondence: (S.F.); (R.S.C.); Tel.: +39-090-6012-8166 (R.S.C.)
| | - Antonino Naro
- IRCCS Centro Neurolesi Bonino Pulejo, 98124 Messina, Italy; (L.B.); (S.P.); (A.N.)
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21
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Pace-Schott EF, Amole MC, Aue T, Balconi M, Bylsma LM, Critchley H, Demaree HA, Friedman BH, Gooding AEK, Gosseries O, Jovanovic T, Kirby LA, Kozlowska K, Laureys S, Lowe L, Magee K, Marin MF, Merner AR, Robinson JL, Smith RC, Spangler DP, Van Overveld M, VanElzakker MB. Physiological feelings. Neurosci Biobehav Rev 2019; 103:267-304. [DOI: 10.1016/j.neubiorev.2019.05.002] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/27/2019] [Accepted: 05/03/2019] [Indexed: 12/20/2022]
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22
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Rivera-Lillo G, Rojas-Líbano D, Burgos P, Egaña JI, Chennu S, Maldonado PE. Reduced delta-band modulation underlies the loss of P300 responses in disorders of consciousness. Clin Neurophysiol 2018; 129:2613-2622. [PMID: 30458356 DOI: 10.1016/j.clinph.2018.09.104] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/16/2018] [Accepted: 09/19/2018] [Indexed: 10/27/2022]
Abstract
OBJECTIVE The P300 component of a sensory event-related potential is one of the major electrophysiological markers used to explore remnants of cognitive function in patients with disorders of consciousness (DoC). However, measuring the P300 in patients is complicated by significant inter-trial variability commonly observed in levels of arousal and awareness. To overcome this limitation, we analyzed single-trial modulation of power in the delta and theta frequency bands, which underlie the P300. METHODS In a preliminary cross-sectional study using a 24-channel EEG and a passive own-name oddball paradigm, we analyzed event-related synchronization (ERS) across trials in the delta and theta bands in a sample of 10 control and 12 DoC subjects. RESULTS In comparison to controls, DoC subjects presented a low percentage of trials where delta ERS was observed. In particular, coordinated modulation between delta and theta in response to the stimulus was absent, with a high percentage of trials where only theta ERS was observed. Further, we found a positive correlation between the percentage of epochs with delta ERS and the strength of the P300. CONCLUSIONS Reduced modulation of spectral activity in the delta band in response to stimuli indicates a dissociation in the activity of the neural networks that oscillate in delta and theta ranges and contribute to the generation of the P300. SIGNIFICANCE The reduction in spectral modulation observed in DoC provides a deeper understanding of neurophysiological dysfunction and the means to develop a more fine-grained marker of residual cognitive function in individual patients.
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Affiliation(s)
- Gonzalo Rivera-Lillo
- Physical Therapy Department, Faculty of Medicine, Universidad de Chile, Chile; Neuroscience Department, Faculty of Medicine, Universidad de Chile, Chile; Center of Integrated Studies in Neurorehabilitation, Clínica Los Coihues, Santiago, Chile
| | - Daniel Rojas-Líbano
- Laboratorio de Neurociencia Cognitiva y Social, Facultad de Psicología, Universidad Diego Portales, Santiago, Chile
| | - Pablo Burgos
- Physical Therapy Department, Faculty of Medicine, Universidad de Chile, Chile; Neuroscience Department, Faculty of Medicine, Universidad de Chile, Chile; Research and Development, Universidad Tecnológica de Chile, Inacap, Chile
| | - Jose I Egaña
- Anesthesia Department, Faculty of Medicine, Universidad de Chile, Chile; Biomedical Neuroscience Institute, Universidad de Chile, Chile
| | - Srivas Chennu
- School of Computing, University of Kent, UK; Department of Clinical Neurosciences, University of Cambridge, UK
| | - Pedro E Maldonado
- Neuroscience Department, Faculty of Medicine, Universidad de Chile, Chile; Biomedical Neuroscience Institute, Universidad de Chile, Chile.
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Song M, Zhang Y, Cui Y, Yang Y, Jiang T. Brain Network Studies in Chronic Disorders of Consciousness: Advances and Perspectives. Neurosci Bull 2018; 34:592-604. [PMID: 29916113 PMCID: PMC6060221 DOI: 10.1007/s12264-018-0243-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 05/07/2018] [Indexed: 02/06/2023] Open
Abstract
Neuroimaging has opened new opportunities to study the neural correlates of consciousness, and provided additional information concerning diagnosis, prognosis, and therapeutic interventions in patients with disorders of consciousness. Here, we aim to review neuroimaging studies in chronic disorders of consciousness from the viewpoint of the brain network, focusing on positron emission tomography, functional MRI, functional near-infrared spectroscopy, electrophysiology, and diffusion MRI. To accelerate basic research on disorders of consciousness and provide a panoramic view of unconsciousness, we propose that it is urgent to integrate different techniques at various spatiotemporal scales, and to merge fragmented findings into a uniform "Brainnetome" (Brain-net-ome) research framework.
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Affiliation(s)
- Ming Song
- National Laboratory of Pattern Recognition, Institute of Automation, The Chinese Academy of Sciences, Beijing, 100190, China
- Brainnetome Center, Institute of Automation, The Chinese Academy of Sciences, Beijing, 100190, China
| | - Yujin Zhang
- National Laboratory of Pattern Recognition, Institute of Automation, The Chinese Academy of Sciences, Beijing, 100190, China
- Brainnetome Center, Institute of Automation, The Chinese Academy of Sciences, Beijing, 100190, China
| | - Yue Cui
- National Laboratory of Pattern Recognition, Institute of Automation, The Chinese Academy of Sciences, Beijing, 100190, China
- Brainnetome Center, Institute of Automation, The Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Yi Yang
- Department of Neurosurgery, PLA Army General Hospital, Beijing, 100700, China
| | - Tianzi Jiang
- National Laboratory of Pattern Recognition, Institute of Automation, The Chinese Academy of Sciences, Beijing, 100190, China.
- Brainnetome Center, Institute of Automation, The Chinese Academy of Sciences, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100190, China.
- CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Beijing, 100190, China.
- Key Laboratory for Neuroinformation of the Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 625014, China.
- The Queensland Brain Institute, University of Queensland, Brisbane, QLD, 4072, Australia.
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Li J, Shen J, Liu S, Chauvel M, Yang W, Mei J, Lei L, Wu L, Gao J, Yang Y. Responses of Patients with Disorders of Consciousness to Habit Stimulation: A Quantitative EEG Study. Neurosci Bull 2018; 34:691-699. [PMID: 30019216 PMCID: PMC6060212 DOI: 10.1007/s12264-018-0258-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 06/13/2018] [Indexed: 01/20/2023] Open
Abstract
Whether habit stimulation is effective in DOC patient arousal has not been reported. In this paper, we analyzed the responses of DOC patients to habit stimulation. Nineteen DOC patients with alcohol consumption or smoking habits were recruited and 64-channel EEG signals were acquired both at the resting state and at three stimulation states. Wavelet transformation and nonlinear dynamics were used to extract the features of EEG signals and four brain lobes were selected to investigate the degree of EEG response to habit stimulation. Results showed that the highest degree of EEG response was from the call-name stimulation, followed by habit and music stimulations. Significant differences in EEG wavelet energy and response coefficient were found both between habit and music stimulation, and between habit and call-name stimulation. These findings prove that habit stimulation induces relatively more intense EEG responses in DOC patients than music stimulation, suggesting that it may be a relevant additional method for eliciting patient arousal.
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Affiliation(s)
- Jingqi Li
- Ming Zhou Nao Kang Rehabilitation Hospital, Hangzhou, 310000, China
| | - Jiamin Shen
- College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China
| | - Shiqin Liu
- College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China
| | - Maelig Chauvel
- Paris Descartes University, 45 Rue des Saints-Peres, 75006, Paris, France
| | - Wenwei Yang
- College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China
| | - Jian Mei
- College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China
| | - Ling Lei
- College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China
| | - Li Wu
- College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China
| | - Jian Gao
- Rehabilitation Center, Wu Jing Hospital, Hangzhou, 310051, China
| | - Yong Yang
- College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China.
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25
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Hauger SL, Schanke AK, Andersson S, Chatelle C, Schnakers C, Løvstad M. The Clinical Diagnostic Utility of Electrophysiological Techniques in Assessment of Patients With Disorders of Consciousness Following Acquired Brain Injury: A Systematic Review. J Head Trauma Rehabil 2018; 32:185-196. [PMID: 27831962 DOI: 10.1097/htr.0000000000000267] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To investigate the diagnostic utility of electrophysiological recordings during active cognitive tasks in detecting residual cognitive capacities in patients with disorders of consciousness (DoC) after severe acquired brain injury. DESIGN Systematic review of empirical research in MEDLINE, Embase, PsycINFO, and Cochrane from January 2002 to March 2016. MAIN MEASURES Data extracted included sample size, type of electrophysiological technique and task design, rate of cognitive responders, false negatives and positives, and excluded subjects from the study analysis. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used for quality appraisal of the retrieved literature. RESULTS Twenty-four studies examining electrophysiological signs of command-following in patients with DoC were identified. Sensitivity rates in healthy controls demonstrated variable accuracy across the studies, ranging from 71% to 100%. In patients with DoC, specificity and sensitivity rates varied in the included studies, ranging from 0% to 100%. Pronounced heterogeneity was found between studies regarding methodological approaches, task design, and procedures of analysis, rendering comparison between studies challenging. CONCLUSION We are still far from establishing precise recommendations for standardized electrophysiological diagnostic procedures in DoC, but electrophysiological methods may add supplemental diagnostic information of covert cognition in some patients with DoC.
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Affiliation(s)
- S L Hauger
- Department of Research, Sunnaas Rehabilitation Hospital, Norway (Mrs Hauger and Drs Løvstad and Schanke); Department of Psychology, University of Oslo, Oslo, Norway (Drs Andersson, Løvstad, and Schanke); Laboratory for NeuroImaging of Coma and Consciousness, Massachusetts General Hospital, Boston, and Acute Neurorehabilitation Unit, Department of Clinical Neurosciences, University Hospital of Lausanne, Switzerland (Dr Chatelle); and Department of Neurosurgery, University of California, Los Angeles (Dr Schnakers)
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26
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Wu M, Bao WX, Zhang J, Hu YF, Gao J, Luo BY. Effect of acoustic stimuli in patients with disorders of consciousness: a quantitative electroencephalography study. Neural Regen Res 2018; 13:1900-1906. [PMID: 30233062 PMCID: PMC6183039 DOI: 10.4103/1673-5374.238622] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Auditory stimuli are proposed as beneficial neurorehabilitation methods in patients with disorders of consciousness. However, precise and accurate quantitative indices to estimate their potential effect remain scarce. Fourteen patients were recruited from the Neuro-Rehabilitation Unit of Hangzhou Hospital of Zhejiang Armed Police Corps of China. Altogether, there were seven cases of unresponsive wakefulness syndrome (five males and two females, aged 45.7 ± 16.8 years) and seven cases of minimally conscious state (six males and one female, aged 42.3 ± 20.8 years). Simultaneously, fourteen healthy controls (10 males and 4 females, aged 51.7 ± 9.7 years) also participated in this case-control experiment. Brain response to music, subjects’ own name, and noise was monitored by quantitative electroencephalography (QEEG) in the resting state and with acoustic stimulation. Predictive QEEG values in various brain regions were investigated. Our results show that cerebral activation was high in subjects stimulated by their own name, especially in the temporal lobe in patients with disorders of consciousness, and the frontal lobe in the control group. Further, during resting and stimulation, QEEG index (δ + θ/α + β ratio) negatively correlated with the Coma Recovery Scale-Revised score in traumatic disorders of consciousness patients. Hence, we speculate that a subject's own name might be an effective awakening therapy for patients with disorders of consciousness. Moreover, QEEG index in specific stimulation states may be used as a prognostic indicator for disorders of consciousness patients (sensitivity, 75%; specificity, 50%). This clinical study has been registered at ClinicalTrials.gov (identifier: NCT03385291).
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Affiliation(s)
- Min Wu
- Department of Neurology & Brain Medical Centre, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Wang-Xiao Bao
- Department of Neurology & Brain Medical Centre, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Jie Zhang
- Department of Neurology & Brain Medical Centre, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yang-Fan Hu
- Department of Computer Science, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Jian Gao
- Department of Rehabilitation, Hangzhou Hospital of Zhejiang Armed Police Corps, Hangzhou, Zhejiang Province, China
| | - Ben-Yan Luo
- Department of Neurology & Brain Medical Centre, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
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27
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Roy N, Sanz-Leon P, Robinson PA. Spectral signatures of activity-dependent neural feedback in the corticothalamic system. Phys Rev E 2017; 96:052310. [PMID: 29347805 DOI: 10.1103/physreve.96.052310] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Indexed: 11/07/2022]
Abstract
The modulation of neural quantities by presynaptic and postsynaptic activities via local feedback processes is investigated by incorporating nonlinear phenomena such as relative refractory period, synaptic enhancement, synaptic depression, and habituation. This is done by introducing susceptibilities, which quantify the response in either firing threshold or synaptic strength to unit change in either presynaptic or postsynaptic activity. Effects on the power spectra are then analyzed for a realistic corticothalamic model to determine the spectral signatures of various nonlinear processes and to what extent these are distinct. Depending on the feedback processes, there can be enhancements or reductions in low-frequency and/or alpha power, splitting of the alpha resonance, and/or appearance of new resonances at high frequencies. These features in the power spectra allow processes to be fully distinguished where they are unique, or partly distinguished if they are common to only a subset of feedbacks, and can potentially be used to constrain the types, strengths, and dynamics of feedbacks present.
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Affiliation(s)
- N Roy
- School of Physics, University of Sydney, New South Wales 2006, Australia and Center for Integrative Brain Function, University of Sydney, New South Wales 2006, Australia
| | - P Sanz-Leon
- School of Physics, University of Sydney, New South Wales 2006, Australia and Center for Integrative Brain Function, University of Sydney, New South Wales 2006, Australia
| | - P A Robinson
- School of Physics, University of Sydney, New South Wales 2006, Australia and Center for Integrative Brain Function, University of Sydney, New South Wales 2006, Australia
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van den Brink RL, Nieuwenhuis S, van Boxtel GJM, van Luijtelaar G, Eilander HJ, Wijnen VJM. Task-free spectral EEG dynamics track and predict patient recovery from severe acquired brain injury. NEUROIMAGE-CLINICAL 2017. [PMID: 29527471 PMCID: PMC5842643 DOI: 10.1016/j.nicl.2017.10.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
For some patients, coma is followed by a state of unresponsiveness, while other patients develop signs of awareness. In practice, detecting signs of awareness may be hindered by possible impairments in the patient's motoric, sensory, or cognitive abilities, resulting in a substantial proportion of misdiagnosed disorders of consciousness. Task-free paradigms that are independent of the patient's sensorimotor and neurocognitive abilities may offer a solution to this challenge. A limitation of previous research is that the large majority of studies on the pathophysiological processes underlying disorders of consciousness have been conducted using cross-sectional designs. Here, we present a study in which we acquired a total of 74 longitudinal task-free EEG measurements from 16 patients (aged 6–22 years, 12 male) suffering from severe acquired brain injury, and an additional 16 age- and education-matched control participants. We examined changes in amplitude and connectivity metrics of oscillatory brain activity within patients across their recovery. Moreover, we applied multi-class linear discriminant analysis to assess the potential diagnostic and prognostic utility of amplitude and connectivity metrics at the individual-patient level. We found that over the course of their recovery, patients exhibited nonlinear frequency band-specific changes in spectral amplitude and connectivity metrics, changes that aligned well with the metrics' frequency band-specific diagnostic value. Strikingly, connectivity during a single task-free EEG measurement predicted the level of patient recovery approximately 3 months later with 75% accuracy. Our findings show that spectral amplitude and connectivity track patient recovery in a longitudinal fashion, and these metrics are robust pathophysiological markers that can be used for the automated diagnosis and prognosis of disorders of consciousness. These metrics can be acquired inexpensively at bedside, and are fully independent of the patient's neurocognitive abilities. Lastly, our findings tentatively suggest that the relative preservation of thalamo-cortico-thalamic interactions may predict the later reemergence of awareness, and could thus shed new light on the pathophysiological processes that underlie disorders of consciousness. Using behavioral criteria, disorders of consciousness are often misdiagnosed We probed the diagnostic and prognostic value of task-free spectral EEG metrics Metrics changed non-linearly across recovery and predicted level of consciousness EEG connectivity predicted the level of patient recovery with 75% accuracy These metrics are fully independent of the patient's neurocognitive abilities
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Affiliation(s)
- R L van den Brink
- Institute of Psychology, Leiden University, Leiden, The Netherlands; Leiden Institute for Brain and Cognition (LIBC), Leiden, The Netherlands; Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - S Nieuwenhuis
- Institute of Psychology, Leiden University, Leiden, The Netherlands; Leiden Institute for Brain and Cognition (LIBC), Leiden, The Netherlands
| | - G J M van Boxtel
- Department of Psychology, Tilburg University, Tilburg, The Netherlands
| | - G van Luijtelaar
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - H J Eilander
- Libra Rehabilitation Medicine and Audiology, Tilburg, The Netherlands; Radboud University Nijmegen Medical Centre, Department of Primary and Community Care, Nijmegen, The Netherlands
| | - V J M Wijnen
- Department of Psychology, Tilburg University, Tilburg, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands; Libra Rehabilitation Medicine and Audiology, Tilburg, The Netherlands; Geriatric Psychiatry Observation Unit, Institution for Mental Health Care 'Dijk and Duin', Parnassia Group, Castricum, Netherlands
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Meiron O, Jaul E. Paroxysmal theta power reactivity is related to survival in anoxic vegetative state patients. Clin Neurophysiol 2017; 128:1255-1257. [DOI: 10.1016/j.clinph.2017.04.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 04/23/2017] [Accepted: 04/24/2017] [Indexed: 10/19/2022]
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31
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Wislowska M, Del Giudice R, Lechinger J, Wielek T, Heib DPJ, Pitiot A, Pichler G, Michitsch G, Donis J, Schabus M. Night and day variations of sleep in patients with disorders of consciousness. Sci Rep 2017; 7:266. [PMID: 28325926 PMCID: PMC5428269 DOI: 10.1038/s41598-017-00323-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 02/21/2017] [Indexed: 02/01/2023] Open
Abstract
Brain injuries substantially change the entire landscape of oscillatory dynamics and render detection of typical sleep patterns difficult. Yet, sleep is characterized not only by specific EEG waveforms, but also by its circadian organization. In the present study we investigated whether brain dynamics of patients with disorders of consciousness systematically change between day and night. We recorded ~24 h EEG at the bedside of 18 patients diagnosed to be vigilant but unaware (Unresponsive Wakefulness Syndrome) and 17 patients revealing signs of fluctuating consciousness (Minimally Conscious State). The day-to-night changes in (i) spectral power, (ii) sleep-specific oscillatory patterns and (iii) signal complexity were analyzed and compared to 26 healthy control subjects. Surprisingly, the prevalence of sleep spindles and slow waves did not systematically vary between day and night in patients, whereas day-night changes in EEG power spectra and signal complexity were revealed in minimally conscious but not unaware patients.
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Affiliation(s)
- Malgorzata Wislowska
- Laboratory for Sleep, Cognition and Consciousness, & Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Renata Del Giudice
- Laboratory for Sleep, Cognition and Consciousness, & Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Julia Lechinger
- Laboratory for Sleep, Cognition and Consciousness, & Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Tomasz Wielek
- Laboratory for Sleep, Cognition and Consciousness, & Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Dominik P J Heib
- Laboratory for Sleep, Cognition and Consciousness, & Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Alain Pitiot
- Laboratory of Image & Data Analysis, Ilixa Ltd., Nottingham, United Kingdom
| | - Gerald Pichler
- Apallic Care Unit, Neurological Division, Albert-Schweitzer-Klinik, Graz, Austria
| | - Gabriele Michitsch
- Apallic Care Unit, Neurological Division, Pflegewohnhaus Donaustadt, Vienna, Austria
| | - Johann Donis
- Apallic Care Unit, Neurological Division, Pflegewohnhaus Donaustadt, Vienna, Austria
| | - Manuel Schabus
- Laboratory for Sleep, Cognition and Consciousness, & Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.
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Şerban CA, Barborică A, Roceanu AM, Mîndruță IR, Ciurea J, Zăgrean AM, Zăgrean L, Moldovan M. EEG Assessment of Consciousness Rebooting from Coma. THE PHYSICS OF THE MIND AND BRAIN DISORDERS 2017. [DOI: 10.1007/978-3-319-29674-6_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Evaluation of Cognitive Function When Hearing One's Own Name in Patients With Brain Injuries in Early Developmental Stages. J Clin Neurophysiol 2016; 34:254-260. [PMID: 27763965 DOI: 10.1097/wnp.0000000000000355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
PURPOSE The level of residual cognitive function in patients with early brain injury is a key factor limiting rehabilitation and the quality of life. Although understanding residual function is necessary for appropriate rehabilitation, the extent of its effects on cognitive improvement remains unknown. This study evaluated cognitive function in patients with severe motor and intellectual disabilities after early brain injuries due to cerebral hemorrhage or periventricular leukomalacia. We focused on neural responses to hearing the subject's own name (SON). According to previous studies, differences in response to SON are associated with several types of cognitive dysfunction. METHODS We examined healthy subjects (aged 21.4 ± 1.10 years; control) and patients with a previous brain injury (aged 13-27 years at the time of our analysis) resulting in periventricular leukomalacia or a cerebral hemorrhage during the perinatal period or childhood. We recorded EEG responses to the SON and to other Japanese words, obtaining EEG-evoked potentials with wavelet transformations. RESULTS Compared with healthy controls, beta power (not alpha power) revealed differences in response to SON by patients with brain injury, especially those with cerebral hemorrhage. CONCLUSIONS We suggest that alpha and beta power differences reflect different cognitive functions and that the SON response reveals more than one process. Beta powers may reflect the intellectual disability of cognitive function in response to self-relevant stimuli, especially in patients with cerebral hemorrhage. Meanwhile, alpha powers did not differ from those of the healthy controls, suggesting that the patients perhaps paid attention to their own names.
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Molteni E, Avantaggiato P, Formica F, Pastore V, Colombo K, Galbiati S, Arrigoni F, Strazzer S. Sleep/Wake Modulation of Polysomnographic Patterns has Prognostic Value in Pediatric Unresponsive Wakefulness Syndrome. J Clin Sleep Med 2016; 12:1131-41. [PMID: 27166297 DOI: 10.5664/jcsm.6052] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/07/2016] [Indexed: 01/18/2023]
Abstract
STUDY OBJECTIVE Sleep patterns of pediatric patients in unresponsive wakefulness syndrome (UWS) have been poorly investigated, and the prognostic potential of polysomnography (PSG) in these subjects is still uncertain. The goal of the study was to identify quantitative PSG indices to be applied as possible prognostic markers in pediatric UWS. METHODS We performed PSG in 27 children and adolescents with UWS due to acquired brain damage in the subacute phase. Patients underwent neurological examination and clinical assessment with standardized scales. Outcome was assessed after 36 mo. PSG tracks were scored for sleep stages and digitally filtered. The spectral difference between sleep and wake was computed, as the percent difference at specific spectral frequencies. We computed (1) the ratio between percent power in the delta and alpha frequency bands, (2) the ratio between alpha and theta frequency bands, and (3) the power ratio index, during wake and sleep, as proposed in previous literature. The predictive role of several clinical and PSG measures was tested by logistic regression. RESULTS Correlation was found between the differential measures of electroencephalographic activity during sleep and wake in several frequency bands and the clinical scales (Glasgow Outcome Score, Level of Cognitive Functioning Assessment Scale, and Disability Rating Scale) at follow-up; the Sleep Patterns for Pediatric Unresponsive Wakefulness Syndrome (SPPUWS) scores correlated with the differential measures, and allowed outcome prediction with 96.3% of accuracy. CONCLUSIONS The differential measure of electroencephalographic activity during sleep and wake in the beta band and, more incisively, SPPUWS can help in determining the capability to recover from pediatric UWS well before the confirmation provided by suitable clinical scales.
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Affiliation(s)
- Erika Molteni
- Acquired Brain Injury Unit, Scientific Institute IRCCS E.Medea, Bosisio Parini, Italy
| | - Paolo Avantaggiato
- Acquired Brain Injury Unit, Scientific Institute IRCCS E.Medea, Bosisio Parini, Italy
| | - Francesca Formica
- Acquired Brain Injury Unit, Scientific Institute IRCCS E.Medea, Bosisio Parini, Italy
| | - Valentina Pastore
- Acquired Brain Injury Unit, Scientific Institute IRCCS E.Medea, Bosisio Parini, Italy
| | - Katia Colombo
- Acquired Brain Injury Unit, Scientific Institute IRCCS E.Medea, Bosisio Parini, Italy
| | - Sara Galbiati
- Acquired Brain Injury Unit, Scientific Institute IRCCS E.Medea, Bosisio Parini, Italy
| | - Filippo Arrigoni
- Neuroimaging Unit, Scientific Institute IRCCS E.Medea, Bosisio Parini, Italy
| | - Sandra Strazzer
- Acquired Brain Injury Unit, Scientific Institute IRCCS E.Medea, Bosisio Parini, Italy
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35
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Can self-relevant stimuli help assessing patients with disorders of consciousness? Conscious Cogn 2016; 44:51-60. [DOI: 10.1016/j.concog.2016.06.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 06/08/2016] [Accepted: 06/18/2016] [Indexed: 11/21/2022]
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36
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Lechinger J, Wielek T, Blume C, Pichler G, Michitsch G, Donis J, Gruber W, Schabus M. Event-related EEG power modulations and phase connectivity indicate the focus of attention in an auditory own name paradigm. J Neurol 2016; 263:1530-43. [PMID: 27216625 PMCID: PMC4971049 DOI: 10.1007/s00415-016-8150-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 11/28/2022]
Abstract
Estimating cognitive abilities in patients suffering from Disorders of Consciousness remains challenging. One cognitive task to address this issue is the so-called own name paradigm, in which subjects are presented with first names including the own name. In the active condition, a specific target name has to be silently counted. We recorded EEG during this task in 24 healthy controls, 8 patients suffering from Unresponsive Wakefulness Syndrome (UWS) and 7 minimally conscious (MCS) patients. EEG was analysed with respect to amplitude as well as phase modulations and connectivity. Results showed that general reactivity in the delta, theta and alpha frequency (event-related de-synchronisation, ERS/ERD, and phase locking between trials and electrodes) toward auditory stimulation was higher in controls than in patients. In controls, delta ERS and lower alpha ERD indexed the focus of attention in both conditions, late theta ERS only in the active condition. Additionally, phase locking between trials and delta phase connectivity was highest for own names in the passive and targets in the active condition. In patients, clear stimulus-specific differences could not be detected. However, MCS patients could reliably be differentiated from UWS patients based on their general event-related delta and theta increase independent of the type of stimulus. In conclusion, the EEG signature of the active own name paradigm revealed instruction-following in healthy participants. On the other hand, DOC patients did not show clear stimulus-specific processing. General reactivity toward any auditory input, however, allowed for a reliable differentiation between MCS and UWS patients.
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Affiliation(s)
- Julia Lechinger
- Laboratory for Sleep and Consciousness Research, Department of Psychology, University of Salzburg, Hellbrunnerstraße 34, 5020, Salzburg, Austria.
- Centre for Cognitive Neuroscience (CCNS), University of Salzburg, Salzburg, Austria.
| | - Tomasz Wielek
- Laboratory for Sleep and Consciousness Research, Department of Psychology, University of Salzburg, Hellbrunnerstraße 34, 5020, Salzburg, Austria
| | - Christine Blume
- Laboratory for Sleep and Consciousness Research, Department of Psychology, University of Salzburg, Hellbrunnerstraße 34, 5020, Salzburg, Austria
- Centre for Cognitive Neuroscience (CCNS), University of Salzburg, Salzburg, Austria
| | - Gerald Pichler
- Apallic Care Unit, Neurological Division, Albert-Schweitzer-Klinik, Graz, Austria
| | - Gabriele Michitsch
- Apallic Care Unit, Neurological Division, Sozialmedizinisches Zentrum Ost-Donauspital, Vienna, Austria
| | - Johann Donis
- Apallic Care Unit, Neurological Division, Sozialmedizinisches Zentrum Ost-Donauspital, Vienna, Austria
| | - Walter Gruber
- Centre for Cognitive Neuroscience (CCNS), University of Salzburg, Salzburg, Austria
| | - Manuel Schabus
- Laboratory for Sleep and Consciousness Research, Department of Psychology, University of Salzburg, Hellbrunnerstraße 34, 5020, Salzburg, Austria
- Centre for Cognitive Neuroscience (CCNS), University of Salzburg, Salzburg, Austria
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del Giudice R, Blume C, Wislowska M, Wielek T, Heib DPJ, Schabus M. The Voice of Anger: Oscillatory EEG Responses to Emotional Prosody. PLoS One 2016; 11:e0159429. [PMID: 27442445 PMCID: PMC4956258 DOI: 10.1371/journal.pone.0159429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 07/01/2016] [Indexed: 11/18/2022] Open
Abstract
Emotionally relevant stimuli and in particular anger are, due to their evolutionary relevance, often processed automatically and able to modulate attention independent of conscious access. Here, we tested whether attention allocation is enhanced when auditory stimuli are uttered by an angry voice. We recorded EEG and presented healthy individuals with a passive condition where unfamiliar names as well as the subject's own name were spoken both with an angry and neutral prosody. The active condition instead, required participants to actively count one of the presented (angry) names. Results revealed that in the passive condition the angry prosody only elicited slightly stronger delta synchronization as compared to a neutral voice. In the active condition the attended (angry) target was related to enhanced delta/theta synchronization as well as alpha desynchronization suggesting enhanced allocation of attention and utilization of working memory resources. Altogether, the current results are in line with previous findings and highlight that attention orientation can be systematically related to specific oscillatory brain responses. Potential applications include assessment of non-communicative clinical groups such as post-comatose patients.
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Affiliation(s)
- Renata del Giudice
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunner Strasse 34, 5020, Salzburg, Austria
- Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria
| | - Christine Blume
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunner Strasse 34, 5020, Salzburg, Austria
- Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria
| | - Malgorzata Wislowska
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunner Strasse 34, 5020, Salzburg, Austria
- Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria
| | - Tomasz Wielek
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunner Strasse 34, 5020, Salzburg, Austria
- Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria
| | - Dominik P. J. Heib
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunner Strasse 34, 5020, Salzburg, Austria
- Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria
| | - Manuel Schabus
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunner Strasse 34, 5020, Salzburg, Austria
- Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg, Hellbrunner Strasse 34, 5020, Salzburg, Austria
- * E-mail:
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Hearing subject's own name induces the late positive component of event-related potential and beta power suppression. Brain Res 2016; 1635:130-42. [PMID: 26820638 DOI: 10.1016/j.brainres.2016.01.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 01/18/2016] [Accepted: 01/20/2016] [Indexed: 11/24/2022]
Abstract
The neuronal response to hearing a subject's own name (SON) has been often investigated using event-related potential (ERP) or time-frequency analysis, but seldom by a combination of these methods. Using this combination of approaches would allow the relationship between memory processes engaged by SON and the neuronal responses to be studied in more detail. Thus, the present study used both ERP and time-frequency analysis to investigate memory process for SON by comparing the responses to SON and to unfamiliar names. Specifically, the SON condition was compared with two control conditions: repeated unfamiliar names and singly presented unfamiliar names. This experimental design allowed us to determine the differences in memory processes between hearing one's own name and hearing unrelated but repeatedly heard names. ERP analysis showed that SON elicited a late positive component in parietal areas, while unfamiliar names elicited no positivity. Beta power suppression was observed in response to SON at 0.4-0.6s after stimulus onset at right central sites, but not in response to unfamiliar names. These results are indicative of an involvement of episodic memory processes on hearing SON, which corresponds to the recognition of one's own name. Further, the ERP results suggest the presence of a "new" stimulus recognition process that is activated by singly presented unfamiliar names but not by repeated unfamiliar names.
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Thul A, Lechinger J, Donis J, Michitsch G, Pichler G, Kochs EF, Jordan D, Ilg R, Schabus M. EEG entropy measures indicate decrease of cortical information processing in Disorders of Consciousness. Clin Neurophysiol 2015; 127:1419-1427. [PMID: 26480834 DOI: 10.1016/j.clinph.2015.07.039] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 07/21/2015] [Accepted: 07/24/2015] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Clinical assessments that rely on behavioral responses to differentiate Disorders of Consciousness are at times inapt because of some patients' motor disabilities. To objectify patients' conditions of reduced consciousness the present study evaluated the use of electroencephalography to measure residual brain activity. METHODS We analyzed entropy values of 18 scalp EEG channels of 15 severely brain-damaged patients with clinically diagnosed Minimally-Conscious-State (MCS) or Unresponsive-Wakefulness-Syndrome (UWS) and compared the results to a sample of 24 control subjects. Permutation entropy (PeEn) and symbolic transfer entropy (STEn), reflecting information processes in the EEG, were calculated for all subjects. Participants were tested on a modified active own-name paradigm to identify correlates of active instruction following. RESULTS PeEn showed reduced local information content in the EEG in patients, that was most pronounced in UWS. STEn analysis revealed altered directed information flow in the EEG of patients, indicating impaired feed-backward connectivity. Responses to auditory stimulation yielded differences in entropy measures, indicating reduced information processing in MCS and UWS. CONCLUSIONS Local EEG information content and information flow are affected in Disorders of Consciousness. This suggests local cortical information capacity and feedback information transfer as neural correlates of consciousness. SIGNIFICANCE The utilized EEG entropy analyses were able to relate to patient groups with different Disorders of Consciousness.
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Affiliation(s)
- Alexander Thul
- Department of Neurology, Klinikum rechts der Isar, Technische Universität München, Germany; Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Germany.
| | - Julia Lechinger
- Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, University of Salzburg, Austria
| | - Johann Donis
- Apallic Care Unit, Neurological Division, Geriatriezentrum am Wienerwald, Vienna, Austria
| | - Gabriele Michitsch
- Apallic Care Unit, Neurological Division, Geriatriezentrum am Wienerwald, Vienna, Austria
| | - Gerald Pichler
- Apallic Care Unit, Neurological Division, Albert-Schweitzer-Klinik, Graz, Austria
| | - Eberhard F Kochs
- Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Germany
| | - Denis Jordan
- Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Germany
| | - Rüdiger Ilg
- Department of Neurology, Klinikum rechts der Isar, Technische Universität München, Germany
| | - Manuel Schabus
- Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, University of Salzburg, Austria; Centre for Cognitive Neuroscience Salzburg (CCNS), Salzburg, Austria
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40
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Phase-locked theta activity evoked in patients with severe motor and intellectual disabilities upon hearing own names. Brain Dev 2015; 37:764-72. [PMID: 25530126 DOI: 10.1016/j.braindev.2014.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 11/28/2014] [Accepted: 11/28/2014] [Indexed: 11/20/2022]
Abstract
BACKGROUND Severe motor and intellectual disability (SMID) patients cannot express their feelings with language. Understanding what they are thinking about or how they feel is thus difficult. This study focused on brain responses to hearing their own names to clarify the situation in these patients. METHODS We performed and analyzed electroencephalography (EEG) for six patients with SMID and eleven healthy subjects. All subjects were presented with auditory stimuli including calling the subject's own name (SON) and reading words. EEG was analyzed by time-frequency analysis, event-related spectral perturbation (ERSP) to detect EEG power changes caused by EEG amplitude, and inter-trial coherence (ITC) to investigate phase-locked changes. RESULTS ERSP results from healthy subjects showed significant theta power increases as a specific response to SON. While we could not identify a similar pattern in the responses of patients with SMID, analysis of ITC revealed that theta phase-locked activity increased in response to SON not only in all healthy subjects, but also in four patients. DISCUSSION These results indicate that theta phase-locked activity in some patients with SMID was strongly associated with SON, as in healthy subjects. Our study suggests the existence of specific neural markers that signal an attentional shift in patients upon hearing SON.
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Balconi M, Arangio R. The Relationship Between Coma Near Coma, Disability Ratings, and Event-Related Potentials in Patients with Disorders of Consciousness: A Semantic Association Task. Appl Psychophysiol Biofeedback 2015. [DOI: 10.1007/s10484-015-9304-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Blume C, Lechinger J, del Giudice R, Wislowska M, Heib DPJ, Schabus M. EEG oscillations reflect the complexity of social interactions in a non-verbal social cognition task using animated triangles. Neuropsychologia 2015; 75:330-40. [PMID: 26111488 DOI: 10.1016/j.neuropsychologia.2015.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 05/28/2015] [Accepted: 06/06/2015] [Indexed: 10/23/2022]
Abstract
The ability to attribute independent mental states (e.g. opinions, perceptions, beliefs) to oneself and others is termed Theory of Mind (ToM). Previous studies investigating ToM usually employed verbal paradigms and functional neuroimaging methods. Here, we studied oscillatory responses in the electroencephalogram (EEG) in a non-verbal social cognition task. The aim of this study was twofold: First, we wanted to investigate differences in oscillatory responses to animations differing with regard to the complexity of social "interactions". Secondly, we intended to evaluate the basic cognitive processes underlying social cognition. To this end, we analyzed theta, alpha, beta and gamma task-related de-/synchronization (TRD/TRS) during presentation of six non-verbal videos differing in the complexity of (social) "interactions" between two geometric shapes. Videos were adopted from Castelli et al. (2000)and belonged to three conditions: Videos designed to evoke attributions of mental states (ToM), interaction descriptions (goal-directed, GD) and videos in which the shapes moved randomly (R). Analyses revealed that only theta activity consistently varied as a function of social "interaction" complexity. Results suggest that ToM/GD videos attract more attention and working-memory resources and may have activated related memory contents. Alpha and beta results were less consistent. While alpha effects suggest that observation of social "interactions" may benefit from inhibition of self-centered processing, oscillatory responses in the beta range could be related to action observation. In summary, the results provide insight into basic cognitive processes involved in social cognition and render the paradigm attractive for the investigation of social cognitive processes in non-verbal populations.
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Affiliation(s)
- Christine Blume
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Austria; University of Salzburg, Centre for Cognitive Neuroscience Salzburg (CCNS), Austria.
| | - Julia Lechinger
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Austria; University of Salzburg, Centre for Cognitive Neuroscience Salzburg (CCNS), Austria.
| | - Renata del Giudice
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Austria; University of Salzburg, Centre for Cognitive Neuroscience Salzburg (CCNS), Austria.
| | - Malgorzata Wislowska
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Austria.
| | - Dominik P J Heib
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Austria; University of Salzburg, Centre for Cognitive Neuroscience Salzburg (CCNS), Austria.
| | - Manuel Schabus
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Austria; University of Salzburg, Centre for Cognitive Neuroscience Salzburg (CCNS), Austria.
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Blume C, Del Giudice R, Wislowska M, Lechinger J, Schabus M. Across the consciousness continuum-from unresponsive wakefulness to sleep. Front Hum Neurosci 2015; 9:105. [PMID: 25805982 PMCID: PMC4354375 DOI: 10.3389/fnhum.2015.00105] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 02/12/2015] [Indexed: 11/13/2022] Open
Abstract
Advances in the development of new paradigms as well as in neuroimaging techniques nowadays enable us to make inferences about the level of consciousness patients with disorders of consciousness (DOC) retain. They, moreover, allow to predict their probable development. Today, we know that certain brain responses (e.g., event-related potentials or oscillatory changes) to stimulation, circadian rhythmicity, the presence or absence of sleep patterns as well as measures of resting state brain activity can serve the diagnostic and prognostic evaluation process. Still, the paradigms we are using nowadays do not allow to disentangle VS/UWS and minimally conscious state (MCS) patients with the desired reliability and validity. Furthermore, even rather well-established methods have, unfortunately, not found their way into clinical routine yet. We here review current literature as well as recent findings from our group and discuss how neuroimaging methods (fMRI, PET) and particularly electroencephalography (EEG) can be used to investigate cognition in DOC or even to assess the degree of residual awareness. We, moreover, propose that circadian rhythmicity and sleep in brain-injured patients are promising fields of research in this context.
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Affiliation(s)
- Christine Blume
- Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, University of Salzburg Salzburg, Austria ; Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg Salzburg, Austria
| | - Renata Del Giudice
- Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, University of Salzburg Salzburg, Austria ; Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg Salzburg, Austria
| | - Malgorzata Wislowska
- Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, University of Salzburg Salzburg, Austria
| | - Julia Lechinger
- Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, University of Salzburg Salzburg, Austria ; Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg Salzburg, Austria
| | - Manuel Schabus
- Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, University of Salzburg Salzburg, Austria ; Centre for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg Salzburg, Austria
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Rosenbaum AM, Giacino JT. Clinical management of the minimally conscious state. HANDBOOK OF CLINICAL NEUROLOGY 2015; 127:395-410. [PMID: 25702230 DOI: 10.1016/b978-0-444-52892-6.00025-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The minimally conscious state (MCS) was defined as a disorder of consciousness (DoC) distinct from the vegetative state more than a decade ago. While this condition has become widely recognized, there are still no guidelines to steer the approach to assessment and treatment. The development of evidence-based practice guidelines for MCS has been hampered by ambiguity around the concept of consciousness, the lack of accurate methods of assessment, and the dearth of well-designed clinical trials. This chapter provides a critical review of existing assessment procedures, critically reviews available treatment options and identifies knowledge gaps. We close with practice-based recommendations for a rational approach to clinical management of this challenging population.
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Affiliation(s)
| | - Joseph T Giacino
- Department of Physical Medicine and Rehabilitation, Harvard Medical School and Spaulding Rehabilitation Hospital, Boston, MA, USA.
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45
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Liberati G, Hünefeldt T, Olivetti Belardinelli M. Questioning the dichotomy between vegetative state and minimally conscious state: a review of the statistical evidence. Front Hum Neurosci 2014; 8:865. [PMID: 25404905 PMCID: PMC4217390 DOI: 10.3389/fnhum.2014.00865] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 10/07/2014] [Indexed: 01/24/2023] Open
Abstract
Given the enormous consequences that the diagnosis of vegetative state (VS) vs. minimally conscious state (MCS) may have for the treatment of patients with disorders of consciousness, it is particularly important to empirically legitimate the distinction between these two discrete levels of consciousness. Therefore, the aim of this contribution is to review all the articles reporting statistical evidence concerning the performance of patients in VS vs. patients in MCS, on behavioral or neurophysiological measures. Twenty-three articles matched these inclusion criteria, and comprised behavioral, electroencephalographic (EEG), positron emission tomography (PET) and magnetic resonance imaging (MRI) measures. The analysis of these articles yielded 47 different statistical findings. More than half of these findings (n = 24) did not reveal any statistically significant difference between VS and MCS. Overall, there was no combination of variables that allowed reliably discriminating between VS and MCS. This pattern of results casts doubt on the empirical validity of the distinction between VS and MCS.
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Affiliation(s)
- Giulia Liberati
- Institute of Neuroscience, Université Catholique de Louvain Brussels, Belgium
| | - Thomas Hünefeldt
- ECONA - Interuniversity Centre for Research on Cognitive Processing in Natural and Artificial Systems, "Sapienza" University of Rome Rome, Italy ; Department of Philosophy, Catholic University of Eichstätt-Ingolstadt Eichstätt, Germany
| | - Marta Olivetti Belardinelli
- ECONA - Interuniversity Centre for Research on Cognitive Processing in Natural and Artificial Systems, "Sapienza" University of Rome Rome, Italy ; Department of Psychology, Sapienza, University of Rome Rome, Italy
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del Giudice R, Lechinger J, Wislowska M, Heib DPJ, Hoedlmoser K, Schabus M. Oscillatory brain responses to own names uttered by unfamiliar and familiar voices. Brain Res 2014; 1591:63-73. [PMID: 25307136 PMCID: PMC4235780 DOI: 10.1016/j.brainres.2014.09.074] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 09/26/2014] [Accepted: 09/30/2014] [Indexed: 11/05/2022]
Abstract
Among auditory stimuli, the own name is one of the most powerful and it is able to automatically capture attention and elicit a robust electrophysiological response. The subject’s own name (SON) is preferentially processed in the right hemisphere, mainly because of its self-relevance and emotional content, together with other personally relevant information such as the voice of a familiar person. Whether emotional and self-relevant information are able to attract attention and can be, in future, introduced in clinical studies remains unclear. In the present study we used EEG and asked participants to count a target name (active condition) or to just listen to the SON or other unfamiliar names uttered by a familiar or unfamiliar voice (passive condition). Data reveals that the target name elicits a strong alpha event related desynchronization with respect to non-target names and triggers in addition a left lateralized theta synchronization as well as delta synchronization. In the passive condition alpha desynchronization was observed for familiar voice and SON stimuli in the right hemisphere. Altogether we speculate that participants engage additional attentional resources when counting a target name or when listening to personally relevant stimuli which is indexed by alpha desynchronization whereas left lateralized theta synchronization may be related to verbal working memory load. After validating the present protocol in healthy volunteers it is suggested to move one step further and apply the protocol to patients with disorders of consciousness in which the degree of residual cognitive processing and self-awareness is still insufficiently understood. EEG during an active–passive task based on first names was time-frequency analyzed. The presented names were uttered either by an unfamiliar or a familiar voice. Counted names elicited alpha desynchronization and left theta synchronization. Own name and familiar voices enhanced strong right alpha desynchronization. Alpha desynchronization reflects attentional engagement and emotional processing.
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Affiliation(s)
- Renata del Giudice
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
| | - Julia Lechinger
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
| | - Malgorzata Wislowska
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
| | - Dominik P J Heib
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
| | - Kerstin Hoedlmoser
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunnerstrasse 34, 5020 Salzburg, Austria; Center for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
| | - Manuel Schabus
- University of Salzburg, Department of Psychology, Laboratory for Sleep, Cognition and Consciousness Research, Hellbrunnerstrasse 34, 5020 Salzburg, Austria; Center for Cognitive Neuroscience Salzburg (CCNS), University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
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47
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Connectivity biomarkers can differentiate patients with different levels of consciousness. Clin Neurophysiol 2014; 125:1545-55. [DOI: 10.1016/j.clinph.2013.12.095] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 12/08/2013] [Accepted: 12/11/2013] [Indexed: 11/22/2022]
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48
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Sitt JD, King JR, El Karoui I, Rohaut B, Faugeras F, Gramfort A, Cohen L, Sigman M, Dehaene S, Naccache L. Large scale screening of neural signatures of consciousness in patients in a vegetative or minimally conscious state. ACTA ACUST UNITED AC 2014; 137:2258-70. [PMID: 24919971 DOI: 10.1093/brain/awu141] [Citation(s) in RCA: 287] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In recent years, numerous electrophysiological signatures of consciousness have been proposed. Here, we perform a systematic analysis of these electroencephalography markers by quantifying their efficiency in differentiating patients in a vegetative state from those in a minimally conscious or conscious state. Capitalizing on a review of previous experiments and current theories, we identify a series of measures that can be organized into four dimensions: (i) event-related potentials versus ongoing electroencephalography activity; (ii) local dynamics versus inter-electrode information exchange; (iii) spectral patterns versus information complexity; and (iv) average versus fluctuations over the recording session. We analysed a large set of 181 high-density electroencephalography recordings acquired in a 30 minutes protocol. We show that low-frequency power, electroencephalography complexity, and information exchange constitute the most reliable signatures of the conscious state. When combined, these measures synergize to allow an automatic classification of patients' state of consciousness.
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Affiliation(s)
- Jacobo Diego Sitt
- 1 Cognitive Neuroimaging Unit, Institut National de la Santé et de la Recherche Médicale, U992, F-91191 Gif/Yvette, France2 NeuroSpin Centre, Institute of BioImaging Commissariat à l'Energie Atomique, F-91191 Gif/Yvette, France3 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Jean-Remi King
- 1 Cognitive Neuroimaging Unit, Institut National de la Santé et de la Recherche Médicale, U992, F-91191 Gif/Yvette, France2 NeuroSpin Centre, Institute of BioImaging Commissariat à l'Energie Atomique, F-91191 Gif/Yvette, France3 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Imen El Karoui
- 3 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Benjamin Rohaut
- 3 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France4 AP-HP, Groupe hospitalier Pitié-Salpêtrière, Department of Neurology, Intensive Care Unit, Paris, France
| | - Frederic Faugeras
- 3 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France5 AP-HP, Groupe hospitalier Pitié-Salpêtrière, Department of Neurophysiology, Paris, France
| | - Alexandre Gramfort
- 2 NeuroSpin Centre, Institute of BioImaging Commissariat à l'Energie Atomique, F-91191 Gif/Yvette, France6 Institut Mines-Télécom, Télécom ParisTech, CNRS LTCI, France
| | - Laurent Cohen
- 3 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France4 AP-HP, Groupe hospitalier Pitié-Salpêtrière, Department of Neurology, Intensive Care Unit, Paris, France
| | - Mariano Sigman
- 7 Integrative Neuroscience Laboratory, Physics Department, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina8 Universidad Torcuato Di Tella, Almirante Juan Saenz Valiente 1010, C1428BIJ Buenos Aires, Argentina
| | - Stanislas Dehaene
- 1 Cognitive Neuroimaging Unit, Institut National de la Santé et de la Recherche Médicale, U992, F-91191 Gif/Yvette, France2 NeuroSpin Centre, Institute of BioImaging Commissariat à l'Energie Atomique, F-91191 Gif/Yvette, France9 Université Paris 11, Orsay, France10 Collège de France, F-75005 Paris, France
| | - Lionel Naccache
- 3 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France5 AP-HP, Groupe hospitalier Pitié-Salpêtrière, Department of Neurophysiology, Paris, France
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Comparison of EEG-features and classification methods for motor imagery in patients with disorders of consciousness. PLoS One 2013; 8:e80479. [PMID: 24282545 PMCID: PMC3839976 DOI: 10.1371/journal.pone.0080479] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 10/03/2013] [Indexed: 12/01/2022] Open
Abstract
Current research aims at identifying voluntary brain activation in patients who are behaviorally diagnosed as being unconscious, but are able to perform commands by modulating their brain activity patterns. This involves machine learning techniques and feature extraction methods such as applied in brain computer interfaces. In this study, we try to answer the question if features/classification methods which show advantages in healthy participants are also accurate when applied to data of patients with disorders of consciousness. A sample of healthy participants (N = 22), patients in a minimally conscious state (MCS; N = 5), and with unresponsive wakefulness syndrome (UWS; N = 9) was examined with a motor imagery task which involved imagery of moving both hands and an instruction to hold both hands firm. We extracted a set of 20 features from the electroencephalogram and used linear discriminant analysis, k-nearest neighbor classification, and support vector machines (SVM) as classification methods. In healthy participants, the best classification accuracies were seen with coherences (mean = .79; range = .53−.94) and power spectra (mean = .69; range = .40−.85). The coherence patterns in healthy participants did not match the expectation of central modulated -rhythm. Instead, coherence involved mainly frontal regions. In healthy participants, the best classification tool was SVM. Five patients had at least one feature-classifier outcome with p0.05 (none of which were coherence or power spectra), though none remained significant after false-discovery rate correction for multiple comparisons. The present work suggests the use of coherences in patients with disorders of consciousness because they show high reliability among healthy subjects and patient groups. However, feature extraction and classification is a challenging task in unresponsive patients because there is no ground truth to validate the results.
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Ruby P, Blochet C, Eichenlaub JB, Bertrand O, Morlet D, Bidet-Caulet A. Alpha reactivity to complex sounds differs during REM sleep and wakefulness. PLoS One 2013; 8:e79989. [PMID: 24260331 PMCID: PMC3832371 DOI: 10.1371/journal.pone.0079989] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 10/08/2013] [Indexed: 01/25/2023] Open
Abstract
We aimed at better understanding the brain mechanisms involved in the processing of alerting meaningful sounds during sleep, investigating alpha activity. During EEG acquisition, subjects were presented with a passive auditory oddball paradigm including rare complex sounds called Novels (the own first name - OWN, and an unfamiliar first name - OTHER) while they were watching a silent movie in the evening or sleeping at night. During the experimental night, the subjects' quality of sleep was generally preserved. During wakefulness, the decrease in alpha power (8-12 Hz) induced by Novels was significantly larger for OWN than for OTHER at parietal electrodes, between 600 and 900 ms after stimulus onset. Conversely, during REM sleep, Novels induced an increase in alpha power (from 0 to 1200 ms at all electrodes), significantly larger for OWN than for OTHER at several parietal electrodes between 700 and 1200 ms after stimulus onset. These results show that complex sounds have a different effect on the alpha power during wakefulness (decrease) and during REM sleep (increase) and that OWN induce a specific effect in these two states. The increased alpha power induced by Novels during REM sleep may 1) correspond to a short and transient increase in arousal; in this case, our study provides an objective measure of the greater arousing power of OWN over OTHER, 2) indicate a cortical inhibition associated with sleep protection. These results suggest that alpha modulation could participate in the selection of stimuli to be further processed during sleep.
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Affiliation(s)
- Perrine Ruby
- Brain Dynamics and Cognition Team, Lyon Neuroscience Research Center (CRNL) - INSERM - CNRS, Lyon, France
- University Lyon 1, Lyon, France
| | - Camille Blochet
- Brain Dynamics and Cognition Team, Lyon Neuroscience Research Center (CRNL) - INSERM - CNRS, Lyon, France
- University Lyon 1, Lyon, France
| | - Jean-Baptiste Eichenlaub
- Brain Dynamics and Cognition Team, Lyon Neuroscience Research Center (CRNL) - INSERM - CNRS, Lyon, France
- University Lyon 1, Lyon, France
| | - Olivier Bertrand
- Brain Dynamics and Cognition Team, Lyon Neuroscience Research Center (CRNL) - INSERM - CNRS, Lyon, France
- University Lyon 1, Lyon, France
| | - Dominique Morlet
- Brain Dynamics and Cognition Team, Lyon Neuroscience Research Center (CRNL) - INSERM - CNRS, Lyon, France
- University Lyon 1, Lyon, France
| | - Aurélie Bidet-Caulet
- Brain Dynamics and Cognition Team, Lyon Neuroscience Research Center (CRNL) - INSERM - CNRS, Lyon, France
- University Lyon 1, Lyon, France
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