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Kotchoubey B. Evoked and event-related potentials in disorders of consciousness: A quantitative review. Conscious Cogn 2017; 54:155-167. [DOI: 10.1016/j.concog.2017.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 04/18/2017] [Accepted: 05/10/2017] [Indexed: 11/25/2022]
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52
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Puggina ACG, da Silva MJP. Patients with disorders of consciousness: vital, facial and muscular responses to music or messages. Rev Bras Enferm 2017; 68:94-102, 102-10. [PMID: 25946501 DOI: 10.1590/0034-7167.2015680114p] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 12/09/2014] [Indexed: 11/21/2022] Open
Abstract
PURPOSES To compare vital signs, facial expression and basal electroneurographic signs with measures during stimuli music, message or "silence" in coma patients, vegetative status or sedated; and relating the score of Glasgow Results Scale with the intervention realized. METHOD A Monoblind Transversal Controlled Clinical Trial to researcher. The distribution, among the three groups, was randomized (experiment with music, experiment with message or control). Two assessments (sessions) were performed with interval of 40 minutes on the same day. RESULTS Most of the 76 patients were male, between 18 to 36 years old and hospitalized due to trauma. Statistically significant changes were found in the variables referred to temperature, facial expression, electroneurography and Glasgow Results Scale; more frequent alterations in second session, in coma and vegetative patients, in frontal muscles and in experiment group. CONCLUSIONS The facial expression and the electroneurography seem to be more trustworthy variables than vital signs to evaluate consciousness.
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Affiliation(s)
| | - Maria Julia Paes da Silva
- Programa de Pós-Graduação em Enfermagem, Escola de Enfermagem, Universidade de São Paulo, São Paulo, SP, Brasil
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53
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Basic discriminative and semantic processing in patients in the vegetative and minimally conscious state. Int J Psychophysiol 2017; 113:8-16. [DOI: 10.1016/j.ijpsycho.2016.12.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 12/03/2016] [Accepted: 12/28/2016] [Indexed: 11/20/2022]
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54
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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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55
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Wu K, Chen Y, Yan C, Huang Z, Wang D, Gui P, Bao J. Effects of percutaneous endoscopic gastrostomy on survival of patients in a persistent vegetative state after stroke. J Clin Nurs 2016; 26:3232-3238. [PMID: 27878869 DOI: 10.1111/jocn.13672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2016] [Indexed: 11/29/2022]
Abstract
AIMS AND OBJECTIVES To assess the effect of percutaneous endoscopic gastrostomy on short- and long-term survival of patients in a persistent vegetative state after stroke and determine the relevant prognostic factors. BACKGROUND Stroke may lead to a persistent vegetative state, and the effect of percutaneous endoscopic gastrostomy on survival of stroke patients in a persistent vegetative state remains unclear. DESIGN Prospective study. METHODS A total of 97 stroke patients in a persistent vegetative state hospitalised from January 2009 to December 2011 at the Second Hospital, University of South China, were assessed in this study. Percutaneous endoscopic gastrostomy was performed in 55 patients, and mean follow-up time was 18 months. Survival rate and risk factors were analysed. RESULTS Median survival in the 55 percutaneous endoscopic gastrostomy-treated patients was 17·6 months, higher compared with 8·2 months obtained for the remaining 42 patients without percutaneous endoscopic gastrostomy treatment. Univariate analyses revealed that age, hospitalisation time, percutaneous endoscopic gastrostomy treatment status, family financial situation, family care, pulmonary infection and nutrition were significantly associated with survival. Multivariate analysis indicated that older age, no gastrostomy, poor family care, pulmonary infection and poor nutritional status were independent risk factors affecting survival. Indeed, percutaneous endoscopic gastrostomy significantly improved the nutritional status and decreased pulmonary infection rate in patients with persistent vegetative state after stroke. Interestingly, median survival time was 20·3 months in patients with no or one independent risk factors of poor prognosis (n = 38), longer compared with 8·7 months found for patients with two or more independent risk factors (n = 59). CONCLUSION Percutaneous endoscopic gastrostomy significantly improves long-term survival of stroke patients in a persistent vegetative state and is associated with improved nutritional status and decreased pulmonary infection. RELEVANCE TO CLINICAL PRACTICE Percutaneous endoscopic gastrostomy is a promising option for the management of stroke patients in a persistent vegetative state.
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Affiliation(s)
- Kunpeng Wu
- Department of Intensive Care Medicine, the Second Hospital Affiliated to South China University, Hengyang, Hunan, China
| | - Ying Chen
- Department of Anesthesia, the Second Hospital Affiliated to South China University, Hengyang, Hunan, China
| | - Caihong Yan
- Department of Intensive Care Medicine, the Second Hospital Affiliated to South China University, Hengyang, Hunan, China
| | - Zhijia Huang
- Department of Intensive Care Medicine, the Second Hospital Affiliated to South China University, Hengyang, Hunan, China
| | - Deming Wang
- Department of Anesthesia, the Second Hospital Affiliated to South China University, Hengyang, Hunan, China
| | - Peigen Gui
- Department of Intensive Care Medicine, the Second Hospital Affiliated to South China University, Hengyang, Hunan, China
| | - Juan Bao
- Department of Intensive Care Medicine, the Second Hospital Affiliated to South China University, Hengyang, Hunan, China
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Evidence of trace conditioning in comatose patients revealed by the reactivation of EEG responses to alerting sounds. Neuroimage 2016; 141:530-541. [DOI: 10.1016/j.neuroimage.2016.07.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/08/2016] [Accepted: 07/17/2016] [Indexed: 11/20/2022] Open
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Abstract
In critically ill patients, evoked potential (EP) testing is an important tool for measuring neurologic function, signal transmission, and secondary processing of sensory information in real time. Evoked potential measures conduction along the peripheral and central sensory pathways with longer-latency potentials representing more complex thalamocortical and intracortical processing. In critically ill patients with limited neurologic exams, EP provides a window into brain function and the potential for recovery of consciousness. The most common EP modalities in clinical use in the intensive care unit include somatosensory evoked potentials, brainstem auditory EPs, and cortical event-related potentials. The primary indications for EP in critically ill patients are prognostication in anoxic-ischemic or traumatic coma, monitoring for neurologic improvement or decline, and confirmation of brain death. Somatosensory evoked potentials had become an important prognostic tool for coma recovery, especially in comatose survivors of cardiac arrest. In this population, the bilateral absence of cortical somatosensory evoked potentials has nearly 100% specificity for death or persistent vegetative state. Historically, EP has been regarded as a negative prognostic test, that is, the absence of cortical potentials is associated with poor outcomes while the presence cortical potentials are prognostically indeterminate. In recent studies, the presence of middle-latency and long-latency potentials as well as the amplitude of cortical potentials is more specific for good outcomes. Event-related potentials, particularly mismatch negativity of complex auditory patterns, is emerging as an important positive prognostic test in patients under comatose. Multimodality predictive algorithms that combine somatosensory evoked potentials, event-related potentials, and clinical and radiographic factors are gaining favor for coma prognostication.
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Bedside functional brain imaging in critically-ill children using high-density EEG source modeling and multi-modal sensory stimulation. NEUROIMAGE-CLINICAL 2016; 12:198-211. [PMID: 27453817 PMCID: PMC4942736 DOI: 10.1016/j.nicl.2016.06.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 06/24/2016] [Accepted: 06/30/2016] [Indexed: 12/03/2022]
Abstract
Acute brain injury is a common cause of death and critical illness in children and young adults. Fundamental management focuses on early characterization of the extent of injury and optimizing recovery by preventing secondary damage during the days following the primary injury. Currently, bedside technology for measuring neurological function is mainly limited to using electroencephalography (EEG) for detection of seizures and encephalopathic features, and evoked potentials. We present a proof of concept study in patients with acute brain injury in the intensive care setting, featuring a bedside functional imaging set-up designed to map cortical brain activation patterns by combining high density EEG recordings, multi-modal sensory stimulation (auditory, visual, and somatosensory), and EEG source modeling. Use of source-modeling allows for examination of spatiotemporal activation patterns at the cortical region level as opposed to the traditional scalp potential maps. The application of this system in both healthy and brain-injured participants is demonstrated with modality-specific source-reconstructed cortical activation patterns. By combining stimulation obtained with different modalities, most of the cortical surface can be monitored for changes in functional activation without having to physically transport the subject to an imaging suite. The results in patients in an intensive care setting with anatomically well-defined brain lesions suggest a topographic association between their injuries and activation patterns. Moreover, we report the reproducible application of a protocol examining a higher-level cortical processing with an auditory oddball paradigm involving presentation of the patient's own name. This study reports the first successful application of a bedside functional brain mapping tool in the intensive care setting. This application has the potential to provide clinicians with an additional dimension of information to manage critically-ill children and adults, and potentially patients not suited for magnetic resonance imaging technologies. We demonstrate the use of high-density EEG combined with multi-modality sensory stimulation and source modeling to generate functional brain activation maps. This is the first demonstration of source-level monitoring of functional brain responses in multiple modalities in children with acute brain injuries in ICU. The set-up is designed to examine higher-level cortical processing by using an auditory oddball paradigm involving the subject’s own name.
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Gosseries O, Pistoia F, Charland-Verville V, Carolei A, Sacco S, Laureys S. The Role of Neuroimaging Techniques in Establishing Diagnosis, Prognosis and Therapy in Disorders of Consciousness. Open Neuroimag J 2016; 10:52-68. [PMID: 27347265 PMCID: PMC4894918 DOI: 10.2174/1874440001610010052] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/06/2016] [Accepted: 04/11/2016] [Indexed: 12/30/2022] Open
Abstract
Non-communicative brain damaged patients raise important clinical and scientific issues. Here, we review three major pathological disorders of consciousness: coma, the unresponsive wakefulness syndrome and the minimally conscious state. A number of clinical studies highlight the difficulty in making a correct diagnosis in patients with disorders of consciousness based only on behavioral examinations. The increasing use of neuroimaging techniques allows improving clinical characterization of these patients. Recent neuroimaging studies using positron emission tomography, functional magnetic resonance imaging, electroencephalography and transcranial magnetic stimulation can help assess diagnosis, prognosis, and therapeutic treatment. These techniques, using resting state, passive and active paradigms, also highlight possible dissociations between consciousness and responsiveness, and are facilitating a more accurate understanding of brain function in this challenging population.
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Affiliation(s)
- Olivia Gosseries
- Coma Science Group, GIGA, University of Liege, Liege, Belgium; Department of Psychology and Psychiatry, University of Wisconsin, Madison, WI, United-States
| | - Francesca Pistoia
- Department of Biotechnological and Applied Clinical Sciences, Neurological Institute, University of L'Aquila, L'Aquila, Italy
| | | | - Antonio Carolei
- Department of Biotechnological and Applied Clinical Sciences, Neurological Institute, University of L'Aquila, L'Aquila, Italy
| | - Simona Sacco
- Department of Biotechnological and Applied Clinical Sciences, Neurological Institute, University of L'Aquila, L'Aquila, Italy
| | - Steven Laureys
- Coma Science Group, GIGA, University of Liege, Liege, Belgium
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Hsu CH, Lee CY, Liang WK. An improved method for measuring mismatch negativity using ensemble empirical mode decomposition. J Neurosci Methods 2016; 264:78-85. [DOI: 10.1016/j.jneumeth.2016.02.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 02/14/2016] [Accepted: 02/16/2016] [Indexed: 11/25/2022]
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61
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Weigl M, Mecklinger A, Rosburg T. Transcranial direct current stimulation over the left dorsolateral prefrontal cortex modulates auditory mismatch negativity. Clin Neurophysiol 2016; 127:2263-72. [DOI: 10.1016/j.clinph.2016.01.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/21/2016] [Accepted: 01/22/2016] [Indexed: 01/23/2023]
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Real RG, Veser S, Erlbeck H, Risetti M, Vogel D, Müller F, Kotchoubey B, Mattia D, Kübler A. Information processing in patients in vegetative and minimally conscious states. Clin Neurophysiol 2016; 127:1395-1402. [DOI: 10.1016/j.clinph.2015.07.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 06/03/2015] [Accepted: 07/05/2015] [Indexed: 11/28/2022]
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Wiens S, Szychowska M, Nilsson ME. Visual Task Demands and the Auditory Mismatch Negativity: An Empirical Study and a Meta-Analysis. PLoS One 2016; 11:e0146567. [PMID: 26741815 PMCID: PMC4704804 DOI: 10.1371/journal.pone.0146567] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 12/18/2015] [Indexed: 02/04/2023] Open
Abstract
Because the auditory system is particularly useful in monitoring the environment, previous research has examined whether task-irrelevant, auditory distracters are processed even if subjects focus their attention on visual stimuli. This research suggests that attentionally demanding visual tasks decrease the auditory mismatch negativity (MMN) to simultaneously presented auditory distractors. Because a recent behavioral study found that high visual perceptual load decreased detection sensitivity of simultaneous tones, we used a similar task (n = 28) to determine if high visual perceptual load would reduce the auditory MMN. Results suggested that perceptual load did not decrease the MMN. At face value, these nonsignificant findings may suggest that effects of perceptual load on the MMN are smaller than those of other demanding visual tasks. If so, effect sizes should differ systematically between the present and previous studies. We conducted a selective meta-analysis of published studies in which the MMN was derived from the EEG, the visual task demands were continuous and varied between high and low within the same task, and the task-irrelevant tones were presented in a typical oddball paradigm simultaneously with the visual stimuli. Because the meta-analysis suggested that the present (null) findings did not differ systematically from previous findings, the available evidence was combined. Results of this meta-analysis confirmed that demanding visual tasks reduce the MMN to auditory distracters. However, because the meta-analysis was based on small studies and because of the risk for publication biases, future studies should be preregistered with large samples (n > 150) to provide confirmatory evidence for the results of the present meta-analysis. These future studies should also use control conditions that reduce confounding effects of neural adaptation, and use load manipulations that are defined independently from their effects on the MMN.
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Affiliation(s)
- Stefan Wiens
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
- * E-mail:
| | - Malina Szychowska
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
- Institute of Acoustics, Department of Physics, Adam Mickiewicz University, Poznan, Poland
| | - Mats E. Nilsson
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
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64
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Kang XG, Yang F, Li W, Ma C, Li L, Jiang W. Predictive value of EEG-awakening for behavioral awakening from coma. Ann Intensive Care 2015; 5:52. [PMID: 26690797 PMCID: PMC4686465 DOI: 10.1186/s13613-015-0094-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 11/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A reliable predictor for early recovery of consciousness in comatose patients is of great clinical significance. Here we aimed to investigate the potentially prognostic value of electroencephalogram-reactivity (EEG-R) in combination with sleep spindles, termed EEG-awakening, for behavioral awakening in etiologically diverse comatose patients. METHODS We performed a prospectively observational study on a sample of patients, all of whom were in coma lasting longer than 3 days. Continuous EEG monitoring was performed for at least 24 h to detect the presence of EEG-R and sleep spindles. We then followed patients for 1 month to determine their subsequent level of consciousness, classifying them as either awakened or non-awakened. Finally, Univariate and multivariate analyses were employed to assess the association of predictors with consciousness recovery. RESULTS One hundred and six patients with different etiologies leading to coma were included in the study. Of these, 48 patients (45.3 %) awoke and 58 patients (54.7 %) did not awake in the month after the onset of the study. Of note, 26 patients (24.5 %) had a good neurological outcome, and 31 patients (29.3 %) died. Univariate analysis revealed that the Glasgow Coma Scale (GCS) score, EEG-R, sleep spindles, and EEG-awakening were all associated with one-month awakening. Comparisons of the area under the receiving operator characteristic curve (AUC) showed that EEG-awakening (0.839; 0.757-0.921) was superior to all of the following: EEG-R (0.798; 0.710-0.886), sleep spindles (0.772; 0.680-0.864), and GCS scores (0.720; 0.623-0.818). However, age, gender, etiology, and pupillary light reflex did not correlate significantly with one-month awakening. Further logistic regression analysis showed that only EEG-awakening and GCS scores at study entry were significant independent predictors of awakening and that the prognostic model containing these two variables yielded an outstanding predictive performance with an AUC of 0.903. CONCLUSIONS EEG-awakening incorporates both EEG-R and sleep spindles and is an excellent predictor for early behavioral awakening in comatose patients. The prognostic model combining EEG-awakening and GCS scores shows an outstanding discriminative power for awakening.
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Affiliation(s)
- Xiao-Gang Kang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
| | - Feng Yang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
| | - Wen Li
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
| | - Chen Ma
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
| | - Li Li
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
| | - Wen Jiang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
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65
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Kotchoubey B, Pavlov YG, Kleber B. Music in Research and Rehabilitation of Disorders of Consciousness: Psychological and Neurophysiological Foundations. Front Psychol 2015; 6:1763. [PMID: 26640445 PMCID: PMC4661237 DOI: 10.3389/fpsyg.2015.01763] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/03/2015] [Indexed: 01/18/2023] Open
Abstract
According to a prevailing view, the visual system works by dissecting stimuli into primitives, whereas the auditory system processes simple and complex stimuli with their corresponding features in parallel. This makes musical stimulation particularly suitable for patients with disorders of consciousness (DoC), because the processing pathways related to complex stimulus features can be preserved even when those related to simple features are no longer available. An additional factor speaking in favor of musical stimulation in DoC is the low efficiency of visual stimulation due to prevalent maladies of vision or gaze fixation in DoC patients. Hearing disorders, in contrast, are much less frequent in DoC, which allows us to use auditory stimulation at various levels of complexity. The current paper overviews empirical data concerning the four main domains of brain functioning in DoC patients that musical stimulation can address: perception (e.g., pitch, timbre, and harmony), cognition (e.g., musical syntax and meaning), emotions, and motor functions. Music can approach basic levels of patients' self-consciousness, which may even exist when all higher-level cognitions are lost, whereas music induced emotions and rhythmic stimulation can affect the dopaminergic reward-system and activity in the motor system respectively, thus serving as a starting point for rehabilitation.
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Affiliation(s)
- Boris Kotchoubey
- Institute for Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
| | - Yuri G. Pavlov
- Institute for Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
- Department of Psychology, Ural Federal University, Yekaterinburg, Russia
| | - Boris Kleber
- Institute for Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
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66
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Neurophysiological Indicators of Residual Cognitive Capacity in the Minimally Conscious State. Behav Neurol 2015; 2015:145913. [PMID: 26504351 PMCID: PMC4609423 DOI: 10.1155/2015/145913] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/07/2015] [Accepted: 09/09/2015] [Indexed: 11/18/2022] Open
Abstract
Background. The diagnostic usefulness of electrophysiological methods in assessing disorders of consciousness (DoC) remains to be established on an individual patient level, and there is need to determine what constitutes robust experimental paradigm to elicit electrophysiological indices of covert cognitive capacity. Objectives. Two tasks encompassing active and passive conditions were explored in an event-related potentials (ERP) study. The task robustness was studied in healthy controls, and their utility to detect covert signs of command-following on an individual patient level was investigated in patients in a minimally conscious state (MCS). Methods. Twenty healthy controls and 20 MCS patients participated. The active tasks included (1) listening for a change of pitch in the subject's own name (SON) and (2) counting SON, both contrasted to passive conditions. Midline ERPs are reported. Results. A larger P3 response was detected in the counting task compared to active listening to pitch change in the healthy controls. On an individual level, the counting task revealed a higher rate of responders among both healthy subjects and MCS patients. Conclusion. ERP paradigms involving actively counting SON represent a robust paradigm in probing for volitional cognition in minimally conscious patients and add important diagnostic information in some patients.
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67
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Hierarchical Organization of Frontotemporal Networks for the Prediction of Stimuli across Multiple Dimensions. J Neurosci 2015; 35:9255-64. [PMID: 26109651 DOI: 10.1523/jneurosci.5095-14.2015] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Brain function can be conceived as a hierarchy of generative models that optimizes predictions of sensory inputs and minimizes "surprise." Each level of the hierarchy makes predictions of neural events at a lower level in the hierarchy, which returns a prediction error when these expectations are violated. We tested the generalization of this hypothesis to multiple sequential deviations, and we identified the most likely organization of the network that accommodates deviations in temporal structure of stimuli. Magnetoencephalography of healthy human participants during an auditory paradigm identified prediction error responses in bilateral primary auditory cortex, superior temporal gyrus, and lateral prefrontal cortex for deviation by frequency, intensity, location, duration, and silent gap. We examined the connectivity between cortical sources using a set of 21 generative models that embedded alternate hypotheses of frontotemporal network dynamics. Bayesian model selection provided evidence for two new features of functional network organization. First, an expectancy signal provided input to the prefrontal cortex bilaterally, related to the temporal structure of stimuli. Second, there are functionally significant lateral connections between superior temporal and/or prefrontal cortex. The results support a predictive coding hypothesis but go beyond previous work in demonstrating the generalization to multiple concurrent stimulus dimensions and the evidence for a temporal expectancy input at the higher level of the frontotemporal hierarchy. We propose that this framework for studying the brain's response to unexpected events is not limited to simple sensory tasks but may also apply to the neurocognitive mechanisms of higher cognitive functions and their disorders.
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68
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Abstract
To observe changes in mismatch negativity (MMN) and P300 in a patient transitioning from a vegetative state (VS) to a minimally conscious state (MCS). One patient with intracerebral hemorrhage and an 8-month disease course was evaluated as being in the VS using the Coma Recovery Scale-Revised. Two weeks after the patient was admitted to the hospital, another evaluation was performed, and the patient was determined to be in an MCS. Using the Oddball paradigm, pure tone and name stimuli were presented to the patient to study event-related potentials (ERPs). A 15-week clinical follow-up was carried out, and four ERP examinations were performed at 2 days and 2, 6, and 15 weeks after admission. One healthy individual was assessed as a control participant. MMN and P300 were elicited in all four ERP examinations. MMN and P300 may occur earlier than believed in patients in persistent VS and MCS; their predictive values for prognosis need to be further confirmed by follow-up studies on a large clinical sample.
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69
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Ehlers MR, López Herrero C, Kastrup A, Hildebrandt H. The P300 in middle cerebral artery strokes or hemorrhages: Outcome predictions and source localization. Clin Neurophysiol 2015; 126:1532-8. [DOI: 10.1016/j.clinph.2014.10.151] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/23/2014] [Accepted: 10/26/2014] [Indexed: 10/24/2022]
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70
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Damaso KAM, Michie PT, Todd J. Paying attention to MMN in schizophrenia. Brain Res 2015; 1626:267-79. [PMID: 26163366 DOI: 10.1016/j.brainres.2015.06.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 05/29/2015] [Accepted: 06/23/2015] [Indexed: 10/23/2022]
Abstract
The aim of this review is to explore the phenomenon of reduced mismatch negativity (MMN) in persons with schizophrenia and the possible relationship it has with attention impairments. In doing so we discuss (i) the prediction error account of MMN, (ii) reduced MMN as a faulty predictive processing system in persons with schizophrenia, (iii) the role of these systems in relevance filtering and attentional resource protection, (iv) attentional impairments in persons with schizophrenia, and (v) research that has explored MMN and attention in schizophrenia groups. Our review of the literature suggests that no study has appropriately examined the functional impact of smaller MMN in schizophrenia on the performance of a concurrent attention task. We conclude that future research should explore this notion further in the hope that it might embed MMN findings within outcomes of functional significance to individuals with the illness and those providing treatment. This article is part of a Special Issue entitled SI: Prediction and Attention.
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Affiliation(s)
- Karlye A M Damaso
- School of Psychology, University of Newcastle, Callaghan, NSW, Australia; Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, Callaghan, NSW, Australia
| | - Patricia T Michie
- School of Psychology, University of Newcastle, Callaghan, NSW, Australia; Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, Callaghan, NSW, Australia; Schizophrenia Research Institute, Sydney, NSW, Australia
| | - Juanita Todd
- School of Psychology, University of Newcastle, Callaghan, NSW, Australia; Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, Callaghan, NSW, Australia; Schizophrenia Research Institute, Sydney, NSW, Australia.
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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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72
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Parvar H, Sculthorpe-Petley L, Satel J, Boshra R, D'Arcy RCN, Trappenberg TP. Detection of event-related potentials in individual subjects using support vector machines. Brain Inform 2015; 2:1-12. [PMID: 27747499 PMCID: PMC4883156 DOI: 10.1007/s40708-014-0006-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 11/08/2014] [Indexed: 11/23/2022] Open
Abstract
Event-related potentials (ERPs) are tiny electrical brain responses in the human electroencephalogram that are typically not detectable until they are isolated by a process of signal averaging. Owing to the extremely smallsize of ERP components (ranging from less than 1 μV to tens of μV), compared to background brain rhythms, statistical analyses of ERPs are predominantly carried out in groups of subjects. This limitation is a barrier to the translation of ERP-based neuroscience to applications such as medical diagnostics. We show here that support vector machines (SVMs) are a useful method to detect ERP components in individual subjects with a small set of electrodes and a small number of trials for a mismatch negativity (MMN) ERP component. Such a reduced experiment setup is important for clinical applications. One hundred healthy individuals were presented with an auditory pattern containing pattern-violating deviants to evoke the MMN. Two-class SVMs were then trained to classify averaged ERP waveforms in response to the standard tone (tones that match the pattern) and deviant tone stimuli (tones that violate the pattern). The influence of kernel type, number of epochs, electrode selection, and temporal window size in the averaged waveform were explored. When using all electrodes, averages of all available epochs, and a temporal window from 0 to 900-ms post-stimulus, a linear SVM achieved 94.5 % accuracy. Further analyses using SVMs trained with narrower, sliding temporal windows confirmed the sensitivity of the SVM to data in the latency range associated with the MMN.
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Affiliation(s)
- Hossein Parvar
- Faculty of Computer Science, Dalhousie University, 6050 University Avenue, P.O. Box 1500, Halifax, NS, B3H 4R2, Canada
| | | | - Jason Satel
- School of Psychology, Faculty of Science, University of Nottingham Malaysia Campus, Semenyih, Selangor, Malaysia
| | - Rober Boshra
- Faculty of Computer Science, Dalhousie University, 6050 University Avenue, P.O. Box 1500, Halifax, NS, B3H 4R2, Canada
| | - Ryan C N D'Arcy
- Applied Sciences, Simon Fraser University, Surrey, BC, Canada
| | - Thomas P Trappenberg
- Faculty of Computer Science, Dalhousie University, 6050 University Avenue, P.O. Box 1500, Halifax, NS, B3H 4R2, Canada.
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73
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Rodriguez RA, Shamy M, Dowlatshahi D, Nathan HJ. Can Mismatch Negativity Reduce Uncertainty in the Prediction of Awakening From Coma During Extracorporeal Membrane Oxygenation? J Cardiothorac Vasc Anesth 2015; 29:1627-31. [PMID: 25604601 DOI: 10.1053/j.jvca.2014.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Dar Dowlatshahi
- Division of Neurology; Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Howard J Nathan
- Department of Anaesthesia, The Ottawa Hospital and University of Ottawa, Ottawa, ON, Canada
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74
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Visual processing during recovery from vegetative state to consciousness: Comparing behavioral indices to brain responses. Neurophysiol Clin 2014; 44:457-69. [DOI: 10.1016/j.neucli.2014.08.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 08/19/2014] [Accepted: 08/23/2014] [Indexed: 11/19/2022] Open
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75
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Erlbeck H, Kübler A, Kotchoubey B, Veser S. Task instructions modulate the attentional mode affecting the auditory MMN and the semantic N400. Front Hum Neurosci 2014; 8:654. [PMID: 25221494 PMCID: PMC4145469 DOI: 10.3389/fnhum.2014.00654] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 08/05/2014] [Indexed: 12/13/2022] Open
Abstract
Event-related potentials (ERPs) have been proven to be a useful tool to complement clinical assessment and to detect residual cognitive functions in patients with disorders of consciousness. These ERPs are often recorded using passive or unspecific instructions. Patient data obtained this way are then compared to data from healthy participants, which are usually recorded using active instructions. The present study investigates the effect of attentive modulations and particularly the effect of active vs. passive instruction on the ERP components mismatch negativity (MMN) and N400. A sample of 18 healthy participants listened to three auditory paradigms: an oddball, a word priming, and a sentence paradigm. Each paradigm was presented three times with different instructions: ignoring auditory stimuli, passive listening, and focused attention on the auditory stimuli. After each task, the participants indicated their subjective effort. The N400 decreased from the focused task to the passive task, and was extinct in the ignore task. The MMN exhibited higher amplitudes in the focused and passive task compared to the ignore task. The data indicate an effect of attention on the supratemporal component of the MMN. Subjective effort was equally high in the passive and focused tasks but reduced in the ignore task. We conclude that passive listening during EEG recording is stressful and attenuates ERPs, which renders the interpretation of the results obtained in such conditions difficult.
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Affiliation(s)
- Helena Erlbeck
- Department of Psychology I, University of Würzburg Würzburg, Germany
| | - Andrea Kübler
- Department of Psychology I, University of Würzburg Würzburg, Germany
| | - Boris Kotchoubey
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen Tübingen, Germany
| | - Sandra Veser
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen Tübingen, Germany
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76
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Gosseries O, Zasler ND, Laureys S. Recent advances in disorders of consciousness: Focus on the diagnosis. Brain Inj 2014; 28:1141-50. [PMID: 25099018 DOI: 10.3109/02699052.2014.920522] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Olivia Gosseries
- Coma Science Group, Cyclotron Research Centre and Neurology Department, University and University Hospital of Liege , Liege , Belgium
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77
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MacLean SE, Ward LM. Temporo-frontal phase synchronization supports hierarchical network for mismatch negativity. Clin Neurophysiol 2014; 125:1604-17. [DOI: 10.1016/j.clinph.2013.12.109] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Revised: 12/19/2013] [Accepted: 12/21/2013] [Indexed: 10/25/2022]
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78
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Automated Auditory Mismatch Negativity Paradigm Improves Coma Prognostic Accuracy After Cardiac Arrest and Therapeutic Hypothermia. J Clin Neurophysiol 2014; 31:356-61. [DOI: 10.1097/wnp.0000000000000082] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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79
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Les mécanismes de la conscience. MEDECINE INTENSIVE REANIMATION 2014. [DOI: 10.1007/s13546-014-0898-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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80
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Brogan ME, Provencio JJ. Spectrum of catastrophic brain injury: coma and related disorders of consciousness. J Crit Care 2014; 29:679-82. [PMID: 24930368 DOI: 10.1016/j.jcrc.2014.04.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 04/20/2014] [Indexed: 10/25/2022]
Affiliation(s)
- Michael E Brogan
- Cerebrovascular Center, Neurological Institute, Cleveland Clinic, Cleveland, OH
| | - J Javier Provencio
- Cerebrovascular Center, Neurological Institute, Cleveland Clinic, Cleveland, OH.
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81
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de Biase S, Gigli GL, Lorenzut S, Bianconi C, Sfreddo P, Rossato G, Basaldella F, Fuccaro M, Corica A, Tonon D, Barbone F, Valente M. The importance of polysomnography in the evaluation of prolonged disorders of consciousness: sleep recordings more adequately correlate than stimulus-related evoked potentials with patients’ clinical status. Sleep Med 2014; 15:393-400. [DOI: 10.1016/j.sleep.2013.09.026] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 09/04/2013] [Accepted: 09/05/2013] [Indexed: 10/25/2022]
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82
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Repeated Measurements of the Auditory Oddball Paradigm Is Related to Recovery From the Vegetative State. J Clin Neurophysiol 2014; 31:65-80. [DOI: 10.1097/01.wnp.0000436894.17749.0c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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83
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Rodriguez RA, Bussière M, Froeschl M, Nathan HJ. Auditory-evoked potentials during coma: Do they improve our prediction of awakening in comatose patients? J Crit Care 2014; 29:93-100. [DOI: 10.1016/j.jcrc.2013.08.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 08/15/2013] [Accepted: 08/25/2013] [Indexed: 10/26/2022]
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84
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Mikołajewska E, Mikołajewski D. Non-invasive EEG-based brain-computer interfaces in patients with disorders of consciousness. Mil Med Res 2014; 1:14. [PMID: 26056608 PMCID: PMC4459059 DOI: 10.1186/2054-9369-1-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 06/12/2014] [Indexed: 11/10/2022] Open
Abstract
Disorders of consciousness (DoCs) are chronic conditions resulting usually from severe neurological deficits. The limitations of the existing diagnosis systems and methodologies cause a need for additional tools for relevant patients with DoCs assessment, including brain-computer interfaces (BCIs). Recent progress in BCIs' clinical applications may offer important breakthroughs in the diagnosis and therapy of patients with DoCs. Thus the clinical significance of BCI applications in the diagnosis of patients with DoCs is hard to overestimate. One of them may be brain-computer interfaces. The aim of this study is to evaluate possibility of non-invasive EEG-based brain-computer interfaces in diagnosis of patients with DOCs in post-acute and long-term care institutions.
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Affiliation(s)
- Emilia Mikołajewska
- Rehabilitation Department, Military Clinical Hospital No. 10 and Polyclinic, Powstańców Warszawy 5, Bydgoszcz, 85-681 Poland ; Disorders of Consciousness Research and Neurorehabilitation Unit, Neurocognitive Laboratory, Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Toruń, Poland
| | - Dariusz Mikołajewski
- Institute of Mechanics and Applied Computer Science, Kazimierz Wielki University, Bydgoszcz, Poland ; Department of Applied Informatics, Department of Physics, Astronomy and Applied Informatics, Nicolaus Copernicus University, Toruń, Poland ; Disorders of Consciousness Research and Neurorehabilitation Unit, Neurocognitive Laboratory, Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Toruń, Poland
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85
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Morlet D, Fischer C. MMN and novelty P3 in coma and other altered states of consciousness: a review. Brain Topogr 2013; 27:467-79. [PMID: 24281786 DOI: 10.1007/s10548-013-0335-5] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 11/13/2013] [Indexed: 10/26/2022]
Abstract
In recent decades, there has been a growing interest in the assessment of patients in altered states of consciousness. There is a need for accurate and early prediction of awakening and recovery from coma. Neurophysiological assessment of coma was once restricted to brainstem auditory and primary cortex somatosensory evoked potentials elicited in the 30 ms range, which have both shown good predictive value for poor coma outcome only. In this paper, we review how passive auditory oddball paradigms including deviant and novel sounds have proved their efficiency in assessing brain function at a higher level, without requiring the patient's active involvement, thus providing an enhanced tool for the prediction of coma outcome. The presence of an MMN in response to deviant stimuli highlights preserved automatic sensory memory processes. Recorded during coma, MMN has shown high specificity as a predictor of recovery of consciousness. The presence of a novelty P3 in response to the subject's own first name presented as a novel (rare) stimulus has shown a good correlation with coma awakening. There is now a growing interest in the search for markers of consciousness, if there are any, in unresponsive patients (chronic vegetative or minimally conscious states). We discuss the different ERP patterns observed in these patients. The presence of novelty P3, including parietal components and possibly followed by a late parietal positivity, raises the possibility that some awareness processes are at work in these unresponsive patients.
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Affiliation(s)
- Dominique Morlet
- Lyon Neuroscience Research Center (CRNL), Brain Dynamics and Cognition Team (Dycog), INSERM U1028, CNRS UMR5292, Lyon, 69000, France,
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86
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Abstract
Hierarchical predictive coding suggests that attention in humans emerges from increased precision in probabilistic inference, whereas expectation biases attention in favor of contextually anticipated stimuli. We test these notions within auditory perception by independently manipulating top-down expectation and attentional precision alongside bottom-up stimulus predictability. Our findings support an integrative interpretation of commonly observed electrophysiological signatures of neurodynamics, namely mismatch negativity (MMN), P300, and contingent negative variation (CNV), as manifestations along successive levels of predictive complexity. Early first-level processing indexed by the MMN was sensitive to stimulus predictability: here, attentional precision enhanced early responses, but explicit top-down expectation diminished it. This pattern was in contrast to later, second-level processing indexed by the P300: although sensitive to the degree of predictability, responses at this level were contingent on attentional engagement and in fact sharpened by top-down expectation. At the highest level, the drift of the CNV was a fine-grained marker of top-down expectation itself. Source reconstruction of high-density EEG, supported by intracranial recordings, implicated temporal and frontal regions differentially active at early and late levels. The cortical generators of the CNV suggested that it might be involved in facilitating the consolidation of context-salient stimuli into conscious perception. These results provide convergent empirical support to promising recent accounts of attention and expectation in predictive coding.
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87
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Harrison AH, Connolly JF. Finding a way in: A review and practical evaluation of fMRI and EEG for detection and assessment in disorders of consciousness. Neurosci Biobehav Rev 2013; 37:1403-19. [PMID: 23680699 DOI: 10.1016/j.neubiorev.2013.05.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 04/26/2013] [Accepted: 05/06/2013] [Indexed: 01/28/2023]
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88
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Paavilainen P. The mismatch-negativity (MMN) component of the auditory event-related potential to violations of abstract regularities: A review. Int J Psychophysiol 2013; 88:109-23. [PMID: 23542165 DOI: 10.1016/j.ijpsycho.2013.03.015] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 03/19/2013] [Accepted: 03/21/2013] [Indexed: 11/26/2022]
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89
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Steppacher I, Eickhoff S, Jordanov T, Kaps M, Witzke W, Kissler J. N400 predicts recovery from disorders of consciousness. Ann Neurol 2013; 73:594-602. [PMID: 23443907 DOI: 10.1002/ana.23835] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 12/05/2012] [Accepted: 12/07/2012] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Patients with the unresponsive wakefulness syndrome (UWS; formerly vegetative state) or in a minimally conscious state (MCS) open their eyes spontaneously but show no (UWS) or only marginal (MCS) signs of awareness. Because these states can become permanent, residual information processing capacities need to be determined, and reliable outcome predictors need to be found. We assessed higher-order cortical information processing in UWS or MCS in a large group of patients using electroencephalographic event-related potentials (ERPs) and determined their long-term prognostic value for recovery. METHODS Cognitive ERPs elicited by sound (P300) and speech (N400) were used to assess information processing in 92 behaviorally unresponsive patients diagnosed as in the state of either UWS (n=53) or MCS (n=39). ERPs were assessed with a clinical standard evaluation method and a computerized method, the t-continuous wavelet transform. The patients' clinical outcome was followed up between 2 and 14 years after discharge from the rehabilitation center. RESULTS Within the first year of the disease, many patients showed an intact P300 and several also an N400, indicating considerable residual information processing. At clinical follow-up, about 25% of the patients recovered and regained communicative capabilities. A highly significant relationship between N400, but not P300, presence and subsequent recovery was found. INTERPRETATION Results specify cognitive capabilities in disorders of consciousness, and determine their prognostic value. Specifically the N400 ERP is suggested as an important tool to assess information-processing capacities that can predict the likelihood of recovery of patients in UWS or MCS.
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Affiliation(s)
- Inga Steppacher
- Department of Psychology, University of Konstanz, Konstanz, Germany.
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90
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Gantner IS, Bodart O, Laureys S, Demertzi A. Our rapidly changing understanding of acute and chronic disorders of consciousness: challenges for neurologists. FUTURE NEUROLOGY 2013. [DOI: 10.2217/fnl.12.77] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A number of recent studies suggest that some ‘vegetative state’ patients have been misdiagnosed, judging by their ability to follow commands and in some cases even communicate through brain activity. Such studies highlight the difficulty in forming a diagnosis based only on behavioral assessments. We think that neuroimaging and electrophysiology methods will be used more frequently in clinical settings, integrated with existing behavioral assessments. Such efforts are expected to lead to a more accurate understanding of individual patients’ cognitive abilities or even provide prognostic indicators. In terms of treatment planning (i.e., pain management and end-of-life decision-making), patients with disorders of consciousness are now offered the possibility of expressing their preferences by means of brain–computer interfaces. What remains to be clarified is the degree to which such indirect responses can be considered reliable and of legal representation.
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Affiliation(s)
- Ithabi S Gantner
- Coma Science Group, Cyclotron Research Center & CHU Neurology Department, University of Liège, Allée du 6 Août no 8, Sart Tilman B30, 4000 Liège, Belgium
| | - Olivier Bodart
- Coma Science Group, Cyclotron Research Center & CHU Neurology Department, University of Liège, Allée du 6 Août no 8, Sart Tilman B30, 4000 Liège, Belgium
| | - Steven Laureys
- Coma Science Group, Cyclotron Research Center & CHU Neurology Department, University of Liège, Allée du 6 Août no 8, Sart Tilman B30, 4000 Liège, Belgium
| | - Athena Demertzi
- Coma Science Group, Cyclotron Research Center & CHU Neurology Department, University of Liège, Allée du 6 Août no 8, Sart Tilman B30, 4000 Liège, Belgium
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91
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Tzovara A, Rossetti AO, Spierer L, Grivel J, Murray MM, Oddo M, De Lucia M. Progression of auditory discrimination based on neural decoding predicts awakening from coma. ACTA ACUST UNITED AC 2012; 136:81-9. [PMID: 23148350 DOI: 10.1093/brain/aws264] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Auditory evoked potentials are informative of intact cortical functions of comatose patients. The integrity of auditory functions evaluated using mismatch negativity paradigms has been associated with their chances of survival. However, because auditory discrimination is assessed at various delays after coma onset, it is still unclear whether this impairment depends on the time of the recording. We hypothesized that impairment in auditory discrimination capabilities is indicative of coma progression, rather than of the comatose state itself and that rudimentary auditory discrimination remains intact during acute stages of coma. We studied 30 post-anoxic comatose patients resuscitated from cardiac arrest and five healthy, age-matched controls. Using a mismatch negativity paradigm, we performed two electroencephalography recordings with a standard 19-channel clinical montage: the first within 24 h after coma onset and under mild therapeutic hypothermia, and the second after 1 day and under normothermic conditions. We analysed electroencephalography responses based on a multivariate decoding algorithm that automatically quantifies neural discrimination at the single patient level. Results showed high average decoding accuracy in discriminating sounds both for control subjects and comatose patients. Importantly, accurate decoding was largely independent of patients' chance of survival. However, the progression of auditory discrimination between the first and second recordings was informative of a patient's chance of survival. A deterioration of auditory discrimination was observed in all non-survivors (equivalent to 100% positive predictive value for survivors). We show, for the first time, evidence of intact auditory processing even in comatose patients who do not survive and that progression of sound discrimination over time is informative of a patient's chance of survival. Tracking auditory discrimination in comatose patients could provide new insight to the chance of awakening in a quantitative and automatic fashion during early stages of coma.
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Affiliation(s)
- Athina Tzovara
- Electroencephalography Brain Mapping Core, Centre for Biomedical Imaging, Lausanne University Hospital and University of Lausanne, CH-1011 Lausanne, Switzerland
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92
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Morgenegg R, Oddo M. Improving prognostic prediction of coma after cardiac arrest: New data, new clinical approach. TRENDS IN ANAESTHESIA AND CRITICAL CARE 2012. [DOI: 10.1016/j.tacc.2012.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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93
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Wieser M, Buetler L, Vallery H, Schaller J, Mayr A, Kofler M, Saltuari L, Zutter D, Riener R. Quantification of clinical scores through physiological recordings in low-responsive patients: a feasibility study. J Neuroeng Rehabil 2012; 9:30. [PMID: 22647145 PMCID: PMC3443429 DOI: 10.1186/1743-0003-9-30] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 04/20/2012] [Indexed: 11/10/2022] Open
Abstract
Clinical scores represent the gold standard in characterizing the clinical condition of patients in vegetative or minimally conscious state. However, they suffer from problems of sensitivity, specificity, subjectivity and inter-rater reliability.In this feasibility study, objective measures including physiological and neurophysiological signals are used to quantify the clinical state of 13 low-responsive patients. A linear regression method was applied in nine patients to obtain fixed regression coefficients for the description of the clinical state. The statistical model was extended and evaluated with four patients of another hospital. A linear mixed models approach was introduced to handle the challenges of data sets obtained from different locations.Using linear backward regression 12 variables were sufficient to explain 74.4% of the variability in the change of the clinical scores. Variables based on event-related potentials and electrocardiogram account for most of the variability.These preliminary results are promising considering that this is the first attempt to describe the clinical state of low-responsive patients in such a global and quantitative way. This new model could complement the clinical scores based on objective measurements in order to increase diagnostic reliability. Nevertheless, more patients are necessary to prove the conclusions of a statistical model with 12 variables.
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Affiliation(s)
- Martin Wieser
- Sensory-Motor Systems Lab, Institute of Robotics and Intelligent Systems, Department of Health Science and Technologies, ETH Zurich, Tannenstrasse 1, Zurich, 8092, Switzerland
- Medical Faculty, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Lilith Buetler
- Sensory-Motor Systems Lab, Institute of Robotics and Intelligent Systems, Department of Health Science and Technologies, ETH Zurich, Tannenstrasse 1, Zurich, 8092, Switzerland
- HELIOS Clinic Zihlschlacht, Center for Neurological Rehabilitation, Zihlschlacht, Switzerland
| | - Heike Vallery
- Sensory-Motor Systems Lab, Institute of Robotics and Intelligent Systems, Department of Health Science and Technologies, ETH Zurich, Tannenstrasse 1, Zurich, 8092, Switzerland
- Medical Faculty, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Biomedical Engineering, Khalifa University, Abu Dhabi, UAE
| | | | - Andreas Mayr
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Leopold Saltuari
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
- Research Unit for Neurorehabilitation South Tyrol, Bolzano, Italy
| | - Daniel Zutter
- HELIOS Clinic Zihlschlacht, Center for Neurological Rehabilitation, Zihlschlacht, Switzerland
| | - Robert Riener
- Sensory-Motor Systems Lab, Institute of Robotics and Intelligent Systems, Department of Health Science and Technologies, ETH Zurich, Tannenstrasse 1, Zurich, 8092, Switzerland
- Medical Faculty, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
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94
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Zanatta P, Messerotti Benvenuti S, Baldanzi F, Bendini M, Saccavini M, Tamari W, Palomba D, Bosco E. Pain-related somatosensory evoked potentials and functional brain magnetic resonance in the evaluation of neurologic recovery after cardiac arrest: a case study of three patients. Scand J Trauma Resusc Emerg Med 2012; 20:22. [PMID: 22463985 PMCID: PMC3355043 DOI: 10.1186/1757-7241-20-22] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 03/31/2012] [Indexed: 01/17/2023] Open
Abstract
This case series investigates whether painful electrical stimulation increases the early prognostic value of both somatosensory-evoked potentials and functional magnetic resonance imaging in comatose patients after cardiac arrest. Three single cases with hypoxic-ischemic encephalopathy were considered. A neurophysiological evaluation with an electroencephalogram and somatosensory-evoked potentials during increased electrical stimulation in both median nerves was performed within five days of cardiac arrest. Each patient also underwent a functional magnetic resonance imaging evaluation with the same neurophysiological protocol one month after cardiac arrest. One patient, who completely recovered, showed a middle latency component at a high intensity of stimulation and the activation of all brain areas involved in cerebral pain processing. One patient in a minimally conscious state only showed the cortical somatosensory response and the activation of the primary somatosensory cortex. The last patient, who was in a vegetative state, did not show primary somatosensory evoked potentials; only the activation of subcortical brain areas occurred. These preliminary findings suggest that the pain-related somatosensory evoked potentials performed to increase the prognosis of comatose patients after cardiac arrest are associated with regional brain activity showed by functional magnetic resonance imaging during median nerves electrical stimulation. More importantly, this cases report also suggests that somatosensory evoked potentials and functional magnetic resonance imaging during painful electrical stimulation may be sensitive and complementary methods to predict the neurological outcome in the acute phase of coma. Thus, pain-related somatosensory-evoked potentials may be a reliable and a cost-effective tool for planning the early diagnostic evaluation of comatose patients.
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Affiliation(s)
- Paolo Zanatta
- Department of Anesthesia and Intensive Care, Neurophysiology, Treviso Regional Hospital, Piazzale Ospedale 1, Treviso, Italy.
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95
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Chennu S, Bekinschtein TA. Arousal modulates auditory attention and awareness: insights from sleep, sedation, and disorders of consciousness. Front Psychol 2012; 3:65. [PMID: 22403565 PMCID: PMC3293189 DOI: 10.3389/fpsyg.2012.00065] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 02/18/2012] [Indexed: 11/13/2022] Open
Abstract
The interplay between attention and consciousness is frequently tested in altered states of consciousness, including transitions between stages of sleep and sedation, and in pathological disorders of consciousness (DoC; the vegetative and minimally conscious states; VS and MCS). One of the most widely used tasks to assess cognitive processing in this context is the auditory oddball paradigm, where an infrequent change in a sequence of sounds elicits, in awake subjects, a characteristic EEG event-related potential called the mismatch negativity, followed by the classic P300 wave. The latter is further separable into the slightly earlier, anterior P3a and the later, posterior P3b, thought to be linked to task-irrelevant "bottom-up" and task-oriented "top-down" attention, respectively. We discuss here the putative dissociations between attention and awareness in DoC, sedation and sleep, bearing in mind the recently emerging evidence from healthy volunteers and patients. These findings highlight the neurophysiological and cognitive parallels (and differences) across these three distinct variations in levels of consciousness, and inform the theoretical framework for interpreting the role of attention therein.
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Affiliation(s)
- Srivas Chennu
- Department of Clinical Neurosciences, University of CambridgeCambridge, UK
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96
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Hoonhorst I, Deltenre P, Markessis E, Collet G, Pablos Martin X, Colin C. Evidence for a dual versus single origin of the MMNs evoked by cued versus cueless deviants. Clin Neurophysiol 2012; 123:1561-7. [PMID: 22321294 DOI: 10.1016/j.clinph.2011.12.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 10/17/2011] [Accepted: 12/12/2011] [Indexed: 11/18/2022]
Abstract
OBJECTIVE This study was designed to separately test the effect of the cued/cueless nature of deviant stimuli and that of temporal distance between sound and deviance onsets on the mismatch negativity (MMN) as well as to look for discrepancies between behavioural discrimination performances and MMN amplitude when deviants are cueless. METHODS Ten healthy adults passively listened to stimuli that were contrasted by the presence or absence of a frequency sweep starting early or late within the sound. Discrimination performances were collected after the electrophysiological sessions. RESULTS MMNs were much larger for cued than for cueless deviants. The temporal distance between sound and deviance onsets affected MMNs evoked by both cued and cueless deviants, even to the point of abolishing the MMN when cueless deviance occurred late in the stimulus. Behavioural data were at ceiling levels for all conditions, contrasting with the absence of MMN evoked by cueless deviants with late onset. CONCLUSIONS Two mechanisms contribute to the MMN evoked by cued deviants: the memory comparison process and the adaptation/fresh-afferent one. Within the temporal window of integration, the delay at which each component disappears is different. SIGNIFICANCE Comparing waveforms evoked by cued versus cueless deviants provides a fairly simple way of isolating the MMN memory-based component.
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Affiliation(s)
- I Hoonhorst
- Unité de Recherches en Neurosciences Cognitives, Université Libre de Bruxelles, Brussels, Belgium
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97
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Usefulness of standard EEG in predicting the outcome of patients with disorders of consciousness after anoxic coma. J Clin Neurophysiol 2012; 28:489-92. [PMID: 21946372 DOI: 10.1097/wnp.0b013e318231c8c8] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Although standard EEG is performed routinely in patients with disorders of consciousness after coma, its prognostic value is still debated. The aim of the present study was to evaluate the role of standard EEG in predicting the recovery of cognitive functioning in patients affected by severe disturbances of consciousness after coma caused by cerebral anoxia. A standard EEG was recorded at admission to our Rehabilitation Department in 15 patients experiencing impaired consciousness because of cerebral anoxia. We quantified EEG abnormalities using the Synek scale (1988). Cognitive functioning was measured with the levels of cognitive functioning scale at the time of admission and after 3 months of recovery. EEG scores were significantly correlated with both levels of cognitive functioning scores at admission (P = 0.004) and change in levels of cognitive functioning score after 3 months (P < 0.001). The first correlation confirms the relationship between EEG and cognitive functioning, while the second correlation indicates the prognostic value of EEG in cognitive outcome. In conclusion, standard EEG is a simple and readily available tool with significant prognostic value in patients with disorders of consciousness after coma caused by cerebral anoxia.
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98
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King JR, Bekinschtein T, Dehaene S. Comment on "Preserved feedforward but impaired top-down processes in the vegetative state". Science 2012. [PMID: 22144601 DOI: 10.1126/science.1210012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Boly et al. (Reports, 13 May 2011, p. 858) investigated cortical connectivity patterns in patients suffering from a disorder of consciousness, using electroencephalography in an auditory oddball paradigm. We point to several inconsistencies in their data, including a failure to replicate the classical mismatch negativity. Data quality, source reconstruction, and statistics would need to be improved to support their conclusions.
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Affiliation(s)
- Jean-Rémi King
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Division of Life Sciences, Institute of Bioimaging, Neurospin, Gif sur Yvette, 91191 France.
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99
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King JR, Bekinschtein T, Dehaene S. Comment on "Preserved feedforward but impaired top-down processes in the vegetative state". Science 2012; 334:1203; author reply 1203. [PMID: 22144601 DOI: 10.1126/science.1210240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Boly et al. (Reports, 13 May 2011, p. 858) investigated cortical connectivity patterns in patients suffering from a disorder of consciousness, using electroencephalography in an auditory oddball paradigm. We point to several inconsistencies in their data, including a failure to replicate the classical mismatch negativity. Data quality, source reconstruction, and statistics would need to be improved to support their conclusions.
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Affiliation(s)
- Jean-Rémi King
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Division of Life Sciences, Institute of Bioimaging, Neurospin, Gif sur Yvette, 91191 France.
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100
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Rosanova M, Gosseries O, Casarotto S, Boly M, Casali AG, Bruno MA, Mariotti M, Boveroux P, Tononi G, Laureys S, Massimini M. Recovery of cortical effective connectivity and recovery of consciousness in vegetative patients. ACTA ACUST UNITED AC 2012; 135:1308-20. [PMID: 22226806 PMCID: PMC3326248 DOI: 10.1093/brain/awr340] [Citation(s) in RCA: 276] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Patients surviving severe brain injury may regain consciousness without recovering their ability to understand, move and communicate. Recently, electrophysiological and neuroimaging approaches, employing simple sensory stimulations or verbal commands, have proven useful in detecting higher order processing and, in some cases, in establishing some degree of communication in brain-injured subjects with severe impairment of motor function. To complement these approaches, it would be useful to develop methods to detect recovery of consciousness in ways that do not depend on the integrity of sensory pathways or on the subject's ability to comprehend or carry out instructions. As suggested by theoretical and experimental work, a key requirement for consciousness is that multiple, specialized cortical areas can engage in rapid causal interactions (effective connectivity). Here, we employ transcranial magnetic stimulation together with high-density electroencephalography to evaluate effective connectivity at the bedside of severely brain injured, non-communicating subjects. In patients in a vegetative state, who were open-eyed, behaviourally awake but unresponsive, transcranial magnetic stimulation triggered a simple, local response indicating a breakdown of effective connectivity, similar to the one previously observed in unconscious sleeping or anaesthetized subjects. In contrast, in minimally conscious patients, who showed fluctuating signs of non-reflexive behaviour, transcranial magnetic stimulation invariably triggered complex activations that sequentially involved distant cortical areas ipsi- and contralateral to the site of stimulation, similar to activations we recorded in locked-in, conscious patients. Longitudinal measurements performed in patients who gradually recovered consciousness revealed that this clear-cut change in effective connectivity could occur at an early stage, before reliable communication was established with the subject and before the spontaneous electroencephalogram showed significant modifications. Measurements of effective connectivity by means of transcranial magnetic stimulation combined with electroencephalography can be performed at the bedside while by-passing subcortical afferent and efferent pathways, and without requiring active participation of subjects or language comprehension; hence, they offer an effective way to detect and track recovery of consciousness in brain-injured patients who are unable to exchange information with the external environment.
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Affiliation(s)
- Mario Rosanova
- Department of Clinical Sciences Luigi Sacco, University of Milan, 20157 Milan, Italy
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