References of "Gosseries, Olivia"
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See detailDisorders of consciousness: new advances in neuroimaging techniques
Soddu, Andrea ULg; Bruno, Marie-Aurélie ULg; VANHAUDENHUYSE, Audrey ULg et al

in Zanotti, Bruno (Ed.) Vegetative State (in press)

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See detailRepeated Behavioral Assessments in Patients with Disorders of Consciousness
Wannez, Sarah ULg; Annen, Jitka ULg; Aubinet, Charlène ULg et al

Conference (2016, March 04)

The Coma Recovery Scale Revised (CRS-R) is considered as the most sensitive scale to assess patients with disorders of consciousness (DOC). Guidelines recommend repeated assessments because patients might ... [more ▼]

The Coma Recovery Scale Revised (CRS-R) is considered as the most sensitive scale to assess patients with disorders of consciousness (DOC). Guidelines recommend repeated assessments because patients might suffer from consciousness fluctuations, but it is not specified how many assessments are needed. The present study included 131 patients with DOC. They have been assessed at least 6 times during a 14-days period with the CRS-R. Results show that 5 CRS-R assessments are needed to reach a reliable diagnosis, and that all the CRS-R subscales are influenced by consciousness fluctuations. We here showed that consciousness fluctuations influence the behavioral diagnosis, and that 5 assessments within a short period of time are needed to get a reliable clinical diagnosis. [less ▲]

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See detailDisorders of Consciousness
Bodart, Olivier ULg; Thibaut, Aurore ULg; Laureys, Steven ULg et al

in Citerio, G.; Smith, M.; Kofke, A. (Eds.) Oxford Textbook of neurocritical care (2016)

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See detailControlled clinical trial of repeated left prefrontal transcranial direct current stimulation in patients with chronic minimally conscious state
Martial, Charlotte ULg; Thibaut, Aurore ULg; Wannez, Sarah ULg et al

Poster (2015, June)

A recent study showed that single-session anodal transcranial direct current stimulation (tDCS) applied to the left dorsolateral prefrontal cortex (LDLPF) transiently improves consciousness in 43% of ... [more ▼]

A recent study showed that single-session anodal transcranial direct current stimulation (tDCS) applied to the left dorsolateral prefrontal cortex (LDLPF) transiently improves consciousness in 43% of patients in minimally conscious state (MCS) (Thibaut et al., 2014). We here test the potential effects and safety of repeated tDCS in severely brain-damaged patients with MCS. In this double-blind cross-over sham-controlled experimental design, we delivered two sessions of repeated (5 days of stimulation) tDCS, either anodal or sham in a randomized order. We stimulated the LDLPF cortex during twenty minutes in 20 MCS patients (12 men, aged 48±16 years, time since onset 78±95 months, 12 post-traumatic). Consciousness was assessed by the French adaptation of the Coma Recovery Scale Revised (CRS-R; Schnakers et al., 2008) before and after each stimulation. A treatment effect was observed for the comparison between CRS-R total scores at baseline and after 5 days of real tDCS (p<0.01). Behaviorally, 10/20 patients showed a tDCS-related improvement; 5 patients responded after the first stimulation and 5 other patients responded after 2, 3 or 4 days of stimulation. No side effect (e.g. epilepsy) was reported. Our results demonstrate that repeated (5 days) anodal LDLPF tDCS is safe and might improve signs of consciousness in about half of patients in MCS. It is important to note that the first session is not predictive for a future positive effect of the efficacy of the non-invasive electrical stimulation. [less ▲]

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See detailCortical responses to transcranial magnetic stimulation during Non-Rapid Eye Movement Sleep
Gosseries, Olivia ULg; Jaakko, Nieminen; Siclari, Francesca et al

Poster (2015, March)

Transcranial magnetic stimulation coupled to high-density electroencephalography (TMS-EEG) allows for directly and non-invasively stimulating the brain and recording the subsequent cortical response ... [more ▼]

Transcranial magnetic stimulation coupled to high-density electroencephalography (TMS-EEG) allows for directly and non-invasively stimulating the brain and recording the subsequent cortical response. Previous TMS-EEG studies have shown clear-cut differences between conscious and unconscious conditions. When subjects are unconscious, as in non-rapid eye movement (NREM) sleep early in the night (stage N3), anesthesia or coma, TMS typically triggers a stereotypical and local slow-wave response. When they are conscious, as in normal wakefulness and rapid eye movement sleep (REM) sleep, brain responses to TMS are long-lasting, widespread, complex, and differentiated. In this study, we performed TMS-EEG during NREM sleep in stage 2 (N2) and N3 on 7 healthy participants. Brain activity was recorded using a 60-channel TMS-compatible EEG and single-pulse TMS was applied (up to 285 pulses per session) on the superior parietal cortex. After each TMS session (5 to 15 sessions per night), subjects were awakened to ask for a dream report. TMS-EEG responses were analyzed using the global mean field amplitude (GMFA), the perturbational complexity index (PCI), as well as time-frequency measures. Our results show that the TMS-EEG response during N3 is larger and slower than during N2 sleep. The GMFA is higher and PCI is lower in N3 as compared to N2 sleep. Moreover, N3 recordings showed activation at lower frequency bands after TMS as compared to N2 sleep. Additionally, TMS-EEG responses vary depending on whether subjects do or do not report a dream. TMS-EEG might provide valuable information for characterizing neurophysiological fluctuations and levels of consciousness within NREM sleep. [less ▲]

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See detailTranscranial magnetic stimulation and electroencephalography
Gosseries, Olivia ULg; Bodart, Olivier ULg; massimini, Marcello

in Rossetti, Andrea; Laureys, Steven (Eds.) Clinical Neurophysiology in Disorders of Consciousness: Brain monitoring in the ICU and Beyond (2015)

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See detailConsciousness and complexity during unresponsiveness induced by propofol, xenon, and ketamine
Sarasso, S.; Boly, M.; Napolitani, M. et al

in Current Biology (2015), 25(23), 3099-3105

A common endpoint of general anesthetics is behavioral unresponsiveness [1], which is commonly associated with loss of consciousness. However, subjects can become disconnected from the environment while ... [more ▼]

A common endpoint of general anesthetics is behavioral unresponsiveness [1], which is commonly associated with loss of consciousness. However, subjects can become disconnected from the environment while still having conscious experiences, as demonstrated by sleep states associated with dreaming [2]. Among anesthetics, ketamine is remarkable [3] in that it induces profound unresponsiveness, but subjects often report ketamine dreams upon emergence from anesthesia [4-9]. Here, we aimed at assessing consciousness during anesthesia with propofol, xenon, and ketamine, independent of behavioral responsiveness. To do so, in 18 healthy volunteers, we measured the complexity of the cortical response to transcranial magnetic stimulation (TMS) - an approach that has proven helpful in assessing objectively the level of consciousness irrespective of sensory processing and motor responses [10]. In addition, upon emergence from anesthesia, we collected reports about conscious experiences during unresponsiveness. Both frontal and parietal TMS elicited a low-amplitude electroencephalographic (EEG) slow wave corresponding to a local pattern of cortical activation with low complexity during propofol anesthesia, a high-amplitude EEG slow wave corresponding to a global, stereotypical pattern of cortical activation with low complexity during xenon anesthesia, and a wakefulness-like, complex spatiotemporal activation pattern during ketamine anesthesia. Crucially, participants reported no conscious experience after emergence from propofol and xenon anesthesia, whereas after ketamine they reported long, vivid dreams unrelated to the external environment. These results are relevant because they suggest that brain complexity may be sensitive to the presence of disconnected consciousness in subjects who are considered unconscious based on behavioral responses. © 2015 Elsevier Ltd All rights reserved. [less ▲]

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See detailThalamic volume as a biomarker for Disorders Of Consciousness. Progress in Biomedical Optics and Imaging
Rubeaux, M; Mahalingam, J; Gomez, F et al

in Proceedings of SPIE (2015)

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See detailChanges in cerebral metabolism in patients with a minimally conscious state responding to zolpidem.
Chatelle, Camille ULg; Thibaut, Aurore ULg; Gosseries, Olivia ULg et al

in Frontiers in Neuroscience (2014)

BACKGROUND: Zolpidem, a short-acting non-benzodiazepine GABA agonist hypnotic, has been shown to induce paradoxical responses in some patients with disorders of consciousness (DOC), leading to recovery of ... [more ▼]

BACKGROUND: Zolpidem, a short-acting non-benzodiazepine GABA agonist hypnotic, has been shown to induce paradoxical responses in some patients with disorders of consciousness (DOC), leading to recovery of arousal and cognitive abilities. We here assessed zolpidem-induced changes in regional brain metabolism in three patients with known zolpidem response in chronic post-anoxic minimally conscious state (MCS). METHODS: [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) and standardized clinical assessments using the Coma Recovery Scale-Revised were performed after administration of 10 mg zolpidem or placebo in a randomized double blind 2-day protocol. PET data preprocessing and comparison with a healthy age-matched control group were performed using statistical parametric mapping (SPM8). RESULTS: Behaviorally, all patients recovered functional communication after administration of zolpidem (i.e., emergence from the MCS). FDG-PET showed increased metabolism in dorsolateral prefrontal and mesiofrontal cortices after zolpidem but not after placebo administration. CONCLUSION: Our data show a metabolic activation of prefrontal areas, corroborating the proposed mesocircuit hypothesis to explain the paradoxical effect of zolpidem observed in some patients with DOC. It also suggests the key role of the prefrontal cortices in the recovery of functional communication and object use in hypoxic patients with chronic MCS. [less ▲]

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See detailTranscranial magnetic stimulation combined with high density EEG in altered states of consciousness
Napolitani, M.; Bodart, Olivier ULg; Canali, P. et al

in Brain injury : [BI] (2014), 28(9), 1180-1189

Background: This review discusses the advantages of transcranial magnetic stimulation combined with high-density electroencephalography (TMS-hdEEG) over other current techniques of brain imaging. Methods ... [more ▼]

Background: This review discusses the advantages of transcranial magnetic stimulation combined with high-density electroencephalography (TMS-hdEEG) over other current techniques of brain imaging. Methods and results: Its application was reviewed, focusing particularly on disorders of consciousness, in the perspective of recent theories of consciousness. Assessment of non-communicative patients with disorders of consciousness remains a clinical challenge and objective measures of the level of consciousness are still needed. Current theories suggest that a key requirement for consciousness is the brain’s capacity to rapidly integrate information across different specialized cortical areas. TMS-EEG allows the stimulation of any given cortical area and the recording of the immediate electrical cortical response. This technique has recently been successfully employed to measure changes in brain complexity under physiological, pharmacological and pathological conditions. Conclusions: This suggests that TMS-EEG is a reliable tool to discriminate between conscious and unconscious patients at the single subject level. Future works are needed to validate and implement this technique as a clinical tool. [less ▲]

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See detailThe Glasgow Coma Scale: time for critical reappraisal?
Laureys, Steven ULg; Bodart, Olivier ULg; Gosseries, Olivia ULg

in Lancet Neurology (2014), Vol 13

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See detailVolitional electromyographic responses in disorders of consciousness
Habbal, Dina; Gosseries, Olivia ULg; Noirhomme, Quentin ULg et al

in Brain Injury (2014)

The aim of the study was to validate the use of electromyography (EMG) for detecting responses to command in patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS) or in minimally ... [more ▼]

The aim of the study was to validate the use of electromyography (EMG) for detecting responses to command in patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS) or in minimally conscious state (MCS). Methods: Thirty-eight patients were included in the study (23 traumatic, 25 patients >1 year post-onset), 10 diagnosed as being in VS/UWS, eight in MCS- (no response to command) and 20 in MCS+ (response to command). Eighteen age-matched controls participated in the experiment. The paradigm consisted of three commands (i.e. 'Move your hands', 'Move your legs' and 'Clench your teeth') and one control sentence (i.e. 'It is a sunny day') presented in random order. Each auditory stimulus was repeated 4-times within one block with a stimulus-onset asynchrony of 30 seconds. Results: Post-hoc analyses with Bonferroni correction revealed that EMG activity was higher solely for the target command in one patient in permanent VS/UWS and in three patients in MCS+. Conclusion: The use of EMG could help clinicians to detect conscious patients who do not show any volitional response during standard behavioural assessments. However, further investigations should determine the sensitivity of EMG as compared to neuroimaging and electrophysiological assessments. [less ▲]

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See detailUnresponsive wakefulness & translational neurorehabilitation.
Charland-Verville, Vanessa ULg; Thibaut, Aurore ULg; Wannez, Sarah ULg et al

Scientific conference (2014, April 10)

The past 15years have provided an unprecedented collection of discoveries that bear upon our scientific understanding of recovery of consciousness in the human brain following severe brain damage ... [more ▼]

The past 15years have provided an unprecedented collection of discoveries that bear upon our scientific understanding of recovery of consciousness in the human brain following severe brain damage. Highlighted among these discoveries are unique demonstrations that patients with little or no behavioral evidence of conscious awareness may retain critical cognitive capacities and the first scientific demonstrations that some patients, with severely injured brains and very longstanding conditions of limited behavioral responsiveness, may nonetheless harbor latent capacities for recovery. Included among such capacities are particularly human functions of language and higher-level cognition that either spontaneously or through direct interventions may reemerge even at long time intervals or remain unrecognized. When patients in “persistent vegetative state” (recently also coined unresponsive wakefulness syndrome) show minimal signs of consciousness but are unable to reliably communicate the term minimally responsive or minimally conscious state (MCS) is used. MCS was recently subcategorized based on the complexity of patients' behaviors: MCS+ describes high-level behavioral responses (i.e., command following, intelligible verbalizations or non-functional communication) and MCS- describes low-level behavioral responses (i.e., visual pursuit, localization of noxious stimulation or contingent behavior such as appropriate smiling or crying to emotional stimuli). Patients who show non-behavioral evidence of consciousness or communication only measurable via ancillary testing (i.e., functional MRI, positron emission tomography, EEG or evoked potentials) can be considered to be in a functional locked-in syndrome. An improved assessment of brain function in coma and related states is not only changing nosology and medical care but also offers a better-documented diagnosis and prognosis and helps to further identify the neural correlates of human consciousness. Taken together, recent studies show that awareness is an emergent property of the collective behavior of frontoparietal top-down connectivity. Within this network, external (sensory) awareness depends on lateral prefrontal/parietal cortices while internal (self) awareness correlates with precuneal/mesiofrontal midline activity. Of clinical importance, this knowledge now permits to improve the diagnosis, prognosis and treatment of patients with disorders of consciousness, which currently remains very challenging. New technological advances now also permit to show command-specific changes in fMRI, EEG or eye-pupil measurements providing motor-independent evidence of conscious thoughts and in come cases even of communication. We will conclude by discussing related ethical issues and the challenge of improving our clinical care and quality of life in these challenging patients with disorders of consciousness. [less ▲]

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See detailDiagnostic precision of PET imaging and functional MRI in disorders of consciousness: a clinical validation study
Stender, Johan; Gosseries, Olivia ULg; Bruno, Marie-Aurélie ULg et al

in Lancet Neurology (2014)

Background: Bedside clinical examinations can have high rates of misdiagnosis of unresponsive wakefulness syndrome (vegetative state) or minimally conscious state. The diagnostic and prognostic usefulness ... [more ▼]

Background: Bedside clinical examinations can have high rates of misdiagnosis of unresponsive wakefulness syndrome (vegetative state) or minimally conscious state. The diagnostic and prognostic usefulness of neuroimaging-based approaches has not been established in a clinical setting. We did a validation study of two neuroimaging-based diagnostic methods: PET imaging and functional MRI (fMRI). Methods: For this clinical validation study, we included patients referred to the University Hospital of Liège, Belgium, between January, 2008, and June, 2012, who were diagnosed by our unit with unresponsive wakefulness syndrome, locked-in syndrome, or minimally conscious state with traumatic or non-traumatic causes. We did repeated standardised clinical assessments with the Coma Recovery Scale—Revised (CRS—R), cerebral 18F-fluorodeoxyglucose (FDG) PET, and fMRI during mental activation tasks. We calculated the diagnostic accuracy of both imaging methods with CRS—R diagnosis as reference. We assessed outcome after 12 months with the Glasgow Outcome Scale—Extended. Findings: We included 41 patients with unresponsive wakefulness syndrome, four with locked-in syndrome, and 81 in a minimally conscious state (48=traumatic, 78=non-traumatic; 110=chronic, 16=subacute). 18F-FDG PET had high sensitivity for identification of patients in a minimally conscious state (93%, 95% CI 85—98) and high congruence (85%, 77—90) with behavioural CRS—R scores. The active fMRI method was less sensitive at diagnosis of a minimally conscious state (45%, 30—61) and had lower overall congruence with behavioural scores (63%, 51—73) than PET imaging. 18F-FDG PET correctly predicted outcome in 75 of 102 patients (74%, 64—81), and fMRI in 36 of 65 patients (56%, 43—67). 13 of 42 (32%) of the behaviourally unresponsive patients (ie, diagnosed as unresponsive with CRS—R) showed brain activity compatible with (minimal) consciousness (ie, activity associated with consciousness, but diminished compared with fully conscious individuals) on at least one neuroimaging test; 69% of these (9 of 13) patients subsequently recovered consciousness. Interpretation: Cerebral 18F-FDG PET could be used to complement bedside examinations and predict long-term recovery of patients with unresponsive wakefulness syndrome. Active fMRI might also be useful for differential diagnosis, but seems to be less accurate. Funding: The Belgian National Funds for Scientific Research (FNRS), Fonds Léon Fredericq, the European Commission, the James McDonnell Foundation, the Mind Science Foundation, the French Speaking Community Concerted Research Action, the University of Copenhagen, and the University of Liège. [less ▲]

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See detailEffect of zolpidem in chronic disorders of consciousness: a prospective open-label study.
Thonnard, Marie ULg; Gosseries, Olivia ULg; Demertzi, Athina ULg et al

in Functional Neurology (2014), 28(4), 259-64

Zolpidem has been reported as an "awakening drug" in some patients with disorders of consciousness (DOC). We here present the results of a prospective openlabel study in chronic DOC patients. Sixty ... [more ▼]

Zolpidem has been reported as an "awakening drug" in some patients with disorders of consciousness (DOC). We here present the results of a prospective openlabel study in chronic DOC patients. Sixty patients (35±15 years; 18 females; mean time since insult ± SD: 4±5.5 years; 31 with traumatic etiology) with a diagnosis of vegetative state/unresponsive wakefulness syndrome (n=28) or minimally conscious state (n=32) were behaviorally assessed using the Coma Recovery Scale-Revised (CRS-R) before and one hour after administration of 10 mg of zolpidem. At the group level, the diagnosis did not change after intake of zolpidem (p=0.10) and CRS-R total scores decreased (p=0.01). Twelve patients (20%) showed improved behaviors and/or CRS-R total scores after zolpidem administration but in only one patient was the diagnosis after zolpidem intake found to show a significant improvement (functional object use), which suggested a change of diagnosis. However, in this patient, a double-blind placebo-controlled trial was performed in order to better specify the effects of zolpidem, but the patient, on this trial, failed to show any clinical improvements. The present open-label study therefore failed to show any clinically significant improvement (i.e., change of Effect of zolpidem in chronic disorders of consciousness: a prospective open-label study diagnosis) in any of the 60 studied chronic DOC patients. [less ▲]

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See detailAssessing consciousness in coma and related states using transcranial magnetic stimulation combined with electroencephalography.
Gosseries, Olivia ULg; Thibaut, Aurore ULg; Boly, Mélanie ULg et al

in Annales Françaises d'Anesthésie et de Réanimation (2014)

Thanks to advances in medical care, an increased number of patients recover from coma. However, some remain in vegetative/unresponsive wakefulness syndrome or in a minimally conscious state. Detection of ... [more ▼]

Thanks to advances in medical care, an increased number of patients recover from coma. However, some remain in vegetative/unresponsive wakefulness syndrome or in a minimally conscious state. Detection of awareness in severely brain-injured patients is challenging because it relies on behavioral assessments, which can be affected by motor, sensory and cognitive impairments of the patients. Other means of evaluation are needed to improve the accuracy of the diagnosis in this challenging population. We will here review the different altered states of consciousness occurring after severe brain damage, and explain the difficulties associated with behavioral assessment of consciousness. We will then describe a non-invasive technique, transcranial magnetic stimulation combined with high-density electroencephalography (TMS-EEG), which has allowed us to detect the presence or absence of consciousness in different physiological, pathological and pharmacological states. Some potential underlying mechanisms of the loss of consciousness will then be discussed. In conclusion, TMS-EEG is highly promising in identifying markers of consciousness at the individual level and might be of great value for clinicians in the assessment of consciousness. [less ▲]

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