References of "Laureys, Steven"
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See detailRecovery of language comprehension in the minimally conscious state studied by FDG-PET
Wannez, Sarah ULg; Thibaut, Aurore ULg; Vitali-Roscini, Gaia et al

Poster (2015, June 21)

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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 detailCognitive auditory evoked potentials in coma: can you hear me?
Piarulli, Andrea; Charland-Verville, Vanessa ULg; Laureys, Steven ULg

in Brain : A Journal of Neurology (2015), 138(Pt5), 1129-1137

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See detailCerebral FDG uptake changes with supraorbital transcutaneous electrical stimulation for episodic migraine prevention
D'Ostilio, Kevin ULg; Thibaut, Aurore ULg; Laureys, Steven ULg et al

Conference (2015, May)

Background: A recent multicentre RCT has shown that supraorbital transcutaneous stimulation (STS) targeting branches of the ophtalmic nerve with the Cefaly® device is effective as a preventive therapy for ... [more ▼]

Background: A recent multicentre RCT has shown that supraorbital transcutaneous stimulation (STS) targeting branches of the ophtalmic nerve with the Cefaly® device is effective as a preventive therapy for migraine (Schoenen et al., Neurology 2013). However, the mechanisms of action in the central nervous system remain unknown. Here, we conducted voxel-based analyses of [18]FDG-PET to evaluate metabolic changes immediately after the first STS session and after 3 months of treatment in patients with migraine. Methods: Twenty-eight subjects participated in the experiment: 14 patients with episodic migraine (ICHD3 beta criteria) and 14 age-matched controls. Healthy volunteers underwent only one [18]FDG-PET scan whereas patients were scanned at baseline, directly after a first session of STS and after 3 months of daily treatment. Results: Compliant patients showed a significant decrease in the number of attacks (p = 0.03). When compared to controls, patients (n = 14) at baseline were hypometabolic in the fronto-temporal regions (p < 0.001), especially in the orbitofrontal (OFC) and perigenual anterior cingulate cortex. OFC hypometabolism was not correlated with medication intake. In compliant patients, daily STS for 3 months was followed by a normalization of the fronto-temporal hypometabolism (p< 0.001; OFC: pFWE<0.01). Conclusion: Our study suggests that the OFC is hypoactive in episodic migraine. STS with the Cefaly° device is able to normalize this hypoactivity. This indicates that STS exerts its beneficial effect via slow neuromodulatory mechanisms, as also previously shown for percutaneous occipital nerve stimulation in refractory cluster headache (Magis et al., BMC Neurology 2011). [less ▲]

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See detailThalamic and extrathalamic mechanisms of consciousness after severe brain injury.
Lutkenhoff, Evan; Chiang, Jeffrey; TSHIBANDA, Luaba ULg et al

in Annals of Neurology (2015)

Abstract OBJECTIVE: What mechanisms underlie the loss and recovery of consciousness after severe brain injury? We sought to establish, in the largest cohort of patients with disorders of consciousness ... [more ▼]

Abstract OBJECTIVE: What mechanisms underlie the loss and recovery of consciousness after severe brain injury? We sought to establish, in the largest cohort of patients with disorders of consciousness (DOC) to date, the link between gold standard clinical measures of awareness and wakefulness, and specific patterns of local brain pathology-thereby possibly providing a mechanistic framework for patient diagnosis, prognosis, and treatment development. METHODS: Structural T1-weighted magnetic resonance images were collected, in a continuous sample of 143 severely brain-injured patients with DOC (and 96 volunteers), across 2 tertiary expert centers. Brain atrophy in subcortical regions (bilateral thalamus, basal ganglia, hippocampus, basal forebrain, and brainstem) was assessed across (1) healthy volunteers and patients, (2) clinical entities (eg, vegetative state, minimally conscious state), (3) clinical measures of consciousness (Coma Recovery Scale-Revised), and (4) injury etiology. RESULTS: Compared to volunteers, patients exhibited significant atrophy across all structures (p < 0.05, corrected). Strikingly, we found almost no significant differences across clinical entities. Nonetheless, the clinical measures of awareness and wakefulness upon which differential diagnosis rely were systematically associated with tissue atrophy within thalamic and basal ganglia nuclei, respectively; the basal forebrain was atrophied in proportion to patients' response to sensory stimulation. In addition, nontraumatic injuries exhibited more extensive thalamic atrophy. INTERPRETATION: These findings provide, for the first time, a grounding in pathology for gold standard behavior-based clinical measures of consciousness, and reframe our current models of DOC by stressing the different links tying thalamic mechanisms to willful behavior and extrathalamic mechanisms to behavioral (and electrocortical) arousal. Ann Neurol 2015. [less ▲]

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See detailImpact of Aphasia on Consciousness Assessment: A Cross-Sectional Study.
Schnakers, C; Bessou, H; Rubi-Fessen, I et al

in Neurorehabilitation & Neural Repair (2015), 29

BACKGROUND: . Previous findings suggest that language disorders may occur in severely brain-injured patients and could interfere with behavioral assessments of consciousness. However, no study ... [more ▼]

BACKGROUND: . Previous findings suggest that language disorders may occur in severely brain-injured patients and could interfere with behavioral assessments of consciousness. However, no study investigated to what extent language impairment could affect patients' behavioral responses. OBJECTIVE: . To estimate the impact of receptive and/or productive language impairments on consciousness assessment. METHODS: . Twenty-four acute and subacute stroke patients with different types of aphasia (global, n = 11; Broca, n = 4; Wernicke, n = 3; anomic, n = 4; mixed, n = 2) were recruited in neurology and neurosurgery units as well as in rehabilitation centers. The Coma Recovery Scale-Revised (CRS-R) was administered. RESULTS: . We observed that 25% (6 out of 24) of stroke patients with a diagnosis of aphasia and 54% (6 out of 11) of patients with a diagnosis of global aphasia did not reach the maximal CRS-R total score of 23. An underestimation of the consciousness level was observed in 3 patients with global aphasia who could have been misdiagnosed as being in a minimally conscious state, even in the absence of any documented period of coma. More precisely, lower subscores were observed on the communication, motor, oromotor, and arousal subscales. CONCLUSION: . Consciousness assessment may be complicated by the co-occurrence of severe language deficits. This stresses the importance of developing new tools or identifying items in existing scales, which may allow the detection of language impairment in severely brain-injured patients. [less ▲]

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See detailNear-Death Experiences in patients with locked-in syndrome: Not always a blissful journey
Charland-Verville, Vanessa ULg; Lugo, Zulay; Jourdan, Jean-Pierre et al

in Consciousness & Cognition (2015), 34

Memories of Near-Death Experiences (NDEs) most often are recounted as emotionally positive events. At present, no satisfactory explanatory model exists to fully account for the rich phenomenology of NDEs ... [more ▼]

Memories of Near-Death Experiences (NDEs) most often are recounted as emotionally positive events. At present, no satisfactory explanatory model exists to fully account for the rich phenomenology of NDEs following a severe acute brain injury. The particular population of patients with locked-in syndrome (LIS) provides a unique opportunity to study NDEs following infratentorial brain lesions. We here retrospectively characterized the content of NDEs in 8 patients with LIS caused by an acute brainstem lesion (i.e., ‘‘LIS NDEs’’) and 23 NDE experiencers after coma with supratentorial lesions (i.e., ‘‘classical NDEs’’). Compared to ‘‘classical NDEs’’, ‘‘LIS NDEs’’ less frequently experienced a feeling of peacefulness or well-being. It could be hypothesized that NDEs containing less positive emotions might have a specific neuroanatomical substrate related to impaired pontine/paralimbic connectivity or alternatively might be related to the emotional distress caused by the presence of conscious awareness in a paralyzed body. [less ▲]

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See detailCerebral responses and role of the prefrontal cortex in conditioned pain modulation: an fMRI study in healthy subjects
Bogdanov, Volodymyr; Vigano, Alessandro; Noirhomme, Quentin ULg et al

in Behavioural Brain Research (2015)

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See detailHypnosis modulates behavioural measures and subjective ratings about external and internal awareness
Demertzi, Athina ULg; VANHAUDENHUYSE, Audrey ULg; Noirhomme, Quentin ULg et al

in Journal of Physiology - Paris (2015), 109(4), 173-179

In altered subjective states, the behavioural quantification of external and internal awareness remains challenging due to the need for reports on the subjects’ behalf. With the aim to characterize the ... [more ▼]

In altered subjective states, the behavioural quantification of external and internal awareness remains challenging due to the need for reports on the subjects’ behalf. With the aim to characterize the behavioural counterpart of external and internal awareness in a modified subjective condition, we used hypnosis during which subjects remain fully responsive. Eleven right-handed subjects reached a satisfactory level of hypnotisability as evidenced by subjective reports on arousal, absorption and dissociation. Compared to normal wakefulness, in hypnosis (a) participants’ self-ratings for internal awareness increased and self-ratings for external awareness decreased, (b) the two awareness components tended to anticorrelate less and the switches between external and internal awareness self-ratings were less frequent, and (c) participants’ reaction times were higher and lapses in key presses were more frequent. The identified imbalance between the two components of awareness is considered as of functional relevance to subjective (meta)cognition, possibly mediated by allocated attentional properties brought about by hypnosis. Our results highlight the presence of a cognitive counterpart in resting state, indicate that the modified contents of awareness are measurable behaviourally, and provide leverage for investigations of more challenging altered conscious states, such as anaesthesia, sleep and disorders of consciousness. [less ▲]

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See detailBeyond the gaze: Communicating in chronic locked-in syndrome
Lugo, Z.R; Bruno, Marie-Aurelie; Gosseries, Olivia ULg et al

in Brain Injury (2015), 29

OBJECTIVE Locked-in syndrome (LIS) usually follows a brainstem stroke and is characterized by paralysis of all voluntary muscles (except eyes' movements or blinking) and lack of speech with preserved ... [more ▼]

OBJECTIVE Locked-in syndrome (LIS) usually follows a brainstem stroke and is characterized by paralysis of all voluntary muscles (except eyes' movements or blinking) and lack of speech with preserved consciousness. Several tools have been developed to promote communication with these patients. The aim of the study was to evaluate the current status regarding communication in a cohort of LIS patients. DESIGN A survey was conducted in collaboration with the French Association of Locked-in syndrome (ALIS). SUBJECTS AND METHODS Two hundred and four patients, members of ALIS, were invited to fill in a questionnaire on communication issues and clinical evolution (recovery of verbal language and movements, presence of visual and/or auditory deficits). RESULTS Eighty-eight responses were processed. All respondents (35% female, mean age = 52 ± 12 years, mean time in LIS = 10 ± 6 years) reported using a yes/no communication code using mainly eyes' movements and 62% used assisting technology; 49% could communicate through verbal language and 73% have recovered some functional movements within the years. CONCLUSION The results highlight the possibility to recover non-eye dependent communication, speech production and some functional movement in the majority of chronic LIS patients. [less ▲]

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See detailConsciousness: And Disorders of Consciousness
Heine, Lizette ULg; Demertzi, Athina ULg; Laureys, Steven ULg et al

in Toga, Arthur W (Ed.) Brain mapping : an encyclopedic reference (2015)

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See detailDetecting Levels of Consciousness
Demertzi, Athina ULg; Laureys, Steven ULg

in Levy, N; Clausen, J (Eds.) Handbook of Neuroethics (2015)

Patients with disordered consciousness due to brain injury pose medical and ethical challenges. Rates of clinical misdiagnosis of “vegetative”/unresponsive, minimally conscious and locked-in syndrome ... [more ▼]

Patients with disordered consciousness due to brain injury pose medical and ethical challenges. Rates of clinical misdiagnosis of “vegetative”/unresponsive, minimally conscious and locked-in syndrome states remain challengingly high. Clinical misdiagnosis raises profound ethical concerns in terms of medical management, treatment of pain, and end-of-life decisions. Therefore, valid diagnosis is of utmost importance in clinical settings. A number of neuroimaging and electrophysiology studies now suggest that some behaviorally “vegetative state” patients may nevertheless show atypical cortical activation during resting state conditions; in some cases, they are able to follow commands or even communicate through willfully modified brain activity. Advances in investigating disorders of consciousness with neuroimaging techniques promise to lead to a more accurate understanding of individual patients’ cognitive abilities and to shed light on the gray zones of these clinical conditions. The formulation of an ethical framework which will strike a balance between the protection of these patients and further research on disorders of consciousness is an ethical, clinical, and scientific demand. [less ▲]

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See detailImaging correlation in non-communicating patients
Heine, Lizette ULg; Di Perri, Carol ULg; Soddu, Andrea ULg et al

in Rossetti, A.O; Laureys, Steven (Eds.) Clinical Neurophysiology in Disorders of Consciousness-Brain Function Monitoring in the ICU and beyond (2015)

The diagnosis and medical management of patients with acute or chronic disorders of consciousness (DOC) are challenging. Motor-independent functional neuroimaging technologies are increasingly employed to ... [more ▼]

The diagnosis and medical management of patients with acute or chronic disorders of consciousness (DOC) are challenging. Motor-independent functional neuroimaging technologies are increasingly employed to study covert cognitive processes in the absence of behavioural reports. Studies with functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) performed in this patient population have utilized active, passive and restingstate paradigms. Active paradigms refer to mental imagery tasks that measure wilful modulation of brain signal in specific brain areas, aiming to detect command-following. Passive paradigms are used to measure brain responses to external sensory stimulation (e.g. auditory, somatosensory and visual). Alternatively, in resting-state paradigms, spontaneous brain function is assessed while subjects receive no external stimulation and are instructed to let their mind wander. Independently from each other, these methods have shown differences between healthy controls and patients, as well as among patients with DOC. However, these techniques cannot yet be used in clinical settings before robust information at the single-subject level will be provided: it is expected that multimodal research will improve the single-patient diagnosis, shed light on the prognostic biomarkers, and eventually promote the medical management of patients with consciousness alterations. [less ▲]

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See detailThinking on patients’ behalf: attitudes of healthcare providers towards medico-ethical issues in non-communicating patients
Demertzi, Athina ULg; Laureys, Steven ULg

in Sturma, D; Honnefelder, L; Fuchs, M (Eds.) Yearbook for Science and Ethics (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 detailBehavioural Diagnosis of Disorders of Consciousness
Thibaut, Aurore ULg; Di Perri, Carol ULg; Bodart, Olivier ULg et al

in Rossetti, Andrea; Laureys, Steven (Eds.) Clinical Neurophysiology in Disorders of Consciousness (2015)

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See detailChronic disorders of consciousness
Thibaut, Aurore ULg; BODART, Olivier ULg; Laureys, Steven ULg et al

in Canavero, Sergio (Ed.) Surgical Principles of Therapeutic Cortical Stimulation (2015)

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See detailClinical Response to tDCS Depends on Residual Brain Metabolism and Grey Matter Integrity in Patients With Minimally Conscious State.
Thibaut, Aurore ULg; Di Perri, Carol; Chatelle, Camille ULg et al

in Brain stimulation (2015), 8(6), 1116-23

BACKGROUND: Transcranial direct current stimulation (tDCS) was recently shown to promote recovery of voluntary signs of consciousness in some patients in minimally conscious state (MCS). However, it ... [more ▼]

BACKGROUND: Transcranial direct current stimulation (tDCS) was recently shown to promote recovery of voluntary signs of consciousness in some patients in minimally conscious state (MCS). However, it remains unclear why clinical improvement is only observed in a subgroup of patients. OBJECTIVES: In this retrospective study, we investigated the relationship between tDCS responsiveness and neuroimaging data from MCS patients. METHODS: Structural Magnetic Resonance Imaging (MRI), Fluorodeoxyglucose Positron emission tomography (FDG-PET) and clinical electroencephalography (EEG) were acquired in 21 sub-acute and chronic MCS patients (8 tDCS responders) who subsequently (<48 h) received left dorsolateral prefrontal (DLPF) tDCS in a double-blind randomized cross-over trial. The behavioral data have been published elsewhere (Thibaut et al., Neurology, 2014). RESULTS: Grey matter atrophy was observed in non-responders as compared with responders in the left DLPF cortex, the medial-prefrontal cortex, the cingulate cortex, the hippocampi, part of the rolandic regions, and the left thalamus. FDG-PET showed hypometabolism in non-responders as compared with responders in the left DLPF cortex, the medial-prefrontal cortex, the precuneus, and the thalamus. EEG did not show any difference between the two groups. CONCLUSION: Our findings suggest that the transient increase of signs of consciousness following left DLPF tDCS in patients in MCS require grey matter preservation and residual metabolic activity in cortical and subcortical brain areas known to be involved in attention and working memory. These results further underline the critical role of long-range cortico-thalamic connections in consciousness recovery, providing important information for guidelines on the use of tDCS in disorders of consciousness. [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 detailAn empirical classification scheme for detection of impossible and improbable CRS-R subscore combinations
Chatelle, Camille ULg; Bodien, Yelena Guller; Carlowicz, Cecilia et al

Poster (2015)

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