References of "Laureys, Steven"
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See detailThe boundaries of consciousness: lessons from coma and related states
Laureys, Steven ULg; Boly, Mélanie ULg; Moonen, Gustave ULg

in Advances in Clinical Neuroscience and Rehabilitation [=ACNR] (2008), 8(2),

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See detailThe Effect of Clonidine Infusion on Distribution of Regional Cerebral Blood Flow in Volunteers
Bonhomme, Vincent ULg; Maquet, Pierre ULg; Phillips, Christophe ULg et al

in Anesthesia and Analgesia (2008), 106(3), 899-909

BACKGROUND: Through their action on the locus coeruleus, alpha2-adrenoceptor agonists induce rapidly reversible sedation while partially preserving cognitive brain functions. Our goal in this ... [more ▼]

BACKGROUND: Through their action on the locus coeruleus, alpha2-adrenoceptor agonists induce rapidly reversible sedation while partially preserving cognitive brain functions. Our goal in this observational study was to map brain regions whose activity is modified by clonidine infusion so as to better understand its loci of action, especially in relation to sedation. METHODS: Six ASA I-II right-handed volunteers were recruited. Electroencephalogram (EEG) was monitored continuously. After a baseline H2(15)O activation scan, clonidine infusion was started at a rate ranging from 6 to 10 microg x kg(-1) x h(-1). A sequence of 11 similar scans was then performed at 8 min intervals. Plasma clonidine concentration was measured. Using statistical parametric mapping, we sought linear correlations between normalized regional cerebral blood flow (rCBF), an indicator of regional brain activity, and plasma clonidine concentration or spindle EEG activity. RESULTS: Clonidine induced clinical sedation and EEG patterns (spindles) comparable to early stage nonrapid eye movement sleep. A significant negative linear correlation between clonidine concentration and rCBF or spindle activity was observed in the thalamus, prefrontal, orbital and parietal association cortex, posterior cingulate cortex, and precuneus. CONCLUSIONS: The EEG patterns and decreases in rCBF of specific brain regions observed during clonidine-induced sedation are similar to those of early stage nonrapid eye movement sleep. Patterns of deactivated brain regions are also comparable to those observed during general anesthesia or vegetative state, reinforcing the hypothesis that alterations in the activity of a common network occur during these modified conscious states. [less ▲]

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See detailAssessment of visual pursuit in post-comatose states: use a mirror
Vanhaudenhuyse, Audrey ULg; Schnakers, Caroline ULg; Brédart, Serge ULg et al

in Journal of Neurology, Neurosurgery & Psychiatry (2008), 79(2),

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See detailPerception of pain in the minimally conscious state with PET activation: an observational study.
Boly, Mélanie ULg; Faymonville, Marie-Elisabeth ULg; Schnakers, Caroline et al

in Lancet Neurology (2008), 7(11), 1013-20

BACKGROUND: Patients in a minimally conscious state (MCS) show restricted self or environment awareness but are unable to communicate consistently and reliably. Therefore, better understanding of cerebral ... [more ▼]

BACKGROUND: Patients in a minimally conscious state (MCS) show restricted self or environment awareness but are unable to communicate consistently and reliably. Therefore, better understanding of cerebral noxious processing in these patients is of clinical, therapeutic, and ethical relevance. METHODS: We studied brain activation induced by bilateral electrical stimulation of the median nerve in five patients in MCS (aged 18-74 years) compared with 15 controls (19-64 years) and 15 patients (19-75 years) in a persistent vegetative state (PVS) with (15)O-radiolabelled water PET. By way of psychophysiological interaction analysis, we also investigated the functional connectivity of the primary somatosensory cortex (S1) in patients and controls. Patients in MCS were scanned 57 (SD 33) days after admission, and patients in PVS 36 (9) days after admission. Stimulation intensities were 8.6 (SD 6.7) mA in patients in MCS, 7.4 (5.9) mA in controls, and 14.2 (8.7) mA in patients in PVS. Significant results were thresholded at p values of less than 0.05 and corrected for multiple comparisons. FINDINGS: In patients in MCS and in controls, noxious stimulation activated the thalamus, S1, and the secondary somatosensory or insular, frontoparietal, and anterior cingulate cortices (known as the pain matrix). No area was less activated in the patients in MCS than in the controls. All areas of the cortical pain matrix showed greater activation in patients in MCS than in those in PVS. Finally, in contrast with patients in PVS, those in MCS had preserved functional connectivity between S1 and a widespread cortical network that includes the frontoparietal associative cortices. INTERPRETATION: Cerebral correlates of pain processing are found in a similar network in controls and patients in MCS but are much more widespread than in patients in PVS. These findings might be objective evidence of a potential pain perception capacity in patients in MCS, which supports the idea that these patients need analgesic treatment. [less ▲]

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See detailAre we equal in death?
Laureys, Steven ULg; Fins, Joseph J.

in Neurology (2008), 70

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See detailLe Locked-In Syndrome : la conscience emmurée
Bruno, Marie-Aurélie ULg; Pellas, F.; Schnakers, Caroline ULg et al

in Revue Neurologique (2008), 164

The Locked-In syndrome(LIS) is defined by: (i) the presence of sustained eye opening (bilateral ptosis should be ruled out as a complicating factor);(ii) preserved awareness; (iii) aphonia or hypophonia ... [more ▼]

The Locked-In syndrome(LIS) is defined by: (i) the presence of sustained eye opening (bilateral ptosis should be ruled out as a complicating factor);(ii) preserved awareness; (iii) aphonia or hypophonia; (iv) quadriplegia or quadriparesis; and (v) a primary mode of communication that uses vertical or lateral eye movement or blinking. Acute ventral pontine lesions are its most common cause. Following such brainstem lesions patients may remain comatose for sometime and then gradually awaken, remaining paralyzed and voiceless, superficially resembling the vegetative state. Background. – It has been shown that more than half of the time physicians fail to recognize early signs of awareness in LIS. Given appropriate medical care,life expectancy may be several decades but the chances of good motor recovery remain small. Eye-controlled computer technology now allows LIS patients to communicate and control their environment. Recent studies show that most LIS patients self-report meaningful quality of life and the demand for euthanasia is infrequent. Conclusion. – Patients suffering from LIS should not be denied the right to die – and to die with dignity –but also they should not be denied the right to live–and to live with dignity and the best possible pain and symptom management and revalidation. [less ▲]

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See detailConsciousness and cerebral baseline activity fluctuations
Boly, Mélanie ULg; Phillips, Christophe ULg; Balteau, Evelyne ULg et al

in Human Brain Mapping (2008), 29

The origin of within-subject variability in perceptual experiments is poorly understood. We here review evidence that baseline brain activity in the areas involved in sensory perception predict subsequent ... [more ▼]

The origin of within-subject variability in perceptual experiments is poorly understood. We here review evidence that baseline brain activity in the areas involved in sensory perception predict subsequent variations in sensory awareness. We place these findings in light of recent findings on the architecture of spontaneous BOLD fluctuations in the awake human brain, and discuss the possible origins of the observed baseline brain activity fluctuations. [less ▲]

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See detailExperiences de mort imminente: phenomenes paranormaux ou neurologiques?
Thonnard, Marie ULg; Schnakers, Caroline ULg; Boly, Mélanie ULg et al

in Revue Médicale de Liège (2008), 63(5-6), 438-44

Seeing a bright light at the end of a tunnel or having a sense of being out of the physical body are phenomena that some patients report after having been close to death. Some spiritual and psychological ... [more ▼]

Seeing a bright light at the end of a tunnel or having a sense of being out of the physical body are phenomena that some patients report after having been close to death. Some spiritual and psychological theories have been developed in order to explain these near-death-experiences. Clinical studies have aimed to determine their frequency and to assess their precipitating factors. Recent neuroimaging studies, however, have shown the involvement of the temporo-parietal cortex in the generation of out-of-body experiences and are offering a physiological, neurological account for the phenomenon, rebuffing dualistic, non-physical explanations. [less ▲]

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See detailIs there anybody in there? Detecting awareness in disorders of consciousness.
Demertzi, Athena; Vanhaudenhuyse, Audrey ULg; Bruno, Marie-Aurelie et al

in Expert Review of Neurotherapeutics (2008), 8(11), 1719-30

The bedside detection of awareness in disorders of consciousness (DOC) caused by acquired brain injury is not an easy task. For this reason, differential diagnosis using neuroimaging and ... [more ▼]

The bedside detection of awareness in disorders of consciousness (DOC) caused by acquired brain injury is not an easy task. For this reason, differential diagnosis using neuroimaging and electrophysiological tools in search for objective markers of consciousness is being employed. However, such tools cannot be considered as diagnostic per se, but as assistants to the clinical evaluation, which, at present, remains the gold standard. Regarding therapeutic management in DOC, no evidence-based recommendations can be made in favor of a specific treatment. The present review summarizes clinical and paraclinical studies that have been conducted with neuroimaging and electrophysiological techniques in search of residual awareness in DOC. We discuss the medical, scientific and ethical implications that derive from these studies and we argue that, in the future, the role of neuroimaging and electrophysiology will be important not only for the diagnosis and prognosis of DOC but also in establishing communication with these challenging patients. [less ▲]

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See detailA twitch of consciousness: defining the boundaries of vegetative and minimally conscious states.
Noirhomme, Quentin ULg; Schnakers, Caroline ULg; Laureys, Steven ULg

in Journal of Neurology, Neurosurgery & Psychiatry (2008), 79(7), 741-2

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See detailLocked-in: don't judge a book by its cover.
Bruno, Marie-Aurélie ULg; Bernheim, J. L.; Schnakers, Caroline ULg et al

in Journal of Neurology, Neurosurgery & Psychiatry (2008), 79(1), 2

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See detailVoluntary brain processing in disorders of consciousness
Schnakers, Caroline ULg; Perrin, F.; Schabus, M. et al

in Neurology (2008), 71(20), 1614-1620

Background: Disentangling the vegetative state from the minimally conscious state is often difficult when relying only on behavioral observation. In this study, we explored a new active evoked related ... [more ▼]

Background: Disentangling the vegetative state from the minimally conscious state is often difficult when relying only on behavioral observation. In this study, we explored a new active evoked related potentials paradigm as an alternative method for the detection of voluntary brain activity. Methods: The participants were 22 right-handed patients (10 traumatic) diagnosed as being in a vegetative state (VS) (n 8) or in a minimally conscious state (MCS) (n 14). They were presented sequences of names containing the patient’s own name or other names, in both passive and active conditions. In the active condition, the patients were instructed to count her or his own name or to count another target name. Results: Like controls, MCS patients presented a larger P3 to the patient’s own name, in the passive and in the active conditions. Moreover, the P3 to target stimuli was higher in the active than in the passive condition, suggesting voluntary compliance to task instructions like controls. These responses were even observed in patients with low behavioral responses (e.g., visual fixationand pursuit). In contrast, no P3 differences between passive and active conditions were observed for VS patients. Conclusions: The present results suggest that active evoked-related potentials paradigms may permit detection of voluntary brain function in patients with severe brain damage who present with a disorder of consciousness, even when the patient may present with very limited to questionablyany signs of awareness. [less ▲]

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See detailBewusstseinsstörungen - Diagnose und Prognose
Laureys, Steven ULg; FAYMONVILLE, Marie-Elisabeth ULg; BOLY, Mélanie ULg et al

in Junginger, T. (Ed.) Grenzsituationen der Intensivmedizin-Entscheidungsgrundlagen (2008)

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See detailRevelations from the unconscious: studying residual brain function in coma and related states.
Laureys, Steven ULg; Boly, Mélanie ULg; Schnakers, Caroline ULg et al

in Bulletin et Mémoires de l'Académie Royale de Médecine de Belgique (2008), 163(7-9), 381-8388-90

The purpose of our research is to contribute to a better understanding of the residual brain function of patients who survive an acute brain damage but remain in a coma, vegetative state, minimally ... [more ▼]

The purpose of our research is to contribute to a better understanding of the residual brain function of patients who survive an acute brain damage but remain in a coma, vegetative state, minimally conscious state or locked-in syndrome. The diagnosis, prognosis, therapy and medical management of these patients remain difficult. These studies are also of interest scientifically, as they help to elucidate the neural correlates of human consciousness. We here review our studies on bedside behavioral evaluation scales, electrophysiology and functional neuroimaging in these disorders of consciousness and conclude by discussing methodological and ethical issues and current concepts of the standards for care and quality of life in these challenging conditions. [less ▲]

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See detailImagerie cérébrale de la réflexion sur soi
Salmon, Eric ULg; D'Argembeau, Arnaud ULg; Bastin, Christine ULg et al

in Revue Médicale de Liège (2008), 63

Precise brain regions are activated when a subject gives a judgment on himself. Those are the medial parietal cortex, essentially related to episodic memory processing, and the ventromedial prefrontal ... [more ▼]

Precise brain regions are activated when a subject gives a judgment on himself. Those are the medial parietal cortex, essentially related to episodic memory processing, and the ventromedial prefrontal cortex, recruited for evaluating the personal valence of an information. These regions are not activated in Alzheimer's disease. The decrease of awareness for own deficits in a patient with Alzheimer's disease would depend on a reduction of episodic memory capacities and a worsening of judgment for self significance. [less ▲]

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See detailComment prédire l'évolution du coma post-anoxique?
Kirsch, Murielle ULg; Boveroux, Pierre ULg; Massion, Paul ULg et al

in Revue Médicale de Liège (2008), 63(5-6), 263-268

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See detailHypnose et perception de la douleur
Vanhaudenhuyse, Audrey ULg; Boveroux, Pierre ULg; Boly, Mélanie ULg et al

in Revue Médicale de Liège (2008), 63(5-6), 424-8

Improvement in functional neuroimaging allows researchers to disentangle the brain mechanisms involved in the pain modulation encountered during hypnosis. It has been shown that the anterior cingulate and ... [more ▼]

Improvement in functional neuroimaging allows researchers to disentangle the brain mechanisms involved in the pain modulation encountered during hypnosis. It has been shown that the anterior cingulate and prefrontal cortices are important in the modulation of incoming sensory and noxious input. Moreover, clinical studies in certain types of surgery (eg thyroidectomy, mastectomy and plastic surgery) have demonstrated that hypnosis may avoid general anesthesia. [less ▲]

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See detailMesurer la douleur chez le patient non communicant.
Chatelle, Camille ULg; Vanhaudenhuyse, Audrey ULg; Mergam, Anne-Nora ULg et al

in Revue Médicale de Liège (2008), 63(5-6), 429-37

Pain is a subjective experience. Its assessment is based on the subject's direct verbal report. This method of assessment is, however, impossible in patients who cannot communicate their feelings. In this ... [more ▼]

Pain is a subjective experience. Its assessment is based on the subject's direct verbal report. This method of assessment is, however, impossible in patients who cannot communicate their feelings. In this context, indirect measurements such as behavioral observations or physiological measurements are needed. To facilitate the assessment of pain in non-communicative patients, numerous standardized behavioral scales have been developed. The aim of this review is to discuss the main validated pain scales employed in end-stage dementia, newborn and preverbal children, and severely brain damaged patients with a disorder of consciousness such as coma, the vegetative state or the minimally conscious state. [less ▲]

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