References of "Laureys, Steven"
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See detailNear-death experiences: actual considerations.
Charland-Verville, Vanessa ULg; Martial, Charlotte ULg; Cassol, Helena ULg et al

in Schnakers, Caroline; Laureys, Steven (Eds.) Coma and Disorders of Consciousness, Second Edition (in press)

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See detailThe effect of spaceflight and microgravity on the human brain
Van Ombergen, Angelique; Demertzi, Athina ULg; Tomilovskaya et al

in Journal of Neurology (in press)

Microgravity, confinement, isolation, and immobilization are just some of the features astronauts have to cope with during space missions. Consequently, long-duration space travel can have detrimental ... [more ▼]

Microgravity, confinement, isolation, and immobilization are just some of the features astronauts have to cope with during space missions. Consequently, long-duration space travel can have detrimental effects on human physiology. Although research has focused on the cardiovascular and musculoskeletal system in particular, the exact impact of spaceflight on the human central nervous system remains to be determined. Previous studies have reported psychological problems, cephalic fluid shifts, neurovestibular problems, and cognitive alterations, but there is paucity in the knowledge of the underlying neural substrates. Previous space analogue studies and preliminary spaceflight studies have shown an involvement of the cerebellum, cortical sensorimotor, and somatosensory areas and the vestibular pathways. Extending this knowledge is crucial, especially in view of long-duration interplanetary missions (e.g., Mars missions) and space tourism. In addition, the acquired insight could be relevant for vestibular patients, patients with neurodegenerative disorders, as well as the elderly population, coping with multisensory deficit syndromes, immobilization, and inactivity. [less ▲]

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See detailA method for independent component graph analysis of resting-state fMRI. Brain and Behavior 2017, in press
Ribeiro de Paula, Demetrius; Ziegler, Erik; Abeyasinghe, P et al

in Brain and Behavior (in press)

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See detailSelf in Dementia
Antoine, Nicolas ULg; Genon, Sarah ULg; Bastin, Christine ULg et al

in Mishara; Corlett, P.; Fletcher, P. (Eds.) et al Phenomenological Neuropsychiatry, How Patient Experience Bridges Clinic with Clinical Neuroscience (in press)

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See detailTemporality of Features in Near-Death Experience Narratives
Martial, Charlotte ULg; Cassol, Helena ULg; Antonopoulos, Georgios ULg et al

in Frontiers in Human Neuroscience (2017)

Background: After an occurrence of a Near-Death Experience (NDE), Near- Death Experiencers (NDErs) usually report extremely rich and detailed narratives. Phenomenologically, a NDE can be described as a ... [more ▼]

Background: After an occurrence of a Near-Death Experience (NDE), Near- Death Experiencers (NDErs) usually report extremely rich and detailed narratives. Phenomenologically, a NDE can be described as a set of distinguishable features. Some authors have proposed regular patterns of NDEs, however, the actual temporality sequence of NDE core features remains a little explored area. Objectives: The aim of the present study was to investigate the frequency distribution of these features (globally and according to the position of features in narratives) as well as the most frequently reported temporality sequences of features. Methods: We collected 154 French freely expressed written NDE narratives (i.e., Greyson NDE scale total score 7/32). A text analysis was conducted on all narratives in order to infer temporal ordering and frequency distribution of NDE features. Results: Our analyses highlighted the following most frequently reported sequence of consecutive NDE features: Out-of-Body Experience, Experiencing a tunnel, Seeing a bright light, Feeling of peace. Yet, this sequence was encountered in a very limited number of NDErs. Conclusion: These findings may suggest that NDEs temporality sequences can vary across NDErs. Exploring associations and relationships among features encountered during NDEs may complete the rigorous definition and scientific comprehension of the phenomenon. [less ▲]

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See detailMultimodal imaging analysis in Charles Bonnet Syndrome: a case report
Martial, Charlotte ULg; Di Perri, Carol ULg; Larroque, Stephen ULg et al

Poster (2017, June)

Charles Bonnet syndrome (CBS) is a rare condition characterized by visual impairment associated with complex visual hallucinations in psychologically normal elderly people. Previous studies have suggested ... [more ▼]

Charles Bonnet syndrome (CBS) is a rare condition characterized by visual impairment associated with complex visual hallucinations in psychologically normal elderly people. Previous studies have suggested that visual hallucinations may be caused by brain damage in the visual system. However, in the case of CBS, specific brain regions in the occipital cortex have not been clearly determined and functional neuroimaging remains relatively unexplored. To our knowledge, functional connectivity by means of resting-state magnetic resonance imaging (MRI) has never been investigated in patients with CBS. We here aimed to investigate structural imaging, brain metabolism and functional connectivity in a patient with CBS. Resting-state functional and structural MRI were acquired in an 85-year-old patient with CBS and 12 age- and gender-matched normally sighted controls. Cognitive functioning was measured by behavioral assessment. A seed-based resting state fMRI was performed to investigate the default mode network (DMN), the executive control network and the visual networks connectivity. A voxel-based morphometry (VBM) analysis was employed to investigate the grey matter volume. Cortical and subcortical grey matter thickness were further investigated. Finally, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was also acquired to observe regional glucose uptake by comparing standard uptake values (SUVs). Increased functional connectivity was found between the DMN and the temporo-occipital fusiform cortex, as well as between the secondary visual cortex and the left frontal cortex, in the CBS patient compared to controls. The patient also demonstrated increased functional connectivity between the primary visual cortex and the left supramarginal gyrus and between the associative visual cortex and the superior temporal gyrus/angular gyrus, as compared to controls. Decreased grey matter volume was observed in the lateral occipital cortex/angular gyrus in our patient as compared to controls. Diminished grey matter thickness values were observed in the lateral geniculate nucleus compared to healthy controls. FDG-PET results confirmed previous work and showed bilateral hypometabolism in the occipital cortex (mean SUV reduction of 5.36%, p<0.001). Our results suggest that structural alterations in visual system in CBS are associated with compensatory/adaptive changes in functional connectivity that involve regions known to support hallucinations of faces in CBS patients. We suggest that this functional connectivity reorganization following visual structural damage may contribute to visual hallucinations. These findings might shed light on the pathophysiology underlining this rare condition. [less ▲]

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See detailEffects of preference and sensory modality on behavioral reaction in patients with disorders of consciousness
Heine, Lizette ULg; Tillmann, Barbara; Hauet, Marjolaine et al

in Brain Injury (2017)

Background: Reliable evaluation of patients with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS) remains a major challenge. It has been suggested that the expression of ... [more ▼]

Background: Reliable evaluation of patients with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS) remains a major challenge. It has been suggested that the expression of residual cerebral function could be improved by allowing patients to listen to their favourite music. However, the potential effect of music on behavioural responsiveness, as well as the effect of preferred stimuli in other sensory modalities (e.g. olfaction), remain poorly understood. Objective: The aim of our study was to investigate the effect of sensory modality (auditory versus olfactory) and preference (preferred versus neutral) of the test stimuli on patients’ subsequent performance on the Coma Recovery Scale-Revised (CRS-R). Research design: Within-subject design because of inter-individual differences between patients. Methods and procedures: We studied four items from the CRS-R (visual pursuit using a mirror, auditory localization of the own name and two movements to command) in 13 patients (7 MCS; 6 UWS). Main outcomes and results: Auditory stimuli triggered higher responsiveness compared to olfactory stimuli, and preferred stimuli were followed by higher scores than did neutral stimuli. Conclusions: Findings suggest that preferred auditory stimuli at the bedside contribute to the expression of residual function and could improve the diagnostic assessment. [less ▲]

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See detailClinical sub-categorization of minimally conscious state according to resting functional connectivity
Aubinet, Charlène ULg; Heine, Lizette ULg; Martial, Charlotte ULg et al

Conference (2017, March 31)

Introduction: Patients in a minimally conscious state (MCS) have been subcategorized in MCS plus and MCS minus, respectively with and without command following capacity. Here we aim to characterize ... [more ▼]

Introduction: Patients in a minimally conscious state (MCS) have been subcategorized in MCS plus and MCS minus, respectively with and without command following capacity. Here we aim to characterize differences in MCS plus as compared to MCS minus by means of functional connectivity (FC). Method: Resting state functional magnetic resonance imagery (fMRI) was acquired in 292 MCS patients and a seed-based analysis was conducted on a convenience sample of 19 MCS patients (10 MCS plus and 9 MCS minus) and 35 healthy controls. We investigated the left and right frontoparietal networks (FPN), the auditory network and the default mode network (DMN). We employed a ROI-to-ROI analysis to investigate the inter-hemispheric connectivity and we investigated inter-group differences in grey and white matter volume by means of voxel-based morphometry. Results: We found a higher FC in MCS plus as compared to MCS minus in the left FPN, specifically between the left dorso-lateral prefrontal cortex and the left temporo-occipital fusiform cortex (TOFC). The FC of auditory network, right FPN and DMN, inter-hemispheric connectivity and structure of grey and white matter did not show differences between patients groups. Discussion: Our results suggest that the clinical sub-categorization of MCS is sustained by FC differences in a language-related executive control network. MCS plus and MCS minus patients are not differentiated by networks involved in auditory processing, perception of surroundings and internal thoughts, nor by differences in inter-hemispheric connectivity and in morphology. [less ▲]

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See detail2 Years outcome of patients in unresponsive wakefulness syndrome/vegetative state and minimally conscious state
Cassol, Helena ULg; LEDOUX, Didier ULg; Thibaut, Aurore ULg et al

Poster (2017, March)

INTRODUCTION: Following severe acute brain damage, patients typically evolve from coma to an unresponsive wakefulness syndrome/vegetative state (UWS/VS; wakefulness without awareness) and later to a ... [more ▼]

INTRODUCTION: Following severe acute brain damage, patients typically evolve from coma to an unresponsive wakefulness syndrome/vegetative state (UWS/VS; wakefulness without awareness) and later to a minimally conscious state (MCS; fluctuating but consistent nonreflex behaviors). MCS is subcategorized in MCS+ (i.e., command following) and MCS- (i.e., visual pursuit, localization of noxious stimulation or contingent behaviours). Reliable and consistent interactive communication and/or functional use of objects indicate the next boundary – emergence from MCS (EMCS). To date, there is still no reliable predictive model of recovery from the UWS/VS and the MCS. A better understanding of patients' outcome would help in decisions regarding patients’ care and rehabilitation, as well as end-of-life decisions. METHODS: We collected demographic information, acute care history and longitudinal follow-up of patients in UWS/VS and MCS admitted in 15 expert centers in Belgium (via the Belgian Federal Public Service Health). Patients were evaluated at 1, 3, 6, 12 and 24 months post injury with the Coma Recovery Scale-Revised and the diagnosis was based on internationally accepted criteria of UWS/VS, MCS or EMCS. Results were considered significant at p<0.001. RESULTS: 24 months follow-up was available for 476 patients including 261 diagnosed in UWS/VS (88 traumatic, 173 non-traumatic) and 215 diagnosed in MCS (80 traumatic, 135 non-traumatic) one month after the injury. Patients who were in MCS one month after the insult were more likely to recover functional communication or object use after 24 months than patients in UWS/VS. Moreover, functional recovery occurred more often in MCS+ (79%) as compared to MCS- (29%), and mortality rate was more important in MCS- patients (68%) as compared to MCS+ (21%). Comparisons within UWS/VS and MCS groups based on etiology showed that traumatic patients had a better outcome at 24 months than non-traumatic patients. Among non-traumatic patients, no difference was found between anoxic patients and patients with other etiologies regarding functional recovery. CONCLUSION: Our study highlights that the outcome is significantly better for patients who are in MCS one month post-injury as compared to patients who remain in UWS/VS at that time. Concerning MCS patients, the outcome is significantly better for patients who are MCS+ one month post-injury as compared to patients who are MCS- at that time. This study also confirms that patients with traumatic etiology have better prognosis than patients with non-traumatic causes. [less ▲]

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See detailCharacterization of minimally conscious state minus and plus according to resting functional connectivity
Aubinet, Charlène ULg; Heine, Lizette; Martial, Charlotte ULg et al

Scientific conference (2017, February 01)

The minimally conscious state (MCS) has been sub-categorized in MCS plus and MCS minus, i.e. respectively with and without command following capacity. Here we aimed at characterizing differences in MCS ... [more ▼]

The minimally conscious state (MCS) has been sub-categorized in MCS plus and MCS minus, i.e. respectively with and without command following capacity. Here we aimed at characterizing differences in MCS plus as compared to MCS minus by means of functional connectivity (FC). Resting state functional magnetic resonance imagery (fMRI) was acquired in 292 MCS patients and a seed-based analysis was conducted on a convenience sample of 19 MCS patients (10 MCS plus and 9 MCS minus) and 35 healthy controls. We investigated the left and right frontoparietal networks (FPN), the auditory network and the default mode network (DMN). We employed a ROI-to-ROI analysis and a voxel-based morphometry in order to investigate the inter-hemispheric connectivity and the grey and white matter volume, respectively. A significantly higher FC was found in MCS plus as compared to MCS minus in the left FPN, specifically between the left dorso-lateral prefrontal cortex and the left temporo-occipital fusiform cortex (TOFC). The FC of auditory network, right FPN and DMN, inter-hemispheric connectivity and structure of grey and white matter did not show differences between patients groups. The clinical sub-categorization of MCS is therefore sustained by FC differences in a language-related executive control network. These patient groups are not differentiated by networks involved in auditory processing, perception of surroundings and internal thoughts, nor by differences in inter-hemispheric connectivity and in morphology. [less ▲]

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See detailSedation of Patients With Disorders of Consciousness During Neuroimaging: Effects on Resting State Functional Brain Connectivity.
KIRSCH, Murielle ULg; Guldenmund, Pieter; Bahri, Mohamed Ali ULg et al

in Anesthesia and Analgesia (2017), 124(2),

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See detailAltered functional brain connectivity in patients with visually induced dizziness
Van Ombergen, Angelique; Heine, Lizette ULg; Jillings, Steven et al

in NeuroImage (2017), 14

Background: Vestibular patients occasionally report aggravation or triggering of their symptoms by visual stimuli, which is called visually induced dizziness (VID). These patients therefore experience ... [more ▼]

Background: Vestibular patients occasionally report aggravation or triggering of their symptoms by visual stimuli, which is called visually induced dizziness (VID). These patients therefore experience dizziness, discomfort, disorientation and postural unsteadiness. The underlying pathophysiology of VID is still poorly understood. Objective: The aimof the current explorative study was to gain a first insight in the underlying neural aspects of VID. Methods:We included 10 VID patients and 10 healthymatched controls, all ofwhich underwent a resting state fMRI scan session. Changes in functional connectivitywere explored bymeans of the intrinsic connectivity contrast (ICC). Seed-based analysis was subsequently performed in visual and vestibular seeds. Results: We found a decreased functional connectivity in the right central operculum (superior temporal gyrus), as well as increased functional connectivity in the occipital pole in VID patients as compared to controls in a hypothesis-free analysis. A weaker functional connectivity between the thalamus and most of the right putamen was measured in VID patients in comparison to controls in a seed-based analysis. Furthermore, also by means of a seed-based analysis, a decreased functional connectivity between the visual associative area and the left parahippocampal gyrus was found in VID patients. Additionally,we found increased functional connectivity between thalamus and occipital and cerebellar areas in the VID patients, as well as between the associative visual cortex and both middle frontal gyrus and precuneus. Conclusions:We found alterations in the visual and vestibular cortical network in VID patients that could underlie the typical VID symptoms such as a worsening of their vestibular symptoms when being exposed to challenging visual stimuli. These preliminary findings provide the first insights into the underlying functional brain connectivity in VID patients. Future studies should extend these findings by employing larger sample sizes, by investigating specific task-based paradigms in these patients and by exploring the implications for treatment. [less ▲]

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See detailPrevalence of coma-recovery scale-revised signs of consciousness in patients in minimally conscious state
Wannez, Sarah ULg; Gosseries, Olivia ULg; Azzolini, Deborah et al

in Neuropsychological Rehabilitation (2017)

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See detailObjective assessment of visual pursuit in patients with disorders of consciousness: an exploratory study.
Wannez, Sarah ULg; Hoyoux, Thomas; Langohr, Thomas et al

in Journal of Neurology (2017)

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See detailTracking dynamic interactions between structural and functional connectivity: a TMS/EEG-dMRI study
Amico, Enrico; Bodart, Olivier ULg; Rosanova, Mario et al

in Brain connectivity (2017)

Transcranial magnetic stimulation (TMS) in combination with neuroimaging techniques allows to measure the effects of a direct perturbation of the brain. When coupled to high density electroencephalography ... [more ▼]

Transcranial magnetic stimulation (TMS) in combination with neuroimaging techniques allows to measure the effects of a direct perturbation of the brain. When coupled to high density electroencephalography (TMS/hd-EEG), TMS pulses revealed electrophysiological signatures of different cortical modules in health and disease. However, the neural underpinnings of these signatures remain unclear. Here, by applying multimodal analyses of cortical response to TMS recordings and diffusion magnetic resonance imaging (dMRI) tractography, we investigated the relationship between functional and structural features of different cortical modules in a cohort of awake healthy volunteers. For each subject we computed directed functional connectivity interactions between cortical areas from the source reconstructed TMS/hd- EEG recordings and correlated them with the correspondent structural connectivity matrix extracted from dMRI tractography, in three different frequency bands (alpha, beta, gamma) and two sites of stimulation (left precuneus and left premotor). Each stimulated area appeared to mainly respond to TMS by being functionally elicited in specific frequency bands, i.e. beta for precuneus and gamma for premotor. We also observed a temporary decrease in the whole-brain correlation between directed functional connectivity and structural connectivity after TMS in all frequency bands. Notably, when focusing on the stimulated areas only, we found that the structurefunction correlation significantly increases over time in the premotor area contralateral to TMS. Our study points out the importance of taking into account the major role played by different cortical oscillations when investigating the mechanisms for integration and segregation of information in the human brain. [less ▲]

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See detailFalse memory susceptibility in coma survivors with and without a near-death experience
Martial, Charlotte ULg; Charland-Verville, Vanessa ULg; Dehon, Hedwige ULg et al

in Psychological Research (2017)

It has been postulated that memories of neardeath experiences (NDEs) could be (at least in part) reconstructions based on experiencers’ (NDErs) previous knowledge and could be built as a result of the ... [more ▼]

It has been postulated that memories of neardeath experiences (NDEs) could be (at least in part) reconstructions based on experiencers’ (NDErs) previous knowledge and could be built as a result of the individual’s attempt to interpret the confusing experience. From the point of view of the experiencer, NDE memories are perceived as being unrivalled memories due to its associated rich phenomenology. However, the scientific literature devoted to the cognitive functioning of NDErs in general, and their memory performance in particular, is rather limited. This study examined NDErs’ susceptibility to false memories using the Deese–Roediger–McDermott (DRM) paradigm. We included 20 NDErs who reported having had their experience in the context of a life-threatening event (Greyson NDE scale total score ≥7/32) and 20 volunteers (matched for age, gender, education level, and time since brain insult) who reported a life-threatening event but without a NDE. Both groups were presented with DRM lists for a recall task during which they were asked to assign “Remember/Know/Guess” judgements to any recalled response. In addition, they were later asked to complete a post-recall test designed to obtain estimates of activation and monitoring of critical lures. Results demonstrated that NDErs and volunteers were equally likely to produce false memories, but that NDErs recalled them more frequently associated with compelling illusory recollection. Of particular interest, analyses of activation and monitoring estimates suggest that NDErs and volunteers groups were equally likely to think of critical lures, but source monitoring was less successful in NDErs compared to volunteers. [less ▲]

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See detailMapping the functional connectome traits of levels of consciousness
Amico, Enrico; Marinazzo, Daniele; Di Perri, Carol ULg et al

in NeuroImage (2017)

Examining task-free functional connectivity (FC) in the human brain offers insights on how spontaneous integration and segregation of information relate to human cognition, and how this organization may ... [more ▼]

Examining task-free functional connectivity (FC) in the human brain offers insights on how spontaneous integration and segregation of information relate to human cognition, and how this organization may be altered in different conditions, and neurological disorders. This is particularly relevant for patients in disorders of consciousness (DOC) following severe acquired brain damage and coma, one of the most devastating conditions in modern medical care. We present a novel data-driven methodology, connICA, which implements Independent Component Analysis (ICA) for the extraction of robust independent FC patterns (FC-traits) from a set of individual functional connectomes, without imposing any a priori data stratification into groups. We here apply connICA to investigate associations between network-traits derived from task-free FC and cognitive features that define levels of consciousness. Three main independent FC-traits were identified and linked to consciousness-related clinical features. The first one represents the functional configuration of an "awake resting" brain, and is associated to the level of arousal. The second FC-trait reflects the disconnection of the visual and sensory-motor connectivity patterns and relates to the ability of communicating with the external environment. The third FC-trait isolates the connectivity pattern encompassing the fronto-parietal and the default-mode network areas as well as the interaction between left and right hemisphere, which are also associated to the awareness of the self and its surroundings. Each FC-trait represents a distinct functional process with a role in the degradation of conscious states in functional brain networks, shedding further light on the functional subcircuits that get disrupted in severe brain-damage. [less ▲]

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