References of "Heine, Lizette"
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See detailMultifaceted Brain Networks Reconfiguration in Disorders of Consciousness Uncovered by Co-Activation Patterns
Di Perri, Carol ULiege; Amico, Enrico; Heine, Lizette ULiege et al

in Human Brain Mapping (in press)

Introduction: Given that recent research has shown that functional connectivity is not a static phenomenon, we aim to investigate the dynamic properties of the default mode network’s (DMN) connectivity in ... [more ▼]

Introduction: Given that recent research has shown that functional connectivity is not a static phenomenon, we aim to investigate the dynamic properties of the default mode network’s (DMN) connectivity in patients with disorders of consciousness. Methods: Resting-state fMRI volumes of a convenience sample of 17 patients in unresponsive wakefulness syndrome (UWS) and controls were reduced to a spatiotemporal point process by selecting critical time points in the posterior cingulate cortex (PCC). Spatial clustering was performed on the extracted PCC time frames to obtain 8 different co-activation patterns (CAPs). We investigated spatial connectivity patterns positively and negatively correlated with PCC using both CAPs and standard stationary method. We calculated CAPs occurrences and the total number of frames. Results: Compared to controls, patients showed (i) decreased within-network positive correlations and between-network negative correlations, (ii) emergence of “pathological” within-network negative correlations and between-network positive correlations (better defined with CAPs), and (iii) “pathological” increases in within-network positive correlations and between-network negative correlations (only detectable using CAPs). Patients showed decreased occurrence of DMN-like CAPs (1–2) compared to controls. No between-group differences were observed in the total number of frames Conclusion: CAPs reveal at a more fine-grained level the multifaceted spatial connectivity reconfiguration following the DMN disruption in UWS patients, which is more complex than previously thought and suggests alternative anatomical substrates for consciousness. BOLD fluctuations do not seem to differ between patients and controls, suggesting that BOLD response represents an intrinsic feature of the signal, and therefore that spatial configuration is more important for consciousness than BOLD activation itself. [less ▲]

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See detailGlobal structural integrity and effective connectivity in patients with disorders of consciousness
BODART, Olivier ULiege; Amico, Enrico; Gomez, Francisco et al

in Brain Stimulation (in press)

Background Previous studies have separately reported impaired functional, structural, and effective connectivity in patients with disorders of consciousness (DOC). The perturbational complexity index (PCI ... [more ▼]

Background Previous studies have separately reported impaired functional, structural, and effective connectivity in patients with disorders of consciousness (DOC). The perturbational complexity index (PCI) is a transcranial magnetic stimulation (TMS) derived marker of effective connectivity. The global fractional anisotropy (FA) is a marker of structural integrity. Little is known about how these parameters are related to each other. Objective We aimed at testing the relationship between structural integrity and effective connectivity. Methods We assessed 23 patients with severe brain injury more than 4 weeks post-onset, leading to DOC or locked-in syndrome, and 14 healthy subjects. We calculated PCI using repeated single pulse TMS coupled with high-density electroencephalography, and used it as a surrogate of effective connectivity. Structural integrity was measured using the global FA, derived from diffusion weighted imaging. We used linear regression modelling to test our hypothesis, and computed the correlation between PCI and FA in different groups. Results Global FA could predict 74% of PCI variance in the whole sample and 56% in the patients' group. No other predictors (age, gender, time since onset, behavioural score) improved the models. FA and PCI were correlated in the whole population (r = 0.86, p < 0.0001), the patients, and the healthy subjects subgroups. Conclusion We here demonstrated that effective connectivity correlates with structural integrity in brain-injured patients. Increased structural damage level decreases effective connectivity, which could prevent the emergence of consciousness. [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 detailEffects of preference and sensory modality on behavioral reaction in patients with disorders of consciousness
Heine, Lizette ULiege; 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 ULiege; Heine, Lizette ULiege; Martial, Charlotte ULiege 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 detailSedation of Patients With Disorders of Consciousness During Neuroimaging: Effects on Resting State Functional Brain Connectivity.
KIRSCH, Murielle ULiege; Guldenmund, Pieter; Bahri, Mohamed Ali ULiege 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 ULiege; 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 ULiege; Gosseries, Olivia ULiege; Azzolini, Deborah et al

in Neuropsychological Rehabilitation (2017)

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See detailTracking dynamic interactions between structural and functional connectivity: a TMS/EEG-dMRI study
Amico, Enrico; Bodart, Olivier ULiege; 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 detailMapping the functional connectome traits of levels of consciousness
Amico, Enrico; Marinazzo, Daniele; Di Perri, Carol ULiege 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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See detailBrain connectivity and sensory stimulation in disorders of consciousness
Heine, Lizette ULiege

Doctoral thesis (2016)

This thesis explores brain connectivity and sensory stimulation in patients with disorders of consciousness (DOC). These are serious conditions where massive brain damage can lead to a dissociation ... [more ▼]

This thesis explores brain connectivity and sensory stimulation in patients with disorders of consciousness (DOC). These are serious conditions where massive brain damage can lead to a dissociation between arousal and awareness (e.g., UWS and MCS). Part I explores brain connectivity. We highlight that brain function and structure are intimately related to each other, and to consciousness. The decrease in brain function can be used to distinguish between the clinically indicated states of consciousness. Part II evaluates passive sensory stimulations. Preferred stimuli may have the power to momentarily enhance brain function, and behavioral responses. [less ▲]

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See detailFunction–structure connectivity in patients with severe brain injury as measured by MRI-DWI and FDG-PET
Annen, Jitka ULiege; Heine, Lizette ULiege; Ziegler, Erik et al

in Human Brain Mapping (2016), 37(11), 3707-3720

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See detailRepeated Behavioral Assessments in Patients with Disorders of Consciousness
Wannez, Sarah ULiege; Annen, Jitka ULiege; Aubinet, Charlène ULiege 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 detailCorrelation between resting state fMRI total neuronal activity and PET metabolism in healthy controls and patients with disorders of consciousness
Soddu, Andrea ULiege; Gomez, Francisco; Heine, Lizette ULiege et al

in Brain and Behavior (2016), 6(1), 1-15

Introduction: The mildly invasive 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established imaging technique to measure ‘resting state’ cerebral metabolism. This technique made ... [more ▼]

Introduction: The mildly invasive 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established imaging technique to measure ‘resting state’ cerebral metabolism. This technique made it possible to assess changes in metabolic activity in clinical applications, such as the study of severe brain injury and disorders of consciousness. Objective: We assessed the possi- bility of creating functional MRI activity maps, which could estimate the rela- tive levels of activity in FDG-PET cerebral metabolic maps. If no metabolic absolute measures can be extracted, our approach may still be of clinical use in centers without access to FDG-PET. It also overcomes the problem of recogniz- ing individual networks of independent component selection in functional mag- netic resonance imaging (fMRI) resting state analysis. Methods: We extracted resting state fMRI functional connectivity maps using independent component analysis and combined only components of neuronal origin. To assess neu- ronality of components a classification based on support vector machine (SVM) was used. We compared the generated maps with the FDG-PET maps in 16 healthy controls, 11 vegetative state/unresponsive wakefulness syndrome patients and four locked-in patients. Results: The results show a significant similarity with q = 0.75  0.05 for healthy controls and q = 0.58  0.09 for vegetative state/unresponsive wakefulness syndrome patients between the FDG- PET and the fMRI based maps. FDG-PET, fMRI neuronal maps, and the conjunction analysis show decreases in frontoparietal and medial regions in vegetative patients with respect to controls. Subsequent analysis in locked-in syndrome patients produced also consistent maps with healthy controls. Conclusions: The constructed resting state fMRI functional connectivity map points toward the possibility for fMRI resting state to estimate relative levels of activity in a metabolic map. [less ▲]

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See detailNeural correlates of consciousness in patients who have emerged from a minimally conscious state: A cross-sectional multimodal imaging study
Di Perri, Carol ULiege; Bahri, Mohamed Ali ULiege; Amico, Enrico ULiege et al

in Lancet Neurology (2016), 15

Background Between pathologically impaired consciousness and normal consciousness exists a scarcely researched transition zone, referred to as emergence from minimally conscious state, in which patients ... [more ▼]

Background Between pathologically impaired consciousness and normal consciousness exists a scarcely researched transition zone, referred to as emergence from minimally conscious state, in which patients regain the capacity for functional communication, object use, or both. We investigated neural correlates of consciousness in these patients compared with patients with disorders of consciousness and healthy controls, by multimodal imaging. Methods In this cross-sectional, multimodal imaging study, patients with unresponsive wakefulness syndrome, patients in a minimally conscious state, and patients who had emerged from a minimally conscious state, diagnosed with the Coma Recovery Scale–Revised, were recruited from the neurology department of the Centre Hospitalier Universitaire de Liège, Belgium. Key exclusion criteria were neuroimaging examination in an acute state, sedation or anaesthesia during scanning, large focal brain damage, motion parameters of more than 3 mm in translation and 3° in rotation, and suboptimal segmentation and normalisation. We acquired resting state functional and structural MRI data and ¹⁸F-fl uorodeoxyglucose (FDG) PET data; we used seed-based functional MRI (fMRI) analysis to investigate positive default mode network connectivity (within-network correlations) and negative default mode network connectivity (between-network anticorrelations). We correlated FDG-PET brain metabolism with fMRI connectivity. We used voxel- based morphometry to test the eff ect of anatomical deformations on functional connectivity. Findings We recruited a convenience sample of 58 patients (21 [36%] with unresponsive wakefulness syndrome, 24 [41%] in a minimally conscious state, and 13 [22%] who had emerged from a minimally conscious state) and 35 healthy controls between Oct 1, 2009, and Oct 31, 2014. We detected consciousness-level-dependent increases (from unresponsive wakefulness syndrome, minimally conscious state, emergence from minimally conscious state, to healthy controls) for positive and negative default mode network connectivity, brain metabolism, and grey matter volume (p<0·05 false discovery rate corrected for multiple comparisons). Positive default mode network connectivity diff ered between patients and controls but not among patient groups (F test p<0·0001). Negative default mode network connectivity was only detected in healthy controls and in those who had emerged from a minimally conscious state; patients with unresponsive wakefulness syndrome or in a minimally conscious state showed pathological between-network positive connectivity (hyperconnectivity; F test p<0·0001). Brain metabolism correlated with positive default mode network connectivity (Spearman’s r=0·50 [95% CI 0·26 to 0·61]; p<0·0001) and negative default mode network connectivity (Spearman’s r=–0·52 [–0·35 to –0·67); p<0·0001). Grey matter volume did not diff er between the studied groups (F test p=0·06). Interpretation Partial preservation of between-network anticorrelations, which are seemingly of neuronal origin and cannot be solely explained by morphological deformations, characterise patients who have emerged from a minimally conscious state. Conversely, patients with disorders of consciousness show pathological between-network correlations. Apart from a deeper understanding of the neural correlates of consciousness, these fi ndings have clinical implications and might be particularly relevant for outcome prediction and could inspire new therapeutic options. [less ▲]

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See detailPrevalence of increases in functional connectivity in visual, somatosensory and language areas in congenital blindness
Heine, Lizette ULiege; Bahri, Mohamed Ali ULiege; cavaliere, Carlo et al

in Frontiers in Neuroanatomy (2015), 3(295),

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

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

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