Publications of Murielle KIRSCH
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See detailGeneral Anesthesia: A Probe to Explore Consciousness
BONHOMME, Vincent ULiege; STAQUET, Cécile ULiege; Montupil, Javier ULiege et al

in Frontiers in Systems Neuroscience (2019)

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See detailBOLD power spectral density differentiates patients with pathological consciousness
Alcauter, Sarael; Carrière, Manon ULiege; Raimondo, Federico ULiege et al

Poster (2019, June 10)

Introduction: Functional connectivity has been successfully used to discriminate non-sedated patients with disorders of consciousness (Demertzi et al., 2015). However, on clinical demand, patients are ... [more ▼]

Introduction: Functional connectivity has been successfully used to discriminate non-sedated patients with disorders of consciousness (Demertzi et al., 2015). However, on clinical demand, patients are evaluated under sedation to restrict motion, which considerably limits the classification of patients based on functional connectivity. It has been previously shown that changes of the frequency properties of spontaneous BOLD signal are of cognitive relevance even in sleeping neonates (Alcauter et al., 2015). We therefore aimed at exploring the automatic discrimination of sedated patients in the clinical entities of minimally consciousness state (MCS) and unresponsive wakefulness syndrome (UWS), based on the frequency profile of the BOLD signal. Methods: Forty-four patients with MCS (n=26) or VS/UWS (n=18), based on the Coma Recovery Scale-Revised (CRS-R), were scanned on a 3T MRI scanner. Images of the whole brain were acquired with BOLD-sensitive sequences (300 volumes, TR=2s, TE=30ms, voxel size=3x3x3 mm3) and a T1 (TR=2.3s, TE=2.47ms, voxel size = 1x1x1.2 mm3). Sedative agents (propofol, sevoflurane, or a combination of both) were administered using the minimum necessary dose. Preprocessing of functional images included slice-time correction, realignment, segmentation, normalisation, and smoothing (6mm FWHM). Noise reduction included detection and regression of motion outliers (ART toolbox), anatomical component-based correction, and regression of motion parameters, no temrporal filtering was applied. The average power density between 0.01 and 0.1 Hz (classic frequency band for resting state analyses) was estimated and divided by the total power density, for each voxel. Supervised classification of patients in MCS or UWS was explored with Support Vector Machine classifiier using stratified 5-fold cross-validation. The clusters with significant differences between groups (p<0.005, uncorrected; cluster size > 10 voxels) in the training sets were selected as features. The 5-fold validation was repeated 20 times to estimate the variability of the classification accuracies and the frequency of each voxel being selected as a relevant feature. Results:The average classification accuracy was 79%±5 (SD), with average sensitivity 76%±10, and specificity 81%±9. The most frequently selected regions as features included the superior parietal lobule (Frequency: 100%; MNI x, y, z (mm): -26, -50, 64), putamen (97%; -30, -6, -8), occipital fusiform gyrus (92%; -34, -70, -20), occipital pole (65%; 22, -98, 16), angular gyrus (54%; -60, -58, 32). Conclusions: The power spectral density of the spontaneous BOLD signal under anesthesia allowed to classify individual patients with MCS and UWS with 79% accuracy. The most frequent selected features included association areas in the parietal and occipital lobes and the putamen. Further validation with independent cohorts is needed to generalize the current findings. Taken together, the use of power spectral density may represent an alternative to functional connectivity to classify patients with consciousness disorders under anesthesia, therefore capturing properties of conscious function beyond reportability. [less ▲]

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See detailMapping the functional connectome traits of levels of consciousness
Amico, Enrico ULiege; 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 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 detailThalamic and extrathalamic mechanisms of consciousness after severe brain injury.
Lutkenhoff, Evan; Chiang, Jeffrey; TSHIBANDA, Luaba ULiege 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 detailMultiple fMRI system-level baseline connectivity is disrupted in patients with consciousness alterations
Demertzi, Athina ULiege; Gomez, Francisco; Crone, Julia-Sophia et al

in Cortex: A Journal Devoted to the Study of the Nervous System and Behavior (2014), 52

Introduction: In healthy conditions, group-level fMRI resting state analyses identify ten resting state networks (RSNs) of cognitive relevance. Here, we aim to assess the tennetwork model in severely ... [more ▼]

Introduction: In healthy conditions, group-level fMRI resting state analyses identify ten resting state networks (RSNs) of cognitive relevance. Here, we aim to assess the tennetwork model in severely brain-injured patients suffering from disorders of consciousness and to identify those networks which will be most relevant to discriminate between patients and healthy subjects. Methods: 300 fMRI volumes were obtained in 27 healthy controls and 53 patients in minimally conscious state (MCS), vegetative state/unresponsive wakefulness syndrome (VS/ UWS) and coma. Independent component analysis (ICA) reduced data dimensionality. The ten networks were identified by means of a multiple template-matching procedure and were tested on neuronality properties (neuronal vs non-neuronal) in a data-driven way. Univariate analyses detected between-group differences in networks’ neuronal properties and estimated voxel-wise functional connectivity in the networks, which were significantly less identifiable in patients. A nearest-neighbor “clinical” classifier was used to determine the networks with high between-group discriminative accuracy. Results: Healthy controls were characterized by more neuronal components compared to patients in VS/UWS and in coma. Compared to healthy controls, fewer patients in MCS and VS/UWS showed components of neuronal origin for the left executive control network, default mode network (DMN), auditory, and right executive control network. The “clinical” classifier indicated the DMN and auditory network with the highest accuracy (85.3%) in discriminating patients from healthy subjects. [less ▲]

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See detailFunctional neuroanatomy underlying the clinical subcategorization of minimally conscious state patients.
Bruno, Marie-Aurélie ULiege; Majerus, Steve ULiege; Boly, Mélanie ULiege et al

in Journal of Neurology (2012), 259(6), 1087-98

Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this ... [more ▼]

Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this entity can be subcategorized into MCS- (i.e., patients only showing nonreflex behavior such as visual pursuit, localization of noxious stimulation and/or contingent behavior) and MCS+ (i.e., patients showing command following).Patterns of cerebral glucose metabolism were studied using [(18)F]-fluorodeoxyglucose-PET in 39 healthy volunteers (aged 46 +/- 18 years) and 27 MCS patients of whom 13 were MCS- (aged 49 +/- 19 years; 4 traumatic; 21 +/- 23 months post injury) and 14 MCS+ (aged 43 +/- 19 years; 5 traumatic; 19 +/- 26 months post injury). Results were thresholded for significance at false discovery rate corrected p < 0.05.We observed a metabolic impairment in a bilateral subcortical (thalamus and caudate) and cortical (fronto-temporo-parietal) network in nontraumatic and traumatic MCS patients. Compared to MCS-, patients in MCS+ showed higher cerebral metabolism in left-sided cortical areas encompassing the language network, premotor, presupplementary motor, and sensorimotor cortices. A functional connectivity study showed that Broca's region was disconnected from the rest of the language network, mesiofrontal and cerebellar areas in MCS- as compared to MCS+ patients.The proposed subcategorization of MCS based on the presence or absence of command following showed a different functional neuroanatomy. MCS- is characterized by preserved right hemispheric cortical metabolism interpreted as evidence of residual sensory consciousness. MCS+ patients showed preserved metabolism and functional connectivity in language networks arguably reflecting some additional higher order or extended consciousness albeit devoid of clinical verbal or nonverbal expression. [less ▲]

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See detailMécanismes de l'anesthésie générale: apport de l'imagerie fonctionnelle
Boveroux, Pierre ULiege; Bonhomme, Vincent ULiege; Kirsch, Murielle ULiege et al

in Revue Médicale de Liège (2009), 64(Synthèse 2009), 36-41

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See detailHypnose et perception de la douleur
Vanhaudenhuyse, Audrey ULiege; Boveroux, Pierre ULiege; Boly, Mélanie ULiege 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 detailComment prédire l'évolution du coma post-anoxique?
Kirsch, Murielle ULiege; Boveroux, Pierre ULiege; Massion, Paul ULiege et al

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

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See detailPrise en charge de la douleur en pediatrie apres chirurgie ambulatoire
Hallet, Claude ULiege; Kirsch, Murielle ULiege; Hick, Gaëtane ULiege et al

in Revue Médicale de Liège (2007), 62(11), 679-84

Over the last fifteen years, child's pain has become one of our major concerns. In spite of this evolution, it remains one of the most frequent complications after ambulatory surgery. It is thus essential ... [more ▼]

Over the last fifteen years, child's pain has become one of our major concerns. In spite of this evolution, it remains one of the most frequent complications after ambulatory surgery. It is thus essential to implement all the resources we have at our disposal in order to optimize pain management. This can be obtained by basing our strategy on the concept of multimode analgesia. It is consequently essential that each team can achieve its own quality program; the corollary will be the development of clear recommendations for the parents with a systematic analgesics regulation at home and the possibility to resort to the family doctor or to the ambulatory centre in the event of persistence of pain. [less ▲]

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See detailActualites therapeutiques en anesthesie-reanimation: cap sur l'hopital de jour
Hick, Gaëtane ULiege; Kirsch, Murielle ULiege; Janssens, Marc ULiege et al

in Revue Médicale de Liège (2007), 62(5-6, May-Jun), 272-6

The one day clinic possesses its own structure and organisation; patient management is also specific. Preoperative visit and assessment are programmed at least 48 hours before anesthesia. Preoperative ... [more ▼]

The one day clinic possesses its own structure and organisation; patient management is also specific. Preoperative visit and assessment are programmed at least 48 hours before anesthesia. Preoperative examinations and choice of anesthetic technique (sedation associated with local anesthesia or not, general anesthesia, locoregional anesthesia, or hypnosedation) are discussed and determined depending upon medical history, clinical examination, and type of procedure. General recommandations, instructions about fasting, interruption of some therapies, and introduction of new medication(s) are explained orally and also provided in a written document. New anesthetics and analgesics allow quick awakening and recovery of vital functions, and subsequently rapid hospital discharge. Prevention and aggressive treatment of postoperative nausea and vomiting are also a major concern in our anesthesic management of ambulatory patient. [less ▲]

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