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See detailA Heartbeat Away From Consciousness: Heart Rate Variability Entropy can discriminate disorders of consciousness and is correlated with resting-state fMRI brain connectivity of the Central Autonomic Network
Riganello, Francesco ULiege; Larroque, Stephen Karl ULiege; Bahri, Mohamed Ali ULiege et al

Poster (2018, October)

Motivation: Heart rate variability (HRV) reflects the heart-brain two-way dynamic interactions[1-5]. HRV entropy analysis quantifies the unpredictability and complexity of the heart rate beats intervals ... [more ▼]

Motivation: Heart rate variability (HRV) reflects the heart-brain two-way dynamic interactions[1-5]. HRV entropy analysis quantifies the unpredictability and complexity of the heart rate beats intervals and over multiple time scales using multiscale entropy (MSE)[6-8]. The complexity index (CI) provides a score of a system’s complexity by aggregating the MSE measures over a range of time scales[8]. Most HRV entropy studies have focused on acute traumatic patients using task-based designs[9]. We here investigate the CI and its discriminative power in chronic patients with unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS) at rest, and its relation to brain functional connectivity. Methods: We investigated the CI in short (CIs) and long (CIl) time scales in 16 UWS and 17 MCS sedated. CI for MCS and UWS groups were compared using a Mann-Whitney exact test. Spearman’s correlation tests were conducted between the Coma Recovery Scale-revised (CRS-R) and both CI. Discriminative power of both CI was assessed with One-R machine learning model. Correlation between CI and brain connectivity (detected with functional magnetic resonance imagery using seed-based and hypothesis-free intrinsic connectivity) was investigated using a linear regression in a subgroup of 12 UWS and 12 MCS patients with sufficient image quality. Results and Discussion: Significant differences were found between MCS and UWS for CIs and CIl (0.0001≤p≤0.006). Significant correlations were found between CRS-R and CIs and CIl (0.0001≤p≤0.026). The One-R classifier selected CIl as the best discriminator between UWS and MCS with 85% accuracy, 19% false positive rate and 12% false negative rate after a 10-fold cross-validation test. Positive correlations were observed between CI and brain areas belonging to the autonomic system. CI was found to be significantly higher in MCS compared to UWS patients, with high discriminative power and lower false negative rate than the reported misdiagnosis rate of human assessors, providing an easy, inexpensive and non-invasive diagnosis tool. CI is correlated to functional connectivity changes in brain regions belonging to the autonomic nervous system, suggesting that CI can provide an indirect way to screen and monitor connectivity changes in this neural system. Future studies should investigate further the extent of CI’s predictive power for other pathologies in the disorders of consciousness spectrum. [less ▲]

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See detailA Heartbeat Away From Consciousness: Heart Rate Variability Entropy Can Discriminate Disorders of Consciousness and Is Correlated With Resting-State fMRI Brain Connectivity of the Central Autonomic Network
Riganello, Francesco ULiege; Larroque, Stephen Karl ULiege; Bahri, Mohamed Ali ULiege et al

in Frontiers in Neurology (2018), 9

Background: Disorders of consciousness are challenging to diagnose, with inconsistent behavioral responses, motor and cognitive disabilities, leading to approximately 40% misdiagnoses. Heart rate ... [more ▼]

Background: Disorders of consciousness are challenging to diagnose, with inconsistent behavioral responses, motor and cognitive disabilities, leading to approximately 40% misdiagnoses. Heart rate variability (HRV) reflects the complexity of the heart-brain two-way dynamic interactions. HRV entropy analysis quantifies the unpredictability and complexity of the heart rate beats intervals. We here investigate the complexity index (CI), a score of HRV complexity by aggregating the non-linear multi-scale entropies over a range of time scales, and its discriminative power in chronic patients with unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS), and its relation to brain functional connectivity. Methods: We investigated the CI in short (CIs) and long (CIl) time scales in 14 UWS and 16 MCS sedated. CI for MCS and UWS groups were compared using a Mann-Whitney exact test. Spearman's correlation tests were conducted between the Coma Recovery Scale-revised (CRS-R) and both CI. Discriminative power of both CI was assessed with One-R machine learning model. Correlation between CI and brain connectivity (detected with functional magnetic resonance imagery using seed-based and hypothesis-free intrinsic connectivity) was investigated using a linear regression in a subgroup of 10 UWS and 11 MCS patients with sufficient image quality. Results: Higher CIs and CIl values were observed in MCS compared to UWS. Positive correlations were found between CRS-R and both CI. The One-R classifier selected CIl as the best discriminator between UWS and MCS with 90% accuracy, 7% false positive and 13% false negative rates after a 10-fold cross-validation test. Positive correlations were observed between both CI and the recovery of functional connectivity of brain areas belonging to the central autonomic networks (CAN). Conclusion: CI of MCS compared to UWS patients has high discriminative power and low false negative rate at one third of the estimated human assessors' misdiagnosis, providing an easy, inexpensive and non-invasive diagnostic tool. CI reflects functional connectivity changes in the CAN, suggesting that CI can provide an indirect way to screen and monitor connectivity changes in this neural system. Future studies should assess the extent of CI's predictive power in a larger cohort of patients and prognostic power in acute patients. [less ▲]

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See detailBrain, behavior, and cognitive interplay in disorders of consciousness: A multiple case study
Aubinet, Charlène ULiege; Murphy, Leslie; Bahri, Mohamed Ali ULiege et al

in Frontiers in Neurology (2018), 9(665), 1-10

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See detailA multiple case study investigating the sub-categorization of the minimally conscious state
Aubinet, Charlène ULiege; Panda, Rajanikant ULiege; Cassol, Helena ULiege et al

Poster (2018, June 28)

The minimally conscious state (MCS) was sub-categorized in MCS+ and MCS- based on language-related behaviors (i.e., command-following, intelligible verbalization or intentional communication). Due to ... [more ▼]

The minimally conscious state (MCS) was sub-categorized in MCS+ and MCS- based on language-related behaviors (i.e., command-following, intelligible verbalization or intentional communication). Due to pronosis implications, it is important to detect signs of MCS+ and evaluate patients’ likelihood to recover such behaviors. We here aim to describe behavioral and neuroimaging data of severe brain-injured patients who evolved from MCS- to MCS+. Four patients were thus assessed at two time points by means of repeated Coma Recovery Scale-Revised. During their first week of assessments, they were diagnosed as MCS-. They later recovered language-related behaviors (i.e., MCS+), when reassessed during their second week of evaluations. All patients underwent a positron emission tomography (PET-scan) and magnetic resonance imaging (including voxel-based morphometry – VBM) exams during both weeks of assessments. We here compared the neuroimaging differences between the two exams in these four patients. PET-scan results showed that all patients presented partial recovery of metabolism in temporal lobules, reflecting compensation either from left-sided language areas or from their contralateral regions. VBM results showed that two patients presented a significant increase of grey matter volume, particularly concerning either bilateral frontal areas or the left caudate, which was related to memory, learning and language abilities. The other two patients did not show difference in grey matter structure between MCS- and MCS+. We conclude that the clinical evolution of patients from MCS- to MCS+ suggests the reappearance of language-based behavioral signs, but also the partial recovery of metabolism and grey matter structure in cerebral regions that are involved in language processing. All patients recovered signs of MCS+ at an advance chronic stage. These neuroimaging results highlight the remaining neuroplasticity in chronic MCS. [less ▲]

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See detailA Heartbeat Away From Consciousness: Heart Rate Variability Entropy can discriminate disorders of consciousness and is correlated with resting-state fMRI brain connectivity of the Central Autonomic Network
Riganello, Francesco ULiege; Larroque, Stephen Karl ULiege; Bahri, Mohamed Ali ULiege et al

Poster (2018, June 21)

Motivation: Heart rate variability (HRV) reflects the heart-brain two-way dynamic interactions[1-5]. HRV entropy analysis quantifies the unpredictability and complexity of the heart rate beats intervals ... [more ▼]

Motivation: Heart rate variability (HRV) reflects the heart-brain two-way dynamic interactions[1-5]. HRV entropy analysis quantifies the unpredictability and complexity of the heart rate beats intervals and over multiple time scales using multiscale entropy (MSE)[6-8]. The complexity index (CI) provides a score of a system’s complexity by aggregating the MSE measures over a range of time scales[8]. Most HRV entropy studies have focused on acute traumatic patients using task-based designs[9]. We here investigate the CI and its discriminative power in chronic patients with unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS) at rest, and its relation to brain functional connectivity. Methods: We investigated the CI in short (CIs) and long (CIl) time scales in 16 UWS and 17 MCS sedated. CI for MCS and UWS groups were compared using a Mann-Whitney exact test. Spearman’s correlation tests were conducted between the Coma Recovery Scale-revised (CRS-R) and both CI. Discriminative power of both CI was assessed with One-R machine learning model. Correlation between CI and brain connectivity (detected with functional magnetic resonance imagery using seed-based and hypothesis-free intrinsic connectivity) was investigated using a linear regression in a subgroup of 12 UWS and 12 MCS patients with sufficient image quality. Results and Discussion: Significant differences were found between MCS and UWS for CIs and CIl (0.0001≤p≤0.006). Significant correlations were found between CRS-R and CIs and CIl (0.0001≤p≤0.026). The One-R classifier selected CIl as the best discriminator between UWS and MCS with 85% accuracy, 19% false positive rate and 12% false negative rate after a 10-fold cross-validation test. Positive correlations were observed between CI and brain areas belonging to the autonomic system. CI was found to be significantly higher in MCS compared to UWS patients, with high discriminative power and lower false negative rate than the reported misdiagnosis rate of human assessors, providing an easy, inexpensive and non-invasive diagnosis tool. CI is correlated to functional connectivity changes in brain regions belonging to the autonomic nervous system, suggesting that CI can provide an indirect way to screen and monitor connectivity changes in this neural system. Future studies should investigate further the extent of CI’s predictive power for other pathologies in the disorders of consciousness spectrum. [less ▲]

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See detailIs oral feeding compatible with an unresponsive wakefulness syndrome?
MELOTTE, Evelyne ULiege; MAUDOUX, Audrey ULiege; DELHALLE, Sabrina ULiege et al

Conference (2018, January)

Introduction : Vegetative state/unresponsive wakefulness syndrome (VS/UWS) is defined by the presence of eye-opening and the absence of awareness and voluntary movement [1]. VS/UWS patients classically ... [more ▼]

Introduction : Vegetative state/unresponsive wakefulness syndrome (VS/UWS) is defined by the presence of eye-opening and the absence of awareness and voluntary movement [1]. VS/UWS patients classically receive hydration and nutrition through an enteral feeding tube. Objective - Methods : We retrospectively reviewed the clinical information of 65 VS/UWS patients (aged 45±12; range 16-85 years) evaluated at the CHU hospital of liege searching for mention of oral feeding. VS/UWS diagnosis was made after repeated behavioral assessments using the standardized coma recovery scale–revised (CRS-R, [2]) in association with complementary evaluations using neuroimaging techniques. Results : Of the 65 VS/UWS patients, two could resume oral feeding (3%). One could achieve full oral feeding and the other had oral feeding in addition to gastrostomy feeding. Neuroimaging evaluations showed in both patients a massive decrease in the spontaneous brain activity and its functional connectivity (using functional magnetic resonance imaging), bilateral cerebral cortex hypometabolism and preserved metabolism in the brainstem and cerebellum (using positron emission tomography). Discussion – Conclusion – Clinical message : oral feeding is rare in VS/UWS patients (3% in our cohort). Based on neuroimaging results, this behaviour does not seem to be incompatible with the diagnosis of VS/UWS but the neuromecanistic root, which allows this behavior, still needs to be elucidate. This study also emphasizes the importance of assess and manage deglutition in patients with altered state of consciousness regardless of their level of consciousness. Tactile oro-facial stimulation, manual therapy, taste stimulation and therapeutic feeding can be another “gateway” to interact with these patients and improve their quality of life. [less ▲]

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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 (2018)

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 detailClinical sub-categorization of minimally conscious state according to resting functional connectivity
Aubinet, Charlène ULiege; Larroque, Stephen Karl ULiege; Heine, Lizette et al

in Human Brain Mapping (2018), 39

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See detailMultimodal imaging analysis in Charles Bonnet Syndrome: a case report
Martial, Charlotte ULiege; Di Perri, Carol ULiege; Larroque, Stephen Karl ULiege 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 detailIs oral feeding compatible with an unresponsive wakefulness syndrome?
MELOTTE, Evelyne ULiege; MAUDOUX, Audrey ULiege; DELHALLE, Sabrina ULiege et al

Conference (2017, May)

INTRODUCTION AND AIMS Vegetative state/Unresponsive wakefulness syndrome (VS/UWS) is defined by the presence of eye-opening and the absence of awareness and voluntary movement (Laureys et al., 2010). VS ... [more ▼]

INTRODUCTION AND AIMS Vegetative state/Unresponsive wakefulness syndrome (VS/UWS) is defined by the presence of eye-opening and the absence of awareness and voluntary movement (Laureys et al., 2010). VS/UWS patients classically receive hydration and nutrition through an enteral feeding tube. We present the cases of two patients that were diagnosed as VS/UWS but were able to resume oral feeding. It is however unclear if the presence of oral feeding is compatible with the diagnosis of VS/UWS or if this observation should lead to a modification of the diagnosis. METHODS AND RESULTS We retrospectively reviewed the clinical information of 65 VS/UWS patients (aged 45±12; range 16-85 years) evaluated at the CHU hospital of Liege searching for mention of oral feeding. VS/UWS diagnosis was made after repeated behavioral assessments using the standardized Coma Recovery Scale–Revised (CRS-R, (Teasdale & Jennet, 1974)) in association with complementary evaluations using neuroimaging techniques. Of the 65 VS/UWS patients, two could resume oral feeding (3%). One could achieve full oral feeding (mixed texture and liquid) and the other had oral feeding (liquid and semi-liquid) in addition to gastrostomy feeding. Neuroimaging evaluations showed in both patients a massive decrease in the spontaneous brain activity and its functional connectivity (using functional magnetic resonance imaging), bilateral cerebral cortex hypometabolism (fronto- parietal associative areas, posterior parietal areas, cingulate cortices, precuneus) and preserved metabolism in the brainstem and cerebellum (using positron emission tomography). CONCLUSIONS Oral feeding is rare in VS/UWS patients (3% in our cohort). Based on neuroimaging results, this behaviour does not seem to be incompatible with the diagnosis of VS/UWS but the neuromecanistic root, which allows this behavior, still needs to be elucidate. This study also emphasizes the importance of systematic swallowing evaluation in patients with altered state of consciousness regardless of their level of consciousness. Moreover, tactile oro-facial stimulation, manual therapy, taste stimulation and therapeutic feeding can be another “gateway” to interact with these patients and improve their quality of life. [less ▲]

Detailed reference viewed: 68 (20 ULiège)