References of "Chatelle, Camille"
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See detailMotor behavior unmasks residual cognition in disorders of consciousness
Pincherle, Alessandro; Johr, Jane; Chatelle, Camille ULiege et al

in Annals of Neurology (in press)

Disorders of consciousness (DOC) are a common consequence of severe brain injuries, and clinical evaluation is critical to provide a correct diagnosis and prognosis. The revised Motor Behavior Tool (MBT-r ... [more ▼]

Disorders of consciousness (DOC) are a common consequence of severe brain injuries, and clinical evaluation is critical to provide a correct diagnosis and prognosis. The revised Motor Behavior Tool (MBT-r) is a clinical complementary tool aiming to identify subtle motor behaviors that might reflect residual cognition in DOC. In this prospective study including 30 DOC patients in the early stage after brain injury, we show that the revised MBT-r has an excellent inter-rater agreement and has the ability to identify a subgroup of patients, underestimated by the Coma Recovery Scale-Revised, showing residual cognition and a subsequent recovery of consciousness. [less ▲]

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See detailDisorders of consciousness: new advances in neuroimaging techniques
Soddu, Andrea ULiege; Bruno, Marie-Aurélie ULiege; VANHAUDENHUYSE, Audrey ULiege et al

in Zanotti, Bruno (Ed.) Vegetative State (in press)

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See detailDiagnostic accuracy of a CRS-R modified score in patients with disorders of consciousness.
Annen, Jitka ULiege; Filippini, Maria Maddalena ULiege; Bonin, Estelle ULiege et al

in Brain Injury (2019, March 16)

Introduction The Coma Recovery Scale-Revised (CRS-R) is the gold standard diagnostic tool for assessing patients with disorders of consciousness (DOC) after severe acquired brain injury (Giacino, Kalmar ... [more ▼]

Introduction The Coma Recovery Scale-Revised (CRS-R) is the gold standard diagnostic tool for assessing patients with disorders of consciousness (DOC) after severe acquired brain injury (Giacino, Kalmar and Whyte, 2004; Seel et al., 2010). Differential diagnosis of DOC includes the unresponsive wakefulness syndrome (UWS;(Laureys et al., 2010)), characterized by the recovery of eye-opening but no behavioral evidence of self or environmental awareness, and the minimally conscious state (MCS; (Giacino et al., 2002)) defined by clearly discernible but inconsistent behavioral signs of conscious awareness. The CRS-R assesses reflexes and cognitively mediated behavior in six domains, namely auditory (4 items), visual (5 items), motor (6 items), oromotor (3 items), communication (2 items) and arousal (3 items). Items in every subscale are hierarchically ordered (i.e. reflexive to cognitively-mediated behaviors; higher level behaviors correspond to higher level of neurologic functioning and ability to demonstrate lower-level behaviors or disappearance of pathological behaviors as sign of recovery) and can be used to infer the patient’s level of consciousness (La Porta et al., 2013; Gerrard, Zafonte and Giacino, 2014). Several studies on DOC investigating markers of consciousness, recovery and treatment used the CRS-R total score (i.e. addition of the highest scores reached for each subscale) as regressor in neuroimaging analyses (Bruno et al., 2012; Thibaut et al., 2012; Margetis et al., 2014; Bagnato et al., 2015). However, ignoring the hierarchy of the subscales in the CRS-R total score reduces the sensitivity for the diagnosis of MCS patients (i.e., 100% specificity for UWS but false negative diagnostic error of 22%, with a cut-off CRS-R total score of 10 (Bodien et al., 2016)). In addition, the ordinal nature of the CRS-R total score make it limited to use with parametric statistical tests (e.g., requiring normal distribution). A solution to this problem has been proposed by Sattin and colleagues (2015) who computed a CRS-R modified score (CRS-R MS1), by considering reflexes and cognitively mediated behaviors separately, reliably distinguishing between UWS and MCS patients. These authors also argue that the interpretation of the total CRS-R scores is limited due to “the underlying assumption that if a patient is able to show higher-level behaviors, he/she is also able to show lower-level responses”. Sattin et al. (2015) propose to account for the number of presented responses in every subscale (i.e., every items in a subscale should be assessed and scored). One major drawback to this approach is that according to the CRS-R guidelines, the assessor should start assessing the highest item and move to the next subscale once an item is scored, in line with the hierarchical organization of the scale. This means that, if the CRS-R is performed according to the guidelines (for which the CRS-R has been validated), the CRS-R modified score cannot be calculated. Even if assessing all items might be valid, it is unlikely to be done in many clinical and research settings as it would increase assessment time and fatigue the patient. We here propose to adapt the CRS-R MS1 by considering only the highest score reached on every subscale, respecting the CRS-R guidelines. Methods One-hundred twenty-four patients admitted to the University Hospital of Liège were assessed multiple times with the CRS-R, at least once including the assessment of all items. Patients for whom the CRS-R assessment including all items provided the same diagnosis as the patient’s final diagnosis were selected. The study was approved by the ethics committee of the University Hospital of Liège and the legal guardians of patients gave written informed consent for participation in the study, in accordance with the Declaration of Helsinki. The CRS-R total score and two CRS-R MS were calculated for every patient. The CRS-R MS combines scores for reflexes and cognitive behaviors of every CRS-R subscale which can be used to obtain the CSR-R MS from a transposition matrix. The CRS-R MS1 was calculated as previously described (Sattin et al., 2015), and the CRS-R MS2 only used the highest score in every subscale (i.e., assuming that lower items were successful). Statistics were performed in R (R Core team, 2012). We assessed group differences in age (two sample t-test), time since injury (two sample t-test) and etiology (χ2 test). Receiver Operating Characteristic were calculated to obtain the sensitivity and specificity at several classification thresholds (package pROC (Robin et al., 2011)). We calculated the correlation between the CRSR MS1 and CRSR MS2 using Pearson correlation, and both scores with the CRS-R total score using Spearman correlation. Finally, we used a Kolmogorov-Smirnoff test to evaluate whether CRSR MS1 and CRSR MS2 come from different distributions (i.e., if one approach provides additional information over the other). Results Eighty-five MCS patients (26 females; mean age 40.4 (SD±17.4) years old; 43 traumatic; mean time since injury 2.7 (SD±4.0) years) and 39 UWS patients (14 females; mean age 50.6 (SD±16.5) years old; 29 traumatic; mean time since injury 1.2 (SD±1.8) years) were included in the study. MCS patients were older (t(77.6)-3.15, p<0.002 95%CI[-16.7, -3.7]), were in a more chronic stage (t(121.9)=2.9, p = 0.005, 95%CI[974,427]), and suffered more often from a traumatic brain injury (χ2=6.8, p = 0.01) than UWS patients. The ROC analysis for both MS showed an AUC of 1 (cut-off:8.315, 100% specificity and sensitivity). The ROC analysis for the CRS-R total score showed an AUC of 0.94 (cut-off:9, sensitivity = 100%, specificity = 67%). A correlation was found between the CRSR total score and both the CRSR MS1 (r = 0.94, p < 0.0001, figure 1A) and CRSR MS2 (r = 0.96, p < 0.0001, figure 1B). The two CRS-R MS correlated (r = 0.96, p = 0.0001, figure 1C). CRSR MS1 and CRSR MS2 were drawn from the same distribution (D(124)= 0.13, p = 0.25). Discussion CRSR MS2 correlated strongly with the CRSR MS1, and perfectly discriminated UWS from MCS patients. As for accurate diagnosis the CRS-R should be repeated (preferably five times (Wannez et al., 2018)) short assessments are preferred, and possibly also reduce effects of fatigue. Second, the CRSR MS2 can be calculated with CRS-R assessments performed according to the CRS-R guidelines, facilitating its use in clinical environments, and in research settings where CRSR MS2 can be used pro- and retrospectively for research protocols. Furthermore, the results indicate that the two modified scores share the same distribution. This suggests that assessing all CRS-R items as proposed previously does not significantly contribute to the stratification of patients. The CRSR MS2 code is available via: Github A remaining limitation of the proposed score is that it does not allow to distinguish MCS minus (i.e. showing language independent signs of awareness, like visual pursuit) from MCS plus (i.e. showing language dependent signs of awareness) patients, or emergence from MCS. However, a clear consensus about the diagnostic criteria is needed before an updated modified score can be provided. In conclusion, the current analyses show that the calculation of the CRS-R modified score using the highest item in every subscale is valid for clinical diagnosis, and provides perspective for its use for research. Figure Figure 1. Correlation between the CRS-R total score and the CRS-R MS1 (1A), CRSR MS2 (1B), and between the two modified CRS-R scores (1C). MCS plus patients are here characterized by command following, intelligible verbalization and/or intentional communication. Acknowledgements This project has received funding from the University and University Hospital of Liege, the Belgian National Funds for Scientific Research (FRS-FNRS), the European Union’s Horizon 2020 Framework Programme for Research and Innovation under the Specific Grant Agreement No. 785907 (Human Brain Project SGA2) the Luminous project (EU-H2020-fetopenga686764), the Center-TBI project (FP7-HEALTH- 602150), the Public Utility Foundation ‘Université Européenne du Travail’, “Fondazione Europea di Ricerca Biomedica”, the Bial Foundation, the Mind Science Foundation and the European Commission, the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 778234, European Space Agency (ESA) and the Belgian Federal Science Policy Office (BELSPO) for their support in the framework of the PRODEX Programme. CC is a post-doctoral Marie Sklodowska-Curie fellow (H2020-MSCA-IF-2016-ADOC-752686), and SL is research director at FRS-FNRS. We are highly grateful to the members of the Liège Coma Science Group for their assistance in clinical evaluations, and we thank all the patients and their families and the Neurology department of the University hospital of Liège. [less ▲]

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See detailIs auditory localization a sign of consciousness? Evidence from neuroimaging and electrophysiology
Carrière, Manon ULiege; Cassol, Helena ULiege; Aubinet, Charlène ULiege et al

Conference (2019, March 16)

Background Auditory localization is often part of the clinical evaluation of patients recovering from coma. There is however no clear consensus whether it should be considered as a reflex or as a ... [more ▼]

Background Auditory localization is often part of the clinical evaluation of patients recovering from coma. There is however no clear consensus whether it should be considered as a reflex or as a conscious behavior. For example, auditory localisation corresponds to the diagnosis of unresponsive wakefulness syndrome (UWS) in the Coma Recovery Scale-Revised, while it is considered a sign of consciousness in other post-coma scales. This study aims to determine if auditory localization reflects conscious processing in patients with disorders of consciousness. Methods We first evaluated the proportion of patients with and without auditory localisation in 186 patients with severe brain injury, including 64 UWS, 28 minimally conscious minus (MCS-), 71 minimally conscious plus (MCS+), i.e., language relatively preserved) and 23 who emerged from MCS (EMCS). We then measured brain metabolism using fluorine-18 fluorodeoxyglucose positron emission tomography, functional connectivity using magnetic resonance imaging (MRI) and high-density electroencephalography (EEG) in patients in UWS with and without auditory localization. Findings Auditory localization was observed in 12% of patients in UWS, 46% of patients in MCS-, 62% of patients in MCS+ and 78% of patients in EMCS. Brain metabolism of patients in UWS without auditory localization was mostly restricted to primary areas, whereas a more widespread activity, including associative areas, was observed in patients in UWS with auditory localisation. Brain functional connectivity was also higher in patients in UWS with auditory localisation in the frontoparietal fMRI resting state network, along with higher EEG connectivity in alpha frequency band, compared to patients without auditory localization. Finally, differences were also found regarding the outcome, as the survival rate at two years appeared to be significantly higher in UWS patients with auditory localization as compared to those without auditory localization. Interpretation. Both clinical data in post-comatose patients and neuroimaging examinations in UWS patients with and without auditory localization support the idea that auditory localization should be considered as a sign of consciousness. [less ▲]

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See detailInternational validation of the Phone Outcome Questionnaire for patients with Disorders Of Consciousness
Wolff, Audrey ULiege; Estraneo, Anna; Noé, Quique et al

Poster (2019, March 15)

Assessing the evolution of severely brain-injured patients with disorders of consciousness (DOC) with current tools like the Glasgow Outcome Scale-Extended (GOS-E) remains a challenge. At the bedside, the ... [more ▼]

Assessing the evolution of severely brain-injured patients with disorders of consciousness (DOC) with current tools like the Glasgow Outcome Scale-Extended (GOS-E) remains a challenge. At the bedside, the most reliable diagnostic tool is currently the Coma Recovery Scale-Revised. The CRS-R distinguishes patients with unresponsive wakefulness syndrome (UWS) from patients in minimally conscious state (MCS) and patients who have emerged from MCS (EMCS). This international multi-centric study aims to validate a phone outcome questionnaire (POQ) based on the CRS-R and compare it to the CRS-R performed at the bedside and to the GOS-E which evaluates the level of disability and assigns patient’s in outcomes categories. The POQ will allow clinicians to probe the evolution of patient’s state of consciousness based on caregivers feedback. This research project is part of the International Brain Injury Association, Disorders of Consciousness-Special Interest Group (DOCSIG) and DOCMA consortium. [less ▲]

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See detailPupil diameter and Behavioral Responsiveness in Disorders of Consciousness
Mortaheb, Sepehr ULiege; Bonin, Estelle ULiege; Laureys, Steven ULiege et al

Poster (2019, March 15)

The clinical diagnosis of consciousness is mainly based on bedside observation of the patient's responses using standardized neurobehavioral scales. By definition, it is common to observe vigilance ... [more ▼]

The clinical diagnosis of consciousness is mainly based on bedside observation of the patient's responses using standardized neurobehavioral scales. By definition, it is common to observe vigilance fluctuation in patients in minimally conscious state (MCS) who would show reproducible but fluctuating signs of consciousness [1]. As the probability to detect voluntary responses depends on the patient's level of vigilance at the time of assessment, multiple assessments are needed in order to detect signs of consciousness and avoid misdiagnosis [2]. If this fluctuation is known in disorders of consciousness (DOC), it remains poorly understood and characterized. In this study, we investigated the relationship between pupil diameter (suggested as an objective physiological measure of alertness level in healthy subjects [3-6]) and behavioral responsiveness in DOC patients. To this end, five patients with chronic DOC (1 unresponsive wakefulness syndrome [UWS; ie, reflexive responses], 2 MCS- [ie, signs of consciousness but no signs of language preservation, 2 MCS+ [ie, signs of language preservation]; 3 males; age=47±15.16 (median ± SD), median TSI=284 days) were enrolled. For each patient, four behavioral assessments were performed in a single day using the Coma Recovery Scale-Revised. Before each assessment, pupil response was recorded for 10 minuttients (MCS-) was excluded from the analysis due to eye closure during whole recording period. Pupil diameter was recorded using Phasya Drowsimeter R100 glasses (eye images acquired at 120 Hz with a high-speed camera integrated into the glasses). Eye closure periods were marked manually. Several parameters were investigated: eye opening percentage (EOP), as well as median, variance, entropy, and Lempel-Ziv complexity of the pupil diameter. We here provide preliminary descriptive results for this small sample. We observed lower EOP and median pupil diameter when the patients were unresponsive (i.e., diagnosis of UWS) vs. when they were responsive at bedside (i.e., MCS; median EOP=74.78% vs 99.6%, median pupil diameter=21 vs 28). Variance did not show any specific pattern; however, complexity measures of entropy and Lempel-Ziv were also lower in the UWS (median entropy=9.83 vs 10.58 and median Lempel-Ziv complexity=121 vs 328). Median pupil diameter also seemed to be more sensitive to behavioural changes across different assessments. These preliminary data suggest that higher responsiveness is related to higher median and complexity of the pupillometry signal and eye opening percentage at rest, supporting that pupillometry markers could be used as potential predictor of behavioral responsiveness in DOC patients. [less ▲]

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See detailNociception Coma Scale Revised allows to identify patients with preserved neural basis for pain experience.
Bonin, Estelle ULiege; Lejeune, Nicolas; Thibaut, Aurore ULiege et al

Poster (2019, March 14)

The Nociception Coma Scale-Revised (NCS-R) was developed to help assessing pain in non-communicative patients with disorders of consciousness (DOC). Several studies have shown its sensitivity in assessing ... [more ▼]

The Nociception Coma Scale-Revised (NCS-R) was developed to help assessing pain in non-communicative patients with disorders of consciousness (DOC). Several studies have shown its sensitivity in assessing responses to acute noxious stimuli. However, they failed to determine a reliable cut-off score that could be used to infer pain processing in these patients. This retrospective cross-sectional study aimed to determine an NCS-R cut-off score supporting preserved neural basis for pain experience, based on brain metabolism as measured by fluorodeoxyglucose positron emission tomography (FDG-PET). We included FDG-PET confirmed patient with unresponsive wakefulness syndrome (UWS) (n=13) and looked at their highest NCS-R total scores. As the highest score was 4, we determined the cut-off of 5 and compared the brain metabolism of these patients with matched DOC patients with a cut-off score ≥ 5 (i.e., potential pain) and healthy controls. We found a higher global cerebral metabolism in healthy subjects compared with both patients’ groups and also in patients with potential pain compared with FDG-PET confirmed UWS. We observed a preserved metabolism in the left insula in patients with potential pain when compared with FDG-PET confirmed UWS. We also found a preservation of the connectivity between the left insula and the medial frontal gyrus in patients with potential pain compared with FDG-PET confirmed UWS. Our data suggest that using the cut-off score of 5 can be helpful to improve pain management in DOC patients. Future studies should focus on patients showing scores below this cut-off to better characterize their profile and improve cares. [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 detailTutorial "Single-case evaluation of consciousness: same patient, different modalities": fMRI-based assessment of a single patient
Demertzi, Athina ULiege; Annen, Jitka ULiege; Chatelle, Camille ULiege et al

Conference (2018, June 24)

Tutorial: Patients with disorders of consciousness are by definition unable to communicate. This makes the evaluation of their state of consciousness a major challenge. To date, there are not standardized ... [more ▼]

Tutorial: Patients with disorders of consciousness are by definition unable to communicate. This makes the evaluation of their state of consciousness a major challenge. To date, there are not standardized guidelines as to how a post-comatose patient can be evaluated by means of assisting technologies. With this tutorial, we bring together specialists from three expert centers dealing with intensive evaluation of the state of consciousness in patients sustaining severe brain injuries. Our aim is to illustrate how we can infer a clinical diagnosis by integrating different data from behavioral and brain function as measured with different technological modalities. Specifically, we will discuss the case of a patient for whom behavioral, electrophysiological and neuroimaging data have been acquired with the aim to provide a global diagnosis of the state of consciousness. We will show how each of these evaluations are performed in step-by-step manner. Each presenter will further illustrate the methodological challenges and pragmatic solutions towards the inference of valid conclusions. In order to integrate the results into a global diagnostic category, we wish to engage the audience to participate interactively towards the composition of a final diagnostic report, as we typically do at our clinical sites [less ▲]

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See detailHeart Rate Variability as an indicator of nociceptive pain in disorders of consciousness?
Riganello, Francesco ULiege; Chatelle, Camille ULiege; Schnakers, Caroline et al

Poster (2018, June 22)

Background: Heart rate variability (HRV) has been proposed as an indicator of nociceptive pain processing1 although its reliability as pain indicator remains under debate. The objective was to study the ... [more ▼]

Background: Heart rate variability (HRV) has been proposed as an indicator of nociceptive pain processing1 although its reliability as pain indicator remains under debate. The objective was to study the interest of an HRV complexity analysis2 method as an indicator of nociceptive pain processing in severely brain-injured patients with disorders of consciousness. Methods: Twenty-two patients (11 in minimally conscious state [MCS], 11 in a vegetative state/unresponsive wakefulness syndrome [VS/UWS]) and 14 healthy subjects [HS] were included in this study. We administered a non-noxious and a noxious stimulation while recording the electrocardiographic response was recorded before, during, and following non-noxious and noxious stimulation. The short-term Complexity Index (CIs) was calculated. Mann-Whitney and Wilcoxon’s test were used to investigate differences in CIs according to the level of consciousness (i.e., HS vs patients and VS/UWS vs MCS) and the three conditions (i.e., baseline, non-noxious, noxious). The correlation between the three conditions and the Coma Recovery Scale-Revised3 were investigated by Spearman’s correlations. Results :We observed higher CIs values in HS as compared with patients during baseline and following the noxious stimulation. We also found higher CIs values in MCS vs VS/UWS patients following the noxious condition and lower values in the noxious vs non-noxious condition solely for the VS/UWS group. A correlation was found between CIs in noxious condition and Coma Recovery Scale-Revised scores. Conclusion: our data suggest a less complex autonomic response to noxious stimuli in VS/UWS patients4. Such analysis may help to better understand sympathovagal response to potentially painful environmental stimulation in brain-injured patients. [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 detailTranscranial direct current stimulation unveils covert consciousness
Thibaut, Aurore ULiege; Chatelle, Camille ULiege; VANHAUDENHUYSE, Audrey ULiege et al

in Brain Stimulation (2018), 11(3), 642-644

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See detailA comparison of the P300 and PET in patients with disorders of consciousness in absence of response to command
Annen, Jitka ULiege; Wolff, Audrey ULiege; Blandiaux, Séverine ULiege et al

in European Journal of Neurology (2018, June), 25(S2),

Detection and interpretation of signs of "covert command following" in patients with disorders of consciousness (DOC) remains a challenge for clinicians. In this study, we used a tactile P3-based BCI in ... [more ▼]

Detection and interpretation of signs of "covert command following" in patients with disorders of consciousness (DOC) remains a challenge for clinicians. In this study, we used a tactile P3-based BCI in 12 patients without behavioral command following, attempting to establish "covert command following." These results were then confronted to cerebral metabolism preservation as measured with glucose PET (FDG-PET). One patient showed "covert command following" (i.e., above-threshold BCI performance) during the active tactile paradigm. This patient also showed a higher cerebral glucose metabolism within the language network (presumably required for command following) when compared with the other patients without "covert command-following" but having a cerebral glucose metabolism indicative of minimally conscious state. Our results suggest that the P3-based BCI might probe "covert command following" in patients without behavioral response to command and therefore could be a valuable addition in the clinical assessment of patients with DOC. [less ▲]

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See detailEvaluations comportementales chez les patients en état de conscience altérée
Wolff, Audrey ULiege; Blandiaux, Séverine ULiege; Cassol, Helena ULiege et al

in Jourdan, C; Pellas, F; Luauté, J (Eds.) et al Etats de conscience altérée - Actualités diagnostiques, pronostiques et thérapeutiques (2018)

A l’heure actuelle, l’évaluation de la conscience chez les patients sortant du coma reste un challenge car elle ne peut directement s’observer et être quantifiée, comme peuvent l’être par exemple le poids ... [more ▼]

A l’heure actuelle, l’évaluation de la conscience chez les patients sortant du coma reste un challenge car elle ne peut directement s’observer et être quantifiée, comme peuvent l’être par exemple le poids ou la taille. Le diagnostic des états de conscience altérés doit donc se baser une évaluation indirecte, et seulement sur ce qui est observable. Les évaluations comportementales restent encore à l’heure actuelle le gold standard pour les cliniciens et des études récentes ont mis en avant la nécessité d’utiliser des outils d’évaluation standardisés. Dans ce chapitre, nous aborderons brièvement quatre échelles utilisées régulièrement dans la pratique clinique en développant plus en profondeur la Coma Recovery Scale – Revised. Le but ici est de donner une vue globale des différentes échelles ainsi que d’apporter quelques recommandations pratiques quant à la réalisation des évaluations comportementales. [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 (2018), 28(8), 1350-1359

Different behavioural signs of consciousness can distinguish patients with an unresponsive wakefulness syndrome from patients in minimally conscious state (MCS). The Coma Recovery Scale-Revised (CRS-R) is ... [more ▼]

Different behavioural signs of consciousness can distinguish patients with an unresponsive wakefulness syndrome from patients in minimally conscious state (MCS). The Coma Recovery Scale-Revised (CRS-R) is the most sensitive scale to differentiate the different altered states of consciousness and eleven items detect the MCS. The aim of this study is to document the prevalence of these items. We analysed behavioural assessments of 282 patients diagnosed in MCS based on the CRS-R. Results showed that some items are particularly frequent among patients in MCS, namely fixation, visual pursuit, and reproducible movement to command, which were observed in more than 50% of patients. These responses were also the most probably observed items when the patients only showed one sign of consciousness. On the other hand, some items were rarely or never observed alone, e.g., object localisation (reaching), object manipulation, intelligible verbalisation, and object recognition. The results also showed that limiting the CRS-R assessment to the five most frequently observed items (i.e., fixation, visual pursuit, reproducible movement to command, automatic motor response and localisation to noxious stimulation) detected 99% of the patients in MCS. If clinicians have only limited time to assess patients with disorders of consciousness, we suggest to evaluate at least these five items of the CRS-R. © 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group. [less ▲]

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See detailConscious while being considered in an unresponsive wakefulness syndrome for 20 years
VANHAUDENHUYSE, Audrey ULiege; Charland-Verville, Vanessa ULiege; Thibaut, Aurore ULiege et al

in Frontiers in Neurology (2018), 9(AUG),

Despite recent advances in our understanding of consciousness disorders, accurate diagnosis of severely brain-damaged patients is still a major clinical challenge. We here present the case of a patient ... [more ▼]

Despite recent advances in our understanding of consciousness disorders, accurate diagnosis of severely brain-damaged patients is still a major clinical challenge. We here present the case of a patient who was considered in an unresponsive wakefulness syndrome/vegetative state for 20 years. Repeated standardized behavioral examinations combined to neuroimaging assessments allowed us to show that this patient was in fact fully conscious and was able to functionally communicate. We thus revised the diagnosis into an incomplete locked-in syndrome, notably because the main brain lesion was located in the brainstem. Clinical examinations of severe brain injured patients suffering from serious motor impairment should systematically include repeated standardized behavioral assessments and, when possible, neuroimaging evaluations encompassing magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography. © 2018 Vanhaudenhuyse, Charland-Verville, Thibaut, Chatelle, Tshibanda, Maudoux, Faymonville, Laureys and Gosseries. [less ▲]

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