References of "Cassol, Helena"
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See detailPET Imaging in Altered States of Consciousness: Coma, Sleep, and Hypnosis
Bonin, Estelle ULiege; Martens, Géraldine ULiege; Cassol, Helena ULiege et al

in van Waarde, A; Otte, A; de Vries, E.F.J (Eds.) et al PET and SPECT in Neurology (in press)

Positron emission tomography (PET) allows studies of cerebral metabolism and blood flow and has been widely used to investigate physiological mechanisms underlying altered states of consciousness ... [more ▼]

Positron emission tomography (PET) allows studies of cerebral metabolism and blood flow and has been widely used to investigate physiological mechanisms underlying altered states of consciousness. Consciousness is characterized by two components: wakefulness and awareness. In this chapter, we review the current literature on brain metabolism during pathological loss of consciousness (vegetative/unresponsive or minimally conscious states), sleep (in healthy subjects and in patients with insomnia), and under hypnosis. By identifying brain areas specifically involved in conscious processing, these studies have contributed to our understanding of the underlying physiology of consciousness. The precuneal and cingulate cortices, for example, seem to be key areas for maintaining conscious awareness. FDG-PET further allowed the identification of the minimal energetic requirement for conscious awareness in this population, which corresponds to 42% of normal cortical activity. Up to now, it is the most accurate neuroimaging tool regarding the diagnosis of patients with disorders of consciousness. In the future, its use as part of multimodal assessment could improve diagnosis and prognosis in this challenging population. In sleep, a greater activity of the precuneus/posterior cingulate cortex and the fronto-parietal areas during non rapid eye movement sleep also seems to play a role in disorders such as insomnia. Other areas such as the hypothalamus, amygdala, or temporo-occipital cortex seem to play a role in different states such as rapid eye movement sleep and hypnosis. PET studies permit a better comprehension of the neural correlates of consciousness and to identify the implication of specific neural areas and networks in altered states of consciousness in post-comatose patients, sleep and induced hypnosis. [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 ULiege; Thibaut, Aurore ULiege et al

in Journal of Pain (in press)

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

The Nociception Coma Scale-Revised (NCS-R) was developed to help assess pain in patients with disorders of consciousness (DOC). Several studies have shown its sensitivity in assessing response 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 a NCS-R cut-off score supporting preserved neural basis for pain experience, based on brain metabolism preservation as measured by fluorodeoxyglucose positron emission tomography (FDG-PET). We included patients in unresponsive wakefulness syndrome (UWS) confirmed by the FDG-PET and examined the NCS-R total scores. As the highest score was 4, we defined the cut-off to be 5 and compared the brain metabolism of these patients to matched patients with DOC and a NCS-R cut-off score ≥ 5 (i.e., potential pain), as well as healthy subjects. We found a higher global cerebral metabolism in healthy subjects compared to both patient 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 compared with FDG-PET confirmed UWS. [less ▲]

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See detailDe NDE als opkomend wetenschappelijk onderzoeksgebied
Martial, Charlotte ULiege; Cassol, Helena ULiege; LAUREYS, Steven ULiege

in Pim van Lommel (Ed.) Het geheim van Elysion: 45 jaar studie naar nabij-de-dood-ervaringen over bewustzijn in liefde zonder waarheen (2020)

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See detailNear-Death Experience Memories Include More Episodic Components Than Flashbulb Memories
Cassol, Helena ULiege; Bonin, Estelle ULiege; Bastin, Christine ULiege et al

in Frontiers in Psychology (2020), 11(888),

Memories of near-death experiences (NDEs) are recalled as “realer” than memories of other real or imagined events. Given their rich phenomenology, emotionality and consequentiality, it was hypothesized ... [more ▼]

Memories of near-death experiences (NDEs) are recalled as “realer” than memories of other real or imagined events. Given their rich phenomenology, emotionality and consequentiality, it was hypothesized that they could meet some aspects of the definition of flashbulb memories. We aimed to identify and compare the episodic and non-episodic information provided in verbal recollections of NDE, flashbulb, and control autobiographical memories. The phenomenological characteristics and centrality of the memories were also compared. Twenty-five participants who had lived a NDE in a life-threatening situation were interviewed and completed the Memory Characteristics Questionnaires as well as the Centrality of Event Scale for their NDE, a flashbulb and another autobiographical memory used as control. Overall, transcribed NDE verbal recollections included a higher overall amount of details and more internal/episodic information than control autobiographical and flashbulb memories. Moreover, flashbulb memories were associated to a lower intensity of feelings while remembering and a lower personal importance, and are less reactivated and less susceptible to be remembered from a first person perspective compared to NDE and control autobiographical memories. Finally, NDE memories are the most central memories to experiencers’ identity, followed by control autobiographical and then by flashbulb memories. These findings corroborate previous studies highlighting the impact and uniqueness of NDE memories. [less ▲]

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See detailCharacterization of near-death experiences using text mining analyses: a preliminary study
Charland-Verville, Vanessa ULiege; Ribeiro de Paula, Demetrius; Martial, Charlotte ULiege et al

in PLoS ONE (2020)

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See detailNear-death experience as a probe to explore (disconnected) consciousness
Martial, Charlotte ULiege; Cassol, Helena ULiege; Laureys, Steven ULiege et al

in Trends in Cognitive Sciences (2020)

Forty-five years ago, the first evidence of near-death experience (NDE) during comatose state was provided, setting the stage for a new paradigm for studying the neural basis of consciousness in ... [more ▼]

Forty-five years ago, the first evidence of near-death experience (NDE) during comatose state was provided, setting the stage for a new paradigm for studying the neural basis of consciousness in unresponsive states. At present, the state of consciousness associated with NDEs remains an open question. In the common view, consciousness is said to disappear in a coma with the brain shutting down, but it is oversimplified. This article argues that the novel framework distinguishing awareness, wakefulness and connectedness is relevant to comprehend the phenomenon. Classical NDEs correspond to internal awareness experienced in unresponsive conditions, thereby corresponding to an episode of disconnected consciousness. Our proposal suggests new directions for NDE research, and more broadly, consciousness science. [less ▲]

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See detailBrain metabolism but not grey matter volume underlies the presence of language function in the minimally conscious state
Aubinet, Charlène ULiege; Cassol, Helena ULiege; Gosseries, Olivia ULiege et al

in Neurorehabilitation and Neural Repair (2020), 34(2), 172-184

Background. The minimally conscious state (MCS) is subcategorized into MCS- and MCS+, depending on the absence or presence of high-level behavioral responses such as command following. Objective. We aim ... [more ▼]

Background. The minimally conscious state (MCS) is subcategorized into MCS- and MCS+, depending on the absence or presence of high-level behavioral responses such as command following. Objective. We aim to investigate the functional and structural neuroanatomy underlying the presence of these responses in MCS- and MCS+ patients. Methods. In this cross-sectional retrospective study, chronic MCS patients were diagnosed using repeated Coma Recovery Scale-Revised assessments. Fluorodeoxyglucose-positron emission tomography data were acquired on 57 patients (16 MCS-; 41 MCS+) and magnetic resonance imaging with voxel-based morphometry analysis was performed on 66 patients (17 MCS-; 49 MCS+). Brain glucose metabolism and grey matter integrity were compared between patient groups and control groups. A metabolic functional connectivity analysis testing the hypothesis of preserved language network in MCS+ compared to MCS- was also done. Results. Patients in MCS+ presented higher metabolism mainly in the left middle temporal cortex, known to be important for semantic processing, compared to the MCS- group. The left angular gyrus was also functionally disconnected from the left prefrontal cortex in MCS- compared to MCS+. No significant differences were found in grey matter volume between patient groups. Conclusions. The clinical sub-categorization of MCS is supported by differences in brain metabolism but not in grey matter structure, suggesting that brain function in the language network is the main support for recovery of command-following, intelligible verbalization and/or intentional communication in the MCS. Better characterizing the neural correlates of residual cognitive abilities of MCS patients contributes to reduce their misdiagnosis and to adapt therapeutic approaches. [less ▲]

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See detailBrain Metabolism but Not Gray Matter Volume Underlies the Presence of Language Function in the Minimally Conscious State (MCS): MCS+ Versus MCS− Neuroimaging Differences
Aubinet, Charlène ULiege; Cassol, Helena ULiege; Gosseries, Olivia ULiege et al

in Neurorehabilitation and Neural Repair (2020), 34(2), 172-184

Background. The minimally conscious state (MCS) is subcategorized into MCS− and MCS+, depending on the absence or presence, respectively, of high-level behavioral responses such as command-following ... [more ▼]

Background. The minimally conscious state (MCS) is subcategorized into MCS− and MCS+, depending on the absence or presence, respectively, of high-level behavioral responses such as command-following. Objective. We aim to investigate the functional and structural neuroanatomy underlying the presence of these responses in MCS− and MCS+ patients. Methods. In this cross-sectional retrospective study, chronic MCS patients were diagnosed using repeated Coma Recovery Scale–Revised assessments. Fluorodeoxyglucose-positron emission tomography data were acquired on 57 patients (16 MCS−; 41 MCS+) and magnetic resonance imaging with voxel-based morphometry analysis was performed on 66 patients (17 MCS−; 49 MCS+). Brain glucose metabolism and gray matter integrity were compared between patient groups and control groups. A metabolic functional connectivity analysis testing the hypothesis of preserved language network in MCS+ compared with MCS− was also done. Results. Patients in MCS+ presented higher metabolism mainly in the left middle temporal cortex, known to be important for semantic processing, compared with the MCS− group. The left angular gyrus was also functionally disconnected from the left prefrontal cortex in MCS− compared with MCS+ group. No significant differences were found in gray matter volume between patient groups. Conclusions. The clinical subcategorization of MCS is supported by differences in brain metabolism but not in gray matter structure, suggesting that brain function in the language network is the main support for recovery of command-following, intelligible verbalization and/or intentional communication in the MCS. Better characterizing the neural correlates of residual cognitive abilities of MCS patients contributes to reduce their misdiagnosis and to adapt therapeutic approaches. © The Author(s) 2020. [less ▲]

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See detailNear-death experiences during altered states of consciousness
Cassol, Helena ULiege

Conference (2019, November 21)

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See detailLes expériences de mort imminente
Cassol, Helena ULiege; Martial, Charlotte ULiege; Laureys, Steven ULiege

in Dechene, Antoine; Dupont, Bruno (Eds.) Crises (2019)

Les expériences de mort imminente (EMI) désignent un ensemble d’événements mentaux émotionnellement variés associant des éléments mystiques et spirituels, et survenant généralement suite à une situation ... [more ▼]

Les expériences de mort imminente (EMI) désignent un ensemble d’événements mentaux émotionnellement variés associant des éléments mystiques et spirituels, et survenant généralement suite à une situation de danger réel ou perçu. Ces phénomènes, caractérisés par une phénoménologie riche et une intensité réaliste, peuvent être considérés comme synonymes de crises, en ce sens qu’ils correspondent à des événements charnières et déterminants dans la vie des expérienceurs (personnes ayant vécu une EMI). En effet, après leur EMI, ces personnes présentent généralement une moindre crainte de la mort, sont davantage spirituelles et sont moins matérialistes. Cet impact sur le long terme exige une meilleure caractérisation ainsi qu’une description rigoureuse de ces phénomènes. Des théories psychologiques aux théories sociologiques, en passant par les analyses des récits de ces expériences, cet article s’intéresse à la répercussion de ces phénomènes sur la vie des expérienceurs. [less ▲]

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See detailExploration of near-death experience accounts
Cassol, Helena ULiege

Doctoral thesis (2019)

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See detailMultimodal improvements after apomorphine treatment for chronic disorders of consciousness: preliminary results
Sanz, Leandro ULiege; Lejeune, Nicolas ULiege; Blandiaux, Séverine ULiege et al

Conference (2019, October 24)

Aims: Treatment with apomorphine, a dopamine agonist, has exhibited behavioral effects on the recovery of patients with disorders of consciousness (DOC)[1,2], but its action on brain activity remains ... [more ▼]

Aims: Treatment with apomorphine, a dopamine agonist, has exhibited behavioral effects on the recovery of patients with disorders of consciousness (DOC)[1,2], but its action on brain activity remains unknown. We report the preliminary results of a prospective open-label study using multimodal assessment methods, which aims to confirm the efficacy and investigate the mechanism of apomorphine treatment among post-coma patients. Methods: Three patients with chronic DOC (1 female, 2 males; 47, 34 and 23 years old; 1 hemorrhage, 2 traumatic; 3.5, 4.5 and 3 months since onset) were administered subcutaneous apomorphine for 30 days. They were followed 30 days before initiation, during treatment and 30 days after withdrawal. Outcome measures included Coma Recovery Scale – Revised (CRS-R)[3], positron emission tomography (PET)[4,5] and electroencephalography-based (EEG) measures such as functional connectivity[6] and multivariate machine-learning classification[7,8]. Results: At baseline, patients 1 and 2 were diagnosed with the CRS-R as minimally conscious state (MCS) minus[9,10] (language-independent signs of consciousness), and patient 3 as MCS plus (language-related signs of consciousness). After the initiation of apomorphine, patient 1 improved to MCS plus, patient 2 remained in MCS minus but showed a new sign of consciousness and more consistent behaviors, and patient 3 emerged from the MCS. PET revealed an improvement of global brain metabolism after compared to before apomorphine treatment for all three patients (difference of +43%, +26%, and +4% for patient 1, 2 and 3 respectively). Functional connectivity measured by EEG network centrality also increased after treatment for all patients in the alpha frequency bands. EEG multivariate classifier improved after treatment for two patients (difference of +25%, +20%, -1% for patient 1, 2, and 3 respectively) with significant increase in most individual EEG markers. Conclusion: After treatment, patients showed multimodal improvements with more frequent conscious behaviors and increased brain activity measures compared to baseline observations. These results suggest that the action of apomorphine on the recovery of DOC patients may be associated with measurable neuroimaging changes. Additional results from the subsequent placebo-controlled randomized controlled trial[11] will be necessary to confirm the efficacy and further define the neural effects of apomorphine treatment in severely brain-injured patients. [less ▲]

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See detailNeurophenomenology of near-death experience memory in hypnotic recall: a within-subject EEG study
Martial, Charlotte ULiege; Mensen, Armand ULiege; CHARLAND-VERVILLE, Vanessa ULiege et al

in Scientific Reports (2019)

The neurobiological basis of near-death experiences (NDEs) is unknown, but a few studies attempted to investigate it by reproducing in laboratory settings phenomenological experiences that seem to closely ... [more ▼]

The neurobiological basis of near-death experiences (NDEs) is unknown, but a few studies attempted to investigate it by reproducing in laboratory settings phenomenological experiences that seem to closely resemble NDEs. So far, no study has induced NDE-like features via hypnotic modulation while simultaneously measuring changes in brain activity using high-density EEG. Five volunteers who previously had experienced a pleasant NDE were invited to re-experience the NDE memory and another pleasant autobiographical memory (dating to the same time period), in normal consciousness and with hypnosis. We compared the hypnosis-induced subjective experience with the one of the genuine experience memory. Continuous high-density EEG was recorded throughout. At a phenomenological level, we succeeded in recreating NDE-like features without any adverse effects. Absorption and dissociation levels were reported as higher during all hypnosis conditions as compared to normal consciousness conditions, suggesting that our hypnosis-based protocol increased the felt subjective experience in the recall of both memories. The recall of a NDE phenomenology was related to an increase of alpha activity in frontal and posterior regions. This study provides a proof-of-concept methodology for studying the phenomenon, enabling to prospectively explore the NDE-like features and associated EEG changes in controlled settings. [less ▲]

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See detailAutomated Machine Learning-based diagnosis of impaired consciousness: cross-center and protocol generalization of EEG biomarkers.
Raimondo, Federico ULiege; Engemann, Denis; King, Jean-Remi et al

Conference (2019, September 24)

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See detailThe self-defining aspect of near-death experiences
Cassol, Helena ULiege

Conference (2019, September 05)

Near-Death Experiences (NDEs) can be defined as profound psychological events with highly emotional and self-related content, typically encompassing transcendental and mystical elements and occurring when ... [more ▼]

Near-Death Experiences (NDEs) can be defined as profound psychological events with highly emotional and self-related content, typically encompassing transcendental and mystical elements and occurring when people come close to death. Studies have highlighted that 6 to 23% of cardiac arrest survivors have reported this phenomenon, which supports its frequent occurrence. Intriguingly, similar experiences have been described after situations that do not imply any danger for physical or mental health. These experiences have been termed “NDEs-like” and have been described in contexts such as meditative states or syncope. Along with its particular circumstances of appearance and its mystical connotation, the widespread NDE phenomenon seems to be characterized by a rich phenomenology and a realistic intensity. Consequently, NDEs appear to have short and long term consequences on people’s lives (so-called NDE experiencers). Specifically, it was recently shown that NDE and NDE-like memories constitute a particular type of autobiographical memories referred to as self-defining memories (SDMs). SDMs are emotionally intense, vivid, and frequently recalled memories that reflect important themes and conflicts in one’s life. These emotional memories are the building blocks of our identity and contribute, in particular, to our sense of self-continuity, which represents the ability to consider oneself as an entity that extends back into the past and forward into the future. This ability is central to numerous processes such as planning future actions, giving meaning to new experiences or taking responsibility. The self-defining status of NDE memories confirms that they constitute an important part of NDE experiencers’ personal identities and highlights the importance for clinicians to facilitate their integration within their selves. The aim of this symposium is to have a closer look at the factors that contribute to making this experience self-defining, such as the content and intensity of the experience, as well as religious beliefs of experiencers. [less ▲]

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

in Brain Injury (2019), 33(11), 1409-1412

Objective: To obtain a CRS-R index suitable for diagnosis of patients with disorders of consciousness (DOC) and compare it to other CRS-R based scores to evaluate its potential for clinics and research ... [more ▼]

Objective: To obtain a CRS-R index suitable for diagnosis of patients with disorders of consciousness (DOC) and compare it to other CRS-R based scores to evaluate its potential for clinics and research. Design: We evaluated the diagnostic accuracy of several CRS-R-based scores in 124 patients with DOC. ROC analysis of the CRS-R total score, the Rasch-based CRS-R score, CRS-R-MS and the CRS-R index evaluated the diagnostic accuracy for patients with the Unresponsive Wakefulness Syndrome (UWS) and Minimally Conscious State (MCS). Correlations were computed between the CRS-R-MS, CRS-R index, the Rasch-based score and the CRS-R total score. Results: Both the CRS-R-MS and CRS-R index ranged from 0 to 100, with a cut-off of 8.315 that perfectly distinguishes between patients with UWS and MCS. The CRS-R total score and Rasch-based score did not provide a cut-off score for patients with UWS and MCS. The proposed CRS-R index correlated with the CRS-R total score, Rasch-based score and the CRS-R-MS. Conclusion: The CRS-R index is reliable to diagnose patients with UWS and MCS and can be used in compliance with the CRS-R scoring guidelines. The obtained index offers the opportunity to improve the interpretation of clinical assessment and can be used in (longitudinal) research protocols. [less ▲]

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See detailTreating chronic disorders of consciousness with apomorphine: preliminary results of a multimodal clinical trial
Sanz, Leandro ULiege; Lejeune, Nicolas ULiege; Blandiaux, Séverine ULiege et al

Poster (2019, June 29)

Background and aims: Treatment with apomorphine, a dopamine agonist, has exhibited promising effects on the recovery of patients with disorders of consciousness (DOC) due to traumatic brain injury. This ... [more ▼]

Background and aims: Treatment with apomorphine, a dopamine agonist, has exhibited promising effects on the recovery of patients with disorders of consciousness (DOC) due to traumatic brain injury. This prospective open-label clinical trial aims to confirm its efficacy and investigate its action on brain activity. Methods: Patients with chronic DOC were administered subcutaneous apomorphine for 30 days. They were monitored 30 days before initiation, during treatment and 30 days after withdrawal. Outcome measures included Coma Recovery Scale – Revised (CRS-R), actigraphy, positron emission tomography (PET) and electroencephalography-based (EEG) metrics such as network centrality and a multivariate machine-learning classifier. Results: A 47-year-old woman in an unresponsive wakefulness state (UWS) due to a ruptured aneurysm underwent apomorphine treatment. CRS-R indicated a minimally conscious state (MCS) diagnosis in 1/9 assessment before treatment, increasing to 6/8 during treatment, and 4/5 after withdrawal (Fig.1). Actigraphy showed higher mean activity and normalised power after treatment. Compared to healthy controls, PET whole-brain metabolism revealed a 59% metabolic decrease before treatment and 51% after, with significant increases in right cortical areas. (Fig.2) EEG multivariate classifier corresponded to UWS before treatment and MCS after, with significant increase in most individual markers. Functional connectivity measured by network centrality increased predominantly in alpha frequency after treatment. (Fig.3) Conclusion: After treatment, this patient showed multimodal improvements with more frequent conscious behaviours and increased brain activity measures. These results suggest that the action of apomorphine on the recovery of DOC patients may be associated with measurable neuroimaging changes. Results of two subsequently treated patients will be reported. Clinical trial identifiers: EudraCT 2018-003144-23; Clinicaltrials.gov NCT03623828 [less ▲]

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See detailStudy of the impact of non-pharmacological techniques (self-hypnosis/self-care) on cognitive complaints in cancer patients
Bicego, Aminata Yasmina ULiege; Grégoire, Charlotte ULiege; Cassol, Helena ULiege et al

Conference (2019, May 30)

Cancer diagnosis generates a number of physical, psychological and cognitive impairments such as memory, attentional and informational processing deficits that can undermine patients’ quality of life (QoL ... [more ▼]

Cancer diagnosis generates a number of physical, psychological and cognitive impairments such as memory, attentional and informational processing deficits that can undermine patients’ quality of life (QoL). Self-hypnosis combined to self-care learning have been used in the past years to treat these symptoms, at the moment of diagnosis, during and/or after the cancer treatments. However, the impact of self-hypnosis/self-care upon cognitive difficulties has not been investigated yet.The aim of this study is to better understand the impact of self hypnosis/self-care upon the cognitive functions by means of the Functional Assessment of Cancer Therapy-Cognitive Function1 (FACT-COG). [less ▲]

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