References of "Demertzi, Athina"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailMultiple fMRI system-level baseline connectivity is disrupted in patients with consciousness alterations
Demertzi, Athina ULg; Gomez, Francisco; Crone, Julia-Sophia et al

in Cortex : A Journal Devoted to the Study of the Nervous System & 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 ▲]

Detailed reference viewed: 80 (9 ULg)
Full Text
Peer Reviewed
See detailBrain dead yet mind alive: A positron emission tomography case study of brain metabolism in Cotard’s syndrome
Charland-Verville, Vanessa ULg; Bruno, Marie-Aurélie ULg; Bahri, Mohamed Ali ULg et al

in Cortex : A Journal Devoted to the Study of the Nervous System & Behavior (2013), 49(7), 1997-1999

Detailed reference viewed: 50 (10 ULg)
Full Text
Peer Reviewed
See detailActigraphy assessments of circadian sleep-wake cycles in the Vegetative and Minimally Conscious States
Cruse, Damian; Thibaut, Aurore ULg; Demertzi, Athina ULg et al

in BMC Neuroscience (2013), 11(18),

Detailed reference viewed: 36 (2 ULg)
See detailDisorders of consciousness and neuroimaging techniques
Charland-Verville, Vanessa ULg; Demertzi, Athina ULg; VANHAUDENHUYSE, Audrey ULg et al

Scientific conference (2013, January)

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailConsciousness supporting networks
Demertzi, Athina ULg; Soddu, Andrea ULg; Laureys, Steven ULg

in Current Opinion in Neurobiology (2013), 23(2), 239244

Functional neuroimaging shows that patients with disorders of consciousness exhibit disrupted system-level functional connectivity. Unresponsive/’’vegetative state’’ patients preserve wakefulness networks ... [more ▼]

Functional neuroimaging shows that patients with disorders of consciousness exhibit disrupted system-level functional connectivity. Unresponsive/’’vegetative state’’ patients preserve wakefulness networks of brainstem and basal forebrain but the cerebral networks accounting for external perceptual awareness and internal self-related mentation are disrupted. Specifically, the ‘external awareness’ network encompassing lateral fronto-temporo-parietal cortices bilaterally, and the ‘internal awareness’ network including midline anterior cingulate/mesiofrontal and posterior cingulate/ precuneal cortices, are functionally disconnected. By contrast, patients in minimally conscious state ‘minus’, who show nonreflex behaviors, are characterized by right-lateralized recovery of the external awareness network. Similarly, patients who evolve to minimally conscious state ‘plus’ and respond to commands recover the dominant left-lateralized language network. Now, the use of active experimental paradigms targeting at detecting motor-independent signs of awareness or even establishing communication with these patients, challenge these two clinical boundaries. Such advances are naturally accompanied by legitimate neuroscientific and ethical queries demanding our attention on the medical implementations of this new knowledge. [less ▲]

Detailed reference viewed: 51 (7 ULg)
Full Text
Peer Reviewed
See detailComa and disorders of consciousness
Bruno, Marie-Aurélie ULg; Laureys, Steven ULg; Demertzi, Athina ULg

in Handbook of Clinical Neurology (2013), Vol 118

Patients in coma, vegetative state/unresponsive wakefulness syndrome, and in minimally conscious states pose medical, scientific, and ethical challenges. As patients with disorders of consciousness are by ... [more ▼]

Patients in coma, vegetative state/unresponsive wakefulness syndrome, and in minimally conscious states pose medical, scientific, and ethical challenges. As patients with disorders of consciousness are by definition unable to communicate, the assessment of pain, quality of life, and end-of-life preferences in these conditions can only be approached by adopting a third-person perspective. Surveys of healthcare workers' attitudes towards pain and end of life in disorders of consciousness shed light on the background of clinical reality, where no standard medical-legal framework is widely accepted. On the other hand, patients with locked-in syndrome, who are severely paralyzed but fully conscious, can inform about subjective quality of life in serious disability and help us to understand better the underlying factors influencing happiness in disease. In the medico-legal arena, such ethical issues may be resolved by previously drafted advance directives and, when absent, by surrogate representation. Lately, functional medical imaging and electrophysiology provide alternative means to communicate with these challenging patients and will potentially mediate to extract responses of medical-ethical content. Eventually, the clinical translation of these advanced technologies in the medical routine is of paramount importance for the promotion of medical management of these challenging patients [less ▲]

Detailed reference viewed: 32 (3 ULg)
Full Text
Peer Reviewed
See detailLooking for the self in pathological unconsciousness.
Demertzi, Athina ULg; Vanhaudenhuyse, Audrey ULg; Brédart, Serge ULg et al

in Frontiers in Human Neuroscience (2013), 7

There is an intimate relationship between consciousness and the notion of self. By studying patients with disorders of consciousness, we are offered with a unique lesion approach to tackle the neural ... [more ▼]

There is an intimate relationship between consciousness and the notion of self. By studying patients with disorders of consciousness, we are offered with a unique lesion approach to tackle the neural correlates of self in the absence of subjective reports. Studies employing neuroimaging techniques point to the critical involvement of midline anterior and posterior cortices in response to the passive presentation of self-referential stimuli, such as the patient’s own name and own face. Also, resting state studies show that these midline regions are severely impaired as a function of the level of consciousness. Theoretical frameworks combining all this progress surpass the functional localization of self-related cognition and suggest a dynamic system-level approach to the phenomenological complexity of subjectivity. Importantly for non-communicating patients suffering from disorders of consciousness, the clinical translation of these technologies will allow medical professionals and families to better comprehend these disorders and plan efficient medical management for these patients. [less ▲]

Detailed reference viewed: 26 (2 ULg)
Peer Reviewed
See detailA multiscale method for a robust detection of the default mode network.
Baquero, Katherine; Gómez, Francisco; Cifuentes, Christian et al

Poster (2013)

Detailed reference viewed: 26 (7 ULg)
Full Text
Peer Reviewed
See detailThalamus, Brainstem and Salience Network Connectivity Changes During Propofol-Induced Sedation and Unconsciousness
Guldenmund, Justus Pieter ULg; Demertzi, Athina ULg; BOVEROUX, Pierre ULg et al

in Brain connectivity (2013), 3

In this functional magnetic resonance imaging study, we examined the effect of mild propofol sedation and propofol-induced unconsciousness on resting state brain connectivity, using graph analysis based ... [more ▼]

In this functional magnetic resonance imaging study, we examined the effect of mild propofol sedation and propofol-induced unconsciousness on resting state brain connectivity, using graph analysis based on independent component analysis and a classical seed-based analysis. Contrary to previous propofol research, which mainly emphasized the importance of connectivity in the default mode network (DMN) and external control network (ECN), we focused on the salience network, thalamus, and brainstem. The importance of these brain regions in brain arousal and organization merits a more detailed examination of their connectivity response to propofol. We found that the salience network disintegrated during propofol-induced unconsciousness. The thalamus decreased connectivity with the DMN, ECN, and salience network, while increasing connectivity with sensorimotor and auditory/insular cortices. Brainstem regions disconnected from the DMN with unconsciousness, while the pontine tegmental area increased connectivity with the insulae during mild sedation. These findings illustrate that loss of consciousness is associated with a wide variety of decreases and increases of both cortical and subcortical connectivity. It furthermore stresses the necessity of also examining resting state connectivity in networks representing arousal, not only those associated with awareness. [less ▲]

Detailed reference viewed: 65 (12 ULg)
Full Text
Peer Reviewed
See detailPain perception in disorders of consciousness: neuroscience, clinical care, and ethics in dialogue
Demertzi, Athina ULg; Racine, Eric; Bruno, Marie-Aurélie ULg et al

in Neuroethics (2013), 6(1), 37-50

Pain, suffering and positive emotions in patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally conscious states (MCS) pose clinical and ethical challenges. Clinically, we ... [more ▼]

Pain, suffering and positive emotions in patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally conscious states (MCS) pose clinical and ethical challenges. Clinically, we evaluate behavioural responses after painful stimulation and also emotionally-contingent behaviours (e.g., smiling). Using stimuli with emotional valence, neuroimaging and electrophysiology technologies can detect subclinical remnants of preserved capacities for pain which might influence decisions about treatment limitation. To date, no data exist as to how healthcare providers think about end-of-life options (e.g., withdrawal of artificial nutrition and hydration) in the presence or absence of pain in non-communicative patients. Here, we aimed to better clarify this issue by re-analyzing previously published data on pain perception (Prog Brain Res 2009 177, 329–38) and end-of-life decisions (J Neurol 2010 258, 1058–65) in patients with disorders of consciousness. In a sample of 2259 European healthcare professionals we found that, for VS/UWS more respondents agreed with treatment withdrawal when they considered that VS/UWS patients did not feel pain (77%) as compared to those who thought VS/UWS did feel pain (59%). This interaction was influenced by religiosity and professional background. For MCS, end-of-life attitudes were not influenced by opinions on pain perception. Within a contemporary ethical context we discuss (1) the evolving scientific understandings of pain perception and their relationship to existing clinical and ethical guidelines; (2) the discrepancies of attitudes within (and between) healthcare providers and their consequences for treatment approaches, and (3) the implicit but complex relationship between pain perception and attitudes toward life-sustaining treatments. [less ▲]

Detailed reference viewed: 28 (2 ULg)
Full Text
Peer Reviewed
See detailConsciousness supporting networks
Demertzi, Athina ULg; Soddu, Andrea ULg; Laureys, Steven ULg

in Current Opinion in Neurobiology (2013), 23(2), 239-244

Functional neuroimaging shows that patients with disorders of consciousness exhibit disrupted system-level functional connectivity. Unresponsive/"vegetative state" patients preserve wakefulness networks ... [more ▼]

Functional neuroimaging shows that patients with disorders of consciousness exhibit disrupted system-level functional connectivity. Unresponsive/"vegetative state" patients preserve wakefulness networks of brainstem and basal forebrain but the cerebral networks accounting for external perceptual awareness and internal self-related mentation are disrupted. Specifically, the 'external awareness' network encompassing lateral fronto-temporo-parietal cortices bilaterally, and the 'internal awareness' network including midline anterior cingulate/mesiofrontal and posterior cingulate/precuneal cortices, are functionally disconnected. By contrast, patients in minimally conscious state 'minus', who show non-reflex behaviors, are characterized by right-lateralized recovery of the external awareness network. Similarly, patients who evolve to minimally conscious state 'plus' and respond to commands recover the dominant left-lateralized language network. Now, the use of active experimental paradigms targeting at detecting motor-independent signs of awareness or even establishing communication with these patients, challenge these two clinical boundaries. Such advances are naturally accompanied by legitimate neuroscientific and ethical queries demanding our attention on the medical implementations of this new knowledge. [less ▲]

Detailed reference viewed: 27 (2 ULg)
Full Text
Peer Reviewed
See detailOur rapidly changing understanding of acute and chronic disorders of consciousness: challenges for neurologists
Gantner, Sylvia ULg; BODART, Olivier ULg; Laureys, Steven ULg et al

in Future Neurology (2013), 8(1), 43-54

A number of recent studies suggest that some ‘vegetative state’ patients have been misdiagnosed, judging by their ability to follow commands and in some cases even communicate through brain activity. Such ... [more ▼]

A number of recent studies suggest that some ‘vegetative state’ patients have been misdiagnosed, judging by their ability to follow commands and in some cases even communicate through brain activity. Such studies highlight the difficulty in forming a diagnosis based only on behavioral assessments. We think that neuroimaging and electrophysiology methods will be used more frequently in clinical settings, integrated with existing behavioral assessments. Such efforts are expected to lead to a more accurate understanding of individual patients’ cognitive abilities or even provide prognostic indicators. In terms of treatment planning (i.e., pain management and end-of-life decision-making), patients with disorders of consciousness are now offered the possibility of expressing their preferences by means of brain–computer interfaces. What remains to be clarified is the degree to which such indirect responses can be considered reliable and of legal representation. [less ▲]

Detailed reference viewed: 108 (3 ULg)
Full Text
Peer Reviewed
See detailThe neuroscience of tinnitus: Perspectives from human neuroimaging studies
Maudoux, Audrey ULg; Vanneste, Sven; De Ridder, Dirk et al

Conference (2012, November)

Detailed reference viewed: 119 (4 ULg)
Full Text
Peer Reviewed
See detailInvestigating the tinnitus brain using resting-state fMRI
Maudoux, Audrey ULg; Vanneste, Sven; De Ridder, Dirk et al

Conference (2012, June)

Detailed reference viewed: 30 (2 ULg)
Full Text
Peer Reviewed
See detailAuditory Resting-State Network Connectivity in Tinnitus: a Functionnal MRI Study.
MAUDOUX, Audrey ULg; LEFEBVRE, Philippe ULg; CABAY, Jean-Evrard ULg et al

in PLoS ONE (2012)

The underlying functional neuroanatomy of tinnitus remains poorly understood. Few studies have focused on functional cerebral connectivity changes in tinnitus patients. The aim of this study was to test ... [more ▼]

The underlying functional neuroanatomy of tinnitus remains poorly understood. Few studies have focused on functional cerebral connectivity changes in tinnitus patients. The aim of this study was to test if functional MRI ‘‘resting-state’’ connectivity patterns in auditory network differ between tinnitus patients and normal controls. Thirteen chronic tinnitus subjects and fifteen age-matched healthy controls were studied on a 3 tesla MRI. Connectivity was investigated using independent component analysis and an automated component selection approach taking into account the spatial and temporal properties of each component. Connectivity in extra-auditory regions such as brainstem, basal ganglia/NAc, cerebellum, parahippocampal, right prefrontal, parietal, and sensorimotor areas was found to be increased in tinnitus subjects. The right primary auditory cortex, left prefrontal, left fusiform gyrus, and bilateral occipital regions showed a decreased connectivity in tinnitus. These results show that there is a modification of cortical and subcortical functional connectivity in tinnitus encompassing attentional, mnemonic, and emotional networks. Our data corroborate the hypothesized implication of non-auditory regions in tinnitus physiopathology and suggest that various regions of the brain seem involved in the persistent awareness of the phenomenon as well as in the development of the associated distress. leading to disabling chronic tinnitus. [less ▲]

Detailed reference viewed: 155 (11 ULg)
Full Text
Peer Reviewed
See detailPain perception in disorders of consciousness: Neuroscience, clinical care, and ethics in dialogue
Demertzi, Athina ULg; Racine, Eric; Bruno, Marie-Aurélie ULg et al

in Neuroethics (2012)

Pain, suffering and positive emotions in patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally conscious states (MCS) pose clinical and ethical challenges. Clinically, we ... [more ▼]

Pain, suffering and positive emotions in patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally conscious states (MCS) pose clinical and ethical challenges. Clinically, we evaluate behavioural responses after painful stimulation and also emotionally-contingent behaviours (e.g., smiling). Using stimuli with emotional valence, neuroimaging and electrophysiology technologies can detect subclinical remnants of preserved capacities for pain which might influence decisions about treatment limitation. To date, no data exist as to how healthcare providers think about end-of-life options (e.g., withdrawal of artificial nutrition and hydration) in the presence or absence of pain in non-communicative patients. Here, we aimed to better clarify this issue by re-analyzing previously published data on pain perception (Prog Brain Res 2009 177, 329–38) and end-of-life decisions (J Neurol 2010 258, 1058–65) in patients with disorders of consciousness. In a sample of 2259 European healthcare professionals we found that, for VS/UWS more respondents agreed with treatment withdrawal when they considered that VS/UWS patients did not feel pain (77%) as compared to those who thought VS/UWS did feel pain (59%). This interaction was influenced by religiosity and professional background. For MCS, end-of-life attitudes were not influenced by opinions on pain perception. Within a contemporary ethical context we discuss (1) the evolving scientific understandings of pain perception and their relationship to existing clinical and ethical guidelines; (2) the discrepancies of attitudes within (and between) healthcare providers and their consequences for treatment approaches, and (3) the implicit but complex relationship between pain perception and attitudes toward life-sustaining treatments. [less ▲]

Detailed reference viewed: 231 (15 ULg)
Full Text
Peer Reviewed
See detailWhat about pain in disorders of consciousness?
Schnakers, Caroline; Chatelle, Camille ULg; Demertzi, Athina ULg et al

in AAPS Journal (2012), 14

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailResting state networks and consciousness Alterations of multiple resting state network connectivity in physiological, pharmacological and pathological consciousness states
Heine, Lizette ULg; Soddu, Andrea ULg; Gomez Jaramillo, Francisco Albeiro ULg et al

in Frontiers in Psychology (2012), 3

In order to better understand the functional contribution of resting state activity to conscious cognition, we aimed to review increases and decreases in fMRI functional connectivity under physiological ... [more ▼]

In order to better understand the functional contribution of resting state activity to conscious cognition, we aimed to review increases and decreases in fMRI functional connectivity under physiological (sleep), pharmacological (anesthesia) and pathological altered states of consciousness, such as brain death, coma, vegetative state/unresponsive wakefulness syndrome, and minimally conscious state. The reviewed RSNs were the DMN, left and right executive control, salience, sensorimotor, auditory and visual networks. We highlight some methodological issues concerning resting state analyses in severely injured brains mainly in terms of hypothesis-driven seed-based correlation analysis and data-driven independent components analysis approaches. Finally, we attempt to contextualize our discussion within theoretical frameworks of conscious processes. We think that this “lesion” approach allows us to better determine the necessary conditions under which normal conscious cognition takes place. At the clinical level, we acknowledge the technical merits of the resting state paradigm. Indeed, fast and easy acquisitions are preferable to activation paradigms in clinical populations. Finally, we emphasize the need to validate the diagnostic and prognostic value of fMRI resting state measurements in non-communicating brain damaged patients. [less ▲]

Detailed reference viewed: 115 (5 ULg)
Full Text
Peer Reviewed
See detailConnectivity graph analysis of the auditory resting state network in tinnitus.
MAUDOUX, Audrey ULg; Lefèbvre, Philippe ULg; Cabay, J.-E. et al

in Brain Research (2012), 1485

Thirteen chronic tinnitus patients and fifteen age-matched healthy controls were studied on a 3T magnetic resonance imaging (MRI) scanner during resting condition (i.e. eyes closed, no task performance ... [more ▼]

Thirteen chronic tinnitus patients and fifteen age-matched healthy controls were studied on a 3T magnetic resonance imaging (MRI) scanner during resting condition (i.e. eyes closed, no task performance). The auditory resting-state component was selected using an automatic component selection approach. Functional connectivity (correlations/anti-correlations) in the extracted network was portrayed by integrating the independent component analysis (ICA) approach with a graph theory method. Tinnitus and control groups showed different graph connectivity patterns. In the control group, the connectivity graph was divided into two distinct anti-correlated networks. The first one encompassed the auditory cortices and the insula. The second one encompassed frontoparietal and anterior cingulate cortices, brainstem, amygdala, basal ganglia/nucleus accumbens and parahippocampal regions. In the tinnitus group, only one of the two previously described networks was observed, encompassing the auditory cortices and the insula. Direct group comparison showed, in the tinnitus group, an increased functional connectivity between auditory cortices and the left parahippocampal region surviving multiple comparisons. We investigated a possible correlation between four tinnitus relevant measures (tinnitus handicap inventory (THI) and tinnitus questionnaire (TQ) scores, tinnitus duration and tinnitus intensity during the scanning session) and the connectivity pattern in the tinnitus population. We observed a significant positive correlation between the beta values of the posterior cingulate/precuneus region and the THI score. Our results show a modified functional connectivity pattern in tinnitus sufferers and highlight the role of the parahippocampal region in tinnitus physiopathology. They also point out the importance of the activity and connectivity pattern of the posterior cingulate cortex/precuneus region to the development of the tinnitus associated distress. This article is part of a Special Issue entitled: Tinnitus Neuroscience. [less ▲]

Detailed reference viewed: 55 (9 ULg)