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See detailBrain mechanisms of propofol-induced loss of consciousness in humans: a positron emission tomographic study.
Fiset, P.; Paus, T.; Daloze, T. et al

in The Journal of neuroscience : the official journal of the Society for Neuroscience (1999), 19(13), 5506-13

In the present study, we used positron emission tomography to investigate changes in regional cerebral blood flow (rCBF) during a general anesthetic infusion set to produce a gradual transition from the ... [more ▼]

In the present study, we used positron emission tomography to investigate changes in regional cerebral blood flow (rCBF) during a general anesthetic infusion set to produce a gradual transition from the awake state to unconsciousness. Five right-handed human volunteers participated in the study. They were given propofol with a computer-controlled infusion pump to achieve three stable levels of plasma concentrations corresponding to mild sedation, deep sedation, and unconsciousness, the latter defined as unresponsiveness to verbal commands. During awake baseline and each of the three levels of sedation, two scans were acquired after injection of an H215O bolus. Global as well as regional CBF were determined and correlated with propofol concentrations. In addition, blood flow changes in the thalamus were correlated with those of the entire scanned volume to determine areas of coordinated changes. In addition to a generalized decrease in global CBF, large regional decreases in CBF occurred bilaterally in the medial thalamus, the cuneus and precuneus, and the posterior cingulate, orbitofrontal, and right angular gyri. Furthermore, a significant covariation between the thalamic and midbrain blood flow changes was observed, suggesting a close functional relationship between the two structures. We suggest that, at the concentrations attained, propofol preferentially decreases rCBF in brain regions previously implicated in the regulation of arousal, performance of associative functions, and autonomic control. Our data support the hypothesis that anesthetics induce behavioral changes via a preferential, concentration-dependent effect on specific neuronal networks rather than through a nonspecific, generalized effect on the brain. [less ▲]

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See detailBrain mechanisms underlying automatic and unconscious control of motor action
D'Ostilio, Kevin ULiege; GARRAUX, Gaëtan ULiege

in Frontiers in Human Neuroscience (2012)

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See detailBrain metabolic dysfunction in Capgras delusion during Alzheimer’s disease: a positron emission tomography study
Jedidi, Haroun ULiege; Daury, Noémy; Rémi, Capa et al

in American Journal of Alzheimer's Disease & Other Dementias (2015), 30(7), 699-706

Capgras delusion is characterized by the misidentification of people and by the delusional belief that the misidentified persons have been replaced by impostors, generally perceived as persecutors. Since ... [more ▼]

Capgras delusion is characterized by the misidentification of people and by the delusional belief that the misidentified persons have been replaced by impostors, generally perceived as persecutors. Since little is known regarding the neural correlates of Capgras syndrome, the cerebral metabolic pattern of a patient with probable Alzheimer’s disease (AD) and Capgras syndrome was compared with those of 24 healthy elderly subjects and 26 AD patients without delusional syndrome. Compared to the healthy and AD groups, the patient had significant hypometabolism in frontal and posterior midline structures. In light of current neural models of face perception, our patient’s Capgras syndrome may be related to impaired recognition of a familiar face, subserved by the posterior cingulate/precuneus cortex, and impaired reflection about personally relevant knowledge related to a face, subserved by the dorsomedial prefrontal cortex. [less ▲]

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See detailBrain metabolic dysfunction in Capgras syndrome during Alzheimer’s disease: a positron emission tomography study
Jedidi, Haroun ULiege; Daury, Noémy; Cappa, Rémi et al

Poster (2013, June)

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See detailBrain natriuretic peptide in asymptomatic degenerative mitral regurgitation: determinants and impact on outcome.
Van de Heyning, C; Magne, Julien ULiege; Mahjoub, H et al

Conference (2011)

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See detailBrain natriuretic peptide release in patients with aortic stenosis: Resting and exercise echocardiographic determinants.
Henri, Christine; Magne, Julien ULiege; Dulgheru, Raluca et al

in International journal of cardiology (2014), 172(3), 611-3

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See detailBrain oxygen transport related to levels of fetal haemoglobin in stable preterm infants.
RAMAEKERS, Vincent ULiege; Daniels, H.; Casaer, P.

in Journal of developmental physiology (1992), 17(5), 209-13

The relative amount of regional cerebral oxygen transport was compared between different preterm infants by performing measurements of cerebral blood flow velocity, mean arterial blood pressure, whole ... [more ▼]

The relative amount of regional cerebral oxygen transport was compared between different preterm infants by performing measurements of cerebral blood flow velocity, mean arterial blood pressure, whole blood viscosity and haemoglobin content for each individual. In addition the percentage of fetal haemoglobin was determined. On 25 occasions measurements of fetal haemoglobin and cerebral oxygen transport have been performed prior to and following a blood transfusion with adult red blood cells. Comparison of the data for cerebral oxygen transport suggests that the actual amount of cerebral oxygen transport is lowest at fetal haemoglobin levels below 30% and will increase progressively as soon as the percentage of fetal haemoglobin rises about 30%. Thus, at increasing fetal haemoglobin levels, cerebral haemodynamic mechanisms in the human neonate cause elevations of regional cerebral blood flow and oxygen transport. The found increase of cerebral blood flow and oxygen transport at high fetal haemoglobin levels will minimize the impeded dissociation and delivery of oxygen to brain tissues. [less ▲]

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See detailBrain perfusion patterns in familial frontotemporal lobar degeneration.
Seelaar, H.; Papma, J. M.; Garraux, Gaëtan ULiege et al

in Neurology (2011), 77(4), 384-92

OBJECTIVE: Frontotemporal lobar degeneration (FTLD) is a clinically, genetically, and pathologically heterogeneous disorder. The aim of this study was to compare clinical features and perfusion patterns ... [more ▼]

OBJECTIVE: Frontotemporal lobar degeneration (FTLD) is a clinically, genetically, and pathologically heterogeneous disorder. The aim of this study was to compare clinical features and perfusion patterns on SPECT of patients with familial FTLD-TAR DNA binding protein 43 kDa (TDP) and MAPT mutations. METHODS: Patients were included if they had MAPT or GRN mutations, positive family history with pathologically proven FTLD in the patient or first-degree relative, or were part of FTD-MND families. All patients and 10 age- and gender-matched controls underwent measurement of brain perfusion using (99m)Tc-HMPAO SPECT. We used SPM8 to perform image processing and voxel-based group analyses (p < 0.001). Gender and age were included as nuisance variables in the design matrices. RESULTS: Of the 29 patients with familial FTLD, 19 had familial FTLD-TDP (GRN mutations in 6), and 10 had MAPT mutations. At clinical presentation, familial FTLD-TDP patients were older at onset (p = 0.030) and had more memory deficits (p = 0.011), whereas patients with MAPT had more naming deficits (p < 0.001) and obsessive-compulsive behavior (p = 0.001). The between-groups SPECT analyses revealed significantly less perfusion in the right frontal lobe, precuneus, cuneus, and inferior parietal lobule in familial FTLD-TDP, whereas significantly less perfusion was found in the left temporal and inferior frontal gyri in MAPT. Post hoc analysis of familial FTLD-TDP with unknown genetic defect vs MAPT revealed less perfusion in the right frontal and parietal lobe. CONCLUSION: Familial FTLD-TDP shows relatively more posterior hypoperfusion, including the precuneus and inferior parietal lobule, possibly related to significant memory impairment. Patients with MAPT were characterized by impaired perfusion of the temporal regions and naming deficits. [less ▲]

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See detailBrain plasticity after implanted droop foot stimulator
Thibaut, Aurore ULiege; Gosseries, Olivia ULiege; LAUREYS, Steven ULiege

Poster (2014, March)

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See detailBrain plasticity after implanted drop foot stimulator in chronic stroke
Thibaut, Aurore ULiege

Conference (2015, June 20)

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See detailBrain plasticity and anti-depressant effects are versatile potential of alpha-linolenic acid to promote stroke recovery
Blondeau, Nicolas; Debruyne D; Piens, Marie et al

in Journal of Cerebral Blood Flow & Metabolism (2009), 29

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See detailBrain plasticity related to the consolidation of motor sequence learning and motor adaptation
Debas, K.; Carrier, J.; Orban, Patricia ULiege et al

in Proceedings of the National Academy of Sciences of the United States of America (2010), 107(41), 17839-44

This study aimed to investigate, through functional MRI (fMRI), the neuronal substrates associated with the consolidation process of two motor skills: motor sequence learning (MSL) and motor adaptation ... [more ▼]

This study aimed to investigate, through functional MRI (fMRI), the neuronal substrates associated with the consolidation process of two motor skills: motor sequence learning (MSL) and motor adaptation (MA). Four groups of young healthy individuals were assigned to either (i) a night/sleep condition, in which they were scanned while practicing a finger sequence learning task or an eight-target adaptation pointing task in the evening (test) and were scanned again 12 h later in the morning (retest) or (ii) a day/awake condition, in which they were scanned on the MSL or the MA tasks in the morning and were rescanned 12 h later in the evening. As expected and consistent with the behavioral results, the functional data revealed increased test-retest changes of activity in the striatum for the night/sleep group compared with the day/awake group in the MSL task. By contrast, the results of the MA task did not show any difference in test-retest activity between the night/sleep and day/awake groups. When the two MA task groups were combined, however, increased test-retest activity was found in lobule VI of the cerebellar cortex. Together, these findings highlight the presence of both functional and structural dissociations reflecting the off-line consolidation processes of MSL and MA. They suggest that MSL consolidation is sleep dependent and reflected by a differential increase of neural activity within the corticostriatal system, whereas MA consolidation necessitates either a period of daytime or sleep and is associated with increased neuronal activity within the corticocerebellar system. [less ▲]

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See detailBRAIN PLASTICITY, COGNITIVE RESERVE AND AGING: AN INSIGHT FROM THE RETIREMENT PERSPECTIVE
Grotz, Catherine ULiege

Doctoral thesis (2016)

Summary Background: Aging would be associated with brain changes that have an impact on certain cognitive functions. However, there is a huge interindividual heterogeneity in age related cognitive decline ... [more ▼]

Summary Background: Aging would be associated with brain changes that have an impact on certain cognitive functions. However, there is a huge interindividual heterogeneity in age related cognitive decline. This variability may be explained by differences in cognitive reserve (CR), a very recent and complex concept which suggests that the central nervous system can maintain its optimal performance over a longer period of time in individuals with certain lifestyle characteristics, evolving in "enriched environments". Thus, the aim of the present thesis was to deepen our understanding of the relationship between activity and brain; in particular, we examined the role of a variable that decisively influences subjects’ level of activity: retirement. Studies: First, we have shown that people aged 60 and over may maintain their cognitive skills through the continuation of their professional and non-professional activities (European Share survey). A cross-country analysis also revealed that cognitive scores of older adults were better in countries in which the eligibility age for retirement benefits was higher (e.g., 65 years old in Sweden) as compared to those where it was lower (e.g., 60 years old in France), suggesting that people benefit from staying longer in employment. Then, we extended our work to the effect of retirement on pathological aging and, in particular, to Alzheimer's disease (AD). We used data collected from the Ictus cohort, a European study of AD patients. We showed that previous research suffered from a methodological bias that led to overestimate the effect of retirement age. After taking into account this bias, we showed that although there is an association between retirement age and onset of the disease, the strength of the link is reduced. These initial results highlight the need for cautiousness when studying such complex relationships and for prospective studies. Thus, we used longitudinal data from the 3 Cities, a French population-based study of older adults. This study revealed that even though deferred retirement is associated with a lower risk of dementia, a longer working life is not associated with such reduced risk. This indicates that the retirement age does not directly contribute to CR but rather that earlier retirement should be considered as a factor of cognitive and psycho-social vulnerability. In the fourth study, we identified psychosocial factors associated with retirement that may influence cognitive functioning using data from the AMI study, which is conducted in rural areas in southwestern France. We found that holding positive consideration towards work and the beneficial effect of activity after retirement favored better cognitive functioning. Finally, we have developed and compared two indices of CR measuring all life experiences (a standard and a detailed indices). This study revealed that while both indices were associated with a minimization of the effects of age on cognition, the detailed index seems to best reflects the level of one’s CR. Conclusion: Although later retirement age is associated with cognition, caution is needed, as the current evidence should not merely serve economic interests aiming to justify an increase in the retirement age. Indeed, one should not suggest, based on these initial results, that increasing the age of retirement would be beneficial for everyone’s health. On the contrary, research on retirement and cognition mostly underlines the importance of activity in a general sense, rather than being limited to the professional occupation. The retirement transition is a complex life event that should be viewed in light of the various individual and social factors that may influence cognitive functioning. A better understanding of retirement-related factors that contribute to cognitive vitality is necessary in order to optimize health policies and to ensure that they are well adjusted to the diverse professional and psychological issues affecting the older population. [less ▲]

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See detailBrain protein and alpha-ketoglutarate dehydrogenase complex activity in Alzheimer's disease
Mastrogiacomo, Frank; Lindsay, J. Gordon; Bettendorff, Lucien ULiege et al

in Annals of Neurology (1996), 39

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See detailBrain response to one's own name in vegetative state, minimally conscious state and locked-in syndrome
Perrin, F.; Schnakers, Caroline ULiege; Schabus, M. et al

in Archives of Neurology (2006), 63

Detailed reference viewed: 39 (7 ULiège)
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See detailBrain responses following sleep loss are predicted by a polymorphism in PERIOD3 as assessed in humans using fMRI
Vandewalle, Gilles ULiege; Archer, Simon N; Wuillaume, Catherine et al

Poster (2008, May)

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See detailBrain responses to violet, blue, and green monochromatic light exposures in humans: prominent role of blue light and the brainstem
Vandewalle, Gilles ULiege; Schmidt, Christina ULiege; Albouy, Geneviève ULiege et al

in PLoS ONE (2007), 2(11), 1247

BACKGROUND: Relatively long duration retinal light exposure elicits nonvisual responses in humans, including modulation of alertness and cognition. These responses are thought to be mediated in part by ... [more ▼]

BACKGROUND: Relatively long duration retinal light exposure elicits nonvisual responses in humans, including modulation of alertness and cognition. These responses are thought to be mediated in part by melanopsin-expressing retinal ganglion cells which are more sensitive to blue light than violet or green light. The contribution of the melanopsin system and the brain mechanisms involved in the establishment of such responses to light remain to be established. METHODOLOGY/PRINCIPAL FINDINGS: We exposed 15 participants to short duration (50 s) monochromatic violet (430 nm), blue (473 nm), and green (527 nm) light exposures of equal photon flux (10(13)ph/cm(2)/s) while they were performing a working memory task in fMRI. At light onset, blue light, as compared to green light, increased activity in the left hippocampus, left thalamus, and right amygdala. During the task, blue light, as compared to violet light, increased activity in the left middle frontal gyrus, left thalamus and a bilateral area of the brainstem consistent with activation of the locus coeruleus. CONCLUSION/SIGNIFICANCE: These results support a prominent contribution of melanopsin-expressing retinal ganglion cells to brain responses to light within the very first seconds of an exposure. The results also demonstrate the implication of the brainstem in mediating these responses in humans and speak for a broad involvement of light in the regulation of brain function. [less ▲]

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See detailBrain Stimulation and Pharmacological Therapy in Disorders of Consciousness
Chatelle, Camille ULiege

Scientific conference (2014)

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See detailBrain stimulation in patients with disorders of consciousness
Thibaut, Aurore ULiege; Laureys, Steven ULiege

in Principles and Practice of Clinical Research (2015), 1(3),

Background and Aim: There is a long history of brain stimulation in medical science, and it was tested for years trying to treat several neurological diseases. On the other hand, the treatment choices for ... [more ▼]

Background and Aim: There is a long history of brain stimulation in medical science, and it was tested for years trying to treat several neurological diseases. On the other hand, the treatment choices for patients with severe brain injury resulting in disorders of consciousness (DOC) are still limited and research in this field remains challenging. In the current literature, only a few techniques of brain stimulation were studied in this population of patients. This review describes noninvasive techniques, namely transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), which permit to stimulate the brain through the scalp, as well as the current status of deep brain stimulation (DBS) as treatment for patients with DOC. For each technique (i.e. TMS, tDCS and DBS) a systematic search on Pubmed was performed including the term “vegetative state” or “minimally conscious state” or “disorders of consciousness” and 16 articles matched the criteria. Conclusion: Currently, repetitive TMS (rTMS) and tDCS studies have shown encouraging results, with transient improvements of behavioral signs of consciousness in patients in minimally conscious state (MCS). DBS showed more impressive and extensive behavioral improvement after the implantation of an electrical stimulator in the thalamus. However, this procedure is riskier and the number of patients who can benefit from this intervention is limited. All these therapeutic approaches are still in their infancy. In the years to follow, controlled clinical studies on potential treatments for patients with DOC should multiply and therapeutic measures should be more accessible, controlled and effective. [less ▲]

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