Functional neuroanatomy underlying the clinical subcategorization of minimally conscious state patients.

in Journal of Neurology (2012), 259(6), 1087-98

Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this ... [more ▼]

Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this entity can be subcategorized into MCS- (i.e., patients only showing nonreflex behavior such as visual pursuit, localization of noxious stimulation and/or contingent behavior) and MCS+ (i.e., patients showing command following).Patterns of cerebral glucose metabolism were studied using [(18)F]-fluorodeoxyglucose-PET in 39 healthy volunteers (aged 46 +/- 18 years) and 27 MCS patients of whom 13 were MCS- (aged 49 +/- 19 years; 4 traumatic; 21 +/- 23 months post injury) and 14 MCS+ (aged 43 +/- 19 years; 5 traumatic; 19 +/- 26 months post injury). Results were thresholded for significance at false discovery rate corrected p < 0.05.We observed a metabolic impairment in a bilateral subcortical (thalamus and caudate) and cortical (fronto-temporo-parietal) network in nontraumatic and traumatic MCS patients. Compared to MCS-, patients in MCS+ showed higher cerebral metabolism in left-sided cortical areas encompassing the language network, premotor, presupplementary motor, and sensorimotor cortices. A functional connectivity study showed that Broca's region was disconnected from the rest of the language network, mesiofrontal and cerebellar areas in MCS- as compared to MCS+ patients.The proposed subcategorization of MCS based on the presence or absence of command following showed a different functional neuroanatomy. MCS- is characterized by preserved right hemispheric cortical metabolism interpreted as evidence of residual sensory consciousness. MCS+ patients showed preserved metabolism and functional connectivity in language networks arguably reflecting some additional higher order or extended consciousness albeit devoid of clinical verbal or nonverbal expression. [less ▲]

Comment prédire l'évolution du coma post-anoxique?

in Revue Médicale de Liège (2008), 63(5-6), 263-268

Evaluation du pronostic neurologique dans les encéphalopathies postanoxiques

in Réanimation (2008), 17

Prise en charge de la douleur en pediatrie apres chirurgie ambulatoire

in Revue Médicale de Liège (2007), 62(11), 679-84

Over the last fifteen years, child's pain has become one of our major concerns. In spite of this evolution, it remains one of the most frequent complications after ambulatory surgery. It is thus essential ... [more ▼]

Over the last fifteen years, child's pain has become one of our major concerns. In spite of this evolution, it remains one of the most frequent complications after ambulatory surgery. It is thus essential to implement all the resources we have at our disposal in order to optimize pain management. This can be obtained by basing our strategy on the concept of multimode analgesia. It is consequently essential that each team can achieve its own quality program; the corollary will be the development of clear recommendations for the parents with a systematic analgesics regulation at home and the possibility to resort to the family doctor or to the ambulatory centre in the event of persistence of pain. [less ▲]

Post-operative analgesia for minor hand surgery: comparison between two dosages of paracetamol

in Acta Anaesthesiologica Belgica (2007), 58(3), 221

Activation of the supplementary motor area and of attentional networks during temporal processing

in Experimental Brain Research (2002), 142(4), 475-485

This paper first provides a survey of the expanding brain imaging literature in the field of time processing. showing that particular task features (discrete vs rhythmic, perceptual vs motor) do not ... [more ▼]

This paper first provides a survey of the expanding brain imaging literature in the field of time processing. showing that particular task features (discrete vs rhythmic, perceptual vs motor) do not significantly affect the basic pattern of activation observed. Next, positron emission tomography (PET) data obtained in a timing task (temporal reproduction) with two distinct duration ranges (2.2-3.2 and 9-13 s) are reported. The stimuli consisted of vibrations applied to the subject's right middle finger. When the vibration ended, the subject estimated an interval identical to its length before pressing a response button. The control task used cued responses with comparable intervals and stimuli, The pattern of activation obtained in the timing task as compared to control mainly included areas having attentional functions (the right dorsolateral prefrontal, inferior parietal, and anterior cingulate cortices), and the supplementary motor area (SMA). No significant difference was seen as a function of the duration range. It is argued, firstly. that involvement of the attentional areas derives from specific relations between attention and the temporal accumulator, as described by dominant timing models. and, secondly, that the SMA, or more probably one of its subregions, subserves time processing [less ▲]

Brain activation induced by estimation of duration : A PET study

in Neuroimage (1996), 3(2), 119-126

Duration information about a visual stimulus requires processing as do other visual features such as size or intensity. Using positron emission tomography, iterative (H2O)-O-15 infusions, and statistical ... [more ▼]

Duration information about a visual stimulus requires processing as do other visual features such as size or intensity. Using positron emission tomography, iterative (H2O)-O-15 infusions, and statistical parametric mapping, we investigated the neural correlates of time processing. Nine normal subjects underwent six serial rCBF. Three tasks were studied: (a) Atemporal generalization task (D task) in which the subjects had to judge (by pressing one of two keys) whether the duration of the illumination of a green LED was equal to or different from that of a previously presented standard; (b) An intensity generalization task. (I task) in which the judgment concerned the intensity of the LED; and (c) A control task (C task) in which the subjects had to press one of the two keys at random in response to LED illumination. A significant increase in rCBF during the D task, compared to that during the C task, was observed in right prefontal cortex, right inferior parietal lobule, anterior cingulate cortex, vermis, and a region corresponding to the left fusiform gyrus. A significant increase in rCBF during the I task, compared to that during the C task, was observed in right prefontal cortex, right inferior parietal lobule, right extrastriate cortex, anterior cingulate cortex, left inferior parietal lobule, vermis, and two symmetrical regions corresponding to the fusiform gyri. No significant activation was observed in the D task when compared to that in the I task. We propose that these cortical maps are best explained by the recruitment of visual attention and memory structures, which play a major role in prospective time judgements as indicated by behavioral studies. The data also suggest that the temporal dimension of a visual stimulus is processed in attributes. the same areas as other visual attributes. [less ▲]