Mapping the functional connectome traits of levels of consciousness

Examining task-free functional connectivity (FC) in the human brain offers insights on how spontaneous integration and segregation of information relate to human cognition, and how this organization may be altered in different conditions, and neurological disorders. This is particularly relevant for patients in disorders of consciousness (DOC) following severe acquired brain damage and coma, one of the most devastating conditions in modern medical care. We present a novel data-driven methodology, connICA, which implements Independent Component Analysis (ICA) for the extraction of robust independent FC patterns (FC-traits) from a set of individual functional connectomes, without imposing any a priori data stratification into groups. We here apply connICA to investigate associations between network traits derived from task-free FC and cognitive/clinical features that define levels of consciousness. Three main independent FC-traits were identified and linked to consciousness-related clinical features. The first one represents the functional configuration it is associated to a sedative (sevoflurane), the overall effect of the pathology and the level of arousal. The second FC-trait reflects the disconnection of the visual and sensory-motor connectivity patterns. It also relates to the time since the insult and to the ability of communicating with the external environment. The third FC-trait isolates the connectivity pattern encompassing the fronto-parietal and the default-mode network areas as well as the interaction between left and right hemispheres, which are also associated to the awareness of the self and its surroundings. Each FC-trait represents a distinct functional process with a role in the degradation of conscious states of functional brain networks, shedding further light on the functional subcircuits that get disrupted in severe brain-damage

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

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

New Developments in Anesthesia-Reanimation for Ambulatory Procedures

peer reviewedThe one day clinic possesses its own structure and organisation; patient management is also specific. Preoperative visit and assessment are programmed at least 48 hours before anesthesia. Preoperative examinations and choice of anesthetic technique (sedation associated with local anesthesia or not, general anesthesia, locoregional anesthesia, or hypnosedation) are discussed and determined depending upon medical history, clinical examination, and type of procedure. General recommandations, instructions about fasting, interruption of some therapies, and introduction of new medication(s) are explained orally and also provided in a written document. New anesthetics and analgesics allow quick awakening and recovery of vital functions, and subsequently rapid hospital discharge. Prevention and aggressive treatment of postoperative nausea and vomiting are also a major concern in our anesthesic management of ambulatory patient

Bronchial thermoplasty : a real advancement in the treatment of asthma

New treatments are needed to improve the care of severe asthmatic patients. Bronchial thermoplasty aims to lessen the airway smooth muscles via the heating of bronchial walls by radiofrequency. The preliminary studies showed a good tolerance and some good efficacy. Randomized controlled trials have been undertaken on moderate to severe asthmatic patients, demonstrating an improvement in quality of life, rate of severe exacerbations and unscheduled medical visits. The main side-effects consist of asthma exacerbations, atelectasis and infections. Bronchial thermoplasty is an innovative treatment with good efficacy and acceptable tolerance for moderate to severe asthmatic patients. More studies are needed to better understand its mechanism of action and more clearly delineate the precise indications of this innovative technique

Mécanismes de l'anesthésie générale: apport de l'imagerie fonctionnelle

peer reviewe

Comment prédire l'évolution du coma post-anoxique?

peer reviewe

Hypnosis and pain perception

peer reviewedImprovement in functional neuroimaging allows researchers to disentangle the brain mechanisms involved in the pain modulation encountered during hypnosis. It has been shown that the anterior cingulate and prefrontal cortices are important in the modulation of incoming sensory and noxious input. Moreover, clinical studies in certain types of surgery (eg thyroidectomy, mastectomy and plastic surgery) have demonstrated that hypnosis may avoid general anesthesia