36 research outputs found

    Influence of cationic phosphorus dendrimers on the surfactant-induced synthesis of mesostructured nanoporous silica

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    The concomitant use of polycationic dendrimers and cationic surfactants for the elaboration of periodic mesoporous silica of type MCM-41 is described. The hexagonal structure is preserved up to about 26% in weight of dendrimer included in the silica. The cationic surfactant can be selectively removed to liberate the pores, while preserving the non-covalently incorporated dendrimers. These dendrimers included in the mesoporous silica are fully accessible through the mesoporous volume to small molecules such as HCl and tetrahydrofuran

    Neurofeedback en psychiatrie : une technique du présent ? [Neurofeedback: one of today's techniques in psychiatry?]

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    International audienceObjectivesNeurofeedback is a technique that aims to teach a subject to regulate a brain parameter measured by a technical interface to modulate his/her related brain and cognitive activities. However, the use of neurofeedback as a therapeutic tool for psychiatric disorders remains controversial. The aim of this review is to summarize and to comment the level of evidence of electroencephalogram (EEG) neurofeedback and real-time functional magnetic resonance imaging (fMRI) neurofeedback for therapeutic application in psychiatry.MethodLiterature on neurofeedback and mental disorders but also on Brain Computer Interfaces (BCI) used in the field of neurocognitive science has been considered by the group of expert of the NExT (Neurofeedback Evaluation & Training) section of the French Association of Biological Psychiatry and Neuropsychopharmacology (AFPBN).ResultsResults show a potential efficacy of EEG-neurofeedback in the treatment of attentional-deficit/hyperactivity disorder (ADHD) in children, even if this is still debated. For other mental disorders, there is too limited research to warrant the use of EEG-neurofeedback in clinical practice. Regarding fMRI-neurofeedback, the level of evidence remains too weak, for now, to justify clinical use. The literature review highlights various unclear points, such as indications (psychiatric disorders, pathophysiologic rationale), protocols (brain signals targeted, learning characteristics), and techniques (EEG, fMRI, signal processing). ConclusionThe field of neurofeedback involves psychiatrists, neurophysiologists and researchers in the field of brain-computer-interfaces. Future studies should determine the criteria for optimizing neurofeedback sessions. A better understanding of the learning processes underpinning neurofeedback could be a key element to develop the use of this technique in clinical practice

    Aspects cliniques et neurofonctionnels impliqués dans le cours évolutif de la dépression : l’expérience d’une cohorte en soins courants

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    The aim of this work is to study anxiety and apathy in treatment resistant depression. These clinical factors and its imaging correlates will be tested in prediction of outcome in a 6-months follow-up. Original data were retrieved in LONGIDEP cohort. This is a prospective study conducted in routine care. Patients suffering from a mood depressive episode benefited from a clinical, neuropsychological and brain imaging. They were assessed once again at 6 months. Our study has shown that 1) apathy in depression is associated with specific clinical and pathophysiological patterns, 2) categorical and dimensional approach of anxiety in treatment resistant depression are not convergent. This latter population exhibited higher brain perfusion of centro-medial amygdala, 3) trait anxiety, cognitive patterns of visuospatial memory were predictive of pejorative outcome. Structural abnormalities in key regions involved in emotion regulation were associated with pejorative outcome of depression. Only anxiety was involved in outcome of depression. The link between anxiety and motivation should be studied in further works.Le but de ce travail est d’étudier deux dimensions sémiologiques, identifiées dans la littérature comme associées au trouble dépressif résistant, l’anxiété et l’apathie. Ces marqueurs cliniques et leurs corrélats radiologiques seront ensuite testés dans une analyse longitudinale du pronostic à 6 mois d’une cohorte de patients souffrant de dépression. Les données originales de ce travail sont issues de la cohorte LONGIDEP. Cette étude prospective, naturalistique, a été menée chez des patients souffrant d’un épisode dépressif majeur qui bénéficiaient, dans le cadre des soins courants, d’une évaluation clinique, neuropsychologique et d’une imagerie cérébrale à l’inclusion. Une nouvelle évaluation a été proposée à 6 mois de l’inclusion. Cette étude nous a permis de montrer que 1) l’apathie dans la dépression est associée à un profil clinique et physiopathologique spécifique, 2) l’analyse catégorielle et sémiologique de l’anxiété dans une population de sujet déprimés résistants n’étaient pas concordantes. Les déprimés résistants présentaient une hyperperfusion amygdale centro-médiane, 3) l’anxiété trait, un pattern cognitif associé à la mémoire visuo-spatiale étaient prédictifs d’une évolution péjorative de la dépression. Des anomalies structurales de régions impliquées dans la régulation émotionnelle et plus précisément l’adaptation au danger/peur, étaient associées à une évolution péjorative de la dépression. Des deux dimensions sémiologiques étudiées, l’anxiété apparaît être impliquées dans le pronostic de la dépression. L’étude des liens entre l’anxiété et les troubles de la motivation est une perspective de recherche pour la dépression résistante

    Clinical and neurofunctional patterns associated with pejorative outcome of depression : results from a routine care cohort

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    Le but de ce travail est d’étudier deux dimensions sémiologiques, identifiées dans la littérature comme associées au trouble dépressif résistant, l’anxiété et l’apathie. Ces marqueurs cliniques et leurs corrélats radiologiques seront ensuite testés dans une analyse longitudinale du pronostic à 6 mois d’une cohorte de patients souffrant de dépression. Les données originales de ce travail sont issues de la cohorte LONGIDEP. Cette étude prospective, naturalistique, a été menée chez des patients souffrant d’un épisode dépressif majeur qui bénéficiaient, dans le cadre des soins courants, d’une évaluation clinique, neuropsychologique et d’une imagerie cérébrale à l’inclusion. Une nouvelle évaluation a été proposée à 6 mois de l’inclusion. Cette étude nous a permis de montrer que 1) l’apathie dans la dépression est associée à un profil clinique et physiopathologique spécifique, 2) l’analyse catégorielle et sémiologique de l’anxiété dans une population de sujet déprimés résistants n’étaient pas concordantes. Les déprimés résistants présentaient une hyperperfusion amygdale centro-médiane, 3) l’anxiété trait, un pattern cognitif associé à la mémoire visuo-spatiale étaient prédictifs d’une évolution péjorative de la dépression. Des anomalies structurales de régions impliquées dans la régulation émotionnelle et plus précisément l’adaptation au danger/peur, étaient associées à une évolution péjorative de la dépression. Des deux dimensions sémiologiques étudiées, l’anxiété apparaît être impliquées dans le pronostic de la dépression. L’étude des liens entre l’anxiété et les troubles de la motivation est une perspective de recherche pour la dépression résistante.The aim of this work is to study anxiety and apathy in treatment resistant depression. These clinical factors and its imaging correlates will be tested in prediction of outcome in a 6-months follow-up. Original data were retrieved in LONGIDEP cohort. This is a prospective study conducted in routine care. Patients suffering from a mood depressive episode benefited from a clinical, neuropsychological and brain imaging. They were assessed once again at 6 months. Our study has shown that 1) apathy in depression is associated with specific clinical and pathophysiological patterns, 2) categorical and dimensional approach of anxiety in treatment resistant depression are not convergent. This latter population exhibited higher brain perfusion of centro-medial amygdala, 3) trait anxiety, cognitive patterns of visuospatial memory were predictive of pejorative outcome. Structural abnormalities in key regions involved in emotion regulation were associated with pejorative outcome of depression. Only anxiety was involved in outcome of depression. The link between anxiety and motivation should be studied in further works

    Shape-based features of white matter fiber-tracts associated with outcome in Major Depression Disorder

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    International audienceMajor depression is a leading cause of disability due to its trend to recurrence and treatment resistance. Currently, there are no biomarkers which could potentially identify patients with risk of treatment resistance. In this original paper, we propose a two-level shape analysis of the white matter bundles based on the Large Diffeomorphic Deformation Metric Mapping framework, to study treatment resistant depression. Fiber bundles are characterised via the deformation of their center line from a centroid shape. We developed two statistical analyses at a global and a local level to identify the most relevant bundles related to treatment resistant depression. Using a prospective longitudinal cohort including 63 patients. We applied this approach at baseline on 50 white matter fiber-tracts, to predict the clinical improvement at 6 months. Our results show a strong association between three bundles and the clinical improvement 6 months after. More precisely, the rightsided thalamo-occipital fascicle and optic radiations are the most robust followed by the splenium. The present study shows the interest in considering white matter shape in the context of depression, contributing to improve our understanding of neurobiological process of treatment resistance depression

    Vers une approche physiologique de la sémiologie en psychiatrie. Partie 2 : perspectives offertes par la biologie systémique

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    International audienceThis second article, in a series of two, on the physiological approach of psychiatric semiology proposes to explore the place of physiology and clinical semiology according to a systemic biology approach. While the approach of psychiatric semiology has been closely linked to the construction of contemporary classifications of psychiatric disorders, two approaches tending to break away from classical nosographies have been proposed the psychosystems project and the Cambridge model. For each of these approaches will be presented the general principle, the link with physiology and semiology, and the main limitations. It will be proposed to include the psychosystems project as well as the Cambridge model from a systemic biology perspective that could reintegrate semiology as an essential level of the psychiatric disorder approach, between biological and social value. The issues of such biological and social constraints will be approached according to an epistemological approach, notably through the questions raised by neurophenomenology, in order to propose a perspective of clinical neurophysiology to psychiatry that is to say of a neurophysiology that takes seriously the clinical knowledge historically constituted of psychiatry, but also a clinic that does not deny the advances in neurophysiology on the understanding of brain function. © 2019 Elsevier Masson SASCe deuxiĂšme article, d’une sĂ©rie de deux portant sur l’approche physiologique de la sĂ©miologie psychiatrique, propose d’explorer la place de la physiologie et de la sĂ©miologie clinique suivant une approche de biologie systĂ©mique. Alors que l’approche de la sĂ©miologie psychiatrique a Ă©tĂ© intiment liĂ©e Ă  la construction des classifications contemporaines des troubles psychiatriques, deux approches tendant Ă  se dĂ©tacher des nosographies classiques ont Ă©tĂ© proposĂ©es : le projet psychosystems et le modĂšle de Cambridge. Pour chacune de ces approches seront prĂ©sentĂ©s le principe gĂ©nĂ©ral, le lien avec la physiologie et la sĂ©miologie, et les limitations principales. Il sera proposĂ© d’englober le projet psychosystems ainsi que le modĂšle de Cambridge suivant une perspective de biologie systĂ©mique qui pourrait permettre de rĂ©intĂ©grer la sĂ©miologie comme un niveau essentiel de l’approche des troubles mentaux, entre fait biologique et valeur sociale. Les enjeux de telles contraintes biologiques et sociales seront abordĂ©s suivant une approche Ă©pistĂ©mologique, notamment Ă  travers les questions soulevĂ©es par la neurophĂ©nomĂ©nologie, afin de proposer une perspective de neurophysiologie clinique Ă  la psychiatrie : c’est-Ă -dire d’une neurophysiologie qui prenne au sĂ©rieux le savoir clinique historiquement constituĂ© de la psychiatrie, mais aussi d’une clinique qui ne dĂ©nigre pas les avancĂ©es en neurophysiologie sur la comprĂ©hension du fonctionnement cĂ©rĂ©bral

    Using recent BCI literature to deepen our understanding of clinical neurofeedback: A short review

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    International audienceIn their recent paper, Alkoby et al. (2017) provide the readership with an extensive and very insightful review of the factors influencing NeuroFeedback (NF) performance. These factors are drawn from both the NF literature and the Brain-Computer Interface (BCI) literature. Our short review aims to complement Alkoby et al.'s review by reporting recent additions to the BCI literature. The object of this paper is to highlight this literature and discuss its potential relevance and usefulness to better understand the processes underlying NF and further improve the design of clinical trials assessing NF efficacy. Indeed, we are convinced that while NF and BCI are fundamentally different in many ways, both the BCI and NF communities could reach compelling achievements by building upon one another. By reviewing the recent BCI literature, we identified three types of factors that influence BCI performance: task-specific, cognitive/motivational and technology-acceptance-related factors. Since BCIs and NF share a common goal (i.e., learning to modulate specific neurophysiological patterns), similar cognitive and neurophysiological processes are likely to be involved during the training process. Thus, the literature on BCI training may help (1) to deepen our understanding of neurofeedback training processes and (2) to understand the variables that influence the clinical efficacy of NF. This may help to properly assess and/or control the influence of these variables during randomized controlled trials
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