Trouble de stress post-traumatique

Le trouble de stress post-traumatique (ou TSPT) désigne un type de trouble anxieux sévère qui se manifeste à la suite d'une expérience vécue comme traumatisante avec une confrontation à des idées de mort. Cette affection est aussi connue sous le nom de syndrome de stress post-traumatique (SSPT) ou état de stress post-traumatique (ESPT) dans la classification CIM10 (F43.1). L'abréviation anglaise PTSD (pour post-traumatic stress disorder) est parfois également utilisée. Le trouble de stress post-traumatique est une réaction bio-neuro-physiologique consécutive à une situation durant laquelle l'intégrité physique ou psychologique du patient, ou celle de son entourage, a été menacée ou effectivement atteinte (notamment en cas de torture, viol, accident grave, mort violente, maltraitance, négligence de soins de la petite enfance, manipulation, agression, maladie grave, naissance, guerre, attentat, accouchement). Les capacités d'adaptation (comment faire face) du sujet sont débordées. La réaction immédiate à l'événement aura été traduite par une peur intense (effroi), par un sentiment d'impuissance ou par un sentiment d'horreur. Le TSPT est moins fréquent que la réponse aiguë au stress. Des symptômes de pathologies traumatiques, au niveau militaire, ont été décrits depuis très longtemps, avant que les médecins psychologues ne les étudient : on en trouve traces dans l'Epopée de Gilgamesh, chez Homère et Hérodote, jusqu'à Dominique Larrey. névrose traumatique Le neurologue allemand Hermann Oppenheim (1889) aurait le premier utilisé le terme de « névrose traumatique » pour décrire la symptomatologie présentée par des accidentés de la construction du chemin de fer. L'expression « Trouble de stress post-traumatique » (TSPT) a ensuite été attribuée à toute une gamme de symptômes et désordres résultant d'accidents industriels ou technologiques. Avec les deux guerres mondiales qui ont marqué le siècle dernier, la psychiatrie militaire s'est à son tour emparée de l'expression, puis, les pacifistes et les féministes des années 1960-1970 en ont élargi la signification pour y inclure les problèmes engendrés par la violence familiale et sociale.

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Publications associées (8)

Personnes associées (3)

Unités associées (2)

Concepts associés (229)

Cours associés (23)

Séances de cours associées (170)

Genetic selection for low glucocorticoid responsiveness recapitulates PTSD-related phenotypes: a behavioral, neuroimaging and sleep-physiology study

Silvia Monari

Humans show inter-individual differences in vulnerability to develop post-traumatic stress disorder (PTSD) following exposure to trauma. Several critical biobehavioral features have been consistently described in PTSD patients, including blunted cortisol levels, smaller hippocampal size, sleep disturbances. However, because of the delay between trauma exposure and the onset of symptoms characteristic of PTSD, only a few longitudinal studies have tried to dissect whether these features constitute pre-trauma risk factors or consequences of the trauma. Enormous effort in animal and human studies has been dedicated to understanding mechanisms of conditioned fear and fear extinction, processes that are at the core of PTSD. However, the same progress has not been translated into psychiatric practice for PTSD. Deepening our understanding of the contribution of key factors to PTSD-related alterations can serve to develop effective treatments.In particular, with regard to low cortisol levels in PTSD pathophysiology, a causative role for blunted glucocorticoid responsiveness in PTSD has not been demonstrated yet.Here, we have addressed this question in lines of Wistar rats genetically-selected for their differential habituation of glucocorticoid responses to stress (LOW-, INTER-, HIGH-CORT Responder rats) and focused on fear extinction, a hallmark of PTSD symptomology, as one of the key features. As a first step, we looked whether divergent trajectories of glucocorticoid responsiveness were associated with brain volume abnormalities, prompted by the influential role of glucocorticoid in brain development. Notably, rats with low or high corticosterone responsiveness exhibit smaller hippocampi, regardless of trauma exposure, compared to rats with normative corticosterone levels. Similarly, the distribution of corticosteroid receptors in the hippocampus presented similarities between the LOW-CR and the HIGH-CR rats with higher mineralocorticoid receptors (MR) and less glucocorticoid receptors (GR). Although LOW- and HIGH-CR rats displayed a similar hippocampal profile at the structural and molecular levels, only LOW-CR male rats exhibited strong deficits in extinction consolidation compared to rats with 'normative' glucocorticoid responses (INTER-CR rats), and showed higher fear response both at few days and at several weeks after trauma exposure. We next tested the causal involvement of corticosterone in the fear extinction consolidation, and found that post-extinction corticosterone treatment markedly prevented the deficits in extinction memory and attenuated fear relapse. In addition, pharmacological inhibition of corticosterone levels during extinction memory consolidation, but not during training, in the INTER-CR rats led to extinction deficits at retrieval one day later. These results indicate that blunted corticosterone levels contribute to confer major vulnerability than having a small hippocampus, and that consolidation processes following extinction are mainly affected by low corticosterone levels.It is well known that glucocorticoids play an important role in memory consolidation processes and that sleep disturbances are a diagnostic criterion of PTSD. Therefore, we investigated in greater detail the sleep architecture in undisturbed condition and during the consolidation period of the extinction phase, which is known to be supported by sleep-dependent processes. In polysomnographic recordings, we found that rats with blunted corticos

EPFL2022

Stress Impacts the Regulation Neuropeptides in the Rat Hippocampus and Prefrontal Cortex

Gregor Rainer, Laura Lozano Montes, Nan Zhao

Adverse life experience increases the lifetime risk to several stress-related psychopathologies, such as anxiety or depressive–like symptom following stress in adulthood. However, the neurochemical modulations triggered by stress have not been fully characterized. Neuropeptides play an important role as signaling molecules that contribute to physiological regulation and have been linked to neurological and psychiatric diseases. However, little is known about the influence of stress on neuropeptide regulation in the brain. Here, we have performed an exploratory study of how neuropeptide expression at adulthood is modulated by experiencing a period of multiple stressful experiences. We have targeted hippocampus and prefrontal cortex (PFC) brain areas, which have previously been shown to be modulated by stressors, employing a targeted Liquid Chromatography-Mass Spectrometry (LC-MS) based approach that permits broad peptide coverage with high sensitivity. We found that in the hippocampus, Met-enkephalin, Met-enkephalin-Arg-Phe and Met-enkephalin-Arg-Gly-Leu were up regulated, while Leu-enkephalin and Little SAAS were down regulated after stress. In the PFC area, Met-enkephalin-Arg-Phe, Met-enkephalin-Arg-Gly-Leu, peptide PHI-27, somatostatin-28 (AA1-12) and Little SAAS were all down regulated. This systematic evaluation of neuropeptide alterations in hippocampus and PFC suggests that stressor impact neuropeptides and that neuropeptide regulation is brain area specific. These findings suggest several potential peptide candidates, which warrant further investigations in terms of correlation with depression-associated behaviors.

2018

Nanocrystalline metals: transient testing during in situ X-ray diffraction and molecular dynamics

Zhen Sun

Nanocrystalline (NC) metals have attracted widespread interest in materials science due to their high strength compared to coarse-grained counterparts. It is well know that during uniaxial deformation, the stress-strain behaviour exhibits an extraordinary work-hardening followed by an early observation of constant flow stress. Information on possible deformation mechanisms have been gathered by extensive research combining in situ deformation experiments, electron microscopy observations and computational modelling. Generally, these mechanisms are categorized into two types: dislocation slip and grain boundary (GB) accommodation processes, as for instance, GB sliding based mechanisms and GB migration eventually coupled to the shear stress. However, the interplay between these mechanisms resulting in the constant deformation resistance is not fully understood. Transient testing has proven to be a suitable tool to gather information on the rate limiting deformation mechanisms that are activated during the deformation path. In particular in stress reduction experiments, after an intermediate/large stress drop thermally activated dislocation slip is suppressed so that other underlying mechanisms are brought into foreground during subsequent transient creep. Those mechanisms may play a minor role in the determination of the flow stress but might still be essential to the development of a constant deformation resistance. Within this thesis, transient testing is combined with in situ X-ray diffraction at the Swiss Light Source. Therefore, the transient responses are captured in terms of evolution of macrostrain as well as diffraction peak broadening. Since dislocation slip and GB accommodation have an opposite footprint on the peak broadening, the presence of these two types of mechanisms can be distinguished. Three electrodeposited NC materials with different grain sizes are investigated: two NC Ni batches and one NC Ni50Fe50 batch. The results reveal that the constant flow stress reached during uniaxial deformation of electrodeposited NC metals reflects a quasi-stationary balance between dislocation-based mechanisms and GB-mediated accommodation. The latter plays an important role in producing plastic strain and recovering the defects and internal stress. Depending on the magnitude of the stress drop, a non-monotonic behaviour of the diffraction peak width is observed, suggesting an alternation of mechanisms. Also, by comparing transient responses among different NC materials, the relative contributions of dislocation slip and GB accommodation mechanisms are discussed in terms of grain size and alloying. Finally, different magnitudes of stress reduction are carried out by molecular dynamics (MD) simulations with the aim to verify in situ experimental results and explore the mechanisms responsible for GB accommodation. MD simulations confirm that dislocation slip is reduced after a moderate stress drop, however can continue to operate after adaption of the GB structures by a variety of GB accommodation mechanisms explaining the non-monotonic behaviour of the peak broadening during transient creep.

EPFL2016

Trouble de stress post-traumatique

Trouble anxieux

Les troubles anxieux sont des peurs et/ou une anxiété anormales ou pathologiques. La classification des troubles mentaux reconnaît une large variété de troubles psychologiques anxieux. L'anxiété n'est pas en soi une émotion pathologique. Elle crée un trouble anxieux si elle devient envahissante (jusqu'au « trouble anxieux généralisé ») et source d'une souffrance significative pour l'individu (souffrance permanente ou discontinue).

Inhibiteur sélectif de la recapture de la sérotonine

Les inhibiteurs sélectifs de la recapture de la sérotonine (ISRS ; SSRI (Selective Serotonin Reuptake Inhibitor) en anglais) sont une classe médicamenteuse de psychotropes, de type antidépresseurs. Ils opèrent dans le cerveau, notamment en augmentant le taux d'un neurotransmetteur appelé sérotonine (5-hydroxytryptamine ou 5-HT). Ils agissent en inhibant la recapture de la sérotonine au niveau de la synapse.

In this course we will see an overview of the exciting field of Micro and Nanomechanical systems. We will go over the dfferent scaling laws that dominate the critical parameters, how size affects mat

Continuum conservation laws (e.g. mass, momentum and energy) will be introduced. Mathematical tools, including basic algebra and calculus of vectors and Cartesian tensors will be taught. Stress and de

Facteur de qualité et stress ME-426: Micro/Nanomechanical devices

Couvre le facteur de qualité et la contrainte dans les dispositifs micro/nanomécaniques, y compris la fabrication, l'actionnement, la détection et les effets de contrainte sur Q.

Facteur de qualité et stress

Discute du facteur de qualité et du stress dans les dispositifs micro/nanomécaniques, explorant les effets du stress sur les performances des dispositifs.

Introduction à la mécanique structurale: stress et contrainte

Couvre l'équilibre des contraintes, la contrainte et les équations constitutives en 2D et 3D.