Exploration of nociceptive cortical processing with steady-state evoked potentials

The periodic presentation of a sensory stimulus induces, at certain frequencies of stimulation, a sustained electroencephalographic response known as steady-state evoked potentials (SS-EP). SS-EPs are considered to reflect entrainment of cortical sensory networks resonating at the frequency of stimulation. In the present study we characterize and compare SS-EPs elicited by the selective electrical activation of nociceptive Aδ-fibers and non-nociceptive Aβ-fibers. Nine subjects took part in the experiment. Ten second trains of nociceptive (intra-epidermal electrical stimulation) and non-nociceptive (transcutaneous electrical stimulation) stimuli were applied to the left and right hand in separate blocks. Trains consisted of 0.5 ms constant-current pulses modulated at 3, 7, 13, 23 and 43 Hz. Consistent nociceptive and non-nociceptive SS-EPs were recorded at all stimulation frequencies. Whereas non-nociceptive SS-EPs were maximal over the parietal region contralateral to the stimulated side, nociceptive SS-EPs were maximal at the vertex and symmetrically distributed over both hemispheres, thus indicating that the two responses reflect the entrainment of distinct neuronal populations. The recording of nociceptive and non-nociceptive somatosensory SS-EPs offers a unique opportunity to study the cortical representation of nociception and touch in humans

Observance des traitements médicamenteux (étude dans une population de sujets très âgés hospitalisés)

PARIS6-Bibl.Pitié-Salpêtrie (751132101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

A developmental research-based teacher education: designing and implementing a new program for preservice teachers in France

International audienceIn many countries, preservice teachers’ (PTs) education programs neglect the importance of connecting research and practice. Reconciling training and research remains problematic for PTs, who often encounter difficulties in making connections between the academic knowledge acquired in university and their experiences in the classroom. This context inhibits the development of their professional skills. Taking this observation as our starting point, the aim of this article is to conceptualize and to illustrate an alternative approach in order to establish a reciprocal link between training and research, sketching the outlines of a developmental research-based program of teacher education. We begin by studying different training-based approaches to research and their respective limitations, identifying the key principles and steps of a developmental research-based approach to teacher education. Then, we illustrate these principles using data from empirical studies. Finally, we discuss the conditions required for the implementation of such an approach to the teacher education of PTs in France

Steady-state evoked potentials to tag specific components of nociceptive cortical processing.

Studies have shown that the periodic repetition of a stimulus induces, at certain stimulation frequencies, a sustained electro-cortical response of corresponding frequency, referred to as steady-state evoked potential (SSEP). Using infrared laser stimulation, we recently showed that SSEPs can be used to explore nociceptive cortical processing. Here, we implemented a novel approach to elicit such responses, using a periodic intra-epidermal electrical stimulation of cutaneous Aδ-nociceptors (Aδ-SSEPs). Using a wide range of frequencies (3-43 Hz), we compared the scalp topographies and temporal dynamics of these Aδ-SSEPs to the Aβ-SSEPs elicited by non-nociceptive transcutaneous electrical stimulation, as well as to the transient ERPs elicited by the onsets of the 10-s stimulation trains, applied to the left and right hand. At 3 Hz, we found that the topographies of Aβ- and Aδ-SSEPs were both maximal at the scalp vertex, and resembled closely that of the late P2 wave of transient ERPs, suggesting activity originating from the same neuronal populations. The responses also showed marked habituation, suggesting that they were mainly related to unspecific, attention-related processes. In contrast, at frequencies >3 Hz, the topographies of Aβ- and Aδ-SSEPs were markedly different. Aβ-SSEPs were maximal over the contralateral parietal region, whereas Aδ-SSEPs were maximal over midline frontal regions, thus indicating an entrainment of distinct neuronal populations. Furthermore, the responses showed no habituation, suggesting more obligatory and specific stages of sensory processing. Taken together, our results indicate that Aβ- and Aδ-SSEPs offer a unique opportunity to study the cortical representation of nociception and touch

Nociceptive and non-nociceptive steady-state evoked potentials tag distinct cortical network.

The periodic presentation of a sensory stimulus induces, at certain frequencies of stimulation, a sustained electroencephalographic response known as steady-state evoked potentials (SSEP). In the present study we characterize and compare SSEPs elicited by the selective electrical activation of nociceptive Aδ-fibers and non-nociceptive Aβ-fibers.Consistent nociceptive and non-nociceptive SSEPs were recorded at all stimulation frequencies. Whereas non-nociceptive SSEPs were maximal over the parietal region contralateral to the stimulated side, nociceptive SSEPs were maximal at the vertex and symmetrically distributed over both hemispheres, thus indicating that the two responses reflect the entrainment of distinct neuronal populations. For both types of SSEPs, the signal-to-noise was smaller at 7 and 13 Hz, possibly because of background alpha-band activity. Unlike conventional nociceptive event-related potentials, nociceptive SSEPs did not habituate, suggesting that they reflect more obligatory stages of sensory processing

Évaluation des facteurs influençant la prise médicamenteuse chez le sujet âgé selon les médecins et les infirmiers de services hospitaliers de gériatrie. Étude préalable avant la mise en place d’un programme d’éducation thérapeutique

Introduction : Les études montrent que près d’un patient âgé sur deux n’adhère pas à son traitement. L’hôpital gériatrique prend en charge un nombre croissant de patients âgés dépendants et polypathologiques. De plus, les facteurs qui peuvent limiter leur adhésion sont nombreux. Objectifs : Dans le but de développer un programme d’éducation thérapeutique, nous avons évalué la fréquence de ces facteurs ou leur importance sur l’adhésion thérapeutique des sujets âgés selon les soignants, afin de proposer des facteurs à aborder en priorité avec les patients. Méthodes : Nous avons choisi d’étudier 8 ensembles de facteurs en interrogeant des médecins et des infirmiers qui travaillent dans les services de court séjour, en consultation et en hôpital de jour de deux hôpitaux gériatriques. Un questionnaire de 20 questions fermées avec une échelle de mesure de type Likert a permis une analyse comparative entre médecins et infirmiers. Résultats : 40 médecins et 40 infirmiers ont répondu au questionnaire. Les réponses ont mis en évidence 4 groupes de facteurs : 12 facteurs fréquents et importants pour les médecins et les infirmiers, dont 3 qui le sont pour au moins 80% des soignants; 5 pour lesquels les résultats sont différents entre les médecins et les infirmiers, les discordances étant significatives pour 3 facteurs (p < 0,01); 8 pour lesquels les avis sont très partagés quel que soit le groupe; 2 facteurs peu fréquents dans les 2 groupes. Discussion/Conclusion : Notre étude permet de repérer des besoins éducatifs prioritaires chez les patients âgés selon le point de vue des professionnels de santé. Pour identifier ces besoins éducatifs à l’origine d’un programme d’éducation thérapeutique, il serait nécessaire de réaliser des entretiens auprès des patients ayant l’expérience du traitement à domicile

« C'est décidé, demain je me mets au sport !»

0info:eu-repo/semantics/publishe

Exploring visuo-tactile crossmodal attention using the frequency tagging of steady state evoked potentials

Covertly directing ones’ attention to the location of a stimulus of one sensory modality can affect the processing of the stimulus of another modality when presented at the same location. Here, we explored these mechanisms using steady-state evoked potentials, suggested to reflect (at least partially) brain processing in primary sensory cortices. Using light emitting diodes, two 16s sustained trains of flickering visual stimulation were concomitantly presented in either side of space. At the same time a train of vibrotactile stimulation was applied on the participant’s hand. In different blocks, the hand was positioned close to either the left or the right diode. Three different frequencies of stimulation were chosen to tag the specific EEG responses to the three different stimuli (visual left, visual right, tactile). Participants were asked to report occasional interruptions in the three streams of stimulation. The preliminary results show a tendency for a modulation of the visual steady-state evoked potentials according to the position of the stimulated hand: amplitude was lower when the stimulated hand was placed close to the visual stimulus. This suggests that body posture influences visual processing in primary visual cortical areas