Facial emotion recognition in Parkinson's disease A review and new hypotheses

International audienceParkinson's disease is a neurodegenerative disorder classically characterized by motor symptoms. Among them, hypomimia affects facial expressiveness and social communication and has a highly negative impact on patients' and relatives' quality of life. Patients also frequently experience nonmotor symptoms, including emotional-processing impairments, leading to difficulty in recognizing emotions from faces. Aside from its theoretical importance, understanding the disruption of facial emotion recognition in PD is crucial for improving quality of life for both patients and caregivers, as this impairment is associated with heightened interpersonal difficulties. However, studies assessing abilities in recognizing facial emotions in PD still report contradictory outcomes. The origins of this inconsistency are unclear, and several questions (regarding the role of dopamine replacement therapy or the possible consequences of hypomimia) remain unanswered. We therefore undertook a fresh review of relevant articles focusing on facial emotion recognition in PD to deepen current understanding of this nonmotor feature, exploring multiple significant potential confounding factors, both clinical and methodological, and discussing probable pathophysiological mechanisms. This led us to examine recent proposals about the role of basal ganglia-based circuits in emotion and to consider the involvement of facial mimicry in this deficit from the perspective of embodied simulation theory. We believe our findings will inform clinical practice and increase fundamental knowledge, particularly in relation to potential embodied emotion impairment in PD. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society

The effect of posterior non-fusion instrumentation on segmental shear loading of the lumbar spine

Background : Lumbar stenosis and facet osteoarthritis represent indications for decompression and instrumentation. It is unclear if degenerative spondylolisthesis grade I with a remaining disc height could be an indication for non-fusion instrumentation. The purpose of this study was to determine the influence of a mobile pedicle screw based device on lumbar segmental shear loading, thus simulating the condition of spondylolisthesis. Materials and methods : Six human cadaver specimens were tested in 3 configurations: intact L4–L5 segment, then facetectomy plus undercutting laminectomy, then instrumentation with lesion. A static axial compression of 400 N was applied to the lumbar segment and anterior displacements of L4 on L5 were measured for posterior-anterior shear forces from 0 to 200 N. The slope of the loading curve was assessed to determine shear stiffness. Results : Homogenous load-displacement curves were obtained for all specimens. The average intact anterior displacement was 1.2 mm. After lesion, the displacement increased by 0.6 mm compared to intact (P = 0.032). The instrumentation decreased the displacement by 0.5 mm compared to lesion (P = 0.046). The stiffness's were: 162 N/mm for intact, 106 N/mm for lesion, 148 N/mm for instrumentation. The difference was not significant between instrumented and intact segments (P = 0.591). Conclusions : Facetectomy plus undercutting laminectomy decreases segmental shear stiffness and increases anterior translational L4–L5 displacement. Shear stiffness of the instrumented segment is higher with the device and anterior displacements under shear loading are similar to the intact spine. This condition could theoretically be interesting for the simulation of non-fusion instrumentation in degenerative spondylolisthesis

Subthalamic Nucleus Stimulation Affects Theory of Mind Network: A PET Study in Parkinson's Disease

Background: There appears to be an overlap between the limbic system, which is modulated by subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson’s disease (PD), and the brain network that mediates theory of mind (ToM). Accordingly, the aim of the present study was to investigate the effects of STN DBS on ToM of PD patients and to correlate ToM modifications with changes in glucose metabolism. Methodology/Principal Findings: To this end, we conducted 18 FDG-PET scans in 13 PD patients in pre- and post-STN DBS conditions and correlated changes in their glucose metabolism with modified performances on the Eyes test, a visual ToM task requiring them to describe thoughts or feelings conveyed by photographs of the eye region. Postoperative PD performances on this emotion recognition task were significantly worse than either preoperative PD performances or those of healthy controls (HC), whereas there was no significant difference between preoperative PD and HC. Conversely, PD patients in the postoperative condition performed within the normal range on the gender attribution task included in the Eyes test. As far as the metabolic results are concerned, there were correlations between decreased cerebral glucos

Stimulation de la région sous-thalamique (résultats cliniques péropératoires)

RENNES1-BU Santé (352382103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Effets de la stimulation électrique subthalamique sur le comportement alimentaire du porc

L observation d une prise de poids anormalement élevée chez les patients parkinsoniens traîtés par stimulation subthalamique chronique, nous a amené à développer un modèle de stimulation subthalamique sur le porc afin d étudier le rôle physiologique de ce noyau sur le comportement alimentaire. Nous avons développé une procédure chirurgicale permettant d implanter des électrodes subthalamiques et, dans un second temps, nous avons évalué, sur une période de trois mois, plusieurs facettes du comportement alimentaire chez quatre animaux implantés en comparaison avec quatre animaux contrôle, vierges de toute intervention neurochirurgicale. Ainsi avons nous analysé les caractéristiques du profil d ingestion lors d un repas test de 30 minutes et en condition de libre accès à la nourriture sur 24 heures. Le choix spontané des animaux face à trois aliments différant de par leur palatabilité et leur contenu énergétique a également été analysé. Enfin, la composante motivationnelle des animaux a été analysée au moyen de deux expériences reposant sur des paradigmes de conditionnement opérant. Nos résultats nous incitent à penser que la stimulation subthalamique interfère essentiellement avec les phases préliminaires dites d approche du comportement alimentaire mais ne modifie pas le profil d ingestion proprement dit. Plus spécifiquement, lors des paradigmes de conditionnement opérant (obtention de nourriture par appuis sur un bouton dont la position variait de manière pseudo-aléatoire), les animaux stimulés ont présenté un nombre de persévérations et d erreurs supérieurs aux animaux contrôle. Ceci traduit très vraisemblablement un défaut de flexibilité des programmes moteurs par adhérence excessive à l action en cours et difficulté à initier une nouvelle action. De manière plus générale, cette étude soulève l intérêt du modèle du porc pour des études fondamentales de neuroimagerie et de neurochirurgie.The observation of abnormally high weight gain in patients with Parkinson s disease undergoing chronic stimulation of the subthalamic nucleus led us to develop a model of chronic subthalamic stimulation in pigs, in order to study the physiological role of this nucleus in food intake behavior. The initial phase of the study consisted in designing the surgical procedure required for bilateral implantation of subthalamic electrodes in a porcine model. In the second phase, we compared, over a three-month period, four implanted animals with four control animals which had never undergone any neurosurgical intervention. Several aspects of their food intake behaviour were investigated, using a range of behavioral tests, some of which being specifically designed for our study. We observed the characteristics of the animals ingestive profile during a 30-minute test meal, as well as in a condition of free access to food over a 24-hour period. The spontaneous feeding behaviour of these animals when given a choice of three foodstuffs with various levels of palatability and energy content was also analysed. Lastly, the animals motivational component was probed in two experiments based on operant conditioning paradigms. Our results suggest that subthalamic stimulus essentially interferes with the preliminary, so-called food approach phases of feeding behaviour and does not modify the actual ingestive profile. More specifically, in the operant conditioning experiments (leaning against a button placed in pseudorandom positions to obtain food), the stimulated animals displayed higher perseveration and error rates than the control animals. In all likelihood, this reflects impaired flexibility of motor programmes due to excessive adherence to the ongoing action and difficulty initiating a new one. More generally, this study highlights the usefulness of using the pig model for fundamental neuroimaging and neurosurgery studies.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

Apomorphine en perfusion sous-cutanée continue dans la maladie de Parkinson : le point de vue pharmacologique

National audienceSubcutaneous infusion with apomorphine is one of the treatments available for Parkinson's disease. Even if increasing evidence of its efficacy on both motor and non-motor symptoms is found in the literature, it is still underused. This article reviews pharmacological and pharmacokinetic properties of apomorphine and its impact on clinical decision making. Despite their complexity, those properties are a key to understanding the effect of the drug and its variability of efficacy and dosage amongst patients.Agoniste dopaminergique le plus ancien et le plus puissant, l’apomorphine n’en reste pas moins sous-utilisée dans la maladie de Parkinson, malgré une efficacité reconnue. Cet article fournit des éléments de compréhension de la pharmacologie et de la pharmacocinétique de cette molécule, à même d’expliquer les effets cliniques ainsi que les différences d’efficacité entre les individus. Pour le clinicien, ces éléments sont d’importance majeure pour comprendre les indications de l’apomorphine et sa place dans la pharmacopée antiparkinsonienne, dans l’objectif de personnaliser et d’optimiser le traitement pour chaque patient

Beta reactivity, prospective facilitation of executive processing, and its dependence on dopaminergic therapy in Parkinson's disease.

International audienceOscillatory activity in the beta frequency band has been shown to be modulated during the preparation and execution of voluntary movements at both cortical and subcortical levels. The exaggeration of beta activity in the basal ganglia of patients with Parkinson's disease has heightened interest in this phenomenon. However, the precise function, if any, subserved by modulations in beta activity remains unclear. Here we test the hypothesis that beta reactivity can be dissociated from processing of specific actions and can index the salience of cues with respect to future behavior in a way that might help prospectively prioritize resources. To this end we used an experimental paradigm designed to dissociate salient warning cues from processing of specific motor or cognitive actions. We recorded local field potential activity from the subthalamic nucleus of humans undergoing functional neurosurgery for the treatment of Parkinson's disease, while the same patients were on or off the dopamine prodrug levodopa. In this way we demonstrate that beta reactivity is indeed dependent on the salience of cues with respect to future motor and cognitive action and is promoted by dopamine. The loss of normal beta encoding of saliency may underlie some of the motor and cognitive features of basal ganglia disorders such as Parkinson's disease

Unusual presentation of neuralgic amyotrophy with impairment of cranial nerve XII

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Deep brain stimulation modulates effects of motivation in Parkinson's disease

It is unclear how motivation leads to improved motor performance. Here we test the hypothesis that motivation interacts with behavioural performance in the basal ganglia. We recorded trial-to-trial performance in a bimanual motor task in 10 patients with Parkinson's disease with electrodes chronically implanted in the subthalamic nucleus for deep brain stimulation. Motivation-associated improvements in trial-to-trial performance were contrasted with and without stimulation at high frequency. Motivation and stimulation improved trial-to-trial performance, but the effect of motivation was halved during stimulation. We conclude that the subthalamic area is mechanistically important in those processes linking motivation to improvement in motor performance. This finding may be relevant to some of the cognitive and emotional changes associated with bilateral subthalamic stimulation. NeuroReport 20:622-626 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

Data-Driven Prediction of the Therapeutic Window during Subthalamic Deep Brain Stimulation Surgery

International audienceBackground Moving from awake surgery under local anesthesia to asleep surgery under general anesthesia will require to precisely predict the outcome of deep brain stimulation. Objective To propose a data-driven prediction of both the therapeutic effect and side effects of the surgery. Methods The retrospective intraoperative data from 30 patients operated on in the subthalamic nucleus were used to train an artificial neural network to predict the deep brain stimulation outcome. A leave-one-out validation was undertaken to give a predictive performance that would reflect the performance of the predictive model in clinical practice. Three-dimensional coordinates and the amount of current of the electrodes were used to train the model. Results 130 electrode positions were reviewed. The areas under the curve were 0.902 and 0.89 for therapeutic and side effects, respectively. The mean sensitivity and specificity were 93.07% (SD 0.95) and 69.24% (SD 5.27) for the therapeutic effect, 73.47% (SD 10.55) and 91.82% (SD 0.12) for the side effect. Conclusion Data-driven prediction could be an additional modality to predict deep brain stimulation outcome. Further validation is needed to precisely use this method for performing surgery under general anesthesia. (C) 2018 S. Karger AG, Base