Devenir clinique et cognitif de patients pédiatriques atteints d'encéphalites à anticorps anti-récepteurs NMDA

Nous avons inclus 14 patients (âge moyen 6,9 +- 5,1 ans), et recueilli les données cliniques et paracliniques initiales, puis les évaluations cliniques et cognitives à long terme. Les évaluations cognitives ont été réalisées par des évaluations neuropsychologiques dont les échelles de Wechsler et par des questionnaires: l échelle du comportement adaptatif de Vineland, la Child Behavior Checklist, la Behavior Rating Inventory of Executive Fonction et la PedsQL.Tous les patients se sont présentés avec des mouvements anormaux et des troubles du langage et la moitié d entre eux ont été hospitalisés en réanimation ou soins intensifs. Les difficultés motrices et les mouvements anormaux sont les premiers à récupérer, les difficultés de langage les derniers. Quatre patients (28%) ont complètement récupéré en 3 à 6 mois. A 27 mois d évolution en moyenne, les patients ont en majorité des difficultés de langage, de mémoire sémantique et verbale à long terme, de mémoire de travail, des fonctions exécutives, bien que les échelles de Wechsler soient peu altérées. Les patients se présentant avec une perte totale des moyens de communication et d autonomie à la phase initiale ont plus de risque d avoir des séquelles. L IRM cérébrale initiale est non spécifique mais les tracés EEG sont corrélés à la gravité de la présentation clinique initiale. La mise en place et le type de traitements ne semble pas avoir d importance sur les risques de séquelles dans notre série. Ainsi, la récupération de ces encéphalites reste longue, et le suivi cognitif régulier est nécessaire pour favoriser les apprentissages, malgré un traitement adaptéPARIS6-Bibl.Pitié-Salpêtrie (751132101) / SudocSudocFranceF

Unilateral predominance of abnormal movements: A characteristic feature of the pediatric anti-NMDA receptor encephalitis?

Anti-NMDA receptor encephalitis is a treatable autoimmune disease characterized by cognitive, motor and psychiatric features that primarily affects young adults and children. We present a case of a 7-year-old boy with asymmetrical (mainly right hemibody) and abnormal polymorphic movements without concomitant scalpictal EEG changes but had background slowing predominating over the left hemisphere. This report illustrates previous descriptions of asymmetric presentation of abnormal movements in pediatric anti-NMDA receptor encephalitis and emphasizes the importance of video-EEG interpreted within the overall clinical context, to differentiate epileptic from non-epileptic abnormal movements in patients with autoimmune encephalitis

Exploring the early organization and maturation of linguistic pathways in the human infant brain

International audienceLinguistic processing is based on a close collaboration between temporal and frontal regions connected by two pathways: the "dorsal" and "ventral pathways" (assumed to support phonological and semantic processing respectively in adults). We investigated here the development of these pathways at the onset of language acquisition, during the first post-natal weeks, using cross-sectional diffusion imaging in 21 healthy infants (6 to 22 weeks of age) and 17 young adults. We compared the bundle organization and microstructure at these two ages using tractography and original clustering analyses of DTI parameters. We observed structural similarities between both groups, especially concerning the dorsal/ventral pathway segregation and the arcuate fasciculus asymmetry. We further highlighted the developmental tempos of the linguistic bundles: the ventral pathway maturation was more advanced than the dorsal pathway maturation, but the latter catches up during the first post-natal months. Its fast development during this period might relate to the learning of speech cross-modal representations and to the first combinatorial analyses of the speech input

GluN2B N-methyl-D-aspartate receptor and excitatory amino acid transporter 3 are upregulated in primary sensory neurons after 7 days of morphine administration in rats

The contribution of the peripheral nervous system to opiate-induced hyperalgesia (OIH) is not well understood. In this study, we determined the changes in excitability of primary sensory neurons after sustained morphine administration for 7 days. Changes in the expression of glutamate receptors and glutamate transporters after morphine administration were ascertained in dorsal root ganglions. Patch clamp recordings from intact dorsal root ganglions (ex vivo preparation) of morphine-treated rats showed increased excitability of small diameter (≤30 μm) neurons with respect to rheobase and membrane threshold, whereas the excitability of large diameter (>30 μm) neurons remained unchanged. Small diameter neurons also displayed increased responses to glutamate, which were mediated mainly by GluN2B containing N-methyl-D-aspartate (NMDA) receptors, and to a lesser degree by the neuronal excitatory amino acid transporter 3/excitatory amino acid carrier 1. Coadministration in vivo of the GluN2B selective antagonist Ro 25-6981 with morphine for 7 days prevented the appearance of OIH and increased morphine-induced analgesia. Administration of morphine for 7 days led to an increased expression of GluN2B and excitatory amino acid transporter 3/excitatory amino acid carrier 1, but not of the α-amino-3-hydroxy-5-methyl-4-isoxazole propionate, kainate, or group I metabotropic glutamate receptors, or of the vesicular glutamate transporter 2. These results suggest that peripheral glutamatergic neurotransmission contributes to OIH and that GluN2B subunit of NMDA receptors in the periphery may be a target for therapy