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Background and aim Feedforward and online controls are two facets of predictive motor control from internal models, which is suspected to be impaired in learning disorders. We examined whether the feedforward component is affected in children (8–12 years) with developmental dyslexia (DD) and/or with developmental coordination disorder (DCD) compared to typically developing (TD) children. Methods Children underwent a bimanual unloading paradigm during which a load supported to one arm, the postural arm, was either unexpectedly unloaded by a computer or voluntary unloaded by the subject with the other arm. Results All children showed a better stabilization (lower flexion) of the postural arm and an earlier inhibition of the arm flexors during voluntary unloading, indicating anticipation of unloading. Between-group comparisons of kinematics and electromyographic activity of the postural arm revealed that the difference during voluntary unloading was between DD-DCD children and the other groups, with the former showing a delayed inhibition of the flexor muscles. Conclusion Deficit of the feedforward component of motor control may particularly apply to comorbid subtypes, here the DD-DCD subtype. The development of a comprehensive framework for motor performance deficits in children with learning disorders will be achieved only by dissociating key components of motor prediction and focusing on subtypes and comorbidities.

National audience; A l'heure actuelle, l'ensemble de la communauté scientifique s'accorde autour de l'idée que la lecture est avant tout une tâche linguistique et elle reconnait la présence d'un déficit de traitement des représentations phonologiques chez les personnes dyslexiques. En ce sens, la plupart des outils de dépistage, diagnostics et pédagogiques, à disposition des professionnels se centrent sur l'évaluation et la remédiation des difficultés de langage oral des enfants et notamment des difficultés d'acquisition des capacités phonologiques (e.g., NEEL, BILO, L2MA2). Cependant, de plus en plus de recherches montrent l'importance des facteurs oculomoteurs et visuo-attentionnels dans l'acquisition de la lecture chez l'enfant. Dans une perspective neuro-constructiviste (e.g. Goswami, 2003), des études longitudinales montrent, par exemple, que l'attention visuelle chez les prelecteurs constitue un important prédicteur de leur futures performances en lecture (e.g. Franceschini, Gori, Ruffino, Pedrolli, & Facoetti, 2012). Ces résultats attestent ainsi de l'intérêt d'évaluer ces capacités dès la maternelle afin de pouvoir repérer précocement les enfants susceptibles de présenter des difficultés en lecture par la suite. De plus, les études portant sur des personnes dyslexiques montrent que, dans certain cas, ce trouble s'accompagne de déficits de l'attention visuelle et du contrôle oculomoteur sous-tendant l'activité de lecture (pour une revue, Bellocchi, Muneaux, Bastien-Toniazzo, & Ducrot, 2013). On constate, par ailleurs, que de plus en plus de centres de référence des troubles des apprentissages ou de services spécialisés auprès d'enfants dyslexiques demandent des bilans oculomoteurs à la recherche de « troubles du regard » (Mazeau & Le Lostec, 2010) voire intègrent, dans leur équipe, des orthoptistes. Face à la très grande hétérogénéité caractérisant la manifestation clinique des troubles neurodéveloppementaux, le développement de l'évaluation des capacités oculomotrices et visuo-attentionnelles permettrait de compléter les tests actuels de dépistage et de diagnostic des troubles de l'apprentissage. C'est dans ce contexte que se place notre étude ; nous présenterons des éléments sur l'évaluation du fonctionnement visuo-attentionnel et oculomoteur d'enfants tout-venant ou avec une dyslexie développementale, ou un trouble de l'acquisition de la coordination (TAC). Les enfants ont entre 8 et 12 ans et ont, dans le cadre de leur participation à un vaste projet de recherche (ANR DYSTAC-MAP), passé un bilan orthophonique, psychomoteur ainsi que des tests visuo-attentionnels [EVADYS (Logiciel d'évaluation de l'empan visuo-attentionnel chez l'enfant dyslexique) (Valdois, Guinet, & Embs, 2014)] et oculomoteurs [DEM (Developmental Eye Movement Test) (Garzia, Richman, Nicholson, & Gaines, 1990)]. Les résultats présentés tentent de mettre en lien les performances des enfants aux tests EVADYS et DEM avec celles présentées dans les tâches de lecture de mots habituellement utilisées dans les bilans de la dyslexie [Alouette-R (Lefavrais, 2005) ; ODEDYS (Outil de Dépistage des Dyslexies) (Jacquier-Roux, Valdois, & Zorman, 2002)]. A la lumière de ces données, nous discuterons (1) de la nécessité de prendre en compte les processus oculomoteurs et visuo-attentionnels dans le diagnostic des troubles de l'apprentissage, ainsi que (2) du pouvoir diagnostique de tests utilisés dans cette étude et (3) de l'utilité de ces tests dans la mise en évidence de différences et de points communs entre troubles différents.

Vigabatrin is an antiepileptic drug that produces intramyelinic edema in several animal models. This study investigates the effect of vigabatrin on the developing human brain. The authors retrospectively blindly review 34 brain magnetic resonance imaging of 22 epileptic infants (age: 9 ± 1 months) that received vigabatrin, focusing on the presence of hyperintensity on T2- and diffusion-weighted images. Patients treated with vigabatrin displayed significant magnetic resonance imaging hyperintensity of basal ganglia and brain stem (P < .001, Wilcoxon test). This hyperintensity was transient and maximal 3 to 6 months after the beginning of vigabatrin. Hyperintensity was independent from duration and type of epilepsy, and from the presence or absence of seizures. The authors conclude that vigabatrin treatment is associated with transient hypersignal of the basal ganglia and brain stem in epileptic infants. Such transient hyperintensity is likely to be age-dependent and time-dependent because it has never been observed in adult patients.

The authors studied 10 patients (mean age 15 years 6 months) with localized developmental gyral disorder detected by MRI. There were two groups of major malformations. Seven patients (group 1) had unilateral 'macrogyric-like' insulo-opercular changes, one of whom died early in life and had extensive microgyria. The six others had mental retardation and epilepsy, three of whom had focal neurological signs. Age at onset of epilepsy varied greatly. Clinical and EEG data suggested a wider cerebral involvement than recognized on MRI. The remaining three patients (group 2) had abnormal gyri of variable topography and extension, with bulging grey matter and ventricular deformity. One had mental retardation, another had neurological signs. All had intractable complex partial seizures and focal EEG anomalies correlating with the MRI lesion site, pointing to a well-defined epileptogenic zone. No clinical or EEG evidence of significant malformation in the remaining brain tissue was observed. Ablative surgery was beneficial for one patient; focal cortical dysplasia was the pathological substrate.

A 10-year review of a neuropediatric department experience with childhood ischemic cerebrovascular disease identified 35 patients with arterial ischemic stroke. The ability to diagnose stroke in children has improved with the development of imaging techniques in the past few years. Children have a wide array of risk factors for ischemic strokes, since some are acquired and others are congenital. Twenty-eight associated conditions (80%) were found in our patients and we identified 17 specific causes (48.5%) among them. The cause of stroke in children is important to recognize because stroke is likely to recur depending on the etiology. (J Child Neurol 1997;12:193-199).

International audience; Background. Mutations in SCN1A can cause Genetic Epilepsy with Febrile Seizures Plus (GEFS+, inherited missense mutations) or Dravet syndrome (DS, de novo mutations of all types). Although the mutational spectra are distinct, these disorders share major features and 10% of DS patients have an inherited SCN1A mutation. Objectives and patients. We studied 19 selected families with at least one DS patients to describe the mechanisms accounting for inherited SCN1A mutations in DS. The mutation identified in the DS probands was searched in available parents and relatives and quantified in the blood cells of the transmitting parent using quantitative allele-specific assays. Results. Mosaicism in the blood cells of the transmitting parent was demonstrated in 12 cases and suspected in another case. The proportion of mutated allele in the blood varied from 0.04% to 85%. In the 6 remaining families, six novel missense mutations were associated with autosomal dominant variable GEFS+ phenotypes including DS as the more severe clinical picture. Conclusion. Our results indicate that mosaicism is found in at least 7% of families with at least one DS patient and that it accounts for 68 % (13/19) of inherited mutations associated with DS. On the contrary, in the remaining cases (6/19, 32%), the patients were part of multiplex GEFS+ families and seemed to represent the extreme end of the GEFS+ clinical spectrum. In this latter case, additional genetic or environmental factors likely modulate the severity of the expression of the mutation.

La sindrome opercolare congenita è ritenuta rara. Lavori classici hanno evidenziato una micropoligiria perisilviana bilaterale come substrato anatomopatologico. Abbiamo studiato mediante RM (0,5T CGR Magniscan o MR MAX CE-CGR) 11 pazienti di età compresa tra 6 e 30 anni (età media 14a9m), affetti da una disprassia oromasticatoria congenita. Sono state utilizzate sequenze SE ottenendo immagini in T1, T2 e DP. La IR è stata eseguita in 4 casi. In tutti i pazienti era presente una anomalia di girazione insulo-opercolare bilaterale, con riduzione dei solchi, ispessimento corticale, riduzione della sostanza bianca soggiacente ed ampliamento degli spazi subaracnoidei sovrastanti. In 2 dei pazienti studiati con IR la corteccia ispessita appariva microgirica, con numerose interdigitazioni tra sostanza grigia e bianca sovrastante da circonvoluzioni piccole ed ammassate. Dieci pazienti avevano ritardo mentale ed epilessia. Tre avevano una artrogriposi multipla congenita. In 8 pazienti la sindrome opercolare era espressa nella forma tipica della diplegia facio-farin-go-glosso-masticatoria (sindrome di Foix-Chavany-Marie). Tre pazienti, con anomalia biopercolare più estesa, avevano anche una tetraparesi spastica, i nostri dati confermano che l'anomalia di girazione biopercolare, associata a ritardo mentale, paralisi pseudobulbare ed epilessia, rappresenta una sindrome anatomo-clinica con estensione lesionale e gravità variabili.

Benign childhood epilepsy with centrotemporal spikes (BECTS) is regarded as a benign form of epilepsy because of its usually favorable outcome, in terms of seizures. Eighteen children with BECTS were studied in terms of neuropsychological and learning abilities: intellectual quotient, oral language (phonological production, naming skills, verbal fluency and syntactic comprehension), drawing and visuo-spatial skills, visual and selective attention, verbal and visuo-spatial memory, reading, numeracy and spelling. The mean IQ of the population was within the normal range, but individual results were heterogeneous. Verbal functions and memory were normal. In contrast, drawing and visuo-spatial skills, attention and visuo-spatial memory were significantly weak compared to the normal range for age. Reading, numeracy and/or spelling ability were significantly delayed by one academic year or more in ten of the children. In conclusion, despite its benign outcome in terms of epilepsy, BECTS can be accompanied by specific cognitive disorders and low academic achievement.

Autorisation No.2100 : TIPA est la revue du Laboratoire Parole et Langage; International audience; In this article, we present the final report of a cooperative project that was conducted by a group of clinicians and three groups of researchers belonging to CNRS or University. The aim of this project was to test a novel unifiying hypothesis in autism : are the communicative and interactive disorders in autism correlated with a temporal processing impairment of sensory and motor events. Autistic children and adolescents were tested in three experimental tasks aimed at testing i) motion vision, ii) phonems categorial perception and iii) motor anticipation. Results indicate that performance of autistic subjects is limited comparatively to that of normal control subjects in each task, which suppose that they have difficulties in processing sensory inputs and producing motor outputs online. These difficulties could account for their communicative and interactive impairments. Neurophysiological explanations involving cerebellum are proposed to explain this temporal processing deficit. Reeducational pathways using slowed down visual motion and speech flow are also suggested.; Nous présentons dans cet article la synthèse d'un projet coopératif qui a regroupé une équipe de cliniciens hospitaliers et trois équipes de chercheurs du CNRS et de l'Université, et destiné à tester une nouvelle hypothèse unificatrice dans l'autisme. La question était de savoir si les troubles communicatifs et relationnels typiques de l'autisme sont corrélés à des troubles du traitement temporel des événements sensoriels et moteurs. Des enfants et adolescents autistes ont été testés dans trois types de tâches expérimentales visant à tester i) la vision du mouvement, ii) la perception catégorielle de phonèmes et iii) l'anticipation motrice. Les résultats montrent que dans chacun de ces trois domaines, les performances des sujets autistes sont limitées par rapport à celles des sujets témoins, et témoignent d'une difficulté à traiter les événements sensoriels et produire des événements moteurs en temps réel. Cette difficulté pourrait rendre compte des anomalies communicatives et relationnelles des sujets autistes. Des explications neurophysiologiques de ce déficit du traitement temporel impliquant notamment le cervelet sont proposées. Des voies de rééducation utilisant le ralentissement des mouvements visuels et du flux verbal sont également suggérées.

SUMMARY The authors studied 10 patients aged between six and 23 years (mean age 14 years 5 months) with magnetic resonance imaging, which detected bilateral ‘macrogyric-like’ maldevelopment of the insulo-opercular regions. The data confirm that biopercular gyral anomaly, associated with mental retardation, pseudobulbar palsy (cortical or central) and epilepsy, represents an anatomo-clinical syndrome. Nevertheless, a wide clinical spectrum was found varying from pictures correlating with the topography and extent of the MRI-detected anomaly to conditions indicating wider cerebral involvement. Epilepsy, varying greatly in age at onset and severity, consistently influenced the prognosis for five patients with diffuse EEG abnormalities and intractable seizures with falls. Anterior callosotomy relieved such seizures in one case. RESUME Donnees neurologiques et devenir comitial chez les enfants presentant des modifications operculaires bilaterales de type macrogyrique a l'IRM Les auteurs ont etudies 10 patients âges de six a 23 ans (moyenne d'âge de 14 ans trois mois) avec imagerie de resonance magnetique (IRM) ayant detecte une anomalie bilaterale de developpement des regions insulo-operculaires, de ‘type macrogyrique’. Les donnees confirment que l'anomalie de circonvolution bioperculaire, associee a un retard mental, une paralysie pseudobulbaire (corticale ou centrale) et une comitialite, traduit un syndrome anatomo-clinique. Les auteurs ont note un large spectre clinique, allant de symptomes correles avec la topographie et l'etendue des lesions detectees a l'IRM jusqu'a des conditions indiquant une atteinte cerebrale plus large. La comitialite, variant beaucoup en âge de debut et gravite, marquait regulierement le pronostic chez cinq patients presentant des anomalies EEG diffuses et des crises irreductibles. Une callosotomie anterieure fit reduire les crises dans un cas. ZUSAMMENFASSUNG Neurologische Befunde und Anfalle bei Kindern mit bilateralen ‘macrogyrus-ahnlichen’, im MRI nachgewiesenen Veranderungen im Bereich des Operculum Die Autoren untersuchten 10 Patienten im Alter zwischen sechs und 23 Jahren (mittleres Alter 14 Jahre und 5 Monate), bei denen im MRI bilaterale ‘macrogyrus-ahnliche’ Veranderungen im Insel-Operculum Bereich festgestellt worden waren. Die Daten bestatigen, das bilaterale Gyrusanomalien im Operculum Bereich in Verbindung mit geistiger Retardierung Pseudobulbarparalyse (cortical oder zentral) und Epilepsie ein anatomisch-klinisches Syndrom darstellen. Die Autoren fanden ein breites klinisches Spektrum, das von Symptomen in Verbindung mit der Topographie und der Ausdehnung der im MRI nachgewiesenen Anomalie bis hin zu Befunden, die eine weitere cerebrale Beteiligung anzeigten, reichte. Die Epilepsie, die in Bezung auf das Anfangsalter und den Schweregrad stark variierte, beeinfluste die Prognose bei funf Patienten, die diffuse EEG Veranderungen und unkontrollierbare Anfallen hatten. In einem Fall konnten diese Anfalle durch eine vordere Callosotomie gebessert werden. RESUMEN Hallazgos neurologicos y curso de las convulsiones en ninos con alteraciones de tipo macrogirico operculares bilaterales detectados por IRM Los autores estudiaron 10 pacientes de seis a 23 anos de edad (promedio de edad 14 anos y 5 meses) con Imagen de Resonancia Magnetica (IRM) y detectaron defectos del desarrollo bilaterales del tipo macrogirico en las regiones insulo-operculares. Los datos confirman que la anomalia giral biopercular, asociada a un retraso mental, paralisis pseudobulbar (cortical o central) y epilepsia representa el sindrome anatomo-clinico. Los autores hallaron un amplio espectro clinico, que variaba desde sintomas en relacion con la topografia y extension de la anomalia detectada por la IRM, hasta sintomas indicadores de una afectacion cerebral mas amplia. La epilepsia, que variaba grandemente por la edad de comienzo y la gravedad, influia grandemente en el pronostico en cinco pacientes que sufrian anomalias difusas en el EEG y convulsiones intratables. Una callosotomia anterior mejoro tales convulsiones en un caso.

Summary The authors have reported a case of cerebral lipidosis (type Jansky-Bielschowsky) in which the presenting features appeared at the age of 2 years 10 months, and consisted of clonic seizures followed by atonic attacks and atypical absences. The association of seizures, severe mental disturbance and EEG abnormalities with an interseizure abnormality (diffuse slow waves) led to an initial misdiagnosis of the Lennox-Gastaut syndrome. The diagnosis which is suspected on the basis of clinical features (epilepsy, mental deterioration, pyramidal features), EEG signs (spikes on photic stimulation at low frequency or isolated) and ophthalmological investigations (ERG reduced response, abnormal VERs) was eventually made by rectal biopsy.

Arterial ischemic strokes are a relatively frequent diagnostic occurrence in pediatric neuroradiology. They occur mostly in three main etiologic contexts: 1) congenital heart disease; 2) neonatal distress ; 3) infections, focal or general inducing vasculitis, but many cases are considered idiopathic. The positive diagnosis is made by CT; in neonates, however, ultrasound appears as a promising tool. The CT features are basically similar at that age and in adults, although the site of the infarct may result from pathologies more particular to children (e.g. basal ganglia infarction due to arteritis of the carotid siphon and its branches). Infarcts may be multiple and also more frequently hemorrhagic at that age, the hemorrhagic phenomena affecting only the gray matter except in young infants in which the subcortical white matter may be affected also. Anatomical sequels include focal atrophy and asymmetry of the brain. Data regarding the etiology can be gathered from angiography which may show the degree of impairment of the arterial bed, its extent, the collateral blood supply and the morphological type of arterial lesion responsible for the cerebral damage. The most particular picture at that age is that of the often diffuse vasculitis, with its various expressions (segmentai narrowing of the lumen, dissecting aneurysm, string-of-beads appearance).

International audience; Most studies today agree about the link between visual-attention and oculomotor control during reading: attention seems to affect saccadic programming, that is, the position where the eyes land in a word. In a previous eye movement study (Bellocchi & Ducrot, submitted), it has been showed that fifth grade typical reading children take the direction of attentional scanning (left-to-right) into account, which results in asymmetrical landing-position pattern: this mechanism depends on the discreteness of the stimulus and interestingly, it is less irrepressible in lower reading level children and in children with reading disability. Furthermore, some studies have demonstrated that increasing inter-letter spacing or inter-word spacing improves the legibility of texts, especially for dyslexic children (e.g. Zorzi et al., 2012): is this improvement linked to a bigger inter-letter saliency which produces, in turn, a more precise saccade programming? To explore this question we assessed the eye movements of three groups of children: dyslexic readers, unimpaired reading-level controls, and unimpaired chronological-age controls, using a lateralized bisection task (participants were asked to move their eyes to a position they thought to be the middle of the stimulus) and a lexical decision task. The type of stimulus – bisection task (words vs. non-linguistic stimuli), LDT (words vs. pseudowords) and crowding (spaced vs. unspaced) - in combination with the stimulus presentation side (left vs. right) were manipulated. Main results showed that saccade computation seems to be modulated by crowding, stimulus presentation side and reading level. Results are discussed with respect to current models of oculomotor control in typical and defective reading.