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Les nanosciences et nanotechnologies constituent un domaine en rapide évolution, toujours en expansionaprès son apparition peu avant les années 2000. Elles contribuent à l’ensemble des défis de l’ANR etimpactent, de manière plus ou moins décisive, un grand nombre de filières industrielles. Dans plusieurspays, des initiatives nationales ont été mises en place pour accompagner, orienter et structurer ledéveloppement du domaine, lequel s’est souvent accompagné d’un débat sociétal actif.Dans ce contexte, l’ARP a été structuré afin d’apporter une vision multifactorielle de la dynamique desnanosciences et nanotechnologies, et d’en appuyer la construction sur une expertise large et diversifiée, àmême de contribuer à la construction de conclusions aussi pertinentes que possible.Les facteurs pris en compte sont :• La prospective sur les axes de développements scientifiques et les opportunités de rupturesassociés aux recherches en nanosciences et nanotechnologies. Ce travail éclaire sur lesdynamiques et perspectives scientifiques et technologiques.• L’analyse des domaines d’impact technologique et de marché, et du transfert vers l’industrie desavancées en nanosciences et nanotechnologies. Cette analyse s’est appuyée sur la méthode desscenarios afin de fournir une vision cohérente des développements probables à venir etd’éclairer les conséquences de futures orientations et décisions.• La comparaison des politiques mises en oeuvre dans d’autres pays (comparaison internationale)• L’analyse des aspects sociétaux et éthiques.L’expertise mobilisée est celle• des 12 membres du comité opérationnel de l’ARP, lequel rassemble des experts principalementissus de la recherche publique et également de l’industrie, et associe la direction de l’OMNT, etdes 18 membres du comité d’orientation stratégique de l’ARP, majoritairement issus del’industrie, et également de la recherche publique, et de syndicats ou de la société civile.• de plus de 30 experts issus largement de l’industrie, également de la recherche publique, destructures de valorisation…, mobilisé par le réseau C’Nano qui ont participé aux séminaires deconstruction des scénarios, conduits en appui sur le cabinet de prospective Futuribles, et desnombreux acteurs interrogés au travers d’un questionnaire.• de plus de 100 experts scientifiques, majoritairement issus de la recherche publique, qui ontvolontairement contribué aux 15 groupes de travail thématiques mis en place par l’OMNT pourréaliser une prospective scientifique à « 5 ans » et « 15-20 ans ».• de 5 experts internationaux, spécialiste notamment en la « nano-éthique », rassemblés pour unséminaire spécifique à Paris.

Background Stroke in patients with acute cervical artery dissection may be anticipated by initial transient ischemic or nonischemic symptoms. Aim Identifying risk factors for delayed stroke upon cervical artery dissection. Methods Cervical artery dissection patients from the multicenter Cervical Artery Dissection and Ischemic Stroke Patients study were classified as patients without stroke ( n = 339), with stroke preceded by nonstroke symptoms (delayed stroke, n = 244), and with stroke at onset ( n = 382). Demographics, clinical, and vascular findings were compared between the three groups. Results Patients with delayed stroke were more likely to present with occlusive cervical artery dissection ( P < 0·001), multiple cervical artery dissection ( P = 0·031), and vertebral artery dissection ( P < 0·001) than patients without stroke. No differences were observed in age, smoking, arterial hypertension, hypercholesterolemia, migraine, body mass index, infections during the last week, and trauma during the last month, but patients with delayed stroke had less often transient ischemic attack ( P < 0·001) and local signs (Horner syndrome and cranial nerve palsy; P < 0·001). Conclusions Occlusive cervical artery dissection, multiple cervical artery dissection, and vertebral artery dissection were associated with an increased risk for delayed stroke. No other risk factors for delayed stroke were identified. Immediate cervical imaging of cervical artery dissection patients without ischemic stroke is needed to identify patients at increased risk for delayed ischemia.

International audience; Analysing the clinical characteristics of seizures constitutes a fundamental aspect of the presurgical evaluation of patients with medial temporal lobe epilepsy and unilateral hippocampal sclerosis (MTLE-HS), the most frequent form of focal epilepsy accessible to surgery. We sought to retrospectively determine whether objective manifestations could have a reliable lateralizing value in a large population of MTLE-HS patients and if their presence could help to identify those patients who would be seizure free after surgery. We analysed the frequency and predictive lateralizing value of objective ictal and postictal signs in 391 patients with MTLE-HS (183 left/208 right). Data were derived from chart review and not from blinded videoEEG analysis. Correlation between the presence of reliable lateralizing signs and postoperative outcome was performed in a subgroup of 302 patients who underwent surgery. Contralateral dystonic posturing was the most frequent and reliable lateralizing sign that correctly lateralized the focus in 96% of patients. Unilateral head/eye deviation was noted in 42% of the patients and predicted unilateral focus in 67%. Ipsilateral postictal nose wiping, contralateral clonus and hypokinesia correctly lateralized the focus in 75%, 81%, respectively, and 100 of patients but were less frequently depicted. Postictal aphasia was a strong lateralizing sign for left MLE-HS. The presence of reliable lateralizing signs was not a predictor of seizure freedom. Seizure semiology is a simple tool that may permit reliable lateralization of the seizure focus in MTLE-HS. The presence of reliable lateralizing signs is not associated with a better postoperative outcome.

BackgroundRecently, the concept of 'clinically relevant penumbra' was defined as an area saved by arterial recanalization and correlated with stroke outcome. This clinically relevant penumbra was located in the subcortical structures, especially the periventricular white matter. Our aims were to confirm this hypothesis, to investigate the impact of admission hyperglycemia and of insulin treatment on the severity of ischemic damages in this area and to study the respective contributions of infarct volume and ischemic damage severity of the clinically relevant penumbra on 3-month outcome.MethodsWe included 99 patients from the INSULINFARCT trial. Voxel-Based Analysis was carried on the Apparent Diffusion Coefficient (ADC) maps obtained at day one to localize the regions, which were more damaged in patients i) with poor clinical outcomes at three months and ii) without arterial recanalization. We determined the intersection of the detected areas, which represents the clinically relevant penumbra and investigated whether hyperglycemic status and insulin regimen affected the severity of ischemic damages in this area. We performed logistic regression to examine the contribution of infarct volume or early ADC decrease in this strategic area on 3-month outcome.FindingsLower ADC values were found in the corona radiata in patients with poor prognosis (p< 0.0001) and in those without arterial recanalization (p< 0.0001). The tracking analysis showed that lesions in this area interrupted many important pathways. ADC values in this area were lower in hyperglycemic than in normoglycemic patients (average decrease of 41.6 ± 20.8 x10(-6) mm2/s) and unaffected by the insulin regimen (p: 0.10). ADC values in the clinically relevant penumbra, but not infarct volumes, were significant predictors of 3-month outcome.ConclusionThese results confirm that the deep hemispheric white matter is part of the clinically relevant penumbra and show that hyperglycaemia exacerbates the apparition of irreversible ischemic damage within 24 hours in this area. However, early intensive insulin therapy fails to protect this area from infarction.Trial registrationClinicalTrials.gov NCT00472381.

BACKGROUND: Outcome following ischemic stroke is strongly related to baseline severity. Differences in baseline balance between arms seen even in larger trials complicate analysis. We developed a method (pPREDICTS) that generates a pooled outcome model from baseline factors taken from randomized clinical trials (RCTs). It visualizes variability to assess whether an individual study treatment arm differs sufficiently from expected outcome to be considered positive if tested in a larger population, without need for any statistical corrections. Here we assessed whether intracerebral hemorrhage (ICH) could be similarly modeled and how blood pressure (BP) interventions fared considering between-trial variance. METHODS: pPREDICTS generates an outcomes and provides multi-dimensional ±p=.05 statistical surfaces to visualize the variance among these trials. ICH RCTs were selected that provided baseline NIHSS, age and 90 day outcomes. Individual results from 4 BP trials were tested against these models to determine whether outcomes surpassed the ±95% prediction interval surfaces. Mortality and mRS0-2, the most frequently reported outcomes were modeled. RESULTS: Outcome functions derived from 12 ICH RCTs representing 2766 subjects were generated (middle surface ± p=.05 surfaces; Fig 1a: Mortality: r 2 =0.84; Fig 1b:mRS0-2:r 2 =0.79; p≤0.005). Control management (green) and treatment arm (red) outcomes of ATACH, ICH-ADAPT, INTERACT and INTERACT2 were plotted (see Figs). No mortality or functional outcome different from control was seen as outcomes are mostly distributed along the middle surface. However, tier 3 of ATACH, BP goal of SBP 110-140 showed increased mortality (>+95%) and decreased mRS 0-2 outcome ( CONCLUSION: Outcome models for mortality and mRS 0-2 were successfully developed. No benefit was seen from any BP intervention. We suspect small differences in outcomes reported as positive are more likely random variation.

BACKGROUND: Although a phase 3 trial using cardiac dose of the GP IIb/IIIa inhibitor abciximab was halted, we previously reported that a 30% lower total intravenous (IV) abciximab dose achieved optimal platelet inhibition (92%) and showed benefit in patients ineligible for tPA when compared using a rigorous matching process to historical controls (Mandava et al, TSR 2010). Given lack of proven alternatives, we were interested in abciximab specifically in the posterior circulation. METHODS: 0.2 mg/kg IV bolus followed by 0.05 ug/kg/hr infusion over 12 hrs of abciximab was administered with suspected large vessel posterior circulation occlusion after informed consent and presentation of alternatives. Patients were ineligible for tPA mostly from time window (24 hrs, later changed to 12 hrs) or elevated INR < 2.5. A weight based heparin protocol was used in most patients to achieve PTT 46-70. Ninety day follow up was obtained. To assess benefit, patients’ baseline characteristics were compared to the NINDS control arms subjects restricted to large vessel and cardioembolic subtypes. Matching was performed for 5 hour baseline NINDS NIHSS, age, glucose, and posterior stroke. An excess of posterior strokes in the abciximab group permitted 2:1 matching with outlier elimination. McNemars test compared 90 day mRS 0-1/0-2, mortality, and hemorrhage RESULTS: 26 subjects were treated in 3 university centers. Post-match baseline variables were slightly more severe in the abciximab group and they were treated later (Table). 90-day functional outcomes were higher in the abciximab group (mRS 0-1:54.5% vs 23.1%, mRS 0-2: 63.6% vs 30.8%; p CONCLUSION: Low dose IV abciximab in extended time window for large vessel posterior stroke shows promise. Given lack of proven alternatives, these results need to be verified prospectively.

Introduction.Reversible cerebral vasoconstriction syndrome is becoming widely accepted as a rare cause of both ischemic and haemorrhagic stroke and should be evocated in case of thunderclap headaches associated with stroke. We present the case of a patient with ischemic stroke associated with cortical subarachnoid haemorrhage (cSAH) and reversible diffuse arteries narrowing, leading to the diagnosis of reversible vasoconstriction syndrome.Case Report.A 48-year-old woman came to the emergency department because of an unusual thunderclap headache. The computed tomography of the brain completed by CT-angiography was unremarkable. Eleven days later, she was readmitted because of a left hemianopsia. One day after her admission, she developed a sudden left hemiparesis. The brain MRI showed ischemic lesions in the right frontal and occipital lobe and diffuse cSAH. The angiography showed vasoconstriction of the right anterior cerebral artery and stenosis of both middle cerebral arteries. Nimodipine treatment was initiated and vasoconstriction completely regressed on day 16 after the first headache.Conclusion.Our case shows a severe reversible cerebral vasoconstriction syndrome where both haemorrhagic and ischemic complications were present at the same time. The history we reported shows that reversible cerebral vasoconstriction syndrome is still underrecognized, in particular in general emergency departments.

Background and Purpose— The aim of the study was to evaluate whether leukoaraiosis (LA) is a risk factor for symptomatic intracerebral hemorrhage (sICH) in patients treated with thrombolysis for acute stroke. Methods— In this retrospective, multicenter analysis, we evaluated data from acute anterior circulation stroke patients (n=449; Results— The rate of sICH was significantly more frequent in patients with moderate to severe LA of the deep white matter (n=12 of 114; 10.5%) than in patients without relevant LA (n=13 of 335; 3.8%), corresponding to an odds ratio of 2.9 (95% CI, 1.29 to 6.59; P =0.015). In a logistic-regression analysis (including age, National Institutes of Health Stroke Scale score at presentation, and type of thrombolytic treatment), LA remained a significant independent risk factor (odds ratio, 2.9; P =0.03). Conclusions— LA of the deep white matter is an independent risk factor for sICH after thrombolytic treatment for acute stroke.

The most common clinical sign of autism spectrum disorders (ASD) is social interaction impairment, which is associated with communication deficits and stereotyped behaviors. Based on recent brain-imaging results, our hypothesis is that abnormalities in the superior temporal sulcus (STS) are highly implicated in ASD. STS abnormalities are characterized by decreased gray matter concentration, rest hypoperfusion and abnormal activation during social tasks. STS anatomical and functional anomalies occurring during early brain development could constitute the first step in the cascade of neural dysfunction underlying ASD. We will focus this review on the STS, which has been highly implicated in social cognition. We will review recent data on the contribution of the STS to normal social cognition and review brain-imaging data implicating this area in ASD. This review is part of the INMED/TINS special issue "Nature and nurture in brain development and neurological disorders", based on presentations at the annual INMED/TINS symposium (http://inmednet.com/).

Resume Introduction La reaction inflammatoire joue un role important dans l’accident ischemique cerebral (AIC). De nombreuses etudes experimentales et cliniques soulignent les effets deleteres, mais parfois aussi benefiques de l’inflammation. Nous decrirons les principaux aspects de cette reponse inflammatoire, ainsi que leurs applications therapeutiques. Etat des connaissances/perspectives Les resultats des etudes descriptives et therapeutiques des marqueurs somatiques a la phase aigue de l’AIC (proteine C-reactive et temperature) sont heterogenes. Les principales cibles etudiees sont les molecules d’adhesion cellulaire — CAM (integrines, selectines et la superfamille des immunoglobulines), la reponse leucocytaire et cytokinique, la microglie et la barriere hemato-encephalique. Les arguments experimentaux, suffisamment nombreux, en particulier sur le caractere deletere de l’adhesion leucocytaire, ont permis d’entreprendre des essais cliniques. Ces etudes, utilisant des molecules anti-inflammatoires (anti-adhesion leucocytaire, antipyretique), ont toutes ete negatives, peut-etre parce que la cinetique de reaction inflammatoire n’est pas suffisamment prise en compte. Des travaux recents suggerent que l’insuline et les statines pourraient modifier la reaction inflammatoire a la phase aigue de l’AIC. Conclusion L’inflammation est aujourd’hui un des axes majeurs de la recherche therapeutique sur la progression de l’infarctus au cours des premieres heures de l’AIC. La comprehension de la physiopathologie de la reponse inflammatoire et de sa cinetique, devra permettre d’ameliorer le protocole des etudes cliniques futures.

The authors have previously described less activation of left speech-related temporal areas in adults with autism when listening to speech-like sounds than in normal adults. Here, they investigated whether this abnormal cortical processing was also present in children with primary autism.Regional cerebral blood flow was measured with positron emission tomography after premedication in 11 autistic children and six nonautistic mentally retarded children during rest and while they were listening to speech-like sounds.As with autistic adults, direct comparison between the two groups revealed significantly less activation in the autistic group localized in left speech-related areas.For the first time to their knowledge, an activation study was performed in children with autism and has confirmed previous results obtained in adults. The abnormal cortical auditory processing observed in both children and adults with autism could be involved in inadequate behavioral responses to sounds and in language impairments characteristic of autism.

Owing to their reduced dimensions, the magnetic properties of ultrathin magnetic films and multilayers, e.g. magnetic anisotropies and exchange coupling, often depend strongly on the surface and interface structure. In addition, chemical composition, crystallinity, grain sizes and their distribution govern the magnetic behaviour. All these structural properties can be modified by light-ion irradiation in an energy range of 5–150 keV due to the energy loss of the ions in the solid along their trajectory. Consequently the magnetic properties can be tailored by ion irradiation. Similar effects can also be observed using Ga+ ion irradiation, which is the common ion source in focused ion beam lithography.Examples of ion-induced modifications of magnetic anisotropies and exchange coupling are presented. This review is limited to radiation-induced structural changes giving rise to a modification of magnetic parameters. Ion implantation is discussed only in special cases.Due to the local nature of the interaction, magnetic patterning without affecting the surface topography becomes feasible, which may be of interest in applications. The main patterning technique is homogeneous ion irradiation through masks. Focused ion beam and ion projection lithography are usually only relevant for larger ion masses. The creation of magnetic feature sizes below 50 nm is shown. In contrast to topographic nanostructures the surrounding area of these nanostructures can be left ferromagnetic, leading to new phenomena at their mutual interface.Most of the material systems discussed here are important for technological applications. The main areas are magnetic data storage applications, such as hard magnetic media with a large perpendicular magnetic anisotropy or patterned media with an improved signal to noise ratio and magnetic sensor elements. It will be shown that light-ion irradiation has many advantages in the design of new material properties and in the fabrication technology of actual devices.

Scanning thermal microscopy is applied to investigate the local thermal properties of thin phase-change (Ge2Sb2Te5) layers. The thermal contrast allows crystalline and amorphous areas to be detected unambiguously, and can be quantitatively linked to the crystalline ratio of the phase change layer. It is demonstrated that the heated tip can be used to locally crystallize parts of an amorphous Ge2Sb2Te5 layer, thereby suggesting thermal probes may be used for data storage applications on phase-change media (write once).

According to a simple anatomical and functional model of word reading, letters displayed in one hemifield are first analysed through a cascade of contralateral retinotopic areas, which compute increasingly abstract representations. Eventually, an invariant representation of letter identities is created in the visual word form area (VWFA), reproducibly located within the left occipito-temporal sulcus. The VWFA then projects to structures involved in phonological or lexico-semantic processing. This model yields detailed predictions on the reading impairments that may follow left occipitotemporal lesions. Those predictions were confronted to behavioural, anatomical and functional MRI data gathered in normals and in patients suffering from left posterior cerebral artery infarcts. In normal subjects, alphabetic stimuli activated both the VWFA and the right-hemispheric symmetrical region (R-VWFA) relative to fixation, but only the VWFA showed a preference for alphabetic strings over simple chequerboards. The comparison of normalized brain lesions with reading-induced activations showed that the critical lesion site for the classical syndrome of pure alexia can be tightly localized to the VWFA. Reading impairments resulting from deafferentation of an intact VWFA from right- or left-hemispheric input were dissected using the same methods, shedding light on the connectivity of the VWFA. Finally, the putative role of right-hemispheric processing in the letter-by-letter reading strategy was clarified. In a letter-by-letter reader, the R-VWFA assumed some of the functional properties normally specific to the VWFA. These data corroborate our initial model of normal word perception and underline that an alternative right-hemispheric pathway can underlie functional recovery from alexia.

SANS offers the possibility to study nanostructures of sizes ranging from 2 to 200 nm. We have explored the possibility of using SANS in a grazing incidence geometry (GISANS) in order to study magnetic nanostructures in thin films (thickness ∼50 nm). Even though the amount of material is tiny in such films (∼50 μg), working in grazing incidence allows to look at the scattered signal from in-plane magnetic nanostructures in the films. We have performed surface diffraction on magnetic nanostructures (∼100 nm in size) on a system consisting of Fe 0.5 Pd 0.5 thin films with a magnetic perpendicular anisotropy. The measurements have been performed in various magnetic field configurations. Magnetic surface diffraction can easily be observed. We present these measurements together with calculations based on a Born approximation. We discuss the information that can be extracted from such polarized neutron measurements.

This study proposes a closer look at the neuropsychological method defined as the study of the neural bases of the behavioural and cognitive functions using an organisation–representation model for current data and knowledge of the brain, and the application of an anatomofunctional database. A Centre of Cognitive Anatomy (CAC) was set up for the collection and processing of neuronatomical, neuropsychological, and psycho-behavioural data for patients presenting sequels of focal brain damage. Such a system would allow concurrent treatment of anatomical and functional data. We would expect the results from such a model to produce stable ‘anatomofunctional laws’ that would be independent of all inter-individual variations in the functioning of the brain and could be checked against the entire database of information. A direct application would be the improvement of cognitive and/or behavioural rehabilitation of patients with brain damage.

Somesthetic and emotional symptoms that are common in patients with mesial temporal lobe epilepsy are usually related to hippocampo-amygdalar complex involvement. Recent stereo-electroencephalographic studies have shown a relationship between such symptoms and epileptic insular discharges. To further investigate this problem, we carried out a positron emission tomography study using fluorodeoxyglucose (18F-FDG) and flumazenil (11C-FMZ) in mesial temporal lobe epilepsy patients. The aim of our study was to assess the existence of a cortical insular involvement in order to examine its clinical correlates and the relationship between the postoperative outcome and the insular involvement. Fluorodeoxyglucose and flumazenil-positron emission tomography studies were carried out in 18 patients with mesial temporal lobe epilepsy patients. A statistical parametric mapping (SPM96) was performed to analyze the data in comparison to 18 healthy volunteers. For each set of fluorodeoxyglucose and flumazenil images a group and an individual analysis were performed. In addition, a region of interest analysis was performed to validate the results. Focusing on the metabolic abnormalities, we also investigated the role of insular cortex in the symptoms experienced by the patients and the prognostic value of insular metabolic abnormalities. Highly significant hypometabolism and BZR binding decreases were detected in the insular cortex. Results were similar using the region of interest approach. Insular involvement (mainly ipsilateral to the seizure focus) was present in 60% of the patients. Emotional symptoms correlated with hypometabolism in the anterior part of the ipsilateral insular cortex, whereas somesthetic symptoms correlated with hypometabolism in the posterior part. No relationship between postoperative outcome and ipsilateral insular hypometabolism was found. Unilateral mesial temporal lobe epilepsy is associated with insular hypometabolism and benzodiazepine receptor loss. Our results also suggest that the anterior part of the insular cortex is involved in the emotional symptoms and the posterior insular cortex is involved in the somesthetic symptoms. Hypometabolism located in the insula did not influence postoperative outcome after anterior lobectomy.

We investigated the neuroanatomical substrate of sound duration discrimination, using the same experimental design as in a previous study on sound intensity discrimination [J. Neurosci. 18 (16) (1998) 6388]. Seven normal subjects were trained to detect deviant sounds presented with a slightly longer duration than a 300 ms long standard harmonic sound, using a Go/No Go paradigm. Individual psychometric curves were assessed using a three-step psychoacoustic procedure. Subjects were then scanned while passively listening to the standard sound, and while discriminating changes in sound duration at four different performance levels (d'=1.5, 2.5, 3.5 and 4.5). Analysis of regional cerebral blood flow (rCBF) data outlined activation, during the discrimination conditions, of a right hemispheric fronto-parietal network very similar to the one previously observed for intensity discrimination, as well as additional activation in the right prefrontal cortex (Brodmann Area (BA) 10), bilateral basal ganglia and cerebellar hemispheres. These findings suggest that discrimination of sound duration, as for discrimination of sound intensity, involves two cerebral networks: a supramodal right fronto-parietal cortical network responsible for allocation of sensory attentional resources, and a network of regions such as the basal ganglia, cerebellum, and right prefrontal cortex, more specifically involved in the temporal aspects of the discrimination task.

International audience; The recent advent of new functional neuroimaging techniques such as functional magnetic resonance imaging (fMRI) makes it possible to examine cerebral activations in healthy individuals. In the present study, we attempted to examine the anatomical distribution of neocortical and mediotemporal activations in control subjects during episodic memory tasks over 24 h. BOLD (blood oxygenation-level-dependent) fMRI data were collected from 10 control subjects. Twenty-two contiguous images covering the whole brain were acquired using an EPI echoplanar sequence. Subjects were instructed to learn a list of 17 words, and to recall it immediately and after a 24-h interval. Individual and group analyses were performed using SPM96. The results demonstrated that a similar left occipito-temporofrontal network was activated during both immediate and 24-h-delayed retrieval conditions. In addition, the 24-h-delayed retrieval also activated a larger parietal region and the right hippocampus. These findings suggest that fMRI is a reliable method with which to perform anatomical studies.

Objectif Les recommandations internationales preconisent l’utilisation de stent retrievers pour le traitement endovasculaire des AVC ischemiques avec occlusion arterielle proximale. Recemment, des resultats prometteurs ont ete rapportes en termes de recanalisation pour les dispositifs de thromboaspiration tels que le systeme Penumbra (Penumbra, Alameda, Californie) associe a la gamme de catheters de revasularisation Penumbra MAX™. Neanmoins, l’efficacite de la thromboaspiration dans les occlusions distales est encore mal connue. Nous rapportons notre experience en termes de securite et d’efficacite concernant l’utilisation du catheter 3MAX (3.8F) pour le traitement endovasculaire des occlusions distales. Materiels et methodes D’aout 2015 a aout 2016, 25 patients consecutifs (15 femmes [60 %] et 10 hommes [40 %] ; âges en moyenne de 68 ans [22–91]) ont beneficie d’une thrombectomie mecanique selon la technique de thromboaspiration ADAPT en utilisant le catheter 3MAX pour 29 occlusions arterielles distales. Le critere de jugement principal etait le taux de recanalisation (definit par un score TICI 2b ou 3) apres thromboaspiration seule. Le critere de jugement secondaire etait le mRS evalue a 3 mois. Un mRS ≤ 2 etait considere comme une evolution neurologique favorable. Resultats Dans 1/29 cas (3,5 %), le 3MAX n’a pas pu etre navigue jusqu’au site d’occlusion. Seize des 28 occlusions restantes (57,1 %) ont ete recanalisees de facon satisfaisante apres thromboaspiration seule. Le taux global de recanalisation etait de 75 %. Quatre (16 %) complications liees a la procedure ont ete rapportees (2 perforations vasculaires, 1 OACR postoperatoire) dont 1 (4 %) directement imputable au 3MAX (embole dans un nouveau territoire). Le taux de mortalite dans les 3 mois etait de 8 %, mais aucun deces n’etait lie a la thrombectomie mecanique. Au total, 40 % des patients avaient un mRS ≤ 2 a 3 mois. Conclusion Notre experience preliminaire montre que le taux de recanalisation obtenu par le catheter d’aspiration 3MAX dans les occlusions distales est encourageant.

CEA-Inserm U1000 Neuroimaging and Psychiatry, Service Hospitalier Frederic Joliot, Orsay, France, CEA, DRM, DSV, Service Hospitalier Frederic-Joliot, Orsay, France, Laboratoire de Correction Auditive, Eric Bizaguet, Paris, France, Inserm, UMR-S 867, Paris, France, AP-HP, Hopital Beaujon, Service d’ORL et de Chirurgie cervico-faciale, Clichy, France, Universite Paris 7 Denis Diderot, Paris, France, AP-HP, Hopital Louis Mourier, Service d’ORL et de Chirurgie cervico-faciale, Colombes, France, AP-HP, Hopital Pitie-Salpetriere, Service Urgences cerebro-vasculaires, Paris, France, Universite Paris 6 Pierre et Marie Curie, Paris, France

International audience; Background and purpose : Medial temporal lobe epilepsy with unilateral hippocampal sclerosis (MTLE-HS) is the most frequent form of surgical temporal lobe epilepsy. In this study, it was aimed to determine whether different types of aura represent a cardinal and characteristic feature of MTLE-HS and might provide a diagnostic complement to help identify patients who will be seizure-free after surgery.Methods : All types of auras and associations of auras reported by 400 MTLE-HS patients referred for surgery were retrospectively collected and their statistical correlation with the postoperative outcome was examined in a subgroup of 305 patients who underwent surgery.Results : A total of 876 auras were collected, classified into 12 categories. Globally, MTLE-HS patients reported widely variable auras and groupings of auras. Most common were autonomic and abdominal visceral auras, followed by psychoaffective and experiential auras; less common, but seen in 10%–15% of patients, were non-specific auras, somatosensory auras and visual auras, and least common, reported by less than 10% of patients, were auditory, gustatory, vestibular, olfactory and intellectual auras. No auras were reported in 10% of patients. 65% of patients experienced more than one type of aura (two to seven). No specific groupings of aura type were apparent. No evidence was found for correlation between postoperative outcome and (i) any category of aura, (ii) the number of categories of aura per patient and (iii) any association of categories of auras.Conclusion : Auras and association of auras vary widely in MTLE-HS and provide no useful insight into surgical outcome.

Erratum in: Familial occurrence and heritable connective tissue disorders in cervical artery dissection. [Neurology. 2016]; International audience; In a large series of patients with cervical artery dissection (CeAD), a major cause of ischemic stroke in young and middle-aged adults, we aimed to examine frequencies and correlates of family history of CeAD and of inherited connective tissue disorders. We combined data from 2 large international multicenter cohorts of consecutive patients with CeAD in 23 neurologic departments participating in the CADISP-plus consortium, following a standardized protocol. Frequency of reported family history of CeAD and of inherited connective tissue disorders was assessed. Putative risk factors, baseline features, and 3-month outcome were compared between groups. Among 1,934 consecutive patients with CeAD, 20 patients (1.0%, 95% confidence interval: 0.6%-1.5%) from 17 families (0.9%, 0.5%-1.3%) had a family history of CeAD. Family history of CeAD was significantly more frequent in patients with carotid location of the dissection and elevated cholesterol levels. Two patients without a family history of CeAD had vascular Ehlers-Danlos syndrome with a mutation in COL3A1. This diagnosis was suspected in 2 additional patients, but COL3A1 sequencing was negative. Two patients were diagnosed with classic and hypermobile Ehlers-Danlos syndrome, one patient with Marfan syndrome, and one with osteogenesis imperfecta, based on clinical criteria only. In this largest series of patients with CeAD to date, family history of symptomatic CeAD was rare and inherited connective tissue disorders seemed exceptional. This finding supports the notion that CeAD is a multifactorial disease in the vast majority of cases.

International audience; The objectives of the study were to compare lipoprotein-associated phospholipase A2 (Lp-PLA2) levels in a prospective cohort including both ischemic and hemorrhagic strokes at the hyperacute phase, and to investigate if these levels were associated with stroke severity. Lp-PLA2 mass and activity were measured during the first 6 hours of symptom onset before any therapeutic intervention. The Lp-PLA2 level was analyzed by comparing the mass and activities in ischemic strokes and spontaneous intracerebral hemorrhages (ICH). Correlations between Lp-PLA2 levels and clinical scores as well as stroke volumes were made. The temporal evolution of Lp-PLA2 during the first week was analyzed in ischemic stroke patients. Lp-PLA2 mass was higher in ICH than in ischemic stroke (P = .001). Lp-PLA2 activity at admission correlated with initial and follow-up stroke volume in ICH (P = .003 and P = .004, respectively) but not in ischemic stroke. None of the measurements correlated with clinical severity for either diagnosis. Lp-PLA2 mass decreased during the first week after the use of statins in ischemic stroke, whereas the activity remained stable. Lp-PLA2 mass is higher in ICH compared with ischemic stroke during the hyperacute stage. Lp-PLA2 activity is associated with stroke volume in ICH but not in ischemic stroke. This suggests that Lp-PLA2 mass and activity could provide different information in the hyperacute stage of stroke.

International audience; The clinical efficiency of thrombolysis is explained by the rescue of ischemic penumbra areas resulting from early arterial recanalization. The perfusion-diffusion weighted imaging mismatch is a commonly used MRI surrogate of the ischemic penumbra. However, the randomized trials testing the mismatch hypothesis have been negative. We will review the 'mismatch concept' and the recent studies that aim to localize the clinically eloquent areas of penumbra in middle cerebral artery (MCA) infarcts. New methods of image analysis have shown that poor outcomes after MCA stroke are related to infarction of an extremely well localized area of the periventricular white matter and adjacent internal capsule, where projections and association tracts are crossing and converging. This area almost colocalizes with the area salvaged by early arterial recanalization and is located extremely close to the initial ischemic core. The location of the area that correlates with disability in MCA stroke patients and that is salvaged by early arterial recanalization is in the same specific region of the deep white matter, close to the initial ischemic core. These findings may have important implications for designing new recanalization trials and support the importance of basic research on white-matter neuroprotection.

Background: Cathodal transcranial direct current stimulation (tDCS) of the right frontal cortex improves language abilities in post-stroke aphasic patients. Yet little is known about the effects of right frontal cathodal tDCS on normal language function. Objective/hypothesis: To explore the cathodal tDCS effects of the right-hemispheric homologue of Broca's area on picture naming in healthy individuals. We hypothesized that cathodal tDCS improves picture naming and that this effect is determined by the anatomical and functional connectivity of the targeted region. Methods: Cathodal and sham tDCS were applied to the right inferior frontal gyrus in 24 healthy subjects before a picture-naming task. All participants were studied with magnetic resonance imaging at pre-interventional baseline. Probabilistic tractography and dynamic causal modeling of functional brain activity during a word repetition task were applied to characterize anatomical and functional connectivity. Results: Subjects named pictures faster after cathodal relative to sham tDCS. The accelerating effect of tDCS was explained by a reduced frequency of very slow responses. tDCS-induced acceleration of picture naming correlated with larger volumes of the tract connecting the right Broca's area and the supplementary motor area (SMA) and greater functional coupling from the right SMA to the right Broca's area. Conclusions: The results support the notion that the after-effects of tDCS on brain function are at least in part determined by the anatomical and functional connectivity of the targeted region.

Background and Purpose— Rapid and precise identification of the penumbra is important for decision-making in acute stroke. We sought to determine whether an early and moderate decrease in the appar...

We have studied the growth conditions to obtain the chemically well ordered L1 0 phase of the FePd alloy deposited on ZnSe and CdZnMgTe II–VI semiconductors. We have observed that the segregation of Se or Te atoms at the surface involved a dramatic effect on the formation of the L1 0 phase. The strong anisotropy exhibited along the growth direction allows to observe, by magnetic force microscopy, the perpendicular magnetic configuration with up and down domains. Comparably, we have grown, on the same materials, Cu/Ni multilayers showing a clear perpendicular magnetic anisotropy. Optical measurements on a semimagnetic heterostructure covered by a ferromagnetic metal layer suggest fluctuations of the Fermi level at the interface between the semiconductor and the metal.

The FePd alloy exhibits an L10 (CuAu-I type) chemically ordered phase which can be grown by molecular beam epitaxy at a low temperature (620 K) on Pd(0 0 1). The surface of the alloy has been observed by scanning tunnelling microscopy to determine the link between the surface morphology and the underlying chemical order. Steps are commonly observed with a bi-atomic height as a result of the surface processes leading to the chemical ordering. Mono-atomic steps are also observed and there is some evidence that they are linked to the antiphase boundaries between ordered domains within the growing layer.

Little is currently known about the brain regions involved in central processing of dyspnea. We performed a functional imaging study with positron emission tomography (PET) to assess brain activation associated with an important component of dyspnea, respiratory discomfort during loaded breathing. We induced respiratory discomfort in eight healthy volunteers by adding external resistive loads during inspiration and expiration. Brain activation was characterized by a significant increase in regional cerebral blood flow (rCBF) (Z score of peak activation > 3.09). As compared with the unloaded control condition, high loaded breathing was associated with neural activation in three distinct brain regions, the right anterior insula, the cerebellar vermis, and the medial pons (respective Z scores = 4.75, 4.44, 4.41). For these brain regions, we further identified a positive correlation between rCBF and the perceived intensity of respiratory discomfort (respective Z scores = 4.45, 4.75, 4.74) as well as between rCBF and the mean amplitude of mouth pressure swings (DeltaPm), the index of the main generating mechanism of the sensation (respective Z scores = 4.67, 4.36, 4.31), suggesting a common activation by these two parameters. Furthermore, we identified an area in the right posterior cingulate cortex where neural activation was specifically associated with perceived intensity of respiratory discomfort that is not related to DeltaPm (Z score = 4.25). Our results suggest that respiratory discomfort related to loaded breathing may be subserved by two distinct neural networks, the first being involved in the concomitant processing of the genesis and perception of respiratory discomfort and the second in the modulation of perceived intensity of the sensation by various factors other than its main generating mechanism, which may include emotional processing.

The magnetic domain configurations of exchange-coupled NiO/Co bilayers were investigated by magnetic force microscopy. These bilayers exhibit a well-defined uniaxial anisotropy resulting from the deposition at oblique incidence of the NiO layer. Two types of magnetic contrast are identified: (i) bipolar contrast due to 180° Neel walls in the parts of the walls which are parallel to the easy axis of magnetization, and (ii) monopolar contrast in the parts of the walls separating domains with meeting head-on magnetizations. These latter domain walls have a zigzag shape which represents a compromise between a decrease in the local density of magnetostatic energy and an increase in the wall length. The effect of the Co thickness of the shape on the domains is also discussed.

OBJECTIVE: The nature of the underlying brain dysfunction of childhood autism, a life-long severe developmental disorder, is not well understood. Although researchers using functional brain imaging have attempted to contribute to this debate, previous studies have failed to report consistent localized neocortical brain dysfunction. The authors reasoned that early methods may have been insensitive to such dysfunction, which may now be detectable with improved technology. METHOD: To test this hypothesis, regional cerebral blood flow was measured with positron emission tomography (PET) in 21 children with primary autism and in 10 nonautistic children with idiopathic mental retardation. Autistic and comparison groups were similar in average age and developmental quotients. The authors first searched for focal brain dysfunction in the autistic group by using a voxel-based whole brain analysis and then assessed the sensitivity of the method to detect the abnormality in individual children. An extension study wa...

The resistive effect of domain walls in FePd films with perpendicular anisotropy was studied experimentally as a function of field and temperature. The films were grown directly on MgO substrates, which induces an unusual virgin magnetic configuration composed of 60 nm wide parallel stripe domains. This allowed us to carry out the first measurements of the anisotropy of domain wall resistivity in the two configurations of current perpendicular and parallel to the walls. At 18 K, we find $8.2%$ and $1.3%$ for the domain wall magnetoresistance normalized to the wall width (8 nm) in these two respective configurations. These values are consistent with the predictions of Levy and Zhang.

FePd thin-film samples with perpendicular magnetic anisotropy (PMA) have been studied with x-ray resonant magnetic scattering, both at the Fe and at the Pd ${L}_{3}$ edges. In these samples the competition between PMA and shape anisotropy leads to the formation of highly ordered striped domain patterns with a magnetization component perpendicular to the film plane. These striped domains give rise to magnetic satellite peaks in the diffraction pattern. Magnetic diffraction rod scans of these satellites were analyzed to obtain information about the magnetic depth profile of the films. It was found that flux closure occurs in samples with a low to medium PMA, while a high PMA impedes the formation of closure domains. Data analysis gives a depth of the closure domains extending to 85 \AA{}, with approximately half the magnetic moment aligned in plane.

Background and Purpose —This study was designed to analyze whether early diffusion-weighted imaging (DWI) provides reliable quantitative information for the prediction of stroke patients at risk of malignant brain infarct. Methods —We selected 28 patients with a middle cerebral artery (MCA) infarct and proven MCA or carotid T occlusion on DWI and MRI angiography performed within 14 hours after onset (mean 6.5±3.5 hours, median 5.2 hours). Of these, 10 patients developed malignant MCA infarct, whereas 18 did not. For the 2 groups, we compared the National Institutes of Health Stroke Scale (NIHSS) score at admission, site of arterial occlusion, standardized visual analysis of DWI abnormalities, quantitative volume measurement of DWI abnormalities (volume DWI ), and apparent diffusion coefficient values. Univariate and multivariate discriminant analysis was used to determine the most accurate predictors of malignant MCA infarct. Results —Univariate analysis showed that an admission NIHSS score >20, total versus partial MCA infarct, and volume DWI >145 cm 3 were highly significant predictors of malignant infarct. The best predictor was volume DWI >145 cm 3 , which achieved 100% sensitivity and 94% specificity. Prediction was further improved by bivariate models combining volume DWI and apparent diffusion coefficient measurements, which reached 100% sensitivity and specificity in this series of patients. Conclusions —Quantitative measurement of infarct volume on DWI is an accurate method for the prediction of malignant MCA infarct in patients with persistent arterial occlusion imaged within 14 hours of onset. This may be of importance for early management of severe stroke patients.

We evaluated the feasibility and use of diffusion-weighted and fluid-attenuated inversion-recovery pulse sequences performed as an emergency for patients with acute ischaemic stroke. A 5-min MRI session was designed as an emergency diagnostic procedure for patients admitted with suspected acute ischaemic stroke. We reviewed routine clinical implementation of the procedure, and its sensitivity and specificity for acute ischaemic stroke over the first 8 months. We imaged 91 patients (80 min to 48 h following the onset of stroke). Clinical deficit had resolved in less than 3 h in 15 patients, and the remaining 76 were classified as stroke (59) or stroke-like (17) after hospital discharge. Sensitivity of MRI for acute ischaemic stroke was 98 %, specificity 100 %. MRI provided an immediate and accurate picture of the number, site, size and age of ischaemic lesions in stroke and simplified diagnosis in stroke-like episodes. The feasibility and high diagnostic accuracy of emergency MRI in acute stroke strongly support its routine use in a stroke centre.

We show that the magnetization profile of magnetic patterns in thin films can be obtained by using circular dichroism to recover the phase relation in X-ray resonant magnetic scattering. This is demonstrated for single-crystalline FePd layers with striped magnetic domain pattern where we obtain unambiguous evidence for the presence of magnetic flux closure domains.

Longitudinal positron emission tomography (PET) studies of 6-18F-L-dopa uptake in the striatum are used to assess the progression of Parkinson's disease or the survival of neuronal cells grafted in parkinsonian patients. These studies are performed over several years, and data analysis may suffer from the change from old tomographs to new machines with better sensitivity and spatial resolution. Furthermore, such studies on parkinsonian patients may be accomplished in either 2D or 3D acquisition mode. The aforementioned improvements offer great benefits for the study of neurodegenerative diseases, especially those affecting the striatum. However, direct comparison of data is not straightforward owing to variation in scanner characteristics. In this study, we assessed the feasibility of comparing the 6-18F-L-dopa striatal uptake values (Kc) measured in two groups of healthy subjects using two tomographs of different generations. We re-studied and compared acquisitions performed on 14 healthy subjects using 6-18F-L-dopa. Half of these studies had been performed in 2D acquisition mode using an ECAT 953B. The other half had been performed in 3D acquisition mode using an ECAT EXACT HR+. Different reconstruction protocols were used and the Kc values obtained were statistically compared. The results showed that lowering the transverse spatial resolution of images obtained with the scanner having the better spatial resolution, so that it more closely matched that of the other machine, allowed similar KC values to be obtained in healthy subjects. This study shows that quantitative results of 6-18F-L-dopa scans can be matched between different scanners with different intrinsic resolutions. This can be accomplished using adequate modifications of the reconstruction parameters. Such modifications can be used to help in the longitudinal monitoring of parkinsonian patients using different tomographs.

NiO films on clean α-Al2O3(0 0 0 1) were prepared by molecular beam epitaxy. Two parameters were considered: the growth temperature (320–700°C) and the film thickness (29–200 nm). Low energy electron diffraction (LEED) patterns of the deposits show a six-fold symmetry. The samples were ex situ characterized by atomic force microscopy (AFM) and by grazing incidence X-ray diffraction. For all samples, NiO islands with different sizes and shapes were observed. A layer of pyramidal NiO islands, with triangular facets is present. Depending on the sample, also hexagonal or square islands were observed. The angles of the triangular facets correspond to (1 0 0) surfaces of the NiO(1 1 1). X-ray diffraction evidences that the NiO film grows with the (1 1 1) plane parallel to the (0 0 0 1)Al2O3 one. Twinned and not-twinned face centered cubic (FCC) NiO(1 1 1) stacking are present in approximately equal quantities. The crystallographic quality of the NiO layers was investigated.

Background and Purpose —We know remarkably little about the mechanisms underlying cortical activation. Such mechanisms might be better understood by studying the effect of well-localized lesions on the cortical activations in simple paradigms. Methods —We used H 2 15 O and positron emission tomography to measure regional cerebral blood flow (rCBF) at rest and during hand vibration in 7 patients with unilateral thalamic lesion involving the ventroposterior (VP) somatosensory thalamic relay nuclei. We compared the results with those obtained in 6 patients with thalamic lesions sparing the VP nuclei and 6 healthy controls. Results —The patients with VP lesions had a selective hypoperfusion at rest in the ipsilesional primary sensorimotor cortex (SM1). This hypoperfusion was significantly correlated with the degree of contralateral somatosensory deficit. This abnormality may reflect the deafferentation of SM1 from its somatosensory thalamic input. Despite this deafferentation, the ipsilesional SM1 was normally activated by the vibration of the hypesthetic hand. Conclusions —The fact that a lesion of the somatosensory thalamic relay nuclei alters the rCBF at rest in SM1 but not its activation by hand vibration indicates that the mechanism of cortical activation is complex, even in the case of simple sensory stimulation. In addition, a dissociation may occur between obvious neurological deficits and apparently normal activation patterns, which suggests that activation studies should be interpreted cautiously in patients with focal brain lesions.

The growth of InGaN on GaN by plasma-assisted molecular beam epitaxy is studied using reflection high energy electron diffraction. We find that InGaN follows a layer-by-layer growth mode for low In contents and a Stranski-Krastanov growth mode for In concentrations above a critical value. Using this 2D–3D transition, nanometric islands are grown. These islands are characterized by atomic force microscopy. Their size is found to be small enough to expect strong confinement effects. Photoluminescence experiments show strong blue light emission at room temperature. The temperature dependence of dots' luminescence is compared to that of a quantum well and a bulk sample.

It is demonstrated that perpendicular magnetic anisotropy may be obtained with a room temperature growth process in ordered (FePd) alloys. Indeed, using atomic layer by atomic layer epitaxy, a partial chemical ordering into the L10 structure is obtained, with a corresponding intermediate perpendicular anisotropy (\(({K_u}/2\pi M_s^2 \sim 0.4)\)). These samples provide an appropriate template for the study of the magnetic reorientation from in plane to out of plane magnetization upon layer's thickness increase. VSM, transverse Kerr measurements and magnetic force microscopy have been used in order to determine the relevant magnetic parameters and the occurrence of the reorientation transition.

Ferromagnetic resonance (FMR) investigations on epitaxial partially ordered FePd thin films with a perpendicular magnetic anisotropy (PMA) are presented. The measurements have been performed over a wide frequency range (6–18 GHz) in the monodomain state. Besides the determination of magnetic parameters (anisotropy constants, gyromagnetic ratio), two main results emerge: (i) the occurrence of well-resolved perpendicular standing spin–wave resonances which depart from the n 2 -law, (ii) the perpendicular uniform resonance linewidth was found to be independent of frequency over the (6–18 GHz) range. These results are discussed in terms of weak volume inhomogeneities (anisotropy, defects) induced by the film growth process.

Specular polarised neutron reflectometry with polarisation analysis allows one to probe in-depth magnetic profiles of thin films (along the normal to the film). Off-specular reflectometry gives information about lateral structures (in the plane of the film) with typical lengthscales ranging from 5 to 100 μm. Furthermore, surface diffraction at grazing angle gives access to transverse dimensions between 10 nm and 300 nm with a resolution in that direction of a few nanometers. The combination of these three techniques applied to magnetic systems can lead to a 3D magnetic structure measurement. Such a technique is however not applicable to the study of a single magnetic dot, but it can generate unique results in several cases including patterns of domain walls in thin films with perpendicular anisotropy, arrays of magnetic dots, and patterned lines in magnetic thin films.

Taking adavantage of the Stranski–Krastanov growth mode of GaN deposited on AlN, the formation of self-organized GaN islands has been achieved in both hexagonal and cubic phases. It has been shown that the dot size variation as a function of time obeys an Ostwald’s ripening mechanism. Vertical correlation effects between stacked layers of dots have been shown to result in a better size homogeneity and a decrease in density. The optical properties of the GaN dots have been studied by photoluminescence. A blue shift is oberved which is definitely assigned to quantum confinement effects.

The magnetic configurations induced by the growth process in a thin film with perpendicular magnetisation have been observed by magnetic force microscopy (MFM). The FePd thin film has been grown by molecular beam epitaxy. A high uniaxial chemical ordering of the alloy into the tetragonal L10 structure induces the development of a large perpendicular anisotropy. As the growth process is performed below the Curie temperature of the FePd alloy, domain nucleation occurs during the growth process. The magnetic configuration has been imaged in the as grown state. As the equilibrium size of the magnetic domains decreases when the thickness of the layer increases, the domains obtained from spontaneous nucleation at the beginning of the growth of the thin film are submitted to very large strains as the layer thickness increases. At low thicknesses (low strains), the domain wall instability gives rise to an undulation of the domain walls. Thereafter, it leads to the formation of well-defined magnetic fingers, thus giving birth to the coexistence of two length scale in the domain structure. A quantitative estimation of the strain leading to the fingering instability is obtained. Last, the implications of these observations on the kinetic of domain wall distortion in ultrathin layers are discussed.