BILAN ET INTERET DE L'IMAGERIE DANS LES LUXATIONS CONGENITALES IRREDUCTIBLES DE LA HANCHE NEONATALE

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

Caractéristiques cliniques, génétiques et IRM chez 40 enfants présentant une dysgénésie calleuse

Introduction: Etude rétrospective clinique, génétique et IRM d'enfants présentant une dysgénésie calleuse. Etablir la fréquence des signes IRM associés et une classification morphologique validée par des paramètres biométriques en étudiant leur corrélation à la sévérité de la déficience intellectuelle et de l'épilepsie. Matériel et méthodes: 40 enfants ayant bénéficié d'une IRM encéphalique, d'examens génétiques (caryotype et/ou MLPA et/ou CGH-Array) et d'une évaluation clinique ont été inclus sur une période de 8 ans. Les paramètres biométriques des différents segments du corps calleux, le type morphologique, les signes IRM indirects, les caractéristiques cliniques et examens génétiques ont été recueillis selon une grille de lecture. Discussion: 19 atrophies (47,5 %), 15 hypoplasies (37,5 %) et 6 agénésies partielles (15 %) sont identifiées. Une disposition radiaire des sillons inter hémisphériques (37,5 %), des anomalies du gyrus cingulaire (37,5 %), un étirement des cornes frontales en cornes de taureaux (37,5 %), une dilatation ventriculaire (27,5 %), une dilatation en clef des cornes temporales (25 %) sont identifiées. Notre classification morphologique est validée sur les paramètres biométriques relatifs à l'épaisseur du corps (p=0,0002), de l'isthme (p=0,042) et la flèche (p=0,025) du corps calleux. Il n'existe pas de différences de sévérité de déficience intellectuelle ou de l'épilepsie. L'atrophie est accompagnée d'une dilatation ventriculaire globale (p=0,003). L'agénésie partielle est associée à une disposition radiaires des sillons inter hémisphériques (p=0,003), des anomalies du gyrus cingulaire (p=0,003), une distance supérieure à 15 mm entre les bords internes de ventricules latéraux )p=0,011) et un étirement en cornes de taureaux des cornes frontales (p=0,031). Une déficience intellectuelle (92,5 %), des troubles de l'apprentissage (87,5 %), du langage (85 %), du comportement (37,5 %), une épilepsie (32,5 %) sont fréquentes. 8 patients (20 %) présentent des anomalies génétiques. Conclusion: La dysgénésie calleuse est associée à un pronostic intellectuel péjoratif. Des anomalies génétiques sont fréquemment identifiées notamment par CGH-Array. Les signes IRM associés sont fréquents, principalement liés à des anomalies ventriculaires.Introduction: Retrospective review of clinical, genetic and MRI features of children with callosal dysgenesis. Establish frequency of associated MRI signs and a morphological classification validated by biometric parameters. Establish a correlation with severity of intellectual impairment and epilepsy. Materials and methods: 40 children who underwent brain MRI, genetic testing (karyotype and/or MLPA and/or CGH-Array) and a clinical evaluation were included over a period of 8 years. Biometric parameters of different segments of corpus callosum, morphological type, indirect MRI signs, clinical features and genetic testing were collected according to a reading form. Discussion: 19 atrophy (47.5 %), 15 hypoplasia (37.5 %) and 6 partial callosal agenesis (15 %) were identified. Radial pattern of interhemisphereic sulcus (37.5 %), abnormal cingulate cortex (37.5 %), bull horns tears of frontal horns (37.5 %), ventricles dilatation (27.5 %), keyholes dilatation of temporal horns (25 %) were identified. Our morphological classification is validated on biometric parameters related to thickness of the body (p= 0.0002), isthmus (p= 0.042) and antero-posterior length of corpus callosum (p=0.025). No difference in severity of intellectual impairment or epilepsy was shown. Atrophy is associated with ventricles dilatation (p=0.003). Partial callosal agenesis is associated with radial pattern of interhemispheric sulcus (p= 0.003), abnormal cingulate cortex (p= 0.003), distance between inner edges of lateral ventricles greater than 15 mm (p= 0.011) and bull horns tears of frontal horns (p= 0.031). Intellectual impairment (92.5 %), learning disabilities (87.5 %), language disorders (85 %), behavioral disorders (37.5 %) and epilepsy (32.5 %) are common. Eight patients (20 %) have genetic abnormalities. Conclusion: Callosal dysgenesis is associated with pejorative intellectual prognosis. Genetic abnormalities are frequently identified especially with CGH-Array. MRI associated signs are common and mainly due to ventricles abnormalities.RENNES1-BU Santé (352382103) / SudocSudocFranceF

Agénésie du septum pellucidum (diagnostic anténatal et néonatal avec corrélations foetopathologiques et devenir pédiatrique (étude du groupe de recherche en imagerie foetale))

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

Modélisation haute-résolution des courants dans le Golfe de Guinée (étude des oscillations bimensuelles)

Dans le Sud du Golfe de Guinée, vers 740 S, des observations de courant le long de la pente continentale ont mis en évidence des oscillations bimensuelles orientées le long de la bathymétrie. Ces oscillations, très énergétiques et intensifiées près du fond, dominent le signal. Un modèle de circulation générale océanique (NEMO/OPA) haute résolution du Golfe de Guinée est construit afin d étudier ces oscillations et leur mécanisme de forçage. Une étude des données de courant permet d écarter la marée comme mécanisme de forçage et le modèle, forcé par le vent, reproduit les différentes caractéristiques des oscillations. Différents jeux de conditions de forçage permettent d explorer l origine de la variabilité. Les simulations numériques mettent en évidence l origine équatoriale des oscillations. Des ondes de Yanaï, forcés par les vents équatoriaux, se propagent vers l Est du bassin puis se propagent en ondes côtières vers le Nord et vers le Sud. La théorie des ondes équatoriales permet d expliquer la focalisation de l énergie autour de la période 15 jours. Pour la bande de période autour de 15 jours, il n existe pas d ondes équatoriales se propageant vers l Ouest. Ainsi toute l énergie bimensuelle se propageant vers l Est est transmise en ondes côtières. Le modèle haute résolution du Golfe de Guinée et un modèle linéaire de l Atlantique équatorial permettent d étudier la structure spatiale et la variabilité basse fréquence des ondes. La prédominance des modes baroclines élevés est établie pour expliquer la signature en profondeur des oscillations et l atténuation du signal vers le sud. L étude de la variabilité temporelle des ondes à partir des données de courant met en évidence des intermittences du signal à 15 jours, reproduites en partie par le modèle du Golfe de Guinée mais absentes dans le modèle linéaire. Nous n avons pas pu établir de corrélation simple entre l intermittence des ondes et celle des vents équatoriaux générateurs de ces ondes.Currentmeter measurements on the continental slope of the Gulf of Guinea (near 740 S) point out a biweekly oscillation of the currents, bottom intensified and oriented along the bathymetry. Those energetic oscillations dominate the signal. A three-dimensional high-resolution primitive equation model (NEMO/OPA) of the Gulf of Guinea has been developed to study the oscillations and their forcing mechanism. The data does flot support the tide as a forcing mechanism and the wind-forced regional model reproduces biweekly oscillations, which fit the data quite well. Experiments with different forcings have been run to explore the origin of the biweekly variability. Those experiments highlight the equatorial origin of the oscillations forced by equatorial winds. At the equator, wind-forced Yanaï waves propagate eastward, reach the coast and propagate poleward in both directions. The dominant period of 1 5-day can be explained by equatorial waves theory. In the equatorial Atlantic, there are no 15-day waves propagating westward, thereby all the incident energy reaching the African coast propagates poleward via coastal-trapped waves. The spatial structure and the temporal variability of the biweekly waves are examined using the regional model and a linear mode of the equatorial Atlantic. High baroclinic modes explain the bottom intensification and the decrease of the signal to the South, because of the fast dissipation of the highest modes. Intermittency of the biweekly signal is underlined by wavelet analysis of the data and partially reproduced by the regional model but not by the linear model. Although being forced by equatorial winds, the temporal variability of the oscillations is not directly correlated with the variability of the equatorial winds.BREST-BU Droit-Sciences-Sports (290192103) / SudocPLOUZANE-Bibl.La Pérouse (290195209) / SudocSudocFranceF

Magnetic resonance imaging in children presenting migraine with aura: Association of hypoperfusion detected by arterial spin labelling and vasospasm on MR angiography findings.

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Whole-body post-mortem computed tomography compared with autopsy in the investigation of unexpected death in infants and children

International audienceTo investigate the contribution of whole-body post-mortem computed tomography (PMCT) in sudden unexpected death in infants and children.METHODS:Forty-seven cases of sudden unexpected death in children investigated with radiographic skeletal survey, whole-body PMCT and autopsy were enrolled. For imaging interpretation, non-specific post-mortem modifications and abnormal findings related to the presumed cause of death were considered separately. All findings were correlated with autopsy findings.RESULTS:There were 31 boys and 16 girls. Of these, 44 children (93.6 %) were younger than 2 years. The cause of death was found at autopsy in 18 cases (38.3 %), with 4 confirmed as child abuse, 12 as infectious diseases, 1 as metabolic disease and 1 as bowel volvulus. PMCT results were in accordance with autopsy in all but three of these 18 cases. Death remains unexplained in 29 cases (61.7 %) and was correlated with no abnormal findings on PMCT in 27 cases. Major discrepancies between PMCT and autopsy findings concerned pulmonary analysis.CONCLUSIONS:Whole-body PMCT may detect relevant findings that can help to explain sudden unexpected death and is essential for detecting non-accidental injuries. We found broad concordance between autopsy and PMCT, except in a few cases of pneumonia. It is a non-invasive technique acceptable to relatives.KEY POINTS:• Whole-body post-mortem computed tomography (PMCT) is an effective non-invasive method. • Whole-body PMCT is essential for detecting child abuse in unexpected death. • There is concordance on cause of death between PMCT and autopsy. • Whole-body PMCT could improve autopsy through dissection and sampling guidance. • PMCT shows findings that may be relevant when parents reject autopsy

Morphological features in juvenile Huntington disease associated with cerebellar atrophy -magnetic resonance imaging morphometric analysis

International audienceBACKGROUND:The imaging features of Huntington disease are well known in adults, unlike in juvenile-onset Huntington disease.OBJECTIVE:To conduct a morphometric magnetic resonance imaging (MRI) analysis in three juvenile Huntington disease patients (ages 2, 4 and 6 years old) to determine whether quantitative cerebral and cerebellar morphological metrics may provide diagnostically interesting patterns of cerebellar and cerebellar atrophy.MATERIALS AND METHODS:We report the cases of three siblings with extremely early presentations of juvenile Huntington disease associated with dramatic expansions of the morbid paternal allele from 43 to more than 100 CAG trinucleotide repeats. Automatic segmentation of MRI images of the cerebrum and cerebellum was performed and volumes of cerebral substructures and cerebellar lobules of juvenile Huntington disease patients were compared to those of 30 normal gender- and age-matched controls. Juvenile Huntington disease segmented volumes were compared to those of age-matched controls by using a z-score.RESULTS:Three cerebral substructures (caudate nucleus, putamen and globus pallidus) demonstrated a reduction in size of more than three standard deviations from the normal mean although it was not salient in one of them at clinical reading and was not diagnosed. The size of cerebellum lobules, cerebellum grey matter and cerebellum cortex was reduced by more than two standard deviations in the three patients. The cerebellar atrophy was predominant in the posterior lobe.CONCLUSION:Our study sheds light on atrophic cerebral and cerebellar structures in juvenile Huntington disease. Automatic segmentations of the cerebellum provide patterns that may be of diagnostic interest in this disease

Deletion 5q12: Delineation of a Phenotype Including Mental Retardation and Ocular Defects

Array-CGH enables the detection of submicroscopic chromosomal deletions and duplications and leads to an accurate delineation of the imbalances, raising the possibility of correlating genotype to phenotype and mapping minimal critical regions associated with particular patterns of clinical features. We report here on four patients sharing common clinical features (psychomotor retardation, coarse facies and ocular anomalies), with proximal 5q deletions identified by oligo array-CGH. The deletions range from 5.75 to 17.26-Mb in size and occurred de novo. A common 2.63-Mb region between the deletions described here can be defined in 5q12.1 (59,390,122-62,021,754 bp bp from 5pter, hg18) and includes 12 genes. Among them, KIF2A, which encodes a kinesin superfamily protein, is a particularly interesting candidate for the phenotype, as it suppresses the growth of axonal collateral branches and is involved in normal brain development. Ocular defects, albeit unspecific, seem to be common in the 5q12.1 deletion. Identification of additional cases of deletions involving the 5q12.1 region will allow more accurate genotype-phenotype correlations. (C) 2011 Wiley-Liss, Inc