RESUMEN
While the main neural networks are in place at term birth, intense changes in cortical microstructure occur during early infancy with the development of dendritic arborization, synaptogenesis and fiber myelination. These maturational processes are thought to relate to behavioral acquisitions and the development of cognitive abilities. Nevertheless, in vivo investigations of such relationships are still lacking in healthy infants. To bridge this gap, we aimed to study the cortical maturation using non-invasive Magnetic Resonance Imaging, over a largely unexplored period (1-5 post-natal months). In a first univariate step, we focused on different quantitative parameters: longitudinal relaxation time (T1), transverse relaxation time (T2), and axial diffusivity from diffusion tensor imaging (λ//) These individual maps, acquired with echo-planar imaging to limit the acquisition time, showed spatial distortions that were first corrected to reliably match the thin cortical ribbon identified on high-resolution T2-weighted images. Averaged maps were also computed over the infants group to summarize the parameter characteristics during early infancy. In a second step, we considered a multi-parametric approach that leverages parameters complementarity, avoids reliance on pre-defined regions of interest, and does not require spatial constraints. Our clustering strategy allowed us to group cortical voxels over all infants in 5 clusters with distinct microstructural T1 and λ// properties The cluster maps over individual cortical surfaces and over the group were in sound agreement with benchmark post mortem studies of sub-cortical white matter myelination, showing a progressive maturation of 1) primary sensori-motor areas, 2) adjacent unimodal associative cortices, and 3) higher-order associative regions. This study thus opens a consistent approach to study cortical maturation in vivo.
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Mapeo Encefálico/métodos , Encéfalo/crecimiento & desarrollo , Red Nerviosa/crecimiento & desarrollo , Encéfalo/diagnóstico por imagen , Análisis por Conglomerados , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Lactante , Imagen por Resonancia Magnética , Masculino , Red Nerviosa/diagnóstico por imagenRESUMEN
Characteristic preterm EEG patterns of "Delta-brushes" (DBs) have been reported in the temporal cortex following auditory stimuli, but their spatio-temporal dynamics remains elusive. Using 32-electrode EEG recordings and co-registration of electrodes' position to 3D-MRI of age-matched neonates, we explored the cortical auditory-evoked responses (AERs) after 'click' stimuli in 30 healthy neonates aged 30-38 post-menstrual weeks (PMW). (1) We visually identified auditory-evoked DBs within AERs in all the babies between 30 and 33 PMW and a decreasing response rate afterwards. (2) The AERs showed an increase in EEG power from delta to gamma frequency bands over the middle and posterior temporal regions with higher values in quiet sleep and on the right. (3) Time-frequency and averaging analyses showed that the delta component of DBs, which negatively peaked around 550 and 750 ms over the middle and posterior temporal regions, respectively, was superimposed with fast (alpha-gamma) oscillations and corresponded to the late part of the cortical auditory-evoked potential (CAEP), a feature missed when using classical CAEP processing. As evoked DBs rate and AERs delta to alpha frequency power decreased until full term, auditory-evoked DBs are thus associated with the prenatal development of auditory processing and may suggest an early emerging hemispheric specialization.
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Audiometría de Respuesta Evocada , Corteza Cerebral/fisiología , Recien Nacido Prematuro/fisiología , Estimulación Acústica , Ritmo alfa/fisiología , Ritmo Delta/fisiología , Electroencefalografía , Potenciales Evocados Auditivos/fisiología , Femenino , Ritmo Gamma , Humanos , Recién Nacido , Imagen por Resonancia Magnética , Masculino , Sueño/fisiologíaRESUMEN
The strong positive-allometric relationship between brain size, cortical extension and gyrification complexity, recently highlighted in the general population, could be modified by brain developmental disorders. Indeed, in case of brain growth insufficiency, the pathophysiological relevance of the "simplified gyral pattern" phenotype is strongly disputed since almost no genotype-phenotype correlations have been found in primary microcephalies. Using surface scaling analysis and newly-developed spectral analysis of gyrification (Spangy), we tested whether the gyral simplification in groups of severe microcephalies related to ASPM, PQBP1 or fetal-alcohol-syndrome could be fully explained by brain size reduction according to the allometric scaling law established in typically-developing control groups, or whether an additional disease effect was to be suspected. We found the surface area reductions to be fully explained by scaling effect, leading to predictable folding intensities measured by gyrification indices. As for folding pattern assessed by spectral analysis, scaling effect also accounted for the majority of the variations, but an additional negative or positive disease effect was found in the case of ASPM and PQBP1-linked microcephalies, respectively. Our results point out the necessity of taking allometric scaling into account when studying the gyrification variability in pathological conditions. They also show that the quantitative analysis of gyrification complexity through spectral analysis can enable distinguishing between even (predictable, non-specific) and uneven (unpredictable, maybe disease-specific) gyral simplifications.
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Corteza Cerebral/patología , Microcefalia/patología , Adolescente , Adulto , Mapeo Encefálico/métodos , Proteínas Portadoras/genética , Niño , Proteínas de Unión al ADN , Femenino , Trastornos del Espectro Alcohólico Fetal/patología , Humanos , Interpretación de Imagen Asistida por Computador , Masculino , Microcefalia/genética , Persona de Mediana Edad , Mutación , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Análisis Espacial , Adulto JovenRESUMEN
Limited studies are available assessing the impact of extended ageing on lamb eating quality of a wide range of cuts. From lamb (n = 153) and young mutton (n = 40) carcasses, seven cuts (eye of rack, eye of shoulder, knuckle, loin, outside, rump and topside) were collected and aged based on three ageing times (5, 14 or 21 days). Additionally, residual glycogen was determined from the loin at the corresponding ageing time. Untrained consumers assessed samples for tenderness, juiciness, flavour liking and overall liking. Increasing ageing time from 5 to 14 or 21 days significantly improved cut eating quality; however, ageing beyond 14 days showed no additional benefit. The ageing effect reduced when corrected for pH and temperature measurements, confirming ageing can improve eating quality when pH and temperature variation exists. Loin residual glycogen had no impact on eating quality at each ageing time. Our results confirm the importance of establishing optimum ageing times for cuts to ensure the highest consumer acceptability.
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Comportamiento del Consumidor , Glucógeno , Carne Roja , Gusto , Temperatura , Animales , Humanos , Concentración de Iones de Hidrógeno , Glucógeno/análisis , Glucógeno/metabolismo , Carne Roja/análisis , Carne Roja/normas , Manipulación de Alimentos/métodos , Oveja Doméstica , Factores de Tiempo , Adulto , Masculino , Femenino , Australia , Calidad de los AlimentosRESUMEN
This study describes the performance of a Marel conveyer vision scanner, across beef carcases (n = 102) from a wide visual marbling score range, in its ability to predict chemical intramuscular fat (IMF%), Meat Standards Australia (MSA) and AUS-MEAT marbling scores of portion steaks. Vision scanner marbling scores were acquired on fresh-cut steaks, with its predictions tested using a leave-one-out cross validation method, which demonstrated precise and accurate predictions of IMF% (R2 = 0.87; RMSEP = 1.16; slope = 0.09; bias = 0.22), MSA (R2 = 0.82; RMSEP = 70.11; slope = 0.09; bias = 17.08) and AUS-MEAT marbling (R2 = 0.79; RMSEP = 0.75; slope = 0.16; bias = 0.08). Care must be taken when calibrating devices on non-fresh-cut steak, as fresh-cut steaks produced different vision scanner marbling values suggesting different prediction equations are warranted. The Marel vision scanner prediction of visual grader scores was relatively less precise and accurate than its prediction of IMF%, however in this case it may have been due to error in the grader scores.
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Carne Roja , Animales , Bovinos , Carne , Australia , Músculo EsqueléticoRESUMEN
The current Meat Standards Australia (MSA) and AUS-MEAT grading system assumes that marbling through the M. longissmus thoracis et lumborum (loin) is represented by the score of the grading site. However, studies have indicated marbling varies within the beef loin, but commercially individual portion steaks are not graded for marbling. Cube rolls from a wide phenotypic marbling range (n = 102) were collected and sliced into 15 mm portion steaks, which were imaged with a Marel vision scanner to obtain objective marbling scores. Additionally, three locations (grading site, middle, cranial) across each cube roll were tested for intramuscular fat percentage (IMF%). The effect of steak location demonstrated marked variation across the length of the cube roll for both vision scanner marbling scores and IMF%. This variation in vision scanner marbling scores, expressed in units of MSA marbling score, equated to 316 MSA units. This work suggests an opportunity for individual portion marbling measurements and segregation of individual portion cut steaks based upon their marbling levels.
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Carne Roja , Animales , Bovinos , Carne/análisis , Australia , Músculo EsqueléticoRESUMEN
Lumbar bone mineral concentration, as predicted by dual energy x-ray absorptiometry (DEXA), may reflect changes in lamb maturity and eating quality. New season (n = 60) and old season (n = 60) lambs were slaughtered and DEXA scanned at a commercial abattoir across 2 kill groups. The second lumbar vertebra was isolated from the spine for determination of calcium, phosphorus, and magnesium concentration (mg/g). The loin and rack cuts were collected for consumer sensory grilling and roasting analyses. Mineral concentration was significantly higher in old season lambs within kill group 1 (P < 0.05). DEXA was a positive predictor of phosphorus and calcium concentration, but only when DEXA lean % (P < 0.05) was included in the model. Calcium and phosphorus were significant positive predictors of overall liking scores (P < 0.05), but only for the rack roast. These effects became insignificant when DEXA lean % was included. These results suggest that DEXA values likely reflect changes in both DEXA lean % and bone minerals, and that DEXA lean % was the driver of eating quality, rather than maturity.
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Huesos , Carne Roja , Absorciometría de Fotón , Animales , Minerales , Carne Roja/análisis , Ovinos , Oveja DomésticaRESUMEN
In order to understand how genetic mutations might have favored language development in our species, we need a better description of the human brain at the beginning of life. As the linguistic network mainly involves the left perisylvian regions in adults, we used anatomical MRI to study the structural asymmetries of these regions in 14 preverbal infants. Our results show four significant asymmetries. First and foremost, they stress an important but little-known asymmetry: the larger depth of the right superior temporal sulcus (STS) at the base of Heschl's gyrus. Then, we characterized the early forward and upward shift of the posterior end of the right Sylvian fissure, the elongation of the left planum temporale as well as the thickening of the left Heschl's gyrus. The rightward bias of the STS is robust and large, and is not correlated with the leftward asymmetries of the planum and Heschl's gyrus, suggesting that different morphogenetic factors drive these asymmetries. As this sulcus is engaged in multiple high-level functions (e.g. language and theory of mind), and has been spotted as abnormal in several developmental disorders (e.g. schizophrenia, autism), this early rightward asymmetry should be further explored as a target for a genetic evolutionary pressure.
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Encéfalo/anatomía & histología , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Lactante , Recién Nacido , Imagen por Resonancia Magnética , MasculinoRESUMEN
Since the first reports of polyglutamine-binding protein 1 (PQBP1) mutations in Renpenning syndrome and related disorders, the spectrum of PQBP1-linked clinical manifestations has been outlined from rare published case reports. The phenotypic description is often obtained from medical archives, and therefore, heterogeneous. Moreover, some aspects such as brain imaging or cognitive and behavioral functioning are rarely described. In this study, 13 PQBP1-mutated French patients were subjected to a standardized clinical, cognitive and behavioral assessment. Physical measurements of their relatives were also collected. We report on a recognizable clinical and radiological phenotype. All patients presented with microcephaly, leanness and mild short stature, relative to familial measurements. Three new clinical features are described: upper back progressive muscular atrophy, metacarpophalangeal ankylosis of the thumb and velar dysfunction. The specific facial dysmorphic features included at least four of the following signs: long triangular face, large ridged nose, half-depilated eyebrows, dysplastic or protruding ears and rough slightly sparse hair. An over-aged appearance was noticed in elderly patients. Cortical gyrification was normal based on available magnetic brain imaging of six patients. PQBP1-linked microcephaly (or Renpenning syndrome) is an X-linked mental retardation syndrome, which has clinically recognizable features.
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Proteínas Portadoras/genética , Mutación , Proteínas Nucleares/genética , Fenotipo , Adolescente , Adulto , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Parálisis Cerebral/complicaciones , Parálisis Cerebral/diagnóstico por imagen , Parálisis Cerebral/genética , Parálisis Cerebral/patología , Niño , Preescolar , Trastornos del Conocimiento/etiología , Proteínas de Unión al ADN , Femenino , Francia , Genotipo , Humanos , Masculino , Discapacidad Intelectual Ligada al Cromosoma X/complicaciones , Discapacidad Intelectual Ligada al Cromosoma X/diagnóstico por imagen , Discapacidad Intelectual Ligada al Cromosoma X/genética , Discapacidad Intelectual Ligada al Cromosoma X/patología , Embarazo , Radiografía , Adulto JovenRESUMEN
Data were obtained from 120 lambs which were slaughtered, scanned using dual energy X-ray absorptiometry (DEXA) and underwent eating quality assessment. DEXA images were used to determine R values, reflecting atomic mass, to predict carcass lean %. Additionally, bone regions (humerus, lumbar, femur and "all carcass bone") were isolated from images to determine bone specific R values (DEXA R Mean and SDev). Prediction of overall liking of cuts across the carcass (scored between 0 and 100) using lean % and bone DEXA was variable. Loin grill overall liking demonstrated significant associations with lumbar DEXA R Mean and SDev, decreasing by 8.6 and 7.6 units across the increasing range of these bone DEXA measures. This association is somewhat independent of carcass lean % and intramuscular fat % of the loin. Given the association of DEXA with eating quality, there are potential benefits for the lamb industry with respect to carcass sorting and marketing during routine processing and DEXA scanning.
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Absorciometría de Fotón/veterinaria , Tejido Adiposo , Carne Roja/análisis , Absorciometría de Fotón/métodos , Adulto , Anciano , Animales , Huesos , Comportamiento del Consumidor , Calidad de los Alimentos , Humanos , Persona de Mediana Edad , Músculo Esquelético , Oveja DomésticaRESUMEN
BACKGROUND: Children who have been treated for a medulloblastoma often suffer long-term cognitive impairments that often negatively affect their academic performance and quality of life. In this article, we will review the neuropsychological consequences of childhood medulloblastoma and discuss the risk factors known to influence the presence and severity of these cognitive impairments and possible interventions to improve their quality of life. METHODS: This narrative review was based on electronic searches of PubMed to identify all relevant studies. RESULTS: Although many types of cognitive impairments often emerge during a child's subsequent development, the core cognitive domains that are most often affected in children treated for a medulloblastoma are processing speed, attention and working memory. The emergence and magnitude of these deficits varies greatly among patients. They are influenced by demographic (age at diagnosis, parental education), medical and treatment-related factors (perioperative complications, including posterior fossa syndrome, radiation therapy dose, etc.), and the quality of interventions such as school adaptations provided to the child or rehabilitation programs that focus on cognitive skills, behavior and psychosocial functioning. CONCLUSION: These patients require specialized and coordinated multidisciplinary rehabilitation follow-up that provides timely and adapted assessments and culminates in personalized intervention goals being set with the patient and the family. Follow-up should be continued until referral to adult services.
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Neoplasias Cerebelosas/psicología , Disfunción Cognitiva/psicología , Meduloblastoma/psicología , Pruebas Neuropsicológicas , Adulto , Atención/fisiología , Neoplasias Cerebelosas/complicaciones , Neoplasias Cerebelosas/terapia , Niño , Preescolar , Cognición/fisiología , Terapia Cognitivo-Conductual/tendencias , Disfunción Cognitiva/etiología , Disfunción Cognitiva/terapia , Femenino , Humanos , Masculino , Meduloblastoma/complicaciones , Meduloblastoma/terapia , Calidad de Vida/psicologíaRESUMEN
Both language capacity and strongly lateralized hand preference are among the most intriguing particularities of the human species. They are associated in the adult brain with functional and anatomical hemispheric asymmetries in the speech perception-production network and in the sensori-motor system. Only studies in early life can help us to understand how such asymmetries arise during brain development, and to which point structural left-right differences are the source or the consequence of functional lateralization. In this study, we aimed to provide new in vivo structural markers of hemispheric asymmetries in infants from 1 to 4 months of age, with diffusion tensor imaging. We used 3 complementary analysis methods based on local diffusion indices and spatial localizations of tracts. After a prospective approach over the whole brain, we demonstrated early leftward asymmetries in the arcuate fasciculus and in the cortico-spinal tract. These results suggest that the early macroscopic geometry, microscopic organization, and maturation of these white matter bundles are related to the development of later functional lateralization.
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Lactante , Lenguaje , Red Nerviosa/anatomía & histología , Envejecimiento/fisiología , Núcleo Arqueado del Hipotálamo/anatomía & histología , Núcleo Arqueado del Hipotálamo/fisiología , Interpretación Estadística de Datos , Imagen de Difusión por Resonancia Magnética , Femenino , Lateralidad Funcional/fisiología , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Red Nerviosa/fisiología , Tractos Piramidales/anatomía & histología , Tractos Piramidales/fisiologíaRESUMEN
Understanding consumer sensory perceptions of sheepmeat is essential for consumer satisfaction post-purchase. Meat Standards Australia (MSA) sensory protocols have been effectively utilised in beef for international consumers however, to date sheepmeat testing is largely limited to Australian consumers. This study measured the sensory responses (liking of odour, tenderness, juiciness, liking of flavour, and overall liking) of 2160 untrained American, Australian and Chinese consumers to grilled longissimus lumborum (LL) and semimembranosus (SM) muscles from 164 lambs and 168 yearlings. Across countries there was no difference in juiciness or overall liking sensory scores. American consumers scored tenderness, flavour and odour slightly higher than Australian consumers, and Chinese consumer scores were lowest. Consistently for all countries, sensory scores were greatest in the LL muscle, in lambs compared to yearlings particularly for the LL, and Merino sired and female lambs. These results indicate that cultural background has minimal impact on sensory perceptions of sheepmeat, and provides valuable information for future eating quality prediction models.
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Comportamiento del Consumidor , Odorantes , Carne Roja/análisis , Gusto , Adulto , Anciano , Animales , Australia , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético , Oveja Doméstica , Estados UnidosRESUMEN
OBJECTIVE: We have recently shown that de novo mutations in the TUBA1A gene are responsible for a wide spectrum of neuronal migration disorders. To better define the range of these abnormalities, we searched for additional mutations in a cohort of 100 patients with lissencephaly spectrum for whom no mutation was identified in DCX, LIS1 and ARX genes and compared these data to five previously described patients with TUBA1A mutations. RESULTS: We detected de novo TUBA1A mutations in six patients and highlight the existence of a prominent form of TUBA1A related lissencephaly. In four patients, the mutations identified, c.1190T>C (p.L397P), c.1265G>A (p.R422H), c.1264C>T (p.R422C), c.1306G>T (p.G436R), have not been reported before and in two others, the mutation corresponds to a recurrent missense mutation, c.790C>T (p.R264C), likely to be a hot spot of mutation. All together, it emerges that the TUBA1A related lissencephaly spectrum ranges from perisylvian pachygyria, in the less severe form, to posteriorly predominant pachygyria in the most severe, associated with dysgenesis of the anterior limb of the internal capsule and mild to severe cerebellar hypoplasia. When compared with a large series of lissencephaly of other origins (ILS17, ILSX or unknown origin), these features appear to be specific to TUBA1A related lissencephaly. In addition, TUBA1A mutated patients share a common clinical phenotype that consists of congenital microcephaly, mental retardation and diplegia/tetraplegia. CONCLUSIONS: Our data highlight the presence of consistent and specific abnormalities that should allow the differentiation of TUBA1A related lissencephalies from those related to LIS1, DCX and ARX genes.
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Lisencefalia/genética , Tubulina (Proteína)/genética , Niño , Preescolar , Femenino , Heterocigoto , Humanos , Lactante , Lisencefalia/patología , Imagen por Resonancia Magnética , Masculino , Mutación Missense , Fenotipo , Tubulina (Proteína)/químicaRESUMEN
Calpains play an important role in the postmortem tenderization process of meat and several SNP in the mu-calpain gene (CAPN1) have been reported to be associated with tenderness in beef cattle. Our objectives were to identify the previously reported CAPN1 331G>C SNP and to detect new polymorphisms in this gene in Spanish maternal beef breeds. A fragment (exon 8 to 10) of the bovine CAPN1 gene was sequenced and genotyped in a sample of the main Spanish maternal beef breeds including Retinta, Morucha, and Avilenã Negra-Ibérica. These breeds are characterized for their high meat quality, their adaptation to adverse environmental conditions, and their good maternal aptitude. This adaptation makes it possible to rear these breeds in the south and west of Spain, where drought and feed shortages occur frequently. Six SNP in the mu-calpain gene were found, five of which (CAPN1 80C>T, 302C>G, 310G>A, 445C>T, 524A>C) have not been reported previously. Sequences obtained for these five newly found SNP were submitted to GenBank (Accessions EU386166 to EU386183).
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Calpaína/genética , Bovinos/genética , Polimorfismo de Nucleótido Simple , Alelos , Animales , Secuencia de Bases , Cartilla de ADN/genética , Femenino , Carne , Datos de Secuencia Molecular , Fenotipo , España , Especificidad de la EspecieRESUMEN
Surgery of partial epilepsies in childhood has largely benefited from the recent advances of imaging techniques, which carry a triple goal: (1) to contribute to the localization of the epilepsy onset zone, (2) to detect and delineate an underlying lesion, and (3) to study the spatial relationship between the epileptogenic zone and the neighboring functional cortex, in order to select patients and plan the resection. This noninvasive presurgical imaging workup must be compared to clinical and electrical data to estimate the postoperative prognosis, while invasive techniques such as SEEG, cortical stimulations, and IAT often remain indispensable in difficult cases, i.e., in cryptogenic epilepsies. As in adults, advances in MRI allow us to detect more and more subtle underlying lesions, but this requires repeating MR studies during early childhood and using adapted sequence parameters to account for ongoing myelination. Ictal SPECT and PET imaging prove especially useful in planning depth electrode placement when video-EEG is not contributive, when MRI looks normal or shows multiple abnormalities, or in cases of discrepant findings. Multimodal imaging greatly enhances the sensitivity of all of these techniques. Finally, functional MRI of motor and language functions provide noninvasive cortical mapping of essential functions, using age-adapted paradigms, in cooperating children from age five to six and from IQs around 60.
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Epilepsia/diagnóstico , Imagen por Resonancia Magnética , Niño , Electroencefalografía , Epilepsia/diagnóstico por imagen , Epilepsia/patología , Epilepsia/cirugía , Humanos , Procedimientos Neuroquirúrgicos , Tomografía de Emisión de Positrones , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
Major efforts in the sheep industry to control eating quality have resulted in reduced product variability. Yet inconsistent eating quality for consumers remains, due to a degree of inaccurate representation of cut quality. Eating quality defined through a complex interplay of different factors can be predicted for individual cuts, and Meat Standards Australia (MSA) grading schemes have been developed to achieve these defined quality outcomes. This review outlines the justifications to refine the current sheepmeat MSA pathways system to transition into a cuts-based prediction model and details some of the factors affecting sheepmeat eating quality as key factors under consideration into the new model. The development of the new sheepmeat MSA prediction model will allow for more efficient carcass sorting to underpin a value based payment system throughout the supply chain. However it requires the inclusion of individual carcass yield and eating quality measurements (i.e. IMF). Furthermore, the adoption challenges internationally of an MSA like model are discussed.
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Carne/clasificación , Carne/normas , Animales , Australia , Comportamiento del Consumidor , Control de Calidad , Ovinos , GustoRESUMEN
Robust spatial alignment of post mortem data and in vivo MRI acquisitions from different ages, especially from the early developmental stages, into standard spaces is still a bottleneck hampering easy comparison with the mainstream neuroimaging results. In this paper, we test a landmark-based spatial normalization strategy as a framework for the seamless integration of any macroscopic dataset in the context of the Human Brain Project (HBP). This strategy stems from an approach called DISCO embedding sulcal constraints in a registration framework used to initialize DARTEL, the widely used spatial normalization approach proposed in the SPM software. We show that this strategy is efficient with a heterogeneous dataset including challenging data as preterm newborns, infants, post mortem histological data and a synthetic atlas computed from averaging the ICBM database, as well as more commonly studied data acquired in vivo in adults. We then describe some perspectives for a research program aiming at improving folding pattern matching for atlas inference in the context of the future HBP's portal.
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Encéfalo/anatomía & histología , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Atlas como Asunto , Bases de Datos Factuales , Humanos , Recién Nacido , Recien Nacido Prematuro , Persona de Mediana Edad , Programas InformáticosRESUMEN
Neuroimaging is critical for the diagnosis of neonatal arterial ischemic stroke (NAIS) and for prognosis estimation. The purpose of this work is to define guidelines of clinical neuroimaging for the diagnosis of NAIS, for the optimization of the imaging timing and for the assessment of the prognostic value of each imaging technique. A systematic search of electronic databases (Medline via Pubmed) for studies whose title and abstract were focused on NAIS has been conducted. One hundred and ten articles were selected and their results were analyzed by three Senior Practitioners of pediatric radiology using common methodology for guidelines elaboration within the group of experts gathered by Scientific Societies in the field. MRI with a diffu si on-weighted sequence (DWI) and T1, T2, and T2*-weighted sequences must be performed in the case of suspected NAIS (no sedation is required). In the first hours after the injury, an acute ischemic lesion is characterized by a hypersignal on the diffusion-weighted sequence, with a decrease of the apparent coefficient of diffusion (ADC). The best time to evaluate the extent of the ischemic lesion is between day 2 and day 4 after injury, when the ADC decrease reaches its nadir. In the acute phase, US may be useful as first imaging at the bedside to exclude other pathologies like large space-occupying hemorrhages, but its specific added value on NAIS diagnosis or prognosis assessment is very low. CT scan has no added value in NAIS, compared to MRI. Motor outcome is correlated with the extent of the lesion and with the presence of a definite injury of the corticospinal tract, which is well seen on the diffusion sequence at the acute stage. A secondary atrophy within the mesencephalon (cerebral peduncles) is tied in with a high risk of hemiplegia. Visual outcome is more often compromised in the case of lesions of the posterior cerebral artery territory.
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Isquemia Encefálica/diagnóstico por imagen , Neuroimagen/métodos , Accidente Cerebrovascular/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Humanos , Recién Nacido , Guías de Práctica Clínica como AsuntoRESUMEN
Neonatal arterial ischemic stroke (NAIS) is a rare event that occurs in approximately one in 5000 term or close-to-term infants. Most affected infants will present with seizures. Although a well-recognized clinical entity, many questions remain regarding diagnosis, risk factors, treatment, and follow-up modalities. In the absence of a known pathophysiological mechanism and lack of evidence-based guidelines, only supportive care is currently provided. To address these issues, a French national committee set up by the French Neonatal Society (Société française de néonatologie) and the national referral center (Centre national de référence) for arterial ischemic stroke in children drew up guidelines based on an HAS (Haute Autorité de santé [HAS]; French national authority for health) methodology. The main findings and recommendations established by the study group are: (1) among the risk factors, male sex, primiparity, caesarean section, perinatal hypoxia, and fetal/neonatal infection (mainly bacterial meningitis) seem to be the most frequent. As for guidelines, the study group recommends the following: (1) the transfer of neonates with suspected NAIS to a neonatal intensive care unit with available equipment to establish a reliable diagnosis with MRI imaging and neurophysiological monitoring, preferably by continuous video EEG; (2) acute treatment of suspected infection or other life-threatening processes should be addressed immediately by the primary medical team. Persistent seizures should be treated with a loading dose of phenobarbital 20mg/kg i.v.; (3) MRI of the brain is considered optimal for the diagnosis of NAIS. Diffusion-weighted imaging with apparent diffusion coefficient is considered the most sensitive measure for identifying infarct in the neonatal brain. The location and extent of the lesions are best assessed between 2 and 4 days after the onset of stroke; (4) routine testing for thrombophilia (AT, PC PS deficiency, FV Leiden or FII20210A) or for detecting other biological risk factors such as antiphospholipid antibodies, high FVIII, homocysteinemia, the Lp(a) test, the MTHFR thermolabile variant should not be considered in neonates with NAIS. Testing for FV Leiden can be performed only in case of a documented family history of venous thromboembolic disease. Testing neonates for the presence of antiphospholipid antibodies should be considered only in case of clinical events arguing in favor of antiphospholipid syndrome in the mother; (5) unlike childhood arterial ischemic stroke, NAIS has a low 5-year recurrence rate (approximately 1 %), except in those children with congenital heart disease or multiple genetic thrombophilia. Therefore, initiation of anticoagulation or antithrombotic agents, including heparin products, is not recommended in the newborn without identifiable risk factors; (6) the study group recommends that in case of delayed motor milestones or early handedness, multidisciplinary rehabilitation is recommended as early as possible. Newborns should have physical therapy evaluation and ongoing outpatient follow-up. Given the risk of later-onset cognitive, language, and behavioral disabilities, neuropsychological testing in preschool and at school age is highly recommended.