Network over-connectivity differentiates autism spectrum disorder from other developmental disorders in toddlers: A diffusion MRI study.

Advanced connectivity studies in toddlers with Autism Spectrum Disorder (ASD) are increasing and consistently reporting a disruption of brain connectivity. However, most of these studies compare ASD and typically developing subjects, thus providing little information on the specificity of the abnormalities detected in comparison with other developmental disorders (other-DD). We recruited subjects aged below 36 months who received a clinical diagnosis of Neurodevelopmental Disorder (32 ASD and 16 other-DD including intellectual disability and language disorder) according to DSM-IV TR. Structural and diffusion MRI were acquired to perform whole brain probabilistic and anatomically constrained tractography. Network connectivity matrices were built encoding the number of streamlines (DNUM ) and the tract-averaged fractional anisotropy (DFA ) values connecting each pair of cortical and subcortical regions. Network Based Statistics (NBS) was finally applied on the connectivity matrices to evaluate the network differences between the ASD and other-DD groups. The network differences resulted in an over-connectivity pattern (i.e., higher DNUM and DFA values) in the ASD group with a significance of P < 0.05. No contra-comparison results were found. The over-connectivity pattern in ASD occurred in networks primarily involving the fronto-temporal nodes, known to be crucial for social-skill development and basal ganglia, related to restricted and repetitive behaviours in ASD. To our knowledge, this is the first network-based diffusion study comparing toddlers with ASD and those with other-DD. Results indicate the detection of different connectivity patterns in ASD and other-DD at an age when clinical differential diagnosis is often challenging. Hum Brain Mapp 38:2333-2344, 2017. © 2017 Wiley Periodicals, Inc.

Are children born after assisted reproductive technology at increased risk of autism spectrum disorders? A systematic review.

STUDY QUESTION: Are children born after assisted reproductive technology (ART) at increased risk of autism spectrum disorders (ASD)? SUMMARY ANSWER: There is no evidence that ART significantly increases the risk of ASD in the offspring. WHAT IS KNOWN ALREADY: A few systematic reviews have explored the correlation between assisted conception and ASD with inconclusive results, partly due to the heterogeneity of diagnostic criteria and methodology in the different studies. STUDY DESIGN, SIZE, DURATION: Systematic review of 7 observational studies (2 cohort and 5 case-control) encompassing 9216 subjects diagnosed with ASD published since 2000. MATERIALS, SETTING, METHODS: Literature searches were conducted to retrieve observational studies on the risk of ASD in ART population. Databases searched included PubMed, EMBASE and PsycINFO. In order to obtain more consistent results, we only included the studies in which (i) subjects with either infantile autism or ASD could be identified according to international classification systems and (ii) the diagnosis was obtained from hospital records. Seven studies matched the inclusion criteria. MAIN RESULTS AND THE ROLE OF CHANCE: Four out of seven studies, including the two with the best quality scores, did not show an association between ART and ASD. The two papers supporting an increased risk of autism following ART had the lowest quality scores, due to major methodological limitations. Only one paper showed a protective role of ART. LIMITATIONS, REASONS FOR CAUTION: In spite of the strict inclusion criteria applied as to the diagnosis of ASD, the papers selected are heterogeneous in many aspects including study design, definitions of ART, data source and analysed confounders. WIDER IMPLICATIONS OF THE FINDINGS: At present, there is no evidence that ART is significantly associated with ASD and hence that current health policies should be modified. The divergent results of some of the studies suggest that further prospective, large and high-quality studies are still needed. STUDY FUNDING/COMPETING INTEREST(S): This work was supported, in part, by the Italian Ministry of Health and by Tuscany Region. The authors have no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.

Serum lactate dehydrogenase activity in canine malignancies.

Lactate dehydrogenase (LDH) is commonly used in human cancer patients for prognostic purposes. Aim of this study was to determine the magnitude of serum LDH elevation in dogs with cancer compared with healthy dogs and dogs with non-neoplastic disease, and to verify whether it may support the diagnosis of specific malignancies. About 128 healthy dogs, 211 diseased dogs and 188 cancer dogs were enrolled. Dogs with cancer had significantly higher LDH than diseased (P < 0.001) and healthy dogs (P < 0.001), but large overlap was found. Dogs with lymphoma showed significantly higher LDH compared with dogs with carcinoma (P < 0.001) or mast cell tumour (MCT; P < 0.05) but not compared with other malignancies. When considering lymphoma and MCT, LDH levels were not different between early and advanced clinical stages. Measuring LDH levels may not be useful as a screening tool for cancer detection. More studies are needed to define its role in specific tumours.

The assessment of visual acuity in children with periventricular damage: a comparison of behavioural and electrophysiological techniques.

It has been controversial whether electrophysiology offers better precision than behavioural techniques in measuring visual acuity in children with brain damage. We investigated the concordance between sweep VEPs and Acuity Cards (AC) in 29 children with periventricular leukomalacia (PVL), the most common type of brain damage in preterm infants. An overall good correlation was shown but with relatively better behavioural acuity values. VEP/AC ratio was significantly correlated to corpus callosum posterior thinning. We propose that this result reflects the efficacy of the compensatory mechanisms following early brain damage which may differentially affect the two methods.

Visual scanning and reading ability in normal and dyslexic children.

Very few studies have investigated the development of visual search of aligned stimuli in relation to normal reading acquisition and in developmental dyslexia. In this study we used a new computerised experimental task which requires a visuo-motor response (RT) to a target appearing unpredictably in one out of seven different spatial positions on a horizontally aligned array of 18 geometrical figures. The aims of the study were to investigate: 1) the visual scanning development in normal children from pre-school to school age; 2) whether visual scanning performance in kindergarten children could predict reading acquisition; 3) the visual scanning abilities in a group of developmental dyslexic children. The main results were: 1) a significant decrement of RTs with age and a progressive increase of the left-to-right gradient with reading experience; 2) visual scanning abilities in kindergarten proved to be a good predictor of reading acquisition; 3) dyslexics were slow scanners and did not present the left-to-right strategy typical of normal readers. The results support the hypothesis of a relationship between visual scanning and reading abilities.

Early assessment of visual information processing and neurological outcome in preterm infants.

Psychological tests based on visual information processing have shown to be promising in predicting neurodevelopmental outcome in infants at risk. In the present study we prospectively investigated the early development in a group of 20 high-risk preterm infants by means of i) the Fagan Test of Infant Intelligence at 7, 9, and 12 months postterm and ii) a detailed battery for the early assessment of visual functions at 6 and 10 months postterm. The results were then correlated to the Griffiths development scales at two years. At around 7 months no correlation was found in our infants between the Fagan test and neurodevelopmental outcome, possibly as a consequence of the influence of abnormal oculomotor behaviour. At around 9 months most of the visual abnormalities were no more present and the Fagan test was significantly correlated with the outcome. At 12 months postterm a decline of the predictive value of the FTII was observed. In conclusion, nine months postterm age appears to be the best age for the early assessment of neurodevelopmental outcome in high-risk preterm infants, as the maturation of the attentional and visual systems allows a more reliable evaluation.

Intraspecific phylogeography of Lacerta vivipara and the evolution of viviparity.

The lacertid lizard Lacerta vivipara is one of the few squamate species with two reproductive modes. We present the intraspecific phylogeny obtained from neighbor-joining and maximum-parsimony analyses of the mtDNA cytochrome b sequences for 15 individuals from Slovenian oviparous populations, 34 individuals from western oviparous populations of southern France and northern Spain, 92 specimens from European and Russian viviparous populations, and 3 specimens of the viviparous subspecies L. v. pannonica. The phylogeny indicates that the evolutionary transition from oviparity to viviparity probably occurred once in L. vivipara. The western oviparous group from Spain and southern France is phylogenetically most closely related to the viviparous clade. However, the biarmed W chromosome characterizing the western viviparous populations is an apomorphic character, whereas the uniarmed W chromosome, existing both in the western oviparous populations and in the geographically distant eastern viviparous populations, is a plesiomorphic character. This suggests an eastern origin of viviparity. Various estimates suggest that the oviparous and viviparous clades of L. vivipara split during the Pleistocene. Our results are discussed in the framework of general evolutionary models: the concept of an oviparity-viviparity continuum in squamates, the cold climate model of selection for viviparity in squamates, and the contraction-expansion of ranges in the Pleistocene resulting in allopatric differentiation.