Pubmed du 13/09/17

Pubmed du jour

2017-09-13 12:03:50

1. {{Pregnant mice illuminate risk factors that could lead to autism}}. {Nature};2017 (Sep 13);549(7671):131-132.

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2. Arias VB, Gomez LE, Moran ML, Alcedo MA, Monsalve A, Fontanil Y. {{Does Quality of Life Differ for Children With Autism Spectrum Disorder and Intellectual Disability Compared to Peers Without Autism?}}. {J Autism Dev Disord};2017 (Sep 11)

The main goal was to test if children with intellectual disability (ID) and autism spectrum disorder (ASD) show lower quality of life (QOL) in comparison to those with only ID. The KidsLife Scale was applied to 1060 children with ID, 25% of whom also had ASD, aged 4-21 years old. Those with ASD showed lower scores in several QOL domains but, when the effect of other variables was controlled, lower scores were only kept for interpersonal relationships, social inclusion, and physical wellbeing. Slightly higher scores were found for material wellbeing. ASD, Level of ID and support needs were the covariables with the greatest influence in most domains, while gender was only significant for social inclusion (girls scored lower than boys).

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3. Bebensee DF, Can K, Muller M. {{Increased Mitochondrial Mass and Cytosolic Redox Imbalance in Hippocampal Astrocytes of a Mouse Model of Rett Syndrome: Subcellular Changes Revealed by Ratiometric Imaging of JC-1 and roGFP1 Fluorescence}}. {Oxid Med Cell Longev};2017;2017:3064016.

Rett syndrome (RTT) is a neurodevelopmental disorder with mutations in the MECP2 gene. Mostly girls are affected, and an apparently normal development is followed by cognitive impairment, motor dysfunction, epilepsy, and irregular breathing. Various indications suggest mitochondrial dysfunction. In Rett mice, brain ATP levels are reduced, mitochondria are leaking protons, and respiratory complexes are dysregulated. Furthermore, we found in MeCP2-deficient mouse (Mecp2-/y ) hippocampus an intensified mitochondrial metabolism and ROS generation. We now used emission ratiometric 2-photon imaging to assess mitochondrial morphology, mass, and membrane potential (DeltaPsim) in Mecp2-/y hippocampal astrocytes. Cultured astrocytes were labeled with the DeltaPsim marker JC-1, and semiautomated analyses yielded the number of mitochondria per cell, their morphology, and DeltaPsim. Mecp2-/y astrocytes contained more mitochondria than wild-type (WT) cells and were more oxidized. Mitochondrial size, DeltaPsim, and vulnerability to pharmacological challenge did not differ. The antioxidant Trolox opposed the oxidative burden and decreased the mitochondrial mass, thereby dampening the differences among WT and Mecp2-/y astrocytes; mitochondrial size and DeltaPsim were not markedly affected. In conclusion, mitochondrial alterations and redox imbalance in RTT also involve astrocytes. Mitochondria are more numerous in Mecp2-/y than in WT astrocytes. As this genotypic difference is abolished by Trolox, it seems linked to the oxidative stress in RTT.

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4. Duffield TC, Parsons TD, Landry A, Karam S, Otero T, Mastel S, Hall TA. {{Virtual environments as an assessment modality with pediatric ASD populations: a brief report}}. {Child Neuropsychol};2017 (Sep 13):1-8.

Virtual environments (VEs) have demonstrated promise as a neuropsychological assessment modality and may be well suited for the evaluation of children suspected of having an autism spectrum disorder (ASD). Some recent studies indicate their potential for enhancing reliability, ecologically validity, and sensitivity over traditional neuropsychological evaluation measures. Although research using VEs with ASD is increasing to the degree that several reviews of the literature have been conducted, the reviews to date lack rigor and are not necessarily specific to cognitive or neuropsychological assessment as many focus on intervention. The aim of this project was to comprehensively examine the current literature status of neuropsychological assessment in pediatric ASD using VEs by conducting a systematic review. Specifically, psychometric comparisons of VEs to traditional neuropsychological assessment measures that examined reliability, validity, and/or diagnostic accuracy for pediatric individuals, age 18 and below, with ASD were sought. The search using key words yielded 899 manuscripts, 894 of which were discarded for not meeting inclusion criteria. The remaining five met exclusion criteria. Therefore, the systematic review was modified to a brief report. These findings (or lack thereof) indicate a significant gap in the literature in that psychometric comparisons of these tools for the neuropsychological assessment of pediatric individuals with ASD are lacking. An important future direction of research will be extending the demonstrated incremental validity of VE neuropsychological assessment with other neurodevelopmental (e.g., attention-deficit/hyperactivity disorder) and adult populations to pediatric ASD populations.

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5. Hoxha E, Lippiello P, Scelfo B, Tempia F, Ghirardi M, Miniaci MC. {{Maturation, Refinement, and Serotonergic Modulation of Cerebellar Cortical Circuits in Normal Development and in Murine Models of Autism}}. {Neural Plast};2017;2017:6595740.

The formation of the complex cerebellar cortical circuits follows different phases, with initial synaptogenesis and subsequent processes of refinement guided by a variety of mechanisms. The regularity of the cellular and synaptic organization of the cerebellar cortex allowed detailed studies of the structural plasticity mechanisms underlying the formation of new synapses and retraction of redundant ones. For the attainment of the monoinnervation of the Purkinje cell by a single climbing fiber, several signals are involved, including electrical activity, contact signals, homosynaptic and heterosynaptic interaction, calcium transients, postsynaptic receptors, and transduction pathways. An important role in this developmental program is played by serotonergic projections that, acting on temporally and spatially regulated postsynaptic receptors, induce and modulate the phases of synaptic formation and maturation. In the adult cerebellar cortex, many developmental mechanisms persist but play different roles, such as supporting synaptic plasticity during learning and formation of cerebellar memory traces. A dysfunction at any stage of this process can lead to disorders of cerebellar origin, which include autism spectrum disorders but are not limited to motor deficits. Recent evidence in animal models links impairment of Purkinje cell function with autism-like symptoms including sociability deficits, stereotyped movements, and interspecific communication by vocalization.

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6. Lepper TL, Petursdottir AI. {{Effects of response-contingent stimulus pairing on vocalizations of nonverbal children with autism}}. {J Appl Behav Anal};2017 (Sep 13)

Research on stimulus-stimulus pairing to induce novel vocalizations in nonverbal children has typically employed response-independent pairing (RIP) procedures to condition speech sounds as reinforcers. The purpose of the present study was to evaluate the effects of a response-contingent pairing (RCP) procedure on the vocalizations of three nonverbal boys diagnosed with autism spectrum disorder. During RCP, adult-delivered sounds that were either paired with a preferred item (target sounds) or not (nontarget sounds) were presented contingent on a button-press response. In Experiment 1, RCP was compared with an RIP procedure, in which the timing of sound presentations was yoked to the preceding RCP session. RCP produced a greater effect on all participants’ target vocalizations than RIP. Experiment 2 demonstrated the effects of differential reinforcement of the vocalizations induced in Experiment 1. The results suggest that RCP may develop vocalizations more reliably than RIP procedures.

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7. Levin AR, Varcin KJ, O’Leary HM, Tager-Flusberg H, Nelson CA. {{EEG power at 3 months in infants at high familial risk for autism}}. {J Neurodev Disord};2017 (Sep 13);9(1):34.

BACKGROUND: Alterations in brain development during infancy may precede the behavioral manifestation of developmental disorders. Infants at increased risk for autism are also at increased risk for other developmental disorders, including, quite commonly, language disorders. Here we assess the extent to which electroencephalographic (EEG) differences in infants at high versus low familial risk for autism are present by 3 months of age, and elucidate the functional significance of EEG power at 3 months in predicting later development. METHODS: EEG data were acquired at 3 months in infant siblings of children with autism (high risk; n = 29) and infant siblings of typically developing children (low risk; n = 19) as part of a prospective, longitudinal investigation. Development across multiple domains was assessed at 6, 9, 12, 18, 24, and 36 months. Diagnosis of autism was determined at 18-36 months. We assessed relationships between 3-month-olds’ frontal EEG power and autism risk, autism outcome, language development, and development in other domains. RESULTS: Infants at high familial risk for autism had reduced frontal power at 3 months compared to infants at low familial risk for autism, across several frequency bands. Reduced frontal high-alpha power at 3 months was robustly associated with poorer expressive language at 12 months. CONCLUSIONS: Reduced frontal power at 3 months may indicate increased risk for reduced expressive language skills at 12 months. This finding aligns with prior studies suggesting reduced power is a marker for atypical brain function, and infants at familial risk for autism are also at increased risk for altered developmental functioning in non-autism-specific domains.

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8. Lyall K, Croen LA, Weiss LA, Kharrazi M, Traglia M, Delorenze GN, Windham GC. {{Prenatal Serum Concentrations of Brominated Flame Retardants and Autism Spectrum Disorder and Intellectual Disability in the Early Markers of Autism Study: A Population-Based Case-Control Study in California}}. {Environ Health Perspect};2017 (Aug 30);125(8):087023.

BACKGROUND: Prior studies suggest neurodevelopmental impacts of polybrominated diphenyl ethers (PBDEs), but few have examined diagnosed developmental disorders. OBJECTIVES: Our aim was to determine whether prenatal exposure to brominated flame retardants (BFRs) is associated with autism spectrum disorder (ASD) or intellectual disability without autism (ID). METHODS: We conducted a population-based case-control study including children with ASD (n=545) and ID (n=181) identified from the California Department of Developmental Services and general population (GP) controls (n=418) from state birth certificates. ASD cases were matched to controls by sex, birth month, and birth year. Concentrations of 10 BFRs were measured in maternal second trimester serum samples stored from routine screening. Logistic regression was used to calculate crude and adjusted odds ratios (AOR) for associations with ASD, and separately for ID, compared with GP controls, by quartiles of analyte concentrations in primary analyses. RESULTS: Geometric mean concentrations of five of the six congeners with >/=55% of samples above the limit of detection were lower in mothers of children with ASD or ID than in controls. In adjusted analyses, inverse associations with several congeners were found for ASD relative to GP (e.g., quartile 4 vs. 1, BDE-153: AOR=0.56, 95% CI: 0.38, 0.84). When stratified by child sex (including 99 females with ASD, 77 with ID, and 73 with GP), estimates were consistent with overall analyses in boys, but in the opposite direction among girls, particularly for BDE-28 and -47 (AOR=2.58, 95% CI: 0.86, 7.79 and AOR=2.64, 95% CI: 0.97, 7.19, respectively). Similar patterns overall and by sex were observed for ID. CONCLUSIONS: Contrary to expectation, higher PBDE concentrations were associated with decreased odds of ASD and ID, though not in girls. These findings require confirmation but suggest potential sexual dimorphism in associations with prenatal exposure to BFRs. https://doi.org/10.1289/EHP1079.

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9. Najdowski AC, Bergstrom R, Tarbox J, Clair MS. {{Teaching children with autism to respond to disguised mands}}. {J Appl Behav Anal};2017 (Sep 13)

Children with autism spectrum disorder (ASD) often have difficulty inferring the private events of others, including private verbal behavior (e.g., thoughts), private emotional responses, and private establishing operations, often referred to as « perspective taking » by the general psychology community. Children with ASD also have difficulty responding to disguised mands. Skinner’s description of the « disguised mand » is verbal behavior wherein the speaker’s mand directly describes neither its reinforcer nor the corresponding establishing operations. Appropriate responding to disguised mands is required for successful social interaction, making it a social skill worth teaching to children with ASD. We used a nonconcurrent multiple baseline across participants design to investigate the effects of a multiple exemplar training package consisting of rules, role play, and feedback for teaching three boys with ASD to respond to disguised mands. The intervention was effective and generalization to novel disguised mands and people was observed.

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10. Pillai AS, McAuliffe D, Lakshmanan BM, Mostofsky SH, Crone NE, Ewen JB. {{Altered task-related modulation of long-range connectivity in children with autism}}. {Autism Res};2017 (Sep 12)

Functional connectivity differences between children with autism spectrum disorder (ASD) and typically developing children have been described in multiple datasets. However, few studies examine the task-related changes in connectivity in disorder-relevant behavioral paradigms. In this paper, we examined the task-related changes in functional connectivity using EEG and a movement-based paradigm that has behavioral relevance to ASD. Resting-state studies motivated our hypothesis that children with ASD would show a decreased magnitude of functional connectivity during the performance of a motor-control task. Contrary to our initial hypothesis, however, we observed that task-related modulation of functional connectivity in children with ASD was in the direction opposite to that of TDs. The task-related connectivity changes were correlated with clinical symptom scores. Our results suggest that children with ASD may have differences in cortical segregation/integration during the performance of a task, and that part of the differences in connectivity modulation may serve as a compensatory mechanism. Autism Res 2017. (c) 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Decreased connectivity between brain regions is thought to cause the symptoms of autism. Because most of our knowledge comes from data in which children are at rest, we do not know how connectivity changes directly lead to autistic behaviors, such as impaired gestures. When typically developing children produced complex movements, connectivity decreased between brain regions. In children with autism, connectivity increased. It may be that behavior-related changes in brain connectivity are more important than absolute differences in connectivity in autism.

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11. Prokup JA, Andridge R, Havercamp SM, Yang EA. {{Health Care Disparities of Ohioans With Developmental Disabilities Across the Lifespan}}. {Ann Fam Med};2017 (Sep);15(5):471-474.

We explored health care differences across the lifespan comparing people with developmental disabilities to people without developmental disabilities. Health care disparities are inequities occurring during the provision of and in access to health care that are experienced by socially disadvantaged populations. We discovered significant disparities between persons with and without developmental disabilities in health status, quality, utilization, access, and unmet health care needs. Our results highlight the need to educate health care clinicians on the care of patients with developmental disabilities of all ages.

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12. Shephard E, Tye C, Ashwood KL, Azadi B, Asherson P, Bolton PF, McLoughlin G. {{Resting-State Neurophysiological Activity Patterns in Young People with ASD, ADHD, and ASD + ADHD}}. {J Autism Dev Disord};2017 (Sep 13)

Altered power of resting-state neurophysiological activity has been associated with autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), which commonly co-occur. We compared resting-state neurophysiological power in children with ASD, ADHD, co-occurring ASD + ADHD, and typically developing controls. Children with ASD (ASD/ASD + ADHD) showed reduced theta and alpha power compared to children without ASD (controls/ADHD). Children with ADHD (ADHD/ASD + ADHD) displayed decreased delta power compared to children without ADHD (ASD/controls). Children with ASD + ADHD largely presented as an additive co-occurrence with deficits of both disorders, although reduced theta compared to ADHD-only and reduced delta compared to controls suggested some unique markers. Identifying specific neurophysiological profiles in ASD and ADHD may assist in characterising more homogeneous subgroups to inform treatment approaches and aetiological investigations.

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13. Stelten BML, Bonnot O, Huidekoper HH, van Spronsen FJ, van Hasselt PM, Kluijtmans LAJ, Wevers RA, Verrips A. {{Autism spectrum disorder: an early and frequent feature in cerebrotendinous xanthomatosis}}. {J Inherit Metab Dis};2017 (Sep 11)

BACKGROUND: Cerebrotendinous xanthomatosis (CTX) is an autosomal recessively inherited inborn error of metabolism (IEM) due to mutations in the CYP27A1 gene. The clinical picture ranges from being nearly asymptomatic in early childhood, up to severe disability at adult age. Infantile-onset diarrhea and juvenile-onset cataract are the earliest symptoms in childhood. In the current study, we evaluated the presence of autism spectrum disorder (ASD) in a large cohort of CTX patients. METHODS: We performed a retrospective patient file study in 77 genetically confirmed Dutch CTX patients to determine the frequency of ASD. In addition, we compared plasma cholestanol levels in CTX patients with and without a diagnosis of ASD and tried to establish a relation between CYP27A1 genotype and ASD. RESULTS: In our CTX cohort, 10 patients (13%; nine pediatric and one adult) with ASD were identified. At the time of diagnosis of ASD, most patients only exhibited symptoms of diarrhea and/or intellectual disability without signs of cataract or neurological symptoms. No correlation was found between the presence of ASD and the level of cholestanol or CYP27A1 genotype. The behavioral problems stabilized or improved after treatment initiation with chenodeoxycholic acid (CDCA) in all pediatric patients. CONCLUSIONS: We conclude that ASD is an early and probably underestimated frequent feature in CTX. Metabolic screening for CTX should be performed in patients with ASD when accompanied by diarrhea, intellectual disability, juvenile cataract, and/or neurological involvement. Early recognition allows for earlier initiation of specific treatment and will improve clinical outcome. Our results add CTX to the list of treatable IEMs associated with ASD.

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14. Stewart ME, Petrou AM, Ota M. {{Categorical Speech Perception in Adults with Autism Spectrum Conditions}}. {J Autism Dev Disord};2017 (Sep 11)

This study tested whether individuals with autism spectrum conditions (n = 23) show enhanced discrimination of acoustic differences that signal a linguistic contrast (i.e., /g/ versus /k/ as in ‘goat’ and ‘coat’) and whether they process such differences in a less categorical fashion as compared with 23 IQ-matched typically developed adults. Tasks administered were nonverbal IQ, verbal IQ, 5 language measures, a speech perception task, and the ADOS. The speech perception task measured the discrimination of paired exemplars along the /g/-/k/ continuum. Individuals with autism spectrum conditions did not show enhanced discrimination of speech perception. Categorical speech perception was correlated with verbal ability of reading, lexical decision, and verbal IQ in individuals with autism spectrum conditions.

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15. Weiss JA, Isaacs B, Diepstra H, Wilton AS, Brown HK, McGarry C, Lunsky Y. {{Health Concerns and Health Service Utilization in a Population Cohort of Young Adults with Autism Spectrum Disorder}}. {J Autism Dev Disord};2017 (Sep 13)

Individuals with autism spectrum disorder (ASD) have many health needs that place demands on the health service sector. This study used administrative data to compare health profiles in young adults 18-24 years of age with ASD to peers with and without other developmental disability. Young adults with ASD were more likely to have almost all the examined clinical health issues and health service use indicators compared to peers without developmental disability. They were more likely to have at least one psychiatric diagnosis, and visit the family physician, pediatrician, psychiatrist, and emergency department for psychiatric reasons, compared to peers with other developmental disability. Planning for the mental health care of transition age adults with ASD is an important priority for health policy.

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16. Xie S, Heuvelman H, Magnusson C, Rai D, Lyall K, Newschaffer CJ, Dalman C, Lee BK, Abel K. {{Prevalence of Autism Spectrum Disorders with and without Intellectual Disability by Gestational Age at Birth in the Stockholm Youth Cohort: a Register Linkage Study}}. {Paediatr Perinat Epidemiol};2017 (Sep 12)

BACKGROUND: Preterm birth has been linked to increased risk of autism spectrum disorders (ASD), but how this risk changes with gestational age at birth has not been well characterised, especially with regard to co-occurring intellectual disability (ID). METHODS: Register-based cohort study of singleton births in 1984-2007 in Stockholm County, Sweden (N total: 480 728; n ASD: 10 025). We assessed overall and sex-specific, gestational week-specific prevalence estimates and risk ratios of ASD with and without ID. RESULTS: Preterm and postterm births were associated with elevated risk of ASD, and the relationship between gestational age at birth and ASD with and without ID differed in males and females. Risk of ASD without ID was higher in preterm births among both sexes and decreased continuously with increasing length of gestation. Risk of ASD with ID was higher in both preterm and postterm births among both sexes, with postterm birth in females being more highly associated with ASD with ID than that in males. CONCLUSIONS: The relationship between gestational age at birth and ASD differs by the presence/absence of co-occurring ID and fetal sex. Both preterm and postterm birth are associated with increased risk of ASD. Risk of ASD is not constant within conventionally defined gestational age at birth periods. Further research on mechanism underlying these associations is needed.

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