1. Chadman KK, Guariglia SR, Yoo JH. {{New directions in the treatment of autism spectrum disorders from animal model research}}. {Expert Opin Drug Discov};2012 (Apr 12)
Introduction: Currently, there is not an effective pharmacotherapy for the core symptoms of the autism spectrum disorders (ASD), which include aberrant social behavior, delayed communication and repetitive behavior and/or restricted interests. There are several drugs that treat the symptoms associated with autism including irritability, aggressiveness and hyperactivity. Current drug research is based on the ongoing genetic, animal model and neuropathologic research. Two areas in particular, the glutamate and oxytocin systems, provide exciting new avenues for drug discovery. Areas covered: This review examines what approaches have been used for the drugs that are currently being used to treat people with ASD. For the most part, drugs that treat other neuropsychiatric disorders have been examined to treat the people with ASD, unfortunately with little effect on the core symptoms. Expert Opinion: Until recently, there was not a plethora of knowledge about the neurobiological substrates of social behavior, pragmatic language usage and repetitive and/or restricted behaviors. Therefore, drug discovery has used the tools available for other neuropsychiatric disorders. Now that more biological information is available, there are many avenues for research for drug targets for ASD.
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2. Djukic A, Valicenti McDermott M. {{Social preferences in rett syndrome}}. {Pediatr Neurol};2012 (Apr);46(4):240-242.
Children with Rett syndrome manifest profound impairments in their ability to speak and use their hands, and exhibit a very limited repertoire of abilities to express themselves, to be neuropsychologically tested, and consequently to be understood. This study examined nonverbal cognitive abilities and visual preferences by analyzing the pattern of visual fixation in 49 girls with Rett syndrome, compared with a group of typical control subjects. The girls with Rett syndrome demonstrated a tendency toward socially weighted stimuli/social preferences. They looked at people, and into people’s eyes. Eye tracking represents a feasible method to assess cognition, and provide insights into the burden of isolation of these children and the mismatch between their social preferences and incompetence, caused by movement disorder and apraxia.
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3. Dufault R, Lukiw WJ, Crider R, Schnoll R, Wallinga D, Deth R. {{A macroepigenetic approach to identify factors responsible for the autism epidemic in the United States}}. {Clin Epigenetics};2012 (Apr 10);4(1):6.
ABSTRACT: The number of children ages 6 to 21 in the United States receiving special education services under the autism disability category increased 91 % between 2005 to 2010 while the number of children receiving special education services overall declined by 5 %. The demand for special education services continues to rise in disability categories associated with pervasive developmental disorders. Neurodevelopment can be adversely impacted when gene expression is altered by dietary transcription factors, such as zinc insufficiency or deficiency, or by exposure to toxic substances found in our environment, such as mercury or organophosphate pesticides. Gene expression patterns differ geographically between populations and within populations. Gene variants of paraoxonase-1 are associated with autism in North America, but not in Italy, indicating regional specificity in gene-environment interactions. In the current review, we utilize a novel macroepigenetic approach to compare variations in diet and toxic substance exposure between these two geographical populations to determine the likely factors responsible for the autism epidemic in the United States.
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4. Keehn B, Shih P, Brenner LA, Townsend J, Muller RA. {{Functional connectivity for an « Island of sparing » in autism spectrum disorder: An fMRI study of visual search}}. {Hum Brain Mapp};2012 (Apr 12)
Although autism is usually characterized with respect to sociocommunicative impairments, visual search is known as a domain of relative performance strength in this disorder. This study used functional MRI during visual search in children with autism spectrum disorder (n = 19; mean age = 13;10) and matched typically developing children (n = 19; mean age = 14;0). We selected regions of interest within two attentional networks known to play a crucial role in visual search processes, such as goal-directed selective attention, filtering of irrelevant distractors, and detection of behaviorally-relevant information, and examined activation and connectivity within and between these attentional networks. Additionally, based on prior research suggesting links between visual search abilities and autism symptomatology, we tested for correlations between sociocommunicative impairments and behavioral and neural indices of search. Contrary to many previous functional connectivity magnetic resonance imaging studies of autism that reported functional underconnectivity for task domains of weakness, we found atypically increased connectivity within and between attentional networks in autism. Additionally, we found increased functional connectivity for occipital regions, both locally and for long-distance connections with frontal regions. Both behavioral and neural indices of search were correlated with sociocommunicative impairment in children with autism. This association suggests that strengths in nonsocial visuospatial processing may be related to the development of core autistic sociocommunicative impairments. Hum Brain Mapp , 2012. (c) 2012 Wiley Periodicals, Inc.
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5. Kerin T, Ramanathan A, Rivas K, Grepo N, Coetzee GA, Campbell DB. {{A noncoding RNA antisense to moesin at 5p14.1 in autism}}. {Sci Transl Med};2012 (Apr 4);4(128):128ra140.
People with autism spectrum disorder (ASD) are characterized by deficits in social interaction, language, and behavioral flexibility. Rare mutations and copy number variations have been identified in individuals with ASD, but in most patients, the causal variants remain unknown. A genome-wide association study (GWAS), designed to identify genes and pathways that contribute to ASD, indicated a genome-wide significant association of ASD with the single-nucleotide polymorphism (SNP) rs4307059 (P = 10(-10)), which is located in a gene-poor region of chromosome 5p14.1. We describe here a 3.9-kb noncoding RNA that is transcribed from the region of the chromosome 5p14.1 ASD GWAS association SNP. The noncoding RNA was encoded by the opposite (antisense) strand of moesin pseudogene 1 (MSNP1), and we therefore designated it as MSNP1AS (moesin pseudogene 1, antisense). Chromosome 5p14.1 MSNP1AS was 94% identical and antisense to the X chromosome transcript of MSN, which encodes a protein (moesin) that regulates neuronal architecture. Individuals who carry the ASD-associated rs4307059 T allele showed increased expression of MSNP1AS. The MSNP1AS noncoding RNA bound to MSN, was highly overexpressed (12.7-fold) in postmortem cerebral cortex of individuals with ASD, and could regulate levels of moesin protein in human cell lines. These data reveal a biologically functional element that may contribute to ASD risk.
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6. Krakowiak P, Walker CK, Bremer AA, Baker AS, Ozonoff S, Hansen RL, Hertz-Picciotto I. {{Maternal Metabolic Conditions and Risk for Autism and Other Neurodevelopmental Disorders}}. {Pediatrics};2012 (Apr 9)
OBJECTIVE:We examined whether metabolic conditions (MCs) during pregnancy (diabetes, hypertension, and obesity) are associated with autism spectrum disorder (ASD), developmental delays (DD), or impairments in specific domains of development in the offspring.METHODS:Children aged 2 to 5 years (517 ASD, 172 DD, and 315 controls) were enrolled in the CHARGE (Childhood Autism Risks from Genetics and the Environment) study, a population-based, case-control investigation between January 2003 and June 2010. Eligible children were born in California, had parents who spoke English or Spanish, and were living with a biological parent in selected regions of California. Children’s diagnoses were confirmed by using standardized assessments. Information regarding maternal conditions was ascertained from medical records or structured interview with the mother.RESULTS:All MCs were more prevalent among case mothers compared with controls. Collectively, these conditions were associated with a higher likelihood of ASD and DD relative to controls (odds ratio: 1.61 [95% confidence interval: 1.10-2.37; odds ratio: 2.35 [95% confidence interval: 1.43-3.88], respectively). Among ASD cases, children of women with diabetes had Mullen Scales of Early Learning (MSEL) expressive language scores 0.4 SD lower than children of mothers without MCs (P < .01). Among children without ASD, those exposed to any MC scored lower on all MSEL and Vineland Adaptive Behavior Scales (VABS) subscales and composites by at least 0.4 SD (P < .01 for each subscale/composite).CONCLUSIONS:Maternal MCs may be broadly associated with neurodevelopmental problems in children. With obesity rising steadily, these results appear to raise serious public health concerns.
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7. Lacaria M, Spencer C, Gu W, Paylor R, Lupski JR. {{Enriched Rearing Improves Behavioral Responses of an Animal Model for CNV-based Autistic-like Traits}}. {Hum Mol Genet};2012 (Apr 5)
Potocki-Lupski syndrome (PTLS; MIM #610883), characterized by neurobehavioral abnormalities, intellectual disability (ID), and congenital anomalies, is caused by a 3.7 Mb duplication in 17p11.2. Neurobehavioral studies determined that ~70-90% of PTLS subjects tested positive for autism or ASD. We previously chromosomally-engineered a mouse model for PTLS (Dp(11)17/+) with duplication of a 2 Mb genomic interval syntenic to the PTLS region and identified consistent behavioral abnormalities in this mouse model. We now report extensive phenotyping with behavioral assays established to evaluate core and associated autistic-like traits, including tests for social abnormalities, ultrasonic vocalizations, perseverative and stereotypic behaviors, anxiety, learning & memory deficits, and motor defects. Alterations were identified in both core and associated ASD-like traits. Rearing this animal model in an enriched environment mitigated some, and even rescued selected, neurobehavioral abnormalities suggesting a role for gene-environment interactions in the determination of CNV-mediated autism severity.
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8. Moss J, Howlin P, Magiati I, Oliver C. {{Characteristics of autism spectrum disorder in Cornelia de Lange syndrome}}. {J Child Psychol Psychiatry};2012 (Apr 10)
Background: The prevalence of autism spectrum disorder (ASD) symptomatology is comparatively high in Cornelia de Lange syndrome (CdLS). However, the profile and developmental trajectories of these ASD characteristics are potentially different to those observed in individuals with idiopathic ASD. In this study we examine the ASD profile in CdLS in comparison to a matched group of individuals with ASD. Method: The Autism Diagnostic Observation Schedule (ADOS) was administered to 20 individuals with CdLS (mean age = 11.34; range = 6-13 years) and 20 individuals with idiopathic ASD (mean age = 10.42; range = 8-11 years). Participants were matched according to adaptive behaviour and receptive language skills. Results: Sixty-five percent (N = 13) of individuals with CdLS met the cut-off score for autism on the total ADOS score. Further analysis at domain and item level indicated that individuals with CdLS showed significantly less repetitive behaviour, (specifically sensory interests); more eye contact, more gestures and less stereotyped speech than the ASD group. The CdLS group also showed higher levels of anxiety. Conclusions: The comparison between CdLS and idiopathic ASD indicates subtle group differences in the profile of ASD symptomatology that are not accounted for by degree of intellectual disability or receptive language skills. These differences may not be evident when relying solely upon clinical and domain level scores, but may be distinguishing features of the ASD presentations in the two disorders. The findings have implications for the conceptualisation and assessment of ASD in individuals with genetic syndromes.
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9. Nagae LM, Zarnow DM, Blaskey L, Dell J, Khan SY, Qasmieh S, Levy SE, Roberts TP. {{Elevated Mean Diffusivity in the Left Hemisphere Superior Longitudinal Fasciculus in Autism Spectrum Disorders Increases with More Profound Language Impairment}}. {AJNR Am J Neuroradiol};2012 (Apr 5)
BACKGROUND AND PURPOSE:Language impairments are observed in a subset of individuals with ASD. To examine microstructural brain white matter features associated with language ability in ASD, we measured the DTI parameters of language-related white matter tracts (SLF) as well as non-language-related white matter tracts (CST) in children with ASD/+LI and ASD/-LI) and in TD.MATERIALS AND METHODS:Eighteen children with ASD/-LI (age range, 6.7-17.5 years), 17 with ASD/+LI (age range, 6.8-14.8 years), and 25 TD (age range, 6.5-18 years) were evaluated with DTI and tractography. Primary DTI parameters considered for analysis were MD and FA.RESULTS:There was a main effect of diagnostic group on age-corrected MD (P < .05) with ASD/+LI significantly elevated compared with TD. This was most pronounced for left hemisphere SLF fiber tracts and for the temporal portion of the SLF. There was significant negative correlation between left hemisphere SLF MD values and the clinical assessment of language ability. There was no main effect of diagnostic group or diagnostic group X hemisphere interaction for FA. Although there was a main effect of diagnostic group on values of MD in the CST, this did not survive hemispheric subanalysis.CONCLUSIONS:Abnormal DTI parameters (specifically significantly elevated MD values in ASD) of the SLF appear to be associated with language impairment in ASD. These elevations are particularly pronounced in the left cerebral hemisphere, in the temporal portion of the SLF, and in children with clinical language impairment.
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10. Sasson NJ, Elison JT. {{Eye tracking young children with autism}}. {J Vis Exp};2012 (61)
The rise of accessible commercial eye-tracking systems has fueled a rapid increase in their use in psychological and psychiatric research. By providing a direct, detailed and objective measure of gaze behavior, eye-tracking has become a valuable tool for examining abnormal perceptual strategies in clinical populations and has been used to identify disorder-specific characteristics(1), promote early identification(2), and inform treatment(3). In particular, investigators of autism spectrum disorders (ASD) have benefited from integrating eye-tracking into their research paradigms(4-7). Eye-tracking has largely been used in these studies to reveal mechanisms underlying impaired task performance(8) and abnormal brain functioning(9), particularly during the processing of social information(1,10-11). While older children and adults with ASD comprise the preponderance of research in this area, eye-tracking may be especially useful for studying young children with the disorder as it offers a non-invasive tool for assessing and quantifying early-emerging developmental abnormalities(2,12-13). Implementing eye-tracking with young children with ASD, however, is associated with a number of unique challenges, including issues with compliant behavior resulting from specific task demands and disorder-related psychosocial considerations. In this protocol, we detail methodological considerations for optimizing research design, data acquisition and psychometric analysis while eye-tracking young children with ASD. The provided recommendations are also designed to be more broadly applicable for eye-tracking children with other developmental disabilities. By offering guidelines for best practices in these areas based upon lessons derived from our own work, we hope to help other investigators make sound research design and analysis choices while avoiding common pitfalls that can compromise data acquisition while eye-tracking young children with ASD or other developmental difficulties.
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11. Wallace GL, Shaw P, Lee NR, Clasen LS, Raznahan A, Lenroot RK, Martin A, Giedd JN. {{Distinct Cortical Correlates of Autistic versus Antisocial Traits in a Longitudinal Sample of Typically Developing Youth}}. {J Neurosci};2012 (Apr 4);32(14):4856-4860.
In humans, behaviors associated with autism and antisociality, disorders characterized by distinct social impairments, can be viewed as quantitative traits that range from frank impairment to normal variation, as found in the general population. Neuroimaging investigations of autism and antisociality demonstrate diagnostically specific aberrant cortical brain structure. However, little is known about structural brain correlates of social behavior in nonclinical populations. Therefore, we sought to determine whether autistic and antisocial traits exhibit dissociable cortical correlates and whether these associations are stable across development among typically developing youth. Three hundred twenty-three typically developing youth (age at first scan: mean = 10.63, SD = 3.71 years) underwent anatomic magnetic resonance imaging (1-6 scans each; total = 742 scans), and provided ratings of autistic and antisocial traits. Higher autistic trait ratings were associated with thinner cortex most prominently in right superior temporal sulcus while higher antisocial trait ratings were associated with thinner cortex in primarily bilateral anterior prefrontal cortices. There was no interaction with age, indicating that these brain-behavior associations were stable across development. Using assessments of both subclinical autistic and subclinical antisocial traits within a large longitudinal sample of typically developing youth, we demonstrate dissociable neuroanatomic correlations that parallel those found in the frank clinical disorders of autism (e.g., superior temporal cortex) and antisociality (e.g., anterior prefrontal cortex). Moreover, these correlations appear to be established in early childhood and remain fixed into early adulthood. These results support the dimensional view of psychopathology and provide neural signatures that can serve as informative endophenotypes for future genetic studies.
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12. Wang JY, Hessl DH, Hagerman RJ, Tassone F, Rivera SM. {{Age-dependent structural connectivity effects in fragile x premutation}}. {Arch Neurol};2012 (Apr);69(4):482-489.
OBJECTIVE: To examine the effects of premutation alleles on major brain fiber tracts in males. DESIGN: Cross-sectional study performed in 2007-2009. SETTING: Institutional practice. Patients Fifteen younger (18-45 years old) carriers, 11 older (>45 years old) unaffected carriers, and 15 older carriers with fragile X-associated tremor/ataxia syndrome, together with 19 younger and 15 older controls matched by age and educational level. MAIN OUTCOME MEASURES: Diffusion tensor imaging was performed on all study participants. Eleven fiber tracts important for motor, social, emotional, and cognitive functions were reconstructed and quantified. Complementary tract-based spatial statistical analyses were performed in core white matter. RESULTS: In the younger carriers, premutation status was associated with a greater age-related connectivity decline in the extreme capsule. Among older carriers, unaffected individuals did not display structural alterations, whereas the affected carriers showed connectivity loss in 5 fiber tracts and exhibited greater age-related connectivity decline in all 11 tracts compared with the controls. In addition, 9 fiber tracts showed significantly higher variability relative to the controls, and symptom severity explained the variability in 6 measurements from the superior cerebellar peduncle, corpus callosum, and cingulum. CONCLUSIONS: The findings revealed widespread alterations in structural connectivity associated with fragile X-associated tremor/ataxia syndrome and preserved or subtle changes in structural connectivity in unaffected carriers. Diffusion tensor imaging is sensitive to pathologic changes in the white matter associated with this neurodegenerative disorder. Wang et al examine the effects of premutation alleles on major brain fiber tracts in males, who are at risk of developing fragile X-associated tremor/ataxia syndrome and may manifest subtle cognitive, social, and emotional disturbances before clinical involvement.
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13. Williams PG, Woods C, Stevenson M, Davis DW, Radmacher P, Smith M. {{Psychotropic Medication Use in Children With Autism in the Kentucky Medicaid Population}}. {Clin Pediatr (Phila)};2012 (Apr 5)
This study reviewed Kentucky Medicaid claims data for children with autism spectrum disorders to determine psychotropic drug (PTD) use in this population. Children with autism spectrum disorders (ICD-9 code 299.XX) in 3 different age-groups from 2005 to 2008 were identified; PTD use was defined as at least 1 prescription per year. PTD use in all age ranges was higher than in previously reported studies. High PTD use in children between 1 and 5 years is particularly of concern and may reflect perceived inadequacies of comprehensive educational/behavioral services for these children.
