1. Adamo N, Huo L, Adelsberg S, Petkova E, Castellanos FX, Di Martino A. {{Response time intra-subject variability: commonalities between children with autism spectrum disorders and children with ADHD}}. {Eur Child Adolesc Psychiatry};2013 (May 29)
Despite the common co-occurrence of symptoms of attention deficit hyperactivity disorder (ADHD) in individuals with autism spectrum disorders (ASD), the underlying mechanisms are under-explored. A potential candidate for investigation is response time intra-subject variability (RT-ISV), a hypothesized marker of attentional lapses. Direct comparisons of RT-ISV in ASD versus ADHD are limited and contradictory. We aimed to examine whether distinct fluctuations in RT-ISV characterize children with ASD and with ADHD relative to typically developing children (TDC). We applied both a priori-based and data-driven strategies to RT performance of 46 children with ASD, 46 with ADHD, and 36 TDC (aged 7-11.9 years). Specifically, we contrasted groups relative to the amplitude of four preselected frequency bands as well as to 400 frequency bins from 0.006 to 0.345 Hz. In secondary analyses, we divided the ASD group into children with and without substantial ADHD symptoms (ASD+ and ASD-, respectively). Regardless of the strategy employed, RT-ISV fluctuations at frequencies between 0.20 and 0.345 Hz distinguished children with ADHD, but not children with ASD, from TDC. Children with ASD+ and those with ADHD shared elevated amplitudes of RT-ISV fluctuations in frequencies between 0.18 and 0.345 Hz relative to TDC. In contrast, the ASD- subgroup did not differ from TDC in RT-ISV frequency fluctuations. RT-ISV fluctuations in frequencies 0.18-0.345 Hz (i.e., periods between 3 and 5 s) are associated with ADHD symptoms regardless of categorical diagnosis and may represent a biomarker. These results suggest that children with ADHD and those with ASD+ share common underlying pathophysiological mechanisms of RT-ISV.
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2. Andersen PN, Hovik KT, Skogli EW, Egeland J, Oie M. {{Symptoms of ADHD in children with high-functioning autism are related to impaired verbal working memory and verbal delayed recall}}. {PLoS One};2013;8(5):e64842.
Symptoms similar to those found in Attention-Deficit/Hyperactivity Disorder (ADHD) often occur in children with Autism Spectrum Disorders (ASD). The objective of the current study was to compare verbal working memory, acquisition and delayed recall in children with High-Functioning Autism (HFA) to children with ADHD and typically developing children (TDC). Thirty-eight children with HFA, 79 with ADHD and 50 TDC (age 8-17) were assessed with a letter/number sequencing task and a verbal list-learning task. To investigate the possible influence of attention problems in children with HFA, we divided the HFA group into children with (HFA+) or without (HFA-) « attention problems » according to the Child Behaviour Checklist 6-18. The children with HFA+ displayed significant impairment compared to TDC on all three neurocognitive measures, while the children with HFA- were significantly impaired compared to TDC only on the working memory and acquisition measures. In addition, the HFA+ group scored significantly below the HFA- group and the ADHD group on the verbal working memory and delayed recall measures. The results support the proposition that children with HFA+, HFA-, and ADHD differ not only on a clinical level but also on a neurocognitive level which may have implications for treatment.
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3. Black K, McCarus C, Collins ML, Jensen A. {{Ocular manifestations of autism in ophthalmology}}. {Strabismus};2013 (Jun);21(2):98-102.
Abstract Purpose: To highlight the ocular manifestations of autism spectrum disorders in a retrospective chart review of the Greater Baltimore Medical Center (GBMC) among children in the pediatric ophthalmology practice setting. Design: Retrospective chart review. Forty-four patients diagnosed with an autism spectrum disorder (ASD) between January 2007 and October 2011 were examined by an orthoptist, orthoptic student, and a pediatric ophthalmologist. Results: Fifty-two percent of patients with ASD at GBMC were found to have an ocular abnormality, with 41% having strabismus, 27% with significant refractive error, 7% with anisometropia, and 11% with amblyopia. Conclusion: The prevalence of strabismus, amblyopia, and anisometropia were found to be higher among patients with ASD seen at the GBMC pediatric ophthalmology practice than in the general population.
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4. Grove R, Baillie A, Allison C, Baron-Cohen S, Hoekstra RA. {{Empathizing, systemizing, and autistic traits: Latent structure in individuals with autism, their parents, and general population controls}}. {J Abnorm Psychol};2013 (May);122(2):600-609.
The search for genes involved in autism spectrum conditions (ASC) may have been hindered by the assumption that the different symptoms that define the condition can be attributed to the same causal mechanism. Instead the social and nonsocial aspects of ASC may have distinct causes at genetic, cognitive, and neural levels. It has been posited that the core features of ASC can be explained by a deficit in empathizing alongside intact or superior systemizing; the drive to understand and derive rules about a system. First-degree relatives also show some mild manifestations that parallel the defining features of ASC, termed the broader autism phenotype. Factor analyses were conducted to assess whether the latent structure of empathizing, systemizing, and autistic traits differs across samples with a high (individuals on the spectrum), medium (first-degree relatives) or low (general population controls) genetic vulnerability to autism. Results highlighted a two-factor model, confirming an empathizing and a systemizing factor. The relationship between these two factors was significantly stronger in first-degree relatives and the autism group compared with controls. The same model provided the best fit among the three groups, suggesting a similar latent structure irrespective of genetic vulnerability. However, results also suggest that although these traits are relatively independent in the general population, they are substantially correlated in individuals with ASC and their parents. This implies that there is substantially more overlap between systemizing and empathizing among individuals with an increased genetic liability to autism. This has potential implications for the genetic, environmental, and cognitive explanations of autism spectrum conditions. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
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5. Jokiranta E, Brown AS, Heinimaa M, Cheslack-Postava K, Suominen A, Sourander A. {{Parental psychiatric disorders and autism spectrum disorders}}. {Psychiatry Res};2013 (May 30);207(3):203-211.
The present population-based, case-control study examines associations between specific parental psychiatric disorders and autism spectrum disorders (ASD) including childhood autism, Asperger’s syndrome and pervasive developmental disorder (PDD-NOS). The cohort includes 4713 children born between 1987 and 2005 with diagnoses of childhood autism, Asperger’s syndrome or PDD-NOS. Cases were ascertained from the Finnish Hospital Discharge Register, and each was matched to four controls by gender, date of birth, place of birth, and residence in Finland. Controls were selected from the Finnish Medical Birth Register. Parents were identified through the Finnish Medical Birth Register and Finnish Central Population Register. Parental psychiatric diagnoses from inpatient care were collected from the Finnish Hospital Discharge Register. Conditional logistic regression models were used to assess whether parents’ psychiatric disorders predicted ASD after controlling for parents’ age, smoking during pregnancy and weight for gestational age. In summary, parental schizophrenia spectrum disorders and affective disorders were associated with the risk of ASD regardless of the subgroup. PDD-NOS was associated with all parental psychiatric disorders investigated. Further studies are needed to replicate these findings. These results may facilitate the investigation of shared genetic and familial factors between ASD and other psychiatric disorders.
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6. Rogers TD, McKimm E, Dickson PE, Goldowitz D, Blaha CD, Mittleman G. {{Is autism a disease of the cerebellum? An integration of clinical and pre-clinical research}}. {Front Syst Neurosci};2013;7:15.
Autism spectrum disorders are a group of neurodevelopmental disorders characterized by deficits in social skills and communication, stereotyped and repetitive behavior, and a range of deficits in cognitive function. While the etiology of autism is unknown, current research indicates that abnormalities of the cerebellum, now believed to be involved in cognitive function and the prefrontal cortex (PFC), are associated with autism. The current paper proposes that impaired cerebello-cortical circuitry could, at least in part, underlie autistic symptoms. The use of animal models that allow for manipulation of genetic and environmental influences are an effective means of elucidating both distal and proximal etiological factors in autism and their potential impact on cerebello-cortical circuitry. Some existing rodent models of autism, as well as some models not previously applied to the study of the disorder, display cerebellar and behavioral abnormalities that parallel those commonly seen in autistic patients. The novel findings produced from research utilizing rodent models could provide a better understanding of the neurochemical and behavioral impact of changes in cerebello-cortical circuitry in autism.
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7. Ruiz-Robledillo N, Moya-Albiol L. {{Self-reported health and cortisol awakening response in parents of people with asperger syndrome: The role of trait anger and anxiety, coping and burden}}. {Psychol Health};2013 (May 29)
Caring for offspring with autism spectrum disorders entails high levels of stress for a long period of time and is associated with several types of health complaints. Few studies have focused on specific effects of particular disorders in the spectrum. This study was carried out with the aim of evaluating the global health of parents of people with Asperger syndrome (N = 53) compared to those of typically developing children (N = 54) through self-reported measures (medication consumption and somatic symptoms) and biological markers (cortisol awakening response [CAR]). Additionally, we analysed various psychological variables as potential predictors of caregiver health. We found that caregivers take more medication and have worse self-reported health than controls, but there were no significant differences in CAR between the groups. However, after controlling for negative affect, differences between groups in CAR reached significance. With regards to predictor variables, anxiety trait, cognitive-coping style, burden and anger temperament were significantly associated with caregiver’s self-reported health. These findings underline the need to develop interventions that foster improvements in the health of caregivers, reduce their burden and enhance their quality of life.
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8. Singman E, Matta N, Fairward A, Silbert D. {{Evaluation of plusoptiX Photoscreening During Examinations of Children with Autism}}. {Strabismus};2013 (Jun);21(2):103-105.
Abstract Purpose: We evaluated the reliability of the the plusoptiX photoscreener compared to a standard pediatric eye exam offered to children with autism. Methods: This is a retrospective chart review of children diagnosed with autism seen at one pediatric ophthalmology practice. Results: Twenty-five children were evaluated. The plusoptiX was found to have a sensitivity of 88% and a specificity of 87% in identifying amblyopia risk factors based on the current American Association for Pediatric Ophthalmology and Strabismus referral criteria. Conclusion: Pediatric vision screening can be especially challenging in children with autism. Minimizing the need for examinations in these children is important. While the plusoptiX does not perform as well when applied to children with autism as it does when offered to children in the general population, it is still a useful tool.
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9. Valencia AV, Paez AL, Sampedro ME, Avila C, Cardona JC, Mesa C, Galvis L, Carrizosa J, Camargo M, Ruiz A, Cornejo W, Bedoya G. {{[Evidence for association and epistasis between the genetic markers SLC6A4 and HTR2A in autism etiology]}}. {Biomedica};2012 (Dec);32(4):585-601.
Introduction. Autism spectrum disorders are severe neurodevelopmental disorders with a strong genetic component. The potential role of the serotoninergic system in the development of autistic disorder has been based on the observation of hyperserotoninemia in autistic subjects and the results of drug treatment studies. Multiple molecules involved in serotonin metabolism and neurotransmission have been studied; however, replication studies have been inconsistent. This may be partially related to the marked genetic heterogeneity of autism in different populations. Objectives. The relationship between autism and single nucleotide polymorphisms of SLC6A4, HTR2A and ITGB3 genes was evaluated in an urban population of northwestern Colombia. Materials and methods. In Antioquia, Colombia, 42 families with history of autism were screened for 10 SNPs in SLC6A4, HTR2A and ITGB3 genes and evaluated for associations with the transmission disequilibrium test. The interactions among these genes and autism was assessed with multidimensional reduction methods. Results. A significant main effect was seen among the SLC6A4 gene variants rs4583306 (OR=2.6, p=0.004) and rs2066713 (OR=2.2, p=0.03). No main effect of the ITGB3 or HTR2A variants was found, however, in the interaction effects, the SLC6A4 and HTR2A genes demonstrated significant evidence of association with autism (p<0.001). Conclusion. Significant association of markers were discovered within the SLC6A4 gene and the combination of SLC6A4 and HTR2A (S-A) genes to autism. These results were consistent with previous studies conducted in other populations and provide further evidence for the implication of the serotoninergic system in the etiology of autistic disorders.
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10. Vardarajan BN, Eran A, Jung JY, Kunkel LM, Wall DP. {{Haplotype structure enables prioritization of common markers and candidate genes in autism spectrum disorder}}. {Transl Psychiatry};2013;3:e262.
Autism spectrum disorder (ASD) is a neurodevelopmental condition that results in behavioral, social and communication impairments. ASD has a substantial genetic component, with 88-95% trait concordance among monozygotic twins. Efforts to elucidate the causes of ASD have uncovered hundreds of susceptibility loci and candidate genes. However, owing to its polygenic nature and clinical heterogeneity, only a few of these markers represent clear targets for further analyses. In the present study, we used the linkage structure associated with published genetic markers of ASD to simultaneously improve candidate gene detection while providing a means of prioritizing markers of common genetic variation in ASD. We first mined the literature for linkage and association studies of single-nucleotide polymorphisms, copy-number variations and multi-allelic markers in Autism Genetic Resource Exchange (AGRE) families. From markers that reached genome-wide significance, we calculated male-specific genetic distances, in light of the observed strong male bias in ASD. Four of 67 autism-implicated regions, 3p26.1, 3p26.3, 3q25-27 and 5p15, were enriched with differentially expressed genes in blood and brain from individuals with ASD. Of 30 genes differentially expressed across multiple expression data sets, 21 were within 10 cM of an autism-implicated locus. Among them, CNTN4, CADPS2, SUMF1, SLC9A9, NTRK3 have been previously implicated in autism, whereas others have been implicated in neurological disorders comorbid with ASD. This work leverages the rich multimodal genomic information collected on AGRE families to present an efficient integrative strategy for prioritizing autism candidates and improving our understanding of the relationships among the vast collection of past genetic studies.
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11. Wallace GL, Robustelli B, Dankner N, Kenworthy L, Giedd JN, Martin A. {{Increased gyrification, but comparable surface area in adolescents with autism spectrum disorders}}. {Brain};2013 (May 28)
Autism spectrum disorders are associated with atypically excessive early brain growth. Recent studies suggest that later cortical development, specifically cortical thickness, during adolescence and young adulthood is also aberrant. Nevertheless, previous studies of other surface-based metrics (e.g. surface area and gyrification) at high-resolution in autism spectrum disorders are limited. Forty-one males with autism spectrum disorders and 39 typically developing males matched on age (mean approximately 17; range = 12-24 years) and IQ (mean approximately 113; range = 85-143) provided high-resolution 3 T anatomical magnetic resonance imaging scans. The FreeSurfer image analysis suite quantified vertex-level surface area and gyrification. There were gyrification increases in the autism spectrum disorders group (relative to typically developing subjects) localized to bilateral posterior cortices (cluster corrected P < 0.01). Furthermore, the association between vocabulary knowledge and gyrification in left inferior parietal cortex (typically developing group: positive correlation; autism spectrum disorders group: no association) differed between groups. Finally, there were no group differences in surface area, and there was no interaction between age and group for either surface area or gyrification (both groups showed decreasing gyrification with increasing age). The present study complements and extends previous work by providing the first evidence of increased gyrification (though no differences in surface area) at high resolution among adolescents and young adults with autism spectrum disorders and by showing a dissociation in the relationship between vocabulary and gyrification in autism spectrum disorders versus typically developing subjects. In contrast with previous findings of age-related cortical thinning in this same autism spectrum disorders sample, here we find that increases in gyrification are maintained across adolescence and young adulthood, implicating developmentally dissociable cortical atypicalities in autism spectrum disorders.
