Pubmed du 02/12/14

Pubmed du jour

2014-12-02 12:03:50

1. Guy A, Seaton SE, Boyle EM, Draper ES, Field DJ, Manktelow BN, Marlow N, Smith LK, Johnson S. {{Infants Born Late/Moderately Preterm Are at Increased Risk for a Positive Autism Screen at 2 Years of Age}}. {J Pediatr}. 2014.

OBJECTIVES: To assess the prevalence of positive screens using the Modified Checklist for Autism in Toddlers (M-CHAT) questionnaire and follow-up interview in late and moderately preterm (LMPT; 32-36 weeks) infants and term-born controls. STUDY DESIGN: Population-based prospective cohort study of 1130 LMPT and 1255 term-born infants. Parents completed the M-CHAT questionnaire at 2-years corrected age. Parents of infants with positive questionnaire screens were followed up with a telephone interview to clarify failed items. The M-CHAT questionnaire was re-scored, and infants were classified as true or false positives. Neurosensory, cognitive, and behavioral outcomes were assessed using parent report. RESULTS: Parents of 634 (57%) LMPT and 761 (62%) term-born infants completed the M-CHAT questionnaire. LMPT infants had significantly higher risk of a positive questionnaire screen compared with controls (14.5% vs 9.2%; relative risk [RR] 1.58; 95% CI 1.18, 2.11). After follow-up, significantly more LMPT infants than controls had a true positive screen (2.4% vs 0.5%; RR 4.52; 1.51, 13.56). This remained significant after excluding infants with neurosensory impairments (2.0% vs 0.5%; RR 3.67; 1.19, 11.3). CONCLUSIONS: LMPT infants are at significantly increased risk for positive autistic screen. An M-CHAT follow-up interview is essential as screening for autism spectrum disorders is especially confounded in preterm populations. Infants with false positive screens are at risk for cognitive and behavioral problems.

Lien vers le texte intégral (Open Access ou abonnement)

2. Jiang YV, Palm BE, DeBolt MC, Goh YS. {{High-Precision Visual Long-Term Memory in Children With High-Functioning Autism}}. {J Abnorm Psychol}. 2014.

Domain-general theories of autism rest on evidence that the disorder impacts not only social communication skills but also nonsocial functions such as memory. Yet recognition memory deficits have been inconsistently documented, especially for stimuli other than faces and sentences. Here we tested school-age children with high-functioning autism (ASD) and IQ, and age-matched comparison children on a visual long-term memory task involving more than 100 photographs of objects, faces, cats, houses, and abstract stimuli. Children viewed each photograph for 2 s. After a 10-min filled delay, we assessed recognition memory for object category as well as for specific exemplars. Data supported the presence of a high-capacity and high-precision visual memory in children with ASD. Both category memory and exemplar memory accuracies were above 90% for categories for which a single exemplar had been encoded. When more exemplars per category were encoded, category memory improved, but exemplar memory declined. An exception was face memory, which remained highly accurate even after many faces had been encoded. Our study provided no evidence that visual memory in general, and face memory in particular, is impaired in children with ASD. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Lien vers le texte intégral (Open Access ou abonnement)

3. Just MA, Cherkassky VL, Buchweitz A, Keller TA, Mitchell TM. {{Identifying autism from neural representations of social interactions: neurocognitive markers of autism}}. {PLoS One}. 2014; 9(12): e113879.

Autism is a psychiatric/neurological condition in which alterations in social interaction (among other symptoms) are diagnosed by behavioral psychiatric methods. The main goal of this study was to determine how the neural representations and meanings of social concepts (such as to insult) are altered in autism. A second goal was to determine whether these alterations can serve as neurocognitive markers of autism. The approach is based on previous advances in fMRI analysis methods that permit (a) the identification of a concept, such as the thought of a physical object, from its fMRI pattern, and (b) the ability to assess the semantic content of a concept from its fMRI pattern. These factor analysis and machine learning methods were applied to the fMRI activation patterns of 17 adults with high-functioning autism and matched controls, scanned while thinking about 16 social interactions. One prominent neural representation factor that emerged (manifested mainly in posterior midline regions) was related to self-representation, but this factor was present only for the control participants, and was near-absent in the autism group. Moreover, machine learning algorithms classified individuals as autistic or control with 97% accuracy from their fMRI neurocognitive markers. The findings suggest that psychiatric alterations of thought can begin to be biologically understood by assessing the form and content of the altered thought’s underlying brain activation patterns.

Lien vers le texte intégral (Open Access ou abonnement)

4. Klusek J, Hunt AW, Mirrett PL, Hatton DD, Hooper SR, Roberts JE, Bailey DB. {{Reading and Phonological Skills in Boys with Fragile X Syndrome}}. {J Autism Dev Disord}. 2014.

Although reading skills are critical for the success of individuals with intellectual disabilities, literacy has received little attention in fragile X syndrome (FXS). This study examined the literacy profile of FXS. Boys with FXS (n = 51; mean age 10.2 years) and mental age-matched boys with typical development (n = 35) participated in standardized assessments of reading and phonological skills. Phonological skills were impaired in FXS, while reading was on-par with that of controls. Phonological awareness predicted reading ability and ASD severity predicted poorer phonological abilities in FXS. Boys with FXS are capable of attaining reading skills that are commensurate with developmental level and phonological awareness skills may play a critical role in reading achievement in FXS.

Lien vers le texte intégral (Open Access ou abonnement)

5. Polussa J, Schneider A, Hagerman R. {{Molecular Advances Leading to Treatment Implications for Fragile X Premutation Carriers}}. {Brain Disord Ther}. 2014; 3.

Fragile X syndrome (FXS) is the most common single gene cause of intellectual disability and it is characterized by a CGG expansion of more than 200 repeats in the FMR1 gene, leading to methylation of the promoter and gene silencing. The fragile X premutation, characterized by a 55 to 200 CGG repeat expansion, causes health problems and developmental difficulties in some, but not all, carriers. The premutation causes primary ovarian insufficiency in approximately 20% of females, psychiatric problems (including depression and/or anxiety) in approximately 50% of carriers and a neurodegenerative disorder, the fragile X-associated tremor ataxia syndrome (FXTAS), in approximately 40% of males and 16% of females later in life. Recent clinical studies in premutation carriers have expanded the health problems that may be seen. Advances in the molecular pathogenesis of the premutation have shown significant mitochondrial dysfunction and oxidative stress in neurons which may be amenable to treatment. Here we review the clinical problems of carriers and treatment recommendations.

Lien vers le texte intégral (Open Access ou abonnement)

6. Scharf SH, Jaeschke G, Wettstein JG, Lindemann L. {{Metabotropic glutamate receptor 5 as drug target for Fragile X syndrome}}. {Curr Opin Pharmacol}. 2014.

Fragile X syndrome (FXS) is the most common monogenic form of inherited mental retardation caused by a trinucleotid repeat expansion and transcriptional shutdown of the FMR1 gene. FXS patients present a complex and often severe neuropsychiatric phenotype yet have mild somatic symptoms, normal life expectancies, and no indications of neurodegeneration. The therapeutic potential of mGlu5 inhibitors was proposed in the ‘mGluR theory of FXS’ based on early insights into the molecular pathophysiology of FXS. Studies in Fragile X mental retardation 1 (Fmr1) knock-out mice, a widely used disease model, demonstrated that mGlu5 inhibitors can correct a broad range of disease-related phenotypes. Recent clinical trials, however, with two different mGlu5 inhibitors (basimglurant and mavoglurant) showed no therapeutic benefit in FXS patients for reasons as yet unclear.

Lien vers le texte intégral (Open Access ou abonnement)

7. Sharda M, Khundrakpam BS, Evans AC, Singh NC. {{Disruption of structural covariance networks for language in autism is modulated by verbal ability}}. {Brain Struct Funct}. 2014.

The presence of widespread speech and language deficits is a core feature of autism spectrum disorders (ASD). These impairments have often been attributed to altered connections between brain regions. Recent developments in anatomical correlation-based approaches to map structural covariance offer an effective way of studying such connections in vivo. In this study, we employed such a structural covariance network (SCN)-based approach to investigate the integrity of anatomical networks in fronto-temporal brain regions of twenty children with ASD compared to an age and gender-matched control group of twenty-two children. Our findings reflected large-scale disruption of inter and intrahemispheric covariance in left frontal SCNs in the ASD group compared to controls, but no differences in right fronto-temporal SCNs. Interhemispheric covariance in left-seeded networks was further found to be modulated by verbal ability of the participants irrespective of autism diagnosis, suggesting that language function might be related to the strength of interhemispheric structural covariance between frontal regions. Additionally, regional cortical thickening was observed in right frontal and left posterior regions, which was predicted by decreasing symptom severity and increasing verbal ability in ASD. These findings unify reports of regional differences in cortical morphology in ASD. They also suggest that reduced left hemisphere asymmetry and increased frontal growth may not only reflect neurodevelopmental aberrations but also compensatory mechanisms.

Lien vers le texte intégral (Open Access ou abonnement)

8. Souza VA, Abreu MH, Resende VL, Castilho LS. {{Factors associated with bruxism in children with developmental disabilities}}. {Braz Oral Res}. 2015; 29(1): 1-5.

The aim of the present study was to investigate factors associated with bruxism in children aged from 1 to 13 years with developmental disabilities. A total of 389 dental records were examined. The bruxism analyzed was determined based on parental reports. The following variables were also analyzed: gender, age, International Code of Diseases (ICD), mouth breathing, history of gastroesophageal reflux, use of psychotropic drugs, gingival status, reports of xerostomia, hyperkinesis, pacifier use, thumb sucking and involuntary movements. For the purposes of analysis, the individuals were categorized as being with and without bruxism. Variables with a p-value < 0.25 in the bivariate analysis were incorporated into the logistic regression models. Females had a 0.44-fold (95%CI: 0.25 to 0.78) greater chance of exhibiting bruxism than males. Individuals with gastroesophageal reflux had a 2.28-fold (95%CI: 1.03 to 5.02) greater chance of exhibiting bruxism. Individuals with reported involuntary movements had a 2.24-fold (95%CI: 1.19 to 4.24) greater chance of exhibiting bruxism than those without such movements. Exhibiting involuntary movements, the male gender and gastroesophageal reflux are factors associated with bruxism in children with developmental disabilities.

Lien vers Pubmed

9. Van Hees V, Moyson T, Roeyers H. {{Higher Education Experiences of Students with Autism Spectrum Disorder: Challenges, Benefits and Support Needs}}. {J Autism Dev Disord}. 2014.

The transition into higher education constitutes a precarious life stage for students with autism spectrum disorder (ASD). Research on how students with ASD navigate college life is needed for the development of adequate support. This study investigated the challenges and support needs of 23 students with ASD in higher education through semi-structured interviews. Data were analyzed following the principles of Grounded Theory. Students faced difficulties with new situations and unexpected changes, social relationships, problems with information processing and time management and had doubts about disclosure. Facing these challenges simultaneously in the domains of education, student life and daily (independent) living, had a major impact on students’ well being. Besides these challenges, students also reported benefits that contributed to success in the three domains. They pointed out to a set of recommendations for support. These findings are linked with previous research and implications for higher education institutions are extrapolated on the basis of these findings.

Lien vers le texte intégral (Open Access ou abonnement)

10. Worsham W, Gray WE, Larson MJ, South M. {{Conflict adaptation and congruency sequence effects to social-emotional stimuli in individuals with autism spectrum disorders}}. {Autism}. 2014.

BACKGROUND: The modification of performance following conflict can be measured using conflict adaptation tasks thought to measure the change in the allocation of cognitive resources in order to reduce conflict interference and improve performance. While previous studies have suggested atypical processing during nonsocial cognitive control tasks, conflict adaptation (i.e. congruency sequence effects) for social-emotional stimuli have not been previously studied in autism spectrum disorder. METHODS: A total of 32 participants diagnosed with autism spectrum disorder and 27 typically developing matched controls completed an emotional Stroop conflict task that required the classification of facial affect while simultaneously ignoring an overlaid affective word. RESULTS: Both groups showed behavioral evidence for emotional conflict adaptation based on response times and accuracy rates. However, the autism spectrum disorder group demonstrated a speed-accuracy trade-off manifested through significantly faster response times and decreased accuracy rates on trials containing conflict between the emotional face and the overlaid emotional word. CONCLUSION: Reduced selective attention toward socially relevant information may bias individuals with autism spectrum disorder toward more rapid processing and decision making even when conflict is present. Nonetheless, the loss of important information from the social stimuli reduces decision-making accuracy, negatively affecting the ability to adapt both cognitively and emotionally when conflict arises.

Lien vers le texte intégral (Open Access ou abonnement)