1. Bjornsdotter M, Wang N, Pelphrey K, Kaiser MD. {{Evaluation of Quantified Social Perception Circuit Activity as a Neurobiological Marker of Autism Spectrum Disorder}}. {JAMA Psychiatry}. 2016.
Importance: Autism spectrum disorder (ASD) is marked by social disability and is associated with dysfunction in brain circuits supporting social cue perception. The degree to which neural functioning reflects individual-level behavioral phenotype is unclear, slowing the search for functional neuroimaging biomarkers of ASD. Objective: To examine whether quantified neural function in social perception circuits may serve as an individual-level marker of ASD in children and adolescents. Design, Setting, and Participants: The cohort study was conducted at the Yale Child Study Center and involved children and adolescents diagnosed as having ASD and typically developing participants. Participants included a discovery cohort and a larger replication cohort. Individual-level social perception circuit functioning was assessed as functional magnetic resonance imaging brain responses to point-light displays of coherent vs scrambled human motion. Main Outcomes and Measures: Outcome measures included performance of quantified brain responses in affected male and female participants in terms of area under the receiver operating characteristic curve (AUC), sensitivity and specificity, and correlations between brain responses and social behavior. Results: Of the 39 participants in the discovery cohort aged 4 to 17 years, 22 had ASD and 30 were boys. Of the 75 participants in the replication cohort aged 7 to 20 years, 37 had ASD and 52 were boys. A relative reduction in social perception circuit responses was identified in discovery cohort boys with ASD at an AUC of 0.75 (95% CI, 0.52-0.89; P = .01); however, typically developing girls and girls with ASD could not be distinguished (P = .54). The results were confirmed in the replication cohort, where brain responses were identified in boys with ASD at an AUC of 0.79 (95% CI, 0.64-0.91; P < .001) and failed to distinguish affected and unaffected girls (P = .82). Across both cohorts, boys were identified at an AUC of 0.77 (95% CI, 0.64-0.86) with corresponding sensitivity and specificity of 76% each. Additionally, brain responses were associated with social behavior in boys but not in girls. Conclusions and Relevance: Quantified social perception circuit activity is a promising individual-level candidate neural marker of the male ASD behavioral phenotype. Our findings highlight the need to better understand effects of sex on social perception processing in relation to ASD phenotype manifestations. Lien vers le texte intégral (Open Access ou abonnement)
2. Hebron J, Oldfield J, Humphrey N. {{Cumulative risk effects in the bullying of children and young people with autism spectrum conditions}}. {Autism}. 2016.
Students with autism are more likely to be bullied than their typically developing peers. However, several studies have shown that their likelihood of being bullied increases in the context of exposure to certain risk factors (e.g. behaviour difficulties and poor peer relationships). This study explores vulnerability to bullying from a cumulative risk perspective, where the number of risks rather than their nature is considered. A total of 722 teachers and 119 parents of young people with autism spectrum conditions participated in the study. Established risk factors were summed to form a cumulative risk score in teacher and parent models. There was evidence of a cumulative risk effect in both models, suggesting that as the number of risks increased, so did exposure to bullying. A quadratic effect was found in the teacher model, indicating that there was a disproportionate increase in the likelihood of being bullied in relation to the number of risk factors to which a young person was exposed. In light of these findings, it is proposed that more attention needs to be given to the number of risks to which children and young people with autism spectrum conditions are exposed when planning interventions and providing a suitable educational environment.
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3. Hoffmann E, Bruck C, Kreifelts B, Ethofer T, Wildgruber D. {{Reduced functional connectivity to the frontal cortex during processing of social cues in autism spectrum disorder}}. {J Neural Transm (Vienna)}. 2016.
People diagnosed with autism spectrum disorder (ASD) characteristically present with severe difficulties in interpreting every-day social signals. Currently it is assumed that these difficulties might have neurobiological correlates in alterations in activation as well as in connectivity in and between regions of the social perception network suggested to govern the processing of social cues. In this study, we conducted functional magnetic resonance imaging (fMRI)-based activation and connectivity analyses focusing on face-, voice-, and audiovisual-processing brain regions as the most important subareas of the social perception network. Results revealed alterations in connectivity among regions involved in the processing of social stimuli in ASD subjects compared to typically developed (TD) controls-specifically, a reduced connectivity between the left temporal voice area (TVA) and the superior and medial frontal gyrus. Alterations in connectivity, moreover, were correlated with the severity of autistic traits: correlation analysis indicated that the connectivity between the left TVA and the limbic lobe, anterior cingulate and the medial frontal gyrus as well as between the right TVA and the frontal lobe, anterior cingulate, limbic lobe and the caudate decreased with increasing symptom severity. As these frontal regions are understood to play an important role in interpreting and mentalizing social signals, the observed underconnectivity might be construed as playing a role in social impairments in ASD.
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4. Ishizuka Y, Yamamoto JI. {{Contingent imitation increases verbal interaction in children with autism spectrum disorders}}. {Autism}. 2016.
Several studies have suggested that contingent adult imitation increase nonverbal communication, such as attention and proximity to adults, in children with autism spectrum disorders. However, few studies have shown the effect of contingent imitation on verbal communication. This study examined whether children with autism were able to promote verbal interaction such as vocal imitation, vocalization, and vocal turn-taking via contingent imitation. We used an alternating treatment design composed of the conditions of contingent imitation and control for six children with autism (aged 33-63 months). For contingent imitation condition, adults imitated children’s vocalization immediately. For control condition, adults did not imitate but gave a vocal response immediately. Results showed that in contingent imitation condition, all children increased the number of vocal imitations and vocal turn-takings compared with control condition. The number of vocalizations increased in both condition for all children. Overall, it is suggested that all children promote verbal interaction via contingent imitation.
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5. Manglunia AS, Puranik AD. {{FDG PET/CT findings in a clinically diagnosed case of childhood autism}}. {Indian J Nucl Med}. 2016; 31(2): 138-40.
Autism is a neurodevelopmental disorder with multifactorial etiology and varied presentation, in which early diagnosis is crucial to the implementation of early treatment. A 6-year-old child clinically diagnosed with autism, and a normal magnetic resonance imaging underwent dedicated 18F-fluorodeoxyglucose brain positron emission tomography (PET) as an ancillary investigation. PET image showed diffuse bilateral temporal hypometabolism. Although PET imaging is currently not indicated in the evaluation of autism, characteristic imaging patterns on PET can provide corroborative information and increase the diagnostic confidence for the same.
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6. Patel S, Day TN, Jones N, Mazefsky CA. {{Association between anger rumination and autism symptom severity, depression symptoms, aggression, and general dysregulation in adolescents with autism spectrum disorder}}. {Autism}. 2016.
Rumination has a large direct effect on psychopathology but has received relatively little attention in autism spectrum disorder despite the propensity to perseverate in this population. This study provided initial evidence that adolescents with autism spectrum disorder self-report more anger-focused rumination than typically developing controls, though there was substantial within-group variability. Anger rumination was positively correlated with autism symptom severity with both groups combined. Future studies that include measures of perseveration on special interests are needed to understand whether anger rumination is a manifestation of a perseverative type of repetitive behavior or a distinct trait. Even when controlling for autism symptom severity, however, anger-focused rumination was associated with poorer functioning, including more depression symptoms and overall emotional and behavioral dysregulation. Therefore, further inquiry regarding anger rumination in autism spectrum disorder is clinically important, and the potential impact of rumination-focused interventions should be explored.
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7. Saffin JM, Tohid H. {{Walk like me, talk like me. The connection between mirror neurons and autism spectrum disorder}}. {Neurosciences (Riyadh)}. 2016; 21(2): 108-19.
Understanding social cognition has become a hallmark in deciphering autism spectrum disorder. Neurobiological theories are taking precedence in causation studies as researchers look to abnormalities in brain development as the cause of deficits in social behavior, cognitive processes, and language. Following their discovery in the 1990s, mirror neurons have become a dominant theory for that the mirror neuron system may play a critical role in the pathophysiology of various symptoms of autism. Over the decades, the theory has evolved from the suggestion of a broken mirror neuron system to impairments in mirror neuron circuitry. The mirror neuron system has not gained total support due to inconsistent findings; a comprehensive analysis of the growing body of research could shed light on the benefits, or the disadvantage of continuing to study mirror neurons and their connection to autism.
8. Smile S. {{Case 2: Persistent skin discolouration in a child with autism spectrum disorder}}. {Paediatr Child Health}. 2016; 21(2): 67-8.
