Pubmed du 24/01/12

Pubmed du jour

2012-01-24 12:03:50

1. {{Neurodevelopmental disorders: Deficient auditory processing identified in children with suspected autism spectrum disorder}}. {Nat Rev Neurol};2012 (Jan 24)

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2. Allison C, Auyeung B, Baron-Cohen S. {{Toward brief « red flags » for autism screening: the short autism spectrum quotient and the short quantitative checklist in 1,000 cases and 3,000 controls}}. {J Am Acad Child Adolesc Psychiatry};2012 (Feb);51(2):202-212 e207.

OBJECTIVE: Frontline health professionals need a « red flag » tool to aid their decision making about whether to make a referral for a full diagnostic assessment for an autism spectrum condition (ASC) in children and adults. The aim was to identify 10 items on the Autism Spectrum Quotient (AQ) (Adult, Adolescent, and Child versions) and on the Quantitative Checklist for Autism in Toddlers (Q-CHAT) with good test accuracy. Method: A case sample of more than 1,000 individuals with ASC (449 adults, 162 adolescents, 432 children and 126 toddlers) and a control sample of 3,000 controls (838 adults, 475 adolescents, 940 children, and 754 toddlers) with no ASC diagnosis participated. Case participants were recruited from the Autism Research Centre’s database of volunteers. The control samples were recruited through a variety of sources. Participants completed full-length versions of the measures. The 10 best items were selected on each instrument to produce short versions. Results: At a cut-point of 6 on the AQ-10 adult, sensitivity was 0.88, specificity was 0.91, and positive predictive value (PPV) was 0.85. At a cut-point of 6 on the AQ-10 adolescent, sensitivity was 0.93, specificity was 0.95, and PPV was 0.86. At a cut-point of 6 on the AQ-10 child, sensitivity was 0.95, specificity was 0.97, and PPV was 0.94. At a cut-point of 3 on the Q-CHAT-10, sensitivity was 0.91, specificity was 0.89, and PPV was 0.58. Internal consistency was >0.85 on all measures. Conclusions: The short measures have potential to aid referral decision making for specialist assessment and should be further evaluated.

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3. Burke MM, Taylor JL, Urbano R, Hodapp RM. {{Predictors of future caregiving by adult siblings of individuals with intellectual and developmental disabilities}}. {Am J Intellect Dev Disabil};2012 (Jan);117(1):33-47.

Abstract With the growing life expectancy for individuals with intellectual and developmental disabilities, siblings will increasingly assume responsibility for the care of their brother or sister with intellectual and developmental disabilities. Using a 163-item survey completed by 757 siblings, the authors identified factors related to future caregiving expectations. Siblings expected to assume greater caregiving responsibility for their brother or sister with disabilities if they were female, had closer relationships with and lived closer to their brother or sister with intellectual and developmental disabilities, and were the lone sibling without a disability. Siblings who expected to assume higher levels of caregiving had parents who were currently more able to care for their brother or sister with disabilities. With a better understanding of who intends to fulfill future caregiving roles, support can be provided to these siblings.

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4. Crittendon JA, Lee EB, Warren ZE. {{Sibling recurrence rate of autism spectrum disorders is 18.7%}}. {Evid Based Ment Health};2012 (Jan 20)

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5. Frazier TW. {{Friends not foes: combined risperidone and behavior therapy for irritability in autism}}. {J Am Acad Child Adolesc Psychiatry};2012 (Feb);51(2):129-131.

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6. Holwerda A, van der Klink JJ, Groothoff JW, Brouwer S. {{Predictors for Work Participation in Individuals with an Autism Spectrum Disorder: A Systematic Review}}. {J Occup Rehabil};2012 (Jan 24)

Introduction Research shows that only about 25% of people with autism are employed. Method We conducted a systematic review on factors facilitating or hindering work participation of people with autism in longitudinal studies. An extensive search in biomedical and psychological databases yielded 204 articles and 18 satisfied all inclusion criteria. We assessed the methodological quality of included studies using an established criteria list. Results Seventeen factors were identified and categorized as disease-related factors, personal factors or external factors. Limited cognitive ability was the only significant predictor consistently found for work outcome. Functional independence and institutionalization were both reported by one study to be significantly related to work outcome. Inconsistent findings or non significant findings were reported for the other fourteen factors. Conclusion These findings emphasize the need for more high quality cohort studies focussing on work participation as the main outcome among people with Autism.

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7. Kana RK, Libero LE, Moore MS. {{Specificity of and extensions to the disrupted connectivity model of autism Reply to comments on « Disrupted cortical connectivity theory as an explanatory model for autism spectrum disorders »}}. {Phys Life Rev};2012 (Jan 17)

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8. Keri S, Benedek G. {{Why is vision impaired in fragile X premutation carriers? The role of fragile X mental retardation protein and potential FMR1 mRNA toxicity}}. {Neuroscience};2012 (Jan 10)

Dysfunctions of the geniculo-striatal magnocellular (M) visual pathway and its cortical recipients have been documented in fragile X syndrome and in FMR1 premutation carriers. However, the mechanism of this impairment is less clear. To elucidate this issue, we completed the measurement of visual functions at different stages of information processing: low-level mechanisms (contrast sensitivity biasing information processing toward the M and parvocellular [P] pathways), primary visual cortex (motion-defined and static Vernier threshold), and higher-level form and motion processing (coherence thresholds). Results revealed that FMR1 premutation carriers, relative to non-carrier controls, exhibited lower contrast sensitivity for M pathway-biased stimuli, higher Vernier threshold for motion-defined stimuli, and higher global motion coherence threshold. Although both elevated FMR1 mRNA and reduced fragile X mental retardation protein (FMRP) levels were associated with impaired visual functions, regression analysis indicated that FMRP was the primary factor. In premutation carriers, a toxic gain-of-function of elevated FMR1 mRNA has been suggested, whereas reduced FMRP is linked to neurodevelopmental aspects. Here, we showed that this latter may the primary factor associated with visual dysfunctions.

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9. Magyar CI, Pandolfi V, Dill CA. {{An Initial Evaluation of the Social Communication Questionnaire for the Assessment of Autism Spectrum Disorders in Children With Down Syndrome}}. {J Dev Behav Pediatr};2012 (Jan 19)

OBJECTIVE:: This study investigated the psychometric properties of the Social Communication Questionnaire (SCQ) in a sample of children with Down syndrome (DS), many of whom had a co-occurring autism spectrum disorder (ASD). The SCQ is a widely used ASD screening measure; however, its measurement properties have not been comprehensively evaluated specifically in children with DS, a group that seems to be at higher risk for an ASD. METHODS:: Exploratory and confirmatory factor analyses, scale reliability, convergent and discriminant correlations, significance tests between groups of children with DS and DS + ASD, and diagnostic accuracy analyses were conducted. RESULTS:: Factor analyses identified 2 reliable factors that we labeled Social-Communication and Stereotyped Behavior and Unusual Interests. Pearson correlations with Autism Diagnostic Interview-Revised subscales indicated support for the SCQ’s convergent validity and some support for the discriminant validity of the factor-based scales. Significance tests and receiver operating characteristic analyses indicated that children with DS + ASD obtained significantly higher SCQ factor-based and total scores than children with DS alone, and that the SCQ Total Score evidenced good sensitivity and adequate specificity. CONCLUSIONS:: Results indicated initial psychometric support for the SCQ as an ASD screening measure in children with DS. The SCQ should be considered as part of a multimethod evaluation when screening children with DS.

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10. McDuffie A, Kover S, Abbeduto L, Lewis P, Brown T. {{Profiles of receptive and expressive language abilities in boys with comorbid fragile x syndrome and autism}}. {Am J Intellect Dev Disabil};2012 (Jan);117(1):18-32.

Abstract The authors examined receptive and expressive language profiles for a group of verbal male children and adolescents who had fragile X syndrome along with varying degrees of autism symptoms. A categorical approach for assigning autism diagnostic classification, based on the combined use of the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule (ADOS), and a continuous approach for representing autism symptom severity, based on ADOS severity scores, were used in 2 separate sets of analyses. All analyses controlled for nonverbal IQ and chronological age. Nonverbal IQ accounted for significant variance in all language outcomes with large effect sizes. Results of the categorical analyses failed to reveal an effect of diagnostic group (fragile X syndrome-autism, fragile X syndrome-no autism) on standardized language test performance. Results of the continuous analyses revealed a negative relationship between autism symptom severity and all of the standardized language measures. Implications for representing autism symptoms in fragile X syndrome research are considered.

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11. Ronesi JA, Collins KA, Hays SA, Tsai NP, Guo W, Birnbaum SG, Hu JH, Worley PF, Gibson JR, Huber KM. {{Disrupted Homer scaffolds mediate abnormal mGluR5 function in a mouse model of fragile X syndrome}}. {Nat Neurosci};2012 (Jan 22)

Enhanced metabotropic glutamate receptor subunit 5 (mGluR5) function is causally associated with the pathophysiology of fragile X syndrome, a leading inherited cause of intellectual disability and autism. Here we provide evidence that altered mGluR5-Homer scaffolds contribute to mGluR5 dysfunction and phenotypes in the fragile X syndrome mouse model, Fmr1 knockout (Fmr1(-/y)). In Fmr1(-/y) mice, mGluR5 was less associated with long Homer isoforms but more associated with the short Homer1a. Genetic deletion of Homer1a restored mGluR5-long Homer scaffolds and corrected several phenotypes in Fmr1(-/y) mice, including altered mGluR5 signaling, neocortical circuit dysfunction and behavior. Acute, peptide-mediated disruption of mGluR5-Homer scaffolds in wild-type mice mimicked many Fmr1(-/y) phenotypes. In contrast, Homer1a deletion did not rescue altered mGluR-dependent long-term synaptic depression or translational control of target mRNAs of fragile X mental retardation protein, the gene product of Fmr1. Our findings reveal new functions for mGluR5-Homer interactions in the brain and delineate distinct mechanisms of mGluR5 dysfunction in a mouse model of cognitive dysfunction and autism.

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12. Rotschafer SE, Trujillo MS, Dansie LE, Ethell IM, Razak KA. {{Minocycline treatment reverses ultrasonic vocalization production deficit in a mouse model of Fragile X Syndrome}}. {Brain Res};2011 (Dec 31)

Fragile X Syndrome (FXS) is the most common inherited form of intellectual disability, with behaviors characteristic of autism. Symptoms include abnormal social behavior, repetitive behavior, communication disorders, and seizures. Many symptoms of FXS have been replicated in the Fmr1 knockout (KO) mice. Whether Fmr1 KO mice exhibit vocal communication deficits is not known. By recording ultrasonic vocalizations (USV) produced by adult male mice during mating, we show that USV calling rate (number of calls/second) is reduced in Fmr1 KO mice compared to WT controls. The WT control and Fmr1 KO groups did not differ in other aspects of mating behavior such as time spent sniffing, mounting, rooting and without contact. Acoustic properties of calls such as mean frequency (in kHz), duration and dynamic range of frequencies were not different. This indicates a specific deficit in USV calling rate in Fmr1 KO mice. Previous studies have shown that treatment of Fmr1 KO mice with minocycline for 4weeks from birth can alleviate some behavioral symptoms. Here we tested if minocycline also reversed vocalization deficits in these mice. Calling rate increased and was similar to WT controls in adult Fmr1 KO mice treated with minocycline for four weeks from birth (P0-P28). All acoustic properties measured were similar in treated and untreated WT control mice indicating minocycline effects were specific to vocalizations in the Fmr1 KO mice. These data suggest that mating-related USVs are robust and relevant biomarkers of FXS, and that minocycline treatment is a promising avenue for treatment of FXS symptoms.

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13. Smith LE, Barker ET, Seltzer MM, Abbeduto L, Greenberg JS. {{Behavioral phenotype of fragile x syndrome in adolescence and adulthood}}. {Am J Intellect Dev Disabil};2012 (Jan);117(1):1-17.

Abstract The present study explored the behavioral profile of individuals with fragile X syndrome during adolescence and adulthood. Individuals with both fragile X syndrome and autism (n = 30) were compared with (a) individuals diagnosed with fragile X syndrome (but not autism; n = 106) and (b) individuals diagnosed with autism (but not fragile X syndrome; n = 135) on measures of autism symptoms, adaptive functioning, behavior problems, and psychological symptoms. Results indicated that individuals dually diagnosed with fragile X syndrome and autism displayed greater communication and social reciprocity impairments than individuals with fragile X syndrome only. Individuals in the dually diagnosed group also exhibited higher levels of repetitive and challenging behaviors than either comparison group, suggesting a unique profile of vulnerability for those diagnosed with both fragile X syndrome and autism.

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14. Voos AC, Pelphrey KA, Kaiser MD. {{Autistic Traits are Associated with Diminished Neural Response to Affective Touch}}. {Soc Cogn Affect Neurosci};2012 (Jan 20)

‘Social brain’ circuitry has recently been implicated in processing slow, gentle touch targeting a class of slow-conducting, unmyelinated nerves, CT afferents, which are present only in the hairy skin of mammals. Given the importance of such ‘affective touch’ in social relationships, the current functional magnetic resonance imaging (fMRI) study aimed to replicate the finding of ‘social brain’ involvement in processing CT-targeted touch and to examine the relationship between the neural response and individuals’ social abilities. During an fMRI scan, nineteen healthy adults received alternating blocks of slow (CT-optimal) and fast (non-optimal) brushing to the forearm. Relative to fast touch, the slow touch activated contralateral insula, superior temporal sulcus (STS), medial prefrontal cortex (mPFC), orbitofrontal cortex (OFC), and amygdala. Connectivity analyses revealed co-activation of the mPFC, insula and amygdala during slow touch. Additionally, participants’ autistic traits negatively correlated with the response to slow touch in the OFC and STS. The current study replicates and extends findings of the involvement of a network of ‘social brain’ regions in processing CT-targeted affective touch, emphasizing the multimodal nature of this system. Variability in the brain response to such touch illustrates a tight coupling of social behavior and social brain function in typical adults.

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15. Yerys BE, Wolff BC, Moody E, Pennington BF, Hepburn SL. {{Brief Report: Impaired Flexible Item Selection Task (FIST) in School-Age Children with Autism Spectrum Disorders}}. {J Autism Dev Disord};2012 (Jan 24)

Cognitive flexibility has been measured with inductive reasoning or explicit rule tasks in individuals with autism spectrum disorders (ASD). The Flexible Item Selection Task (FIST) differs from previous cognitive flexibility tasks in ASD research by giving children an abstract, ambiguous rule to switch. The ASD group (N = 22; Mean age = 8.28 years, SD = 1.52) achieved a lower shift percentage than the typically developing verbal mental-age control group (N = 22; Mean age = 6.26 years, SD = 0.82). There was a significant positive correlation between verbal mental age and shift percentage for children with ASD. Group differences on the FIST converge and extend prior evidence documenting an impaired ability to adapt rapidly to changes in task demands for individuals with ASD.

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