1. Bennett E, Heaton P. {{Is Talent in Autism Spectrum Disorders Associated with a Specific Cognitive and Behavioural Phenotype?}}. {J Autism Dev Disord};2012 (Apr 24)
Parents of 125 children, adolescents and young adults with autism spectrum disorders completed a newly developed questionnaire aimed at identifying cognitive and behavioural characteristics associated with savant skills in this group. Factors distinguishing skilled individuals were then further investigated in case studies of three individuals with exceptional skills for music, art and mathematics. The findings from the case studies largely confirmed the results from the questionnaire study in showing that special skills are associated with superior working memory and highly focused attention that is not associated with increased obsessesionality. Although intellectual impairment and a local bias have been widely associated with special skills in the savant literature, neither the screening nor case studies provided strong evidence for such associations.
Lien vers le texte intégral (Open Access ou abonnement)
2. Burnand G. {{Inter-hemispheric competition relieved in both: Hypotheses for autism and schizophrenia from problem theory}}. {Med Hypotheses};2012 (Apr 21)
A logical relationship exists among six general problems that people face in life. Using hope about something for its subjective probability, its expected likelihood, the problems form a series where the method of assessing hope changes in a simple manner from one problem to the next. The central hypothesis is that human beings exploit this. Brain structures and predispositions have evolved accordingly, leading to the hemispheres having different predispositions. The hemispheres are effectively joined at 5months. Infants will then find that they engage in two unrelated activities. Typical infants label the activities in detail, using visual images, as part of gaining control over them. Hypotheses are: (a) autistic children fail labelling at the start, and hence they encounter uncontrolled competition between the hemispheres; (b) with some, serotonin abnormality impairs sensory information processing and hence the labelling; (c) with some, a delay in myelination from autoimmune effects disrupts labelling; (d) the likelihood of this ‘delay autism’ is reduced by long chain omega oils; (e) self-pressuring, which underlies taking on challenges and play like Hide and Seek, brings relief from the competition by raising the influence of one side; (f) the same left-right competition occurs in confused episodes and schizophrenia in vulnerable people who encounter pressures to use both hemispheres at the same time; (g) some symptoms raise the influence on one side ideationally. This leads to coherent theories of autism and schizophrenia. In both competition between the hemispheres is relieved primarily by self-pressuring, which raises influence on one side.
Lien vers le texte intégral (Open Access ou abonnement)
3. Carrasco M, Volkmar FR, Bloch MH. {{Pharmacologic Treatment of Repetitive Behaviors in Autism Spectrum Disorders: Evidence of Publication Bias}}. {Pediatrics};2012 (Apr 23)
OBJECTIVE:The goal of this study was to examine the efficacy of serotonin receptor inhibitors (SRIs) for the treatment of repetitive behaviors in autism spectrum disorders (ASD).METHODS:Two reviewers searched PubMed and Clinicaltrials.gov for randomized, double-blind, placebo-controlled trials evaluating the efficacy of SRIs for repetitive behaviors in ASD. Our primary outcome was mean improvement in ratings scales of repetitive behavior. Publication bias was assessed by using a funnel plot, the Egger’s test, and a meta-regression of sample size and effect size.RESULTS:Our search identified 5 published and 5 unpublished but completed trials eligible for meta-analysis. Meta-analysis of 5 published and 1 unpublished trial (which provided data) demonstrated a small but significant effect of SRI for the treatment of repetitive behaviors in ASD (standardized mean difference: 0.22 [95% confidence interval: 0.07-0.37], z score = 2.87, P < .005). There was significant evidence of publication bias in all analyses. When Duval and Tweedie's trim and fill method was used to adjust for the effect of publication bias, there was no longer a significant benefit of SRI for the treatment of repetitive behaviors in ASD (standardized mean difference: 0.12 [95% confidence interval: -0.02 to 0.27]). Secondary analyses demonstrated no significant effect of type of medication, patient age, method of analysis, trial design, or trial duration on reported SRI efficacy.CONCLUSIONS:Meta-analysis of the published literature suggests a small but significant effect of SRI in the treatment of repetitive behaviors in ASD. This effect may be attributable to selective publication of trial results. Without timely, transparent, and complete disclosure of trial results, it remains difficult to determine the efficacy of available medications. Lien vers le texte intégral (Open Access ou abonnement)
4. Chauhan A, Audhya T, Chauhan V. {{Brain Region-Specific Glutathione Redox Imbalance in Autism}}. {Neurochem Res};2012 (Apr 12)
Autism is a heterogeneous, behaviorally defined neurodevelopmental disorder. Recently, we reported a brain region-specific increase in lipid peroxidation, and deficits in mitochondrial electron transport chain complexes in autism, suggesting the role of oxidative stress and mitochondrial dysfunction in the pathophysiology of autism. However, the antioxidant status of the brain is not known in autism. Glutathione is a major endogenous antioxidant that plays a crucial role in protecting cells from exogenous and endogenous toxins, particularly in the central nervous system. The present study examines the concentrations of glutathione (GSH, reduced form; and GSSG, oxidized form) and the redox ratio of GSH to GSSG (marker of oxidative stress) in different regions of brains from autistic subjects and age-matched control subjects. In the cerebellum and temporal cortex from subjects with autism, GSH levels were significantly decreased by 34.2 and 44.6 %, with a concomitant increase in the levels of GSSG by 38.2 and 45.5 %, respectively, as compared to the control group. There was also a significant decrease in the levels of total GSH (tGSH) by 32.9 % in the cerebellum, and by 43.1 % in the temporal cortex of subjects with autism. In contrast, there was no significant change in GSH, GSSG and tGSH levels in the frontal, parietal and occipital cortices in autism versus control group. The redox ratio of GSH to GSSG was also significantly decreased by 52.8 % in the cerebellum and by 60.8 % in the temporal cortex of subjects with autism, suggesting glutathione redox imbalance in the brain of individuals with autism. These findings indicate that autism is associated with deficits in glutathione antioxidant defense in selective regions of the brain. We suggest that disturbances in brain glutathione homeostasis may contribute to oxidative stress, immune dysfunction and apoptosis, particularly in the cerebellum and temporal lobe, and may lead to neurodevelopmental abnormalities in autism.
Lien vers le texte intégral (Open Access ou abonnement)
5. Chown N. {{‘History and First Descriptions’ of Autism: A response to Michael Fitzgerald}}. {J Autism Dev Disord};2012 (Apr 18)
Letter to the editor in response to Michael Fitzgerald’s controversial allegation that one of the two pioneers of autism-Leo Kanner-may have been influenced by an earlier paper by the other autism pioneer-Hans Asperger-without acknowledging the debt, and that Kanner may even have been guilty of plagiarising Asperger. In correspondence, Professor Fitzgerald has suggested that I « consider doing my take on the matter ». This is it.
Lien vers le texte intégral (Open Access ou abonnement)
6. Cox DJ. {{From Interdisciplinary to Integrated Care of the Child with Autism: the Essential Role for a Code of Ethics}}. {J Autism Dev Disord};2012 (Apr 17)
To address the developmental deficits of children with autism, several disciplines have come to the forefront within intervention programs. These are speech-pathologists, psychologists/counselors, occupational-therapists/physical-therapists, special-education consultants, behavior analysts, and physicians/medical personnel. As the field of autism therapy moves toward a more comprehensive, holistic and interdisciplinary model, the complexity of an interdisciplinary service delivery model could pose significant challenges. The difficulty of carrying out this approach could lead to sub-par programs being established. With integration among the disciplines a necessity, the ethical principles and language common to all the contributing disciplines is argued as the appropriate integrating force. An outline of these principles and a draft code of ethics are offered to introduce high standards and expectations for all participating in such a program.
Lien vers le texte intégral (Open Access ou abonnement)
7. Curran J. {{Book review: Mental health of children and adolescents with intellectual and developmental disabilities: a framework for professional practice}}. {Australas Psychiatry};2012 (Apr);20(2):162-163.
Lien vers le texte intégral (Open Access ou abonnement)
8. Dundas E, Gastgeb H, Strauss MS. {{Left Visual Field Biases when Infants Process Faces: A Comparison of Infants at High- and Low-Risk for Autism Spectrum Disorder}}. {J Autism Dev Disord};2012 (Apr 24)
While it is well-known that individuals with autism spectrum disorder (ASD) have difficulties processing faces, very little is known about the origins of these deficits. The current study focused on 6- and 11-month-old infants who were at either high-risk (n = 43) or low-risk (n = 31) for developing ASD based on having a sibling already diagnosed with the disorder. Eye-tracking data were collected while the infants viewed color photographs of faces. Similar to previous studies with both typically developing adults and infants, low-risk infants demonstrated a preference for looking at the left side of the face (known as a left visual field bias) that emerged by 11 months of age. In contrast, high-risk infants did not demonstrate a left visual field bias at either age. Comparisons of the amount of attention given to the eye versus mouth regions indicated no differences between the two risk groups.
Lien vers le texte intégral (Open Access ou abonnement)
9. Dunst CJ, Hamby DW. {{Guide for calculating and interpreting effect sizes and confidence intervals in intellectual and developmental disability research studies}}. {J Intellect Dev Disabil};2012 (Apr 25)
This paper includes a nontechnical description of methods for calculating effect sizes in intellectual and developmental disability studies. Different hypothetical studies are used to illustrate how null hypothesis significance testing (NHST) and effect size findings can result in quite different outcomes and therefore conflicting results. Whereas NHST uses probability levels (e.g., p < .05) to evaluate the results of studies, effect size analyses focus on the magnitude of differences between groups or contrasting conditions and the strength of the relationship among variables of interest to report and interpret study results. Two families of effect sizes are described (mean difference, correlation coefficients) that are likely to be applicable to most intellectual and developmental disability studies. Sources of information on effect size calculators are included to provide researchers ready-available data analysis procedures for computing effect sizes and confidence intervals for different types of research designs and studies. Lien vers le texte intégral (Open Access ou abonnement)
10. Hall SS, Hammond JL, Hirt M, Reiss AL. {{A ‘learning platform’ approach to outcome measurement in fragile X syndrome: a preliminary psychometric study}}. {J Intellect Disabil Res};2012 (Apr 25)
Background Clinical trials of medications to alleviate the cognitive and behavioural symptoms of individuals with fragile X syndrome (FXS) are now underway. However, there are few reliable, valid and/or sensitive outcome measures available that can be directly administered to individuals with FXS. The majority of assessments employed in clinical trials may be suboptimal for individuals with intellectual disability (ID) because they require face-to-face interaction with an examiner, taxing administration periods, and do not provide reinforcement and/or feedback during the test. We therefore examined the psychometric properties of a new computerised ‘learning platform’ approach to outcome measurement in FXS. Method A brief computerised test, incorporated into the Discrete Trial Trainer(c)- a commercially available software program designed for children with ID – was administered to 13 girls with FXS, 12 boys with FXS and 15 matched ID controls aged 10 to 23 years (mental age = 4 to 12 years). The software delivered automated contingent access to reinforcement, feedback, token delivery and prompting procedures (if necessary) on each trial to facilitate responding. The primary outcome measure was the participant’s learning rate, derived from the participant’s cumulative record of correct responses. Results All participants were able to complete the test and floor effects appeared to be minimal. Learning rates averaged approximately five correct responses per minute, ranging from one to eight correct responses per minute in each group. Test-retest reliability of the learning rates was 0.77 for girls with FXS, 0.90 for boys with FXS and 0.90 for matched ID controls. Concurrent validity with raw scores obtained on the Arithmetic subtest of the Wechsler Intelligence Scale for Children-III was 0.35 for girls with FXS, 0.80 for boys with FXS and 0.56 for matched ID controls. The learning rates were also highly sensitive to change, with effect sizes of 1.21, 0.89 and 1.47 in each group respectively following 15 to 20, 15-min sessions of intensive discrete trial training conducted over 1.5 days. Conclusions These results suggest that a learning platform approach to outcome measurement could provide investigators with a reliable, valid and highly sensitive measure to evaluate treatment efficacy, not only for individuals with FXS but also for individuals with other ID.
Lien vers le texte intégral (Open Access ou abonnement)
11. Hamlin AA, Sukharev D, Campos L, Mu Y, Tassone F, Hessl D, Nguyen DV, Loesch D, Hagerman RJ. {{Hypertension in FMR1 premutation males with and without fragile X-associated tremor/ataxia syndrome (FXTAS)}}. {Am J Med Genet A};2012 (Apr 23)
Fragile X-associated tremor ataxia syndrome (FXTAS) is a late onset neurodegenerative disease that affects carriers of the fragile X premutation. This study seeks to assess hypertension risk and susceptibility in male premutation carriers with FXTAS. Although many symptoms and diagnostic criteria have been identified, hypertension risk has not been examined in this population. Data from 92 premutation carriers without FXTAS, 100 premutation carriers with FXTAS, and 186 controls was collected via patient medical interview. Age-adjusted logistic regression analysis was used to examine the relative odds of hypertension. We observed a significantly elevated odds ratio (OR) of hypertension relative to controls for premutation carriers with FXTAS (OR = 3.22, 95% CI: 1.72-6.04; P = 0.0003) among participants over 40-year old. The age-adjusted estimated odds of hypertension in premutation carriers without FXTAS in the over 40-year-old age group was higher compared to controls (OR = 1.61, 95% CI: 0.82-3.16), but was not statistically significant (P = 0.164). Chronic hypertension contributes to cardiovascular complications, dementia, and increased risk of stroke. Our results indicate that the risk of hypertension is significantly elevated in male premutation carriers with FXTAS compared with carriers without FXTAS and controls. Thus, evaluation of hypertension in patients diagnosed with FXTAS should be a routine part of the treatment monitoring and intervention for this disease. (c) 2012 Wiley Periodicals, Inc.
Lien vers le texte intégral (Open Access ou abonnement)
12. Harris JC. {{Autism risk factors: moving from epidemiology to translational epidemiology}}. {J Am Acad Child Adolesc Psychiatry};2012 (May);51(5):461-463.
Lien vers le texte intégral (Open Access ou abonnement)
13. Hobson RP, Hobson JA, Garcia-Perez R, Du Bois J. {{Dialogic Linkage and Resonance in Autism}}. {J Autism Dev Disord};2012 (Apr 20)
We evaluated how children with autism make linguistic adjustments when talking with someone else. We devised two novel measures to assess (a) overall conversational linkage and (b) utterance-by-utterance resonance within dialogue between an adult and matched participants with and without autism (n = 12 per group). Participants with autism were less able to establish ‘cognitive linkage’ with an interlocutor. As predicted, only among children with autism was there a positive correlation between the ability to link in with speaker’s meanings and ratings of emotional connectedness with the conversational partner. Participants with autism were not less likely to show a basic form of dialogic resonance across successive utterances (the ‘frame grab’), but more often elaborated their responses in an atypical manner.
Lien vers le texte intégral (Open Access ou abonnement)
14. Jacot-Descombes S, Uppal N, Wicinski B, Santos M, Schmeidler J, Giannakopoulos P, Heinsen H, Schmitz C, Hof PR. {{Erratum to: Decreased pyramidal neuron size in Brodmann areas 44 and 45 in patients with autism}}. {Acta Neuropathol};2012 (Apr 24)
Lien vers le texte intégral (Open Access ou abonnement)
15. Kasari C, Gulsrud A, Freeman S, Paparella T, Hellemann G. {{Longitudinal follow-up of children with autism receiving targeted interventions on joint attention and play}}. {J Am Acad Child Adolesc Psychiatry};2012 (May);51(5):487-495.
OBJECTIVE: This study examines the cognitive and language outcomes of children with an autism spectrum disorder (ASD) over a 5-year period after receiving targeted early interventions that focused on joint attention and play skills. METHOD: Forty children from the original study (n = 58) had complete data at the 5-year follow-up. RESULTS: In all, 80% of children had achieved functional use of spoken language with baseline play level predicting spoken language at the 5-year follow-up. Of children who were using spoken language at age 8 years, several baseline behaviors predicted their later ability, including earlier age of entry into the study, initiating joint attention skill, play level, and assignment to either the joint attention or symbolic play intervention group. Only baseline play diversity predicted cognitive scores at age 8 years. CONCLUSIONS: This study is one of the only long-term follow-up studies of children who participated in preschool early interventions aimed at targeting core developmental difficulties. The study findings suggest that focusing on joint attention and play skills in comprehensive treatment models is important for long-term spoken language outcomes.
Lien vers le texte intégral (Open Access ou abonnement)
16. Lutz HR, Patterson BJ, Klein J. {{Coping with autism: a journey toward adaptation}}. {J Pediatr Nurs};2012 (Jun);27(3):206-213.
As the number of individuals with autism grows, it is critical for nurses in all settings to understand how autism influences the family unit, as they will likely interact with these children, the adults, and their families. The intent of this descriptive narrative study was to explore the experiences of families of individuals with autism as perceived by the mother. Through personal interviews, 16 mothers’ perceptions of the impact of autism on the family unit during different stages of the life cycle were revealed through a constructivist lens. Pediatric nurses employed in acute care settings, community, and schools are poised to assess and support these families following diagnosis and throughout the child’s life.
Lien vers le texte intégral (Open Access ou abonnement)
17. Main PA, Angley MT, O’Doherty CE, Thomas P, Fenech M. {{The potential role of the antioxidant and detoxification properties of glutathione in autism spectrum disorders: a systematic review and meta-analysis}}. {Nutr Metab (Lond)};2012 (Apr 24);9(1):35.
ABSTRACT: BACKGROUND: Glutathione has a wide range of functions; it is an endogenous anti-oxidant and plays a key role in the maintenance of intracellular redox balance and detoxification of xenobiotics. Several studies have indicated that children with autism spectrum disorders may have altered glutathione metabolism which could play a key role in the condition. METHODS: A systematic literature review and meta-analysis was conducted of studies examining metabolites, interventions and/or genes of the glutathione metabolism pathways i.e. the gamma-glutamyl cycle and trans-sulphuration pathway in autism spectrum disorders. RESULTS: Thirty nine studies were included in the review comprising an in vitro study, thirty two metabolite and/or co-factor studies, six intervention studies and six studies with genetic data as well as eight studies examining enzyme activity. CONCLUSIONS: The review found evidence for the involvement of the gamma-glutamyl cycle and trans-sulphuration pathway in autistic disorder is sufficiently consistent, particularly with respect to the glutathione redox ratio, to warrant further investigation to determine the significance in relation to clinical outcomes. Large, well designed intervention studies that link metabolites, cofactors and genes of the gamma-glutamyl cycle and trans-sulphuration pathway with objective behavioural outcomes in children with autism spectrum disorders are required. Future risk factor analysis should include consideration of multiple nutritional status and metabolite biomarkers of pathways linked with the gamma-glutamyl cycle and the interaction of genotype in relation to these factors.
Lien vers le texte intégral (Open Access ou abonnement)
18. Molnar-Szakacs I, Heaton P. {{Music: a unique window into the world of autism}}. {Ann N Y Acad Sci};2012 (Apr);1252(1):318-324.
Understanding emotions is fundamental to our ability to navigate the complex world of human social interaction. Individuals with autism spectrum disorders (ASD) experience difficulties with the communication and understanding of emotions within the social domain. Their ability to interpret other people’s nonverbal, facial, and bodily expressions of emotion is strongly curtailed. However, there is evidence to suggest that many individuals with ASD show a strong and early preference for music and are able to understand simple and complex musical emotions in childhood and adulthood. The dissociation between emotion recognition abilities in musical and social domains in individuals with ASD provides us with the opportunity to consider the nature of emotion processing difficulties characterizing this disorder. There has recently been a surge of interest in musical abilities in individuals with ASD, and this has motivated new behavioral and neuroimaging studies. Here, we review this new work. We conclude by providing some questions for future directions.
Lien vers le texte intégral (Open Access ou abonnement)
19. Osada H, Tachimori H, Koyama T, Kurita H. {{Longitudinal Developmental Courses in Japanese Children with Autism Spectrum Disorder}}. {Child Psychiatry Hum Dev};2012 (Apr 20)
We followed up 67 children with autistic disorder (AD) and 31 children with pervasive developmental disorder not otherwise specified (PDDNOS) for more than 10 years by reviewing medical records at a clinic for children with developmental disabilities. The participants’ data were collected between their first visit to the clinic and the visit at which they applied for basic disability benefits. The standardized IQ scores and autistic symptoms were examined as measures of the children’s personal functioning. For environmental factors, we examined the participants’ educational placements and work and residential status. Using structural equation modeling, we examined the longitudinal developmental courses of AD and PDDNOS. Participants diagnosed with AD consistently showed lower IQ and more severe autistic symptoms than those diagnosed with PDDNOS. Relationships between personal functioning and environmental factors differed between the two groups. AD and PDDNOS are heterogeneous, so they must be treated differently to improve children’s prognoses.
Lien vers le texte intégral (Open Access ou abonnement)
20. Ouimet T, Foster NE, Tryfon A, Hyde KL. {{Auditory-musical processing in autism spectrum disorders: a review of behavioral and brain imaging studies}}. {Ann N Y Acad Sci};2012 (Apr);1252(1):325-331.
Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by atypical social and communication skills, repetitive behaviors, and atypical visual and auditory perception. Studies in vision have reported enhanced detailed (« local ») processing but diminished holistic (« global ») processing of visual features in ASD. Individuals with ASD also show enhanced processing of simple visual stimuli but diminished processing of complex visual stimuli. Relative to the visual domain, auditory global-local distinctions, and the effects of stimulus complexity on auditory processing in ASD, are less clear. However, one remarkable finding is that many individuals with ASD have enhanced musical abilities, such as superior pitch processing. This review provides a critical evaluation of behavioral and brain imaging studies of auditory processing with respect to current theories in ASD. We have focused on auditory-musical processing in terms of global versus local processing and simple versus complex sound processing. This review contributes to a better understanding of auditory processing differences in ASD. A deeper comprehension of sensory perception in ASD is key to better defining ASD phenotypes and, in turn, may lead to better interventions.
Lien vers le texte intégral (Open Access ou abonnement)
21. Park CJ, Yelland GW, Taffe JR, Gray KM. {{Brief Report: The Relationship Between Language Skills, Adaptive Behavior, and Emotional and Behavior Problems in Pre-schoolers with Autism}}. {J Autism Dev Disord};2012 (Apr 24)
This study investigated the relationship between structural language skills, and communication skills, adaptive behavior, and emotional and behavior problems in pre-school children with autism. Participants were aged 3-5 years with autism (n = 27), and two comparison groups of children with developmental delay without autism (n = 12) and typically developing children (n = 20). The participants were administered standardised tests of structural language skills, and parents completed the Vineland Adaptive Behavior Scales and the Developmental Behaviour Checklist. Results indicated that for children with autism, communication skills, and in particular receptive communication skills, were associated with social and daily living skills, and behavior problems. Receptive structural language skills were associated with expressive communication skills. There were no associations found between structural language skills and social or daily living skills, nor behavior problems. The results of this study suggest that communication skills are more closely linked to functional and behavioral outcomes in autism than structural language skills.
Lien vers le texte intégral (Open Access ou abonnement)
22. Rai D, Lewis G, Lundberg M, Araya R, Svensson A, Dalman C, Carpenter P, Magnusson C. {{Parental socioeconomic status and risk of offspring autism spectrum disorders in a Swedish population-based study}}. {J Am Acad Child Adolesc Psychiatry};2012 (May);51(5):467-476 e466.
OBJECTIVE: Epidemiological studies in the United States consistently find autism spectrum disorders (ASD) to be overrepresented in high socioeconomic status (SES) families. These findings starkly contrast with SES gradients of many health conditions, and may result from SES inequalities in access to services. We hypothesized that prenatal measures of low, not high, parental SES would be associated with an increased risk of offspring ASD, once biases in case ascertainment are minimized. METHOD: We tested this hypothesis in a population-based study in Sweden, a country that has free universal healthcare, routine screening for developmental problems, and thorough protocols for diagnoses of ASD. In a case-control study nested in a total population cohort of children aged 0 to 17 years living in Stockholm County between 2001 and 2007 (N = 589,114), we matched ASD cases (n = 4,709) by age and sex to 10 randomly selected controls. We retrieved parental SES measures collected at time of birth by record linkage. RESULTS: Children of families with lower income, and of parents with manual occupations (OR = 1.4, 95% CI = 1.3-1.6) were at higher risk of ASD. No important relationships with parental education were observed. These associations were present after accounting for parental ages, migration status, parity, psychiatric service use, maternal smoking during pregnancy, and birth characteristics; and regardless of comorbid intellectual disability. CONCLUSIONS: Lower, not higher, socioeconomic status was associated with an increased risk of ASD. Studies finding the opposite may be underestimating the burden of ASD in lower SES groups.
Lien vers le texte intégral (Open Access ou abonnement)
23. Robinson L, Guy J, McKay L, Brockett E, Spike RC, Selfridge J, De Sousa D, Merusi C, Riedel G, Bird A, Cobb SR. {{Morphological and functional reversal of phenotypes in a mouse model of Rett syndrome}}. {Brain};2012 (Apr 23)
Rett syndrome is a neurological disorder caused by mutation of the X-linked MECP2 gene. Mice lacking functional Mecp2 display a spectrum of Rett syndrome-like signs, including disturbances in motor function and abnormal patterns of breathing, accompanied by structural defects in central motor areas and the brainstem. Although routinely classified as a neurodevelopmental disorder, many aspects of the mouse phenotype can be effectively reversed by activation of a quiescent Mecp2 gene in adults. This suggests that absence of Mecp2 during brain development does not irreversibly compromise brain function. It is conceivable, however, that deep-seated neurological defects persist in mice rescued by late activation of Mecp2. To test this possibility, we have quantitatively analysed structural and functional plasticity of the rescued adult male mouse brain. Activation of Mecp2 in approximately 70% of neurons reversed many morphological defects in the motor cortex, including neuronal size and dendritic complexity. Restoration of Mecp2 expression was also accompanied by a significant improvement in respiratory and sensory-motor functions, including breathing pattern, grip strength, balance beam and rotarod performance. Our findings sustain the view that MeCP2 does not play a pivotal role in brain development, but may instead be required to maintain full neurological function once development is complete.
Lien vers le texte intégral (Open Access ou abonnement)
24. Rodgers J, Glod M, Connolly B, McConachie H. {{The Relationship Between Anxiety and Repetitive Behaviours in Autism Spectrum Disorder}}. {J Autism Dev Disord};2012 (Apr 17)
Children with Autism Spectrum Disorder are vulnerable to anxiety. Repetitive behaviours are a core feature of Autism Spectrum Disorder (ASD) and have been associated anxiety. This study examined repetitive behaviours and anxiety in two groups of children with autism spectrum disorder, those with high anxiety and those with lower levels of anxiety. Children with high anxiety had more repetitive behaviours than those without anxiety. Within the anxiety sample, higher levels of insistence on sameness were associated with more anxiety. No association was found between sensory motor repetitive behaviours and anxiety in this group. In the non-anxious sample, anxiety was associated with sensory motor repetitive behaviours. These findings indicate a differential relationship for repetitive behaviours in relation to anxious and non-anxious children with ASD.
Lien vers le texte intégral (Open Access ou abonnement)
25. Sandin S, Hultman CM, Kolevzon A, Gross R, Maccabe JH, Reichenberg A. {{Advancing maternal age is associated with increasing risk for autism: a review and meta-analysis}}. {J Am Acad Child Adolesc Psychiatry};2012 (May);51(5):477-486 e471.
OBJECTIVE: We conducted a meta-analysis of epidemiological studies investigating the association between maternal age and autism. METHOD: Using recommended guidelines for performing meta-analyses, we systematically selected, and extracted results from, epidemiological scientific studies reported before January 2012. We calculated pooled risk estimates comparing categories of advancing maternal age with and without adjusting for possible confounding factors. We investigated the influence of gender ratio among cases, ratio of infantile autism to autism spectrum disorder (ASD), and median year of diagnosis as effect moderators in mixed-effect meta-regression. RESULTS: We found 16 epidemiological papers fulfilling the a priori search criteria. The meta-analysis included 25,687 ASD cases and 8,655,576 control subjects. Comparing mothers >/=35 years with mothers 25 to 29 years old, the crude relative risk (RR) for autism in the offspring was 1.52 (95% confidence interval [CI] = 1.12-1.92). Comparing mothers >/=35 with mothers 25 to 29, the adjusted relative risk (RR) for autism in the offspring was 1.52 (95% CI = 1.12-1.92). For mothers <20 compared with mothers 25 to 29 years old, there was a statistically significant decrease in risk (RR = 0.76; 95% confidence interval = 0.60-0.97). Almost all studies showed a dose-response effect of maternal age on risk of autism. The meta-regression suggested a stronger maternal age effect in the studies with more male offspring and for children diagnosed in later years. CONCLUSIONS: The results of this meta-analysis support an association between advancing maternal age and risk of autism. The RR increased monotonically with increasing maternal age. The association persisted after the effects of paternal age and other potential confounders had been considered, supporting an independent relation between higher maternal age and autism.
Lien vers le texte intégral (Open Access ou abonnement)
26. Veenstra-Vanderweele J. {{In this issue/abstract thinking: evolving picture of susceptibility factors in autism spectrum disorders}}. {J Am Acad Child Adolesc Psychiatry};2012 (May);51(5):453-454.
Lien vers le texte intégral (Open Access ou abonnement)
27. Vernon TW, Koegel RL, Dauterman H, Stolen K. {{An Early Social Engagement Intervention for Young Children with Autism and their Parents}}. {J Autism Dev Disord};2012 (Apr 24)
The social vulnerabilities associated with young children with autism are recognized as important intervention targets due to their influence on subsequent development. Current research suggests that interventions that combine motivational and social components can create meaningful changes in social functioning. Simultaneously, it is hypothesized that parent delivery of such strategies can invoke increases in these core social behaviors and parent engagement. This study examined the effects of teaching parents to implement a social engagement intervention with their children. The results indicated that the use of this parent-delivered social intervention led to (a) increases in their children’s use of eye contact, directed positive affect, and verbal initiations, (b) increases in parent positive affect and synchronous engagement, and (c) generalized increases in parent and child behaviors.
Lien vers le texte intégral (Open Access ou abonnement)
28. Wan CY, Marchina S, Norton A, Schlaug G. {{Atypical hemispheric asymmetry in the arcuate fasciculus of completely nonverbal children with autism}}. {Ann N Y Acad Sci};2012 (Apr);1252(1):332-337.
Despite the fact that as many as 25% of the children diagnosed with autism spectrum disorders are nonverbal, surprisingly little research has been conducted on this population. In particular, the mechanisms that underlie their absence of speech remain unknown. Using diffusion tensor imaging, we compared the structure of a language-related white matter tract (the arcuate fasciculus, AF) in five completely nonverbal children with autism to that of typically developing children. We found that, as a group, the nonverbal children did not show the expected left-right AF asymmetry-rather, four of the five nonverbal children actually showed the reversed pattern. It is possible that this unusual pattern of asymmetry may underlie some of the severe language deficits commonly found in autism, particularly in children whose speech fails to develop. Furthermore, novel interventions (such as auditory-motor mapping training) designed to engage brain regions that are connected via the AF may have important clinical potential for facilitating expressive language in nonverbal children with autism.
Lien vers le texte intégral (Open Access ou abonnement)
29. Wong N, Beidel DC, Sarver DE, Sims V. {{Facial Emotion Recognition in Children with High Functioning Autism and Children with Social Phobia}}. {Child Psychiatry Hum Dev};2012 (Apr 17)
Recognizing facial affect is essential for effective social functioning. This study examines emotion recognition abilities in children aged 7-13 years with High Functioning Autism (HFA = 19), Social Phobia (SP = 17), or typical development (TD = 21). Findings indicate that all children identified certain emotions more quickly (e.g., happy < anger, disgust, sad < fear) and more accurately (happy) than other emotions (disgust). No evidence was found for negative interpretation biases in children with HFA or SP (i.e., all groups showed similar ability to discriminate neutral from non-neutral facial expressions). However, distinct between-group differences emerged when considering facial expression intensity. Specifically, children with HFA detected mild affective expressions less accurately than TD peers. Behavioral ratings of social effectiveness or social anxiety were uncorrelated with facial affect recognition abilities across children. Findings have implications for social skills treatment programs targeting youth with skill deficits.
