1. Bao X, Downs J, Wong K, Williams S, Leonard H. {{Using a large international sample to investigate epilepsy in Rett syndrome}}. {Dev Med Child Neurol};2013 (Feb 19)
AIM: The aim of this study was to identify characteristics of epilepsy in Rett syndrome (RTT), and relationships between epilepsy and genotype. METHOD: Information on 685 females with RTT recruited to the international Rett syndrome database (InterRett) with a pathogenic MECP2 mutation was obtained from family and clinician questionnaires. Individuals with RTT were aged 1 year 4 months to 54 years 2 months (mean 11y 1mo; SD 9y 4mo). RESULTS: Among them, 61% had epilepsy, with half diagnosed by the age of 5 years. Those with a large deletion had the earliest median age at epilepsy onset and those with p.R133C the latest age at onset. The highest rate of active epilepsy (54%) was in those aged 12 to 17 years. Compared with those with a p.R133C mutation, active seizures were more likely to be reported in those with a large deletion (odds ratio 3.71; 95% confidence interval 1.13-12.17) or p.T158M (odds ratio 2.92; 95% confidence interval 1.04-8.20). Commonly used medicines included valproate (47%), carbamazepine (39%), lamotrigine (30%), levetiracetam (24%), and topiramate (19%). INTERPRETATION: Genotype influences the age at onset and severity of epilepsy in RTT. Large sample sizes as available through InterRett assist in understanding the complexity of epilepsy in RTT in relation to genotype.
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2. Barneveld PS, de Sonneville L, van Rijn S, van Engeland H, Swaab H. {{Impaired Response Inhibition in Autism Spectrum Disorders, a Marker of Vulnerability to Schizophrenia Spectrum Disorders?}}. {J Int Neuropsychol Soc};2013 (Feb 21):1-10.
In this study, we addressed the relation between specific deficits in cognitive control and schizotypal symptomatology in adolescents with autism spectrum disorders (ASD) diagnosed in childhood. We aimed to identify cognitive control deficits as markers of vulnerability to the development of schizophrenia spectrum pathology in ASD. Symptoms of autism and the risk for schizotypal symptomatology were assessed in 29 high-functioning adolescents with ASD, and compared with 40 typically developing adolescents. Cognitive control (response inhibition, mental flexibility, visuo-motor control, interference control, and perseveration) was evaluated for specific association with schizotypal symptomatology. Impaired response inhibition appeared to be strongly and specifically associated with schizotypal symptomatology in adolescents with ASD, especially those with positive and disorganized symptoms. Response inhibition problems could indicate vulnerability to the development of schizotypal symptomatology in ASD. (JINS, 2013, 19, 1-10).
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3. Benvenuto A, Marciano S, Capuano I, Curatolo P. {{An update on autism spectrum disorders in children}}. {Minerva Pediatr};2013 (Feb);65(1):19-36.
Autism spectrum disorders (ASDs) constitute a class of severe neurodevelopmental conditions caused by atypical brain development beginning during early prenatal or postnatal life. Autistic features begin to be evident in children between 12 and 18 months of age and are considered to be life-long conditions, with core symptoms being permanent across the lifespan. Etiology is multifactorial, involving a strong genetic underpinning. Studies of genetic and environmental epigenetic factors are beginning to provide some clues to clarify the complexities of autism pathogenesis, associated with altered functional and structural connectivity patterns in several brain regions that occur early in life. Genetic syndromes, defined chromosomal abnormalities, and metabolic diseases account for less than 20% of autistic patients and etiologic causes of ASDs remain elusive in more than 80% of cases. Currently, no treatments have been proven to completely reverse the core symptoms but progress in early detection of autistic symptoms in young children has promoted earlier interventions, which should begin soon after the diagnosis is made and be individualized and intensive, for reaching more positive outcomes in terms of cognitive improvement and decrease of symptoms severity. The management of individuals with ASDs requires a multimodal approach of behavioral, medical and pharmacological treatments. Therefore, it is highly important for pediatricians to recognize early signs of ASDs and to know multiple genetic and non genetic disorders that underlie autistic phenotype.
4. Brock J, Bzishvili S. {{Deconstructing Frith and Snowling’s homograph-reading task: Implications for autism spectrum disorders}}. {Q J Exp Psychol (Hove)};2013 (Feb 21)
The poor performance of autistic individuals on a test of homograph reading is widely interpreted as evidence for a reduction in sensitivity to context termed « weak central coherence ». To better understand the cognitive processes involved in completing the homograph-reading task, we monitored the eye movements of nonautistic adults as they completed the task. Using single trial analysis, we determined that the time between fixating and producing the homograph (eye-to-voice span) increased significantly across the experiment and predicted accuracy of homograph pronunciation, suggesting that participants adapted their reading strategy to minimize pronunciation errors. Additionally, we found evidence for interference from previous trials involving the same homograph. This progressively reduced the initial advantage for dominant homograph pronunciations as the experiment progressed. Our results identify several additional factors that contribute to performance on the homograph reading task and may help to reconcile the findings of poor performance on the test with contradictory findings from other studies using different measures of context sensitivity in autism. The results also undermine some of the broader theoretical inferences that have been drawn from studies of autism using the homograph task. Finally, we suggest that this approach to task deconstruction might have wider applications in experimental psychology.
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5. Carter M, Scherer S. {{Autism spectrum disorder in the genetics clinic: a review}}. {Clin Genet};2013 (Feb 21)
Autism spectrum disorders (ASDs) are a heterogeneous group of neurodevelopmental disorders affecting social communication, language and behavior. The underlying cause(s) in a given individual is often elusive, with the exception of clinically recognizable genetic syndromes with readily available molecular diagnosis, such as fragile X syndrome. Clinical geneticists approach patients with ASDs by ruling out known genetic and genomic syndromes, leaving more than 80% of families without a definitive diagnosis and an uncertain risk of recurrence. Advances in microarray technology and next-generation sequencing are revealing rare variants in genes with important roles in synapse formation, function and maintenance. This review will focus on the clinical approach to ASDs, given the current state of knowledge about their complex genetic architecture.
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6. Clarke A. {{How much further can large international databases take Rett syndrome research?}}. {Dev Med Child Neurol};2013 (Feb 19)
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7. Coffey MJ. {{Resolution of self-injury with phenytoin in a man with autism and intellectual disability: the role of frontal lobe seizures and catatonia}}. {J ECT};2013 (Mar);29(1):e12-13.
ABSTRACT: Self-injurious behaviors are common, distressing features of developmental disorders. Safe and effective therapies are needed, and the pathophysiology is not well understood. We present a young man with autism who developed self-injurious behaviors due to frontal lobe seizures that resolved with phenytoin.
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8. Guglielmo R, Ioime L, Grandinetti P, Janiri L. {{Managing Disruptive and Compulsive Behaviors in Adult With Autistic Disorder With Gabapentin}}. {J Clin Psychopharmacol};2013 (Feb 14)
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9. James SJ, Shpyleva S, Melnyk S, Pavliv O, Pogribny IP. {{Complex epigenetic regulation of Engrailed-2 (EN-2) homeobox gene in the autism cerebellum}}. {Transl Psychiatry};2013;3:e232.
The elucidation of epigenetic alterations in the autism brain has potential to provide new insights into the molecular mechanisms underlying abnormal gene expression in this disorder. Given strong evidence that engrailed-2 (EN-2) is a developmentally expressed gene relevant to cerebellar abnormalities and autism, the epigenetic evaluation of this candidate gene was undertaken in 26 case and control post-mortem cerebellar samples. Assessments included global DNA methylation, EN-2 promoter methylation, EN-2 gene expression and EN-2 protein levels. Chromatin immunoprecipitation was used to evaluate trimethylation status of histone H3 lysine 27 (H3K27) associated with gene downregulation and histone H3 lysine 4 (H3K4) associated with gene activation. The results revealed an unusual pattern of global and EN-2 promoter region DNA hypermethylation accompanied by significant increases in EN-2 gene expression and protein levels. Consistent with EN-2 overexpression, histone H3K27 trimethylation mark in the EN-2 promoter was significantly decreased in the autism samples relative to matched controls. Supporting a link between reduced histone H3K27 trimethylation and increased EN-2 gene expression, the mean level of histone H3K4 trimethylation was elevated in the autism cerebellar samples. Together, these results suggest that the normal EN-2 downregulation that signals Purkinje cell maturation during late prenatal and early-postnatal development may not have occurred in some individuals with autism and that the postnatal persistence of EN-2 overexpression may contribute to autism cerebellar abnormalities.
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10. Latham K, Chung ST, Allen PM, Tavassoli T, Baron-Cohen S. {{Spatial localisation in autism: evidence for differences in early cortical visual processing}}. {Mol Autism};2013 (Feb 19);4(1):4.
ABSTRACT: BACKGROUND: Vision in people with autism spectrum conditions (ASC) is reported to be different from people without ASC, but the neural level at which the differences begin to occur is not yet known. Here we examine two variants of a vernier acuity task to determine if differences are evident in early visual processing. FINDINGS: Abutting and separated vernier acuity was assessed in 16 people with ASC and 14 matched controls. In controls, abutting and separated thresholds were unrelated (r = 0.13, p = 0.65), suggesting thresholds are determined by two separate mechanisms. In contrast, the abutting and separated thresholds of ASC observers were strongly correlated (r = 0.88, p < 0.0001), with separated thresholds tending towards being superior to those of controls [t(28) = -2.46, p = 0.02]. CONCLUSIONS: The findings suggest the mechanisms employed by ASC observers in separated vernier tasks are different to those of controls. This psychophysical evidence suggests that visual differences in ASC may begin at an early cortical stage of visual processing.
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11. Marsh KL, Isenhower RW, Richardson MJ, Helt M, Verbalis AD, Schmidt RC, Fein D. {{Autism and social disconnection in interpersonal rocking}}. {Front Integr Neurosci};2013;7:4.
Individuals with autism spectrum disorders (ASDs) have significant visuomotor processing deficits, atypical motoric behavior, and often substantial problems connecting socially. We suggest that the perceptual, attentional, and adaptive timing deficiencies associated with autism might directly impact the ability to become a socially connected unit with others. Using a rocking chair paradigm previously employed with typical adults, we demonstrate that typically-developing (TD) children exhibit spontaneous social rocking with their caregivers. In contrast, children diagnosed with ASD do not demonstrate a tendency to rock in a symmetrical state with their parents. We argue that the movement of our bodies is one of the fundamental ways by which we connect with our environment and, especially, ground ourselves in social environments. Deficiencies in perceiving and responding to the rhythms of the world may have serious consequences for the ability to become adequately embedded in a social context.
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12. Tallantyre E, Robertson NP. {{Autism and intellectual disability}}. {J Neurol};2013 (Feb 20)
