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ABSTRACT: Current theories of brain function propose that the coordinated integration of transient activity patterns in distinct brain regions is the essence of brain information processing. The behavioural manifestations of individuals with autism spectrum disorders (ASD) suggest that their brains have a different style of information processing. Specifically, a current trend is to invoke functional disconnection in the brains of individuals with ASD as a possible explanation for some atypicalities in the behaviour of these individuals. Our observations indicate that the coordinated activity in brains of children with autism is lower than that found in control participants. Disruption of long-range phase synchronization among frontal, parietal and occipital areas was found, derived from magnetoencephalographic (MEG) recordings, in high-functioning children with ASD during the performance of executive function tasks and was associated with impaired execution, while enhanced long-range brain synchronization was observed in control children. Specifically, a more significant prefrontal synchronization was found in control participants during task performance. In addition, a robust enhancement in synchrony was observed in the parietal cortex of children with ASD relative to controls, which may be related to parietal lobe abnormalities detected in these individuals. These results, using synchronization analysis of brain electrical signals, provide support for the contention that brains of individuals with autism may not be as functionally connected as that of the controls, and may suggest some therapeutic interventions to improve information processing in specific brain areas, particularly prefrontal cortices.
International journal of psychophysiology: official journal of the International Organization of Psychophysiology 06/2009; 73(3):341-9. · 3.05 Impact Factor
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ABSTRACT: Earlier intervention improves outcomes for children with autism spectrum disorders (ASDs), but existing identification tools are at the limits of standardization with 18-month-olds. We assessed potential behavioural markers of ASD at 18 months in a high-risk cohort of infant siblings of children with ASD. Prospective data were collected using the Autism Diagnostic Observation Schedule (ADOS) and Autism Observation Scale for Infants (AOSI) on 155 infant siblings and 73 low-risk controls at 18 months. Infants were classified into three groups (ASD sibs, non-ASD sibs, controls) based on blind best-estimate diagnosis at age 3. Fisher's exact tests, followed by discriminant function analyses, revealed that the majority of informative ADOS items came from the social and behavioural domains, and AOSI items measuring behavioural reactivity and motor control contributed additional information. Findings highlight the importance of considering not only social-communication deficits, but also basic dimensions of temperament including state regulation and motor control when assessing toddlers with suspected ASD.
Autism 10/2008; 12(5):433-56. · 2.27 Impact Factor
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ABSTRACT: Anecdotal reports on the efficacy of secretin in autism raised great hopes for the treatment of children with this disorder. Initial single-dose, randomized, controlled trials failed to demonstrate any therapeutic effects of secretin. The present study is the first to test the outcome of repeated doses and to examine whether there is a subgroup of children who are more likely to achieve positive effects.
Sixty-four children with autism (ages 2-7 years; 55 boys and 9 girls) with a range of intelligence quotient and verbal ability were randomly assigned, in a double-blind manner, to secretin or placebo groups. Children received 2 doses of placebo or porcine secretin, 6 weeks apart. Assessments were performed at baseline and 3 weeks after each injection using several outcome measures.
There were no group differences on formal measures of language, cognition, or autistic symptomatology. Subgroupings based on cognitive level, the presence or absence of diarrhea, or a history of regression failed to show any significant therapeutic effects of secretin.
No evidence is provided for the efficacy of repeated doses of porcine secretin in the treatment of children with autism. The possible relationship between relief of biological symptoms and enhanced skill performance is discussed.
PEDIATRICS 06/2001; 107(5):E71. · 4.47 Impact Factor
