Pubmed du 11/07/09

Pubmed du jour

2009-07-11 12:03:50

1. Ames CS, Jarrold C. {{Identifying Symbolic Relationships in Autism Spectrum Disorders: A Deficit in the Identification of Temporal Co-occurrence?}}{ J Autism Dev Disord};2009 (Jul 11)

Individuals with Autism spectrum disorders (ASD) experience difficulties understanding the non-verbal cues conveyed by others that provide symbolic information about relationships between self, other, and environmental events. This study examined whether these difficulties reflect underlying problems in the identification of temporal co-occurrence, or in memorial, associative, or inference skills. The performance of a group of adolescents with ASD was compared to that of typically developing children and adolescents with learning difficulties on four tasks assessing these processes. The ASD group experienced specific difficulties when they were required to identify relationships signalled by the temporal co-occurrence of stimuli. These results are discussed in relation to theories of conceptual deduction in ASD, and a hypothesised role in social cognitive development for attention processes is outlined.

2. Chawarska K, Shic F. {{Looking But Not Seeing: Atypical Visual Scanning and Recognition of Faces in 2 and 4-Year-Old Children with Autism Spectrum Disorder}}. {J Autism Dev Disord};2009 (Jul 10)

This study used eye-tracking to examine visual scanning and recognition of faces by 2- and 4-year-old children with autism spectrum disorder (ASD) (N = 44) and typically developing (TD) controls (N = 30). TD toddlers at both age levels scanned and recognized faces similarly. Toddlers with ASD looked increasingly away from faces with age, atypically attended to key features of faces, and were impaired in face recognition. Deficits in recognition were associated with imbalanced attention between key facial features. This study illustrates that face processing in ASD may be affected early and become further compromised with age. We propose that deficits in face processing likely impact the effectiveness of toddlers with ASD as social partners and thus should be targeted for intervention.

3. De Giacomo A, Portoghese C, Martinelli D, Fanizza I, L’Abate L, Margari L. {{Imitation and communication skills development in children with pervasive developmental disorders}}. {Neuropsychiatr Dis Treat};2009 (Jul);5(3):355-362.

This study evaluates the correlation between failure to develop spontaneous imitation and language skills in pervasive developmental disorders. Sixty-four children between the age of 3 and 8 years were assessed using the Autism Diagnostic Interview-Revised (ADI-R), the Childhood Autism Rating Scale (CARS), and the Autism Diagnostic Observation Schedule (ADOS), as well as direct observation of imitation. The sample was subdivided into a verbal and a nonverbal group. Analysis of mean scores on the CARS « imitation » items and of ADI-R « spontaneous imitation » and « pointing to express interest » revealed a statistically significant difference between verbal and nonverbal groups, with more severe impairment/higher scores in the nonverbal than the verbal group. These results suggest that nonverbal children have specifically impaired imitation and pointing skills.

4. Lubisch N, Roskos R, Berkenbosch JW. {{Dexmedetomidine for procedural sedation in children with autism and other behavior disorders}}. {Pediatr Neurol};2009 (Aug);41(2):88-94.

Dexmedetomidine has been increasingly in use for pediatric noninvasive procedural sedation. This retrospective study examined experience in children with autism and other neurobehavioral disorders, populations often difficult to sedate. Records of children with autism or neurobehavioral disorders sedated with dexmedetomidine at Chris Evert Children’s Hospital and Kosair Children’s Hospital were reviewed. Demographic and sedation-related data were collected, including sedative doses, time to sedation, efficacy, and complications. Comparisons of sedative doses, efficacy between autism and neurobehavioral patients, and analysis of age-related factors were performed. In all, 315 patients were sedated, most commonly for magnetic resonance imaging. Mean induction and total dexmedetomidine doses were 1.4 +/- 0.6 and 2.6 +/- 1.6 microg/kg, respectively, with no differences between autism and neurobehavior patients. Most patients (90%) patients received concomitant midazolam. There was an age-related decrease in dexmedetomidine dose, independent of midazolam use. Seven patients required intervention for hypotension, bradycardia, or both, and only one adverse respiratory event (obstruction requiring nasopharyngeal airway placement) occurred. There were two episodes of overt recovery-related agitation. All but four procedures were successfully completed (4/315, or 98.7%). Dexmedetomidine with or without midazolam was an effective sedative in this population. The regimen appeared to be well tolerated with few adverse events, including recovery-related agitation, and appears to be an attractive option for this population.

5. Reichow B, Sabornie EJ. {{Brief Report: Increasing Verbal Greeting Initiations for a Student with Autism Via a Social Story Intervention}}. {J Autism Dev Disord};2009 (Jul 11)

Social Stories are a common intervention for addressing the social skills deficits individuals with autism often demonstrate. In this study, a Social Story intervention was used to increase acceptable verbal greeting initiations with an 11-year-old boy who had a diagnosis of high functioning autism. A withdrawal design with a comparison condition examined the frequency of acceptable verbal greeting initiations during 5 min observation periods. Results showed no acceptable verbal greeting initiations during both baseline conditions, increased frequency of acceptable verbal greeting initiations during both intervention conditions, and maintenance of intervention levels of behavior with visual supports during the comparison condition.

6. Simms ML, Kemper TL, Timbie CM, Bauman ML, Blatt GJ. {{The anterior cingulate cortex in autism: heterogeneity of qualitative and quantitative cytoarchitectonic features suggests possible subgroups}}. {Acta Neuropathol};2009 (Jul 10)

Autism is a behaviorally defined disorder with deficits in social interaction, communication, atypical behaviors, and restricted areas of interest. Postmortem studies of the brain in autism have shown a broad spectrum of abnormalities in the cerebellum and neocortex, involving limbic regions such as anterior cingulate cortex (ACC, Brodmann’s area 24). Using stereological techniques, we analyzed quantitatively cytoarchitectonic subdomains of the ACC (areas 24a, b, c) with regard to cell packing density and cell size. Microscopic examination of the ACC was also done to identify any neuropathologies. Results showed a significant decrease in cell size in layers I-III and layers V-VI of area 24b and in cell packing density in layers V-VI of area 24c. Direct comparisons revealed irregular lamination in three of nine autism brains and increased density of neurons in the subcortical white matter in the remaining cases. Because previous studies have suggested that von Economo neurons (VENs) may be altered in autism, a preliminary study of their density and size was undertaken. VEN density did not differ between autism and control brains overall. However, among the nine autism cases, there were two subsets; three brains with significantly increased VEN density and the remaining six cases with reduced VEN density compared to controls. Collectively, the findings of this pilot study may reflect the known heterogeneity in individuals with autism and variations in clinical symptomotology. Further neuroanatomic analyses of the ACC, from carefully documented subjects with autism, could substantially expand our understanding of ACC functions and its role in autism.

7. Stokstad E. {{Scientific community. Resignations highlight disagreement on vaccines in autism group}}. {Science};2009 (Jul 10);325(5937):135.