1. Enticott PG, Bradshaw JL, Iansek R, Tonge BJ, Rinehart NJ. {{Electrophysiological signs of supplementary-motor-area deficits in high-functioning autism but not Asperger syndrome: an examination of internally cued movement-related potentials}}. {Dev Med Child Neurol};2009 (Mar 9)
Aims Motor dysfunction is common to both autism and Asperger syndrome, but the underlying neurophysiological impairments are unclear. Neurophysiological examinations of motor dysfunction can provide information about likely sites of functional impairment and can contribute to the debate about whether autism and Asperger syndrome are variants of the same disorder or fundamentally distinct neurodevelopmental conditions. We investigated the neurophysiology of internally determined motor activity in autism and Asperger syndrome via examination of movement-related potentials (MRPs). Method We used electroencephalography to investigate MRPs, via an internally cued movement paradigm, in the following three groups: (1) individuals with high-functioning autism (14 males, one female; mean age 13y 1mo, SD 4y 2mo, range 7y 8mo to 20y 9mo; mean Full-scale IQ 93.40, SD 20.72); (2) individuals with Asperger syndrome (10 males, two females; mean age 13y 7mo, SD 3y 9mo, range 8y 11mo to 20y 4mo; mean Full-scale IQ 103.25, SD 19.37), and (3) a healthy control group (13 males, seven females; mean age 14y 0mo, SD 3y 11mo; range 8y 4mo to 21y 0mo; mean Full-scale IQ 114.25, SD 11.29). Results Abnormal MRPs can reflect disruption of motor-related neural networks involving the basal ganglia, thalamus, and supplementary motor area. There was evidence for abnormal MRPs in autism (e.g. increased post-movement cortical activity, abnormal peak time) but not in Asperger syndrome. Interpretation The results support basal ganglia, thalamus, and supplementary motor area involvement as a likely source of motor dysfunction in autism, and provide further evidence for the neurobiological separateness of autism and Asperger syndrome.
2. Hu VW, Sarachana T, Kim KS, Nguyen A, Kulkarni S, Steinberg ME, Luu T, Lai Y, Lee NH. {{Gene expression profiling differentiates autism case-controls and phenotypic variants of autism spectrum disorders: evidence for circadian rhythm dysfunction in severe autism}}.{ Autism Res};2009 (May 5)
Autism spectrum disorders (ASD) are neurodevelopmental disorders characterized by delayed/abnormal language development, deficits in social interaction, repetitive behaviors and restricted interests. The heterogeneity in clinical presentation of ASD, likely due to different etiologies, complicates genetic/biological analyses of these disorders. DNA microarray analyses were conducted on 116 lymphoblastoid cell lines (LCL) from individuals with idiopathic autism who are divided into three phenotypic subgroups according to severity scores from the commonly used Autism Diagnostic Interview-Revised questionnaire and age-matched, nonautistic controls. Statistical analyses of gene expression data from control LCL against that of LCL from ASD probands identify genes for which expression levels are either quantitatively or qualitatively associated with phenotypic severity. Comparison of the significant differentially expressed genes from each subgroup relative to the control group reveals differentially expressed genes unique to each subgroup as well as genes in common across subgroups. Among the findings unique to the most severely affected ASD group are 15 genes that regulate circadian rhythm, which has been shown to have multiple effects on neurological as well as metabolic functions commonly dysregulated in autism. Among the genes common to all three subgroups of ASD are 20 novel genes mostly in putative noncoding regions, which appear to associate with androgen sensitivity and which may underlie the strong 4:1 bias toward affected males.
3. Lawson R. {{A quality GP consultation with an autistic spectrum disorder child: a mother’s perspective}}. {Qual Prim Care};2009;17(2):149-150.
4. Marcu I, Oppenheim D, Koren-Karie N, Dolev S, Yirmiya N. {{Attachment and Symbolic Play in Preschoolers with Autism Spectrum Disorders}}. {J Autism Dev Disord};2009 (May 7)
The association between attachment and symbolic play was examined in a sample of 45 preschool age boys with autism spectrum disorders. Attachment was assessed using the strange situation procedure, and the frequency, duration, diversity and complexity of child-initiated symbolic play was assessed from observations of mother-child interactions during free play and doll play. We hypothesized that children with secure attachments will score higher on measures of symbolic play compared to children with insecure attachments, and that children with organized attachments will also score higher on measures of symbolic play compared to children with disorganized attachments. Only the second hypothesis received support, and the reasons for this, as well as the implications of the findings for attachment theory, are discussed.
5. Schendel DE, Autry A, Wines R, Moore C. {{The co-occurrence of autism and birth defects: prevalence and risk in a population-based cohort}}. {Dev Med Child Neurol};2009 (Mar 30)
Aim To estimate the prevalence of major birth defects among children with autism, the prevalence of autism in children with birth defects, and the risk for autism associated with having birth defects. Method Retrospective cohort including all children born in Atlanta, GA, USA, 1986 to 1993, who survived to age 3 years and were identified through Georgia vital records. Children with autism and other developmental disabilities residing in Atlanta at ages 3 to 10 years in 1996 were identified through the Metropolitan Atlanta Developmental Disabilities Surveillance Program. Children with major birth defects through age 6 years were identified by the Metropolitan Atlanta Congenital Defects Program. Results Birth defects were found among 6% of children with autism (total n=617; 488 males, 129 females) and was associated with a near twofold increased risk for autism overall. However, the risk magnitude and statistical significance varied by type of birth defect. With any type of birth defect, the risk for autism accompanied by intellectual disability or other developmental disabilities was typically higher than the risk for autism alone. A 6:1 to 8:1 male bias was observed among children with autism and a birth defect. Interpretation Investigation of the association between autism and birth defects is warranted, especially for the role of birth defects in autism among sex-specific or autism subgroups.
6. Tesink CM, Buitelaar JK, Petersson KM, van der Gaag RJ, Kan CC, Tendolkar I, Hagoort P. {{Neural correlates of pragmatic language comprehension in autism spectrum disorders}}. {Brain};2009 (May 7)
Difficulties with pragmatic aspects of communication are universal across individuals with autism spectrum disorders (ASDs). Here we focused on an aspect of pragmatic language comprehension that is relevant to social interaction in daily life: the integration of speaker characteristics inferred from the voice with the content of a message. Using functional magnetic resonance imaging (fMRI), we examined the neural correlates of the integration of voice-based inferences about the speaker’s age, gender or social background, and sentence content in adults with ASD and matched control participants. Relative to the control group, the ASD group showed increased activation in right inferior frontal gyrus (RIFG; Brodmann area 47) for speaker-incongruent sentences compared to speaker-congruent sentences. Given that both groups performed behaviourally at a similar level on a debriefing interview outside the scanner, the increased activation in RIFG for the ASD group was interpreted as being compensatory in nature. It presumably reflects spill-over processing from the language dominant left hemisphere due to higher task demands faced by the participants with ASD when integrating speaker characteristics and the content of a spoken sentence. Furthermore, only the control group showed decreased activation for speaker-incongruent relative to speaker-congruent sentences in right ventral medial prefrontal cortex (vMPFC; Brodmann area 10), including right anterior cingulate cortex (ACC; Brodmann area 24/32). Since vMPFC is involved in self-referential processing related to judgments and inferences about self and others, the absence of such a modulation in vMPFC activation in the ASD group possibly points to atypical default self-referential mental activity in ASD. Our results show that in ASD compensatory mechanisms are necessary in implicit, low-level inferential processes in spoken language understanding. This indicates that pragmatic language problems in ASD are not restricted to high-level inferential processes, but encompass the most basic aspects of pragmatic language processing.
7. van Daalen E, Kemner C, Dietz C, Swinkels SH, Buitelaar JK, van Engeland H. {{Inter-rater reliability and stability of diagnoses of autism spectrum disorder in children identified through screening at a very young age}}. {Eur Child Adolesc Psychiatry};2009 (May 7)
To examine the inter-rater reliability and stability of autism spectrum disorder (ASD) diagnoses made at a very early age in children identified through a screening procedure around 14 months of age. In a prospective design, preschoolers were recruited from a screening study for ASD. The inter-rater reliability of the diagnosis of ASD was measured through an independent assessment of a randomly selected subsample of 38 patients by two other psychiatrists. The diagnoses at 23 months and 42 months of 131 patients, based on the clinical assessment and the diagnostic classifications of standardised instruments, were compared to evaluate stability of the diagnosis of ASD. Inter-rater reliability on a diagnosis of ASD versus non-ASD at 23 months was 87% with a weighted kappa of 0.74 (SE 0.11). The stability of the different diagnoses in the autism spectrum was 63% for autistic disorder, 54% for pervasive developmental disorder, not otherwise specified (PDD-NOS), and 91% for the whole category of ASD. Most diagnostic changes at 42 months were within the autism spectrum from autistic disorder to PDD-NOS and were mainly due to diminished symptom severity. Children who moved outside the ASD category at 42 months made significantly larger gains in cognitive and language skills than children with a stable ASD diagnosis. In conclusion, the inter-rater reliability and stability of the diagnoses of ASD established at 23 months in this population-based sample of very young children are good.
8. Vignoli A, La Briola F, Canevini MP. {{Evolution of stereotypies in adolescents and women with Rett syndrome}}. {Mov Disord};2009 (May 7)
Stereotypies in Rett syndrome (RTT) are a diagnostic hallmark present in all stages of the disease, but descriptions of movement disorders in adults are very scant. Among 30 patients with RTT followed-up at San Paolo Hospital in Milan, we selected those aged >/=14 years and studied 12 patients (mean age 18. 6 years, range: 14-31) with MECP2 mutations. Mean age at stereotypies onset was 19.4 months; stereotypies at onset tend to be maintained during evolution, while new stereotyped movements can be detected in the follow-up. All patients still present stereotypies involving separated or joined hands: most frequently mouthing, pill rolling, and twisting. We underline that stereotyped movements persist in older patients and can be useful to suspect RTT diagnosis in adult age in otherwise unclassified patients. (c) 2009 Movement Disorder Society.
