1. Duerden EG, Card D, Roberts SW, Mak-Fan KM, Chakravarty MM, Lerch JP, Taylor MJ. {{Self-injurious behaviours are associated with alterations in the somatosensory system in children with autism spectrum disorder}}. {Brain Struct Funct};2013 (May 5)
Children with autism spectrum disorder (ASD) frequently engage in self-injurious behaviours, often in the absence of reporting pain. Previous research suggests that altered pain sensitivity and repeated exposure to noxious stimuli are associated with morphological changes in somatosensory and limbic cortices. Further evidence from postmortem studies with self-injurious adults has indicated alterations in the structure and organization of the temporal lobes; however, the effect of self-injurious behaviour on cortical development in children with ASD has not yet been determined. Thirty children and adolescents (mean age = 10.6 +/- 2.5 years; range 7-15 years; 29 males) with a clinical diagnosis of ASD and 30 typically developing children (N = 30, mean age = 10.7 +/- 2.5 years; range 7-15 years, 26 males) underwent T1-weighted magnetic resonance and diffusion tensor imaging. No between-group differences were seen in cerebral volume, surface area or cortical thickness. Within the ASD group, self-injury scores negatively correlated with thickness in the right superior parietal lobule t = 6.3, p < 0.0001, bilateral primary somatosensory cortices (SI) (right: t = 4.4, p = 0.02; left: t = 4.48, p = 0.004) and the volume of the left ventroposterior (VP) nucleus of the thalamus (r = -0.52, p = 0.008). Based on these findings, we performed an atlas-based region-of-interest diffusion tensor imaging analysis between SI and the VP nucleus and found that children who engaged in self-injury had significantly lower fractional anisotropy (r = -0.4, p = 0.04) and higher mean diffusivity (r = 0.5, p = 0.03) values in the territory of the left posterior limb of the internal capsule. Additionally, greater incidence of self-injury was associated with increased radial diffusivity values in bilateral posterior limbs of the internal capsule (left: r = 0.5, p = 0.02; right: r = 0.5, p = 0.009) and corona radiata (left: r = 0.6, p = 0.005; right: r = 0.5, p = 0.009). Results indicate that self-injury is related to alterations in somatosensory cortical and subcortical regions and their supporting white-matter pathways. Findings could reflect use-dependent plasticity in the somatosensory system or disrupted brain development that could serve as a risk marker for self-injury.
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2. van Steensel FJ, Dirksen CD, Bogels SM. {{A Cost of Illness Study of Children with High-Functioning Autism Spectrum Disorders and Comorbid Anxiety Disorders as Compared to Clinically Anxious and Typically Developing Children}}. {J Autism Dev Disord};2013 (May 5)
The study’s aim was to estimate the societal costs of children with high-functioning ASD and comorbid anxiety disorder(s) (ASD + AD-group; n = 73), and to compare these costs to children with anxiety disorders (AD-group; n = 34), and typically developing children (controls; n = 87). Mean total costs for the ASD + AD-group amounted <euro>17,380 per year. Societal costs were estimated at almost 142 million euro per year. Costs in the ASD + AD-group were four times higher compared to the AD-group, and 27 times higher compared to controls. ASD-related costs were higher in the ASD + AD-group; anxiety-related costs did not differ between the ASD + AD- and AD-group; costs due to physical or other reasons did not differ across groups. The findings suggest that costs can be decreased if effective treatment options for treating anxiety in ASD are established, however, the remaining costs associated with ASD would still be large. A limitation of the study is that a group of children with ASD without anxiety disorders is lacking.
