Objectives: Therefore, in this study, we (1) investigate brain development, and especially development of striatal structures in autism, using a longitudinal design; (2) examine the relationship of striatal development with repetitive behaviour.
Methods: We acquired sMRI scans from 68 individuals (35 subjects with autism, 33 matched controls). Each individual was scanned twice, with a mean scan interval time of 2.4 years. Mean age was 9.9 at time 1 and 12.3 at time 2. An automated image processing pipeline was used to determine volumes of total brain, grey and white matter, cerebellum and lateral ventricles. Striatal structures were traced manually. Multivariate analyses of variance were used to investigate differences in brain development between diagnostic groups. To examine the relationship with behaviour, correlations between changes in brain volume and measures of repetitive and stereotyped behaviour were calculated.
Results: Our results show differences in the developmental pattern for striatal structures: growth rate of these structures was increased in the autism group in comparison to controls. Effects were most robust for caudate nucleus. Results were not accounted for by overall changes in brain growth, or scan processing differences. Second, the increased rate of striatal growth was related to measurements of repetitive behaviour: faster growth was correlated with more severe behaviour.
Conclusions: These findings substantiate the involvement of striatum in the aetiology of autism and provide further evidence of the significance of altered trajectories of brain development in this disorder.
See more of: Brain Imaging: fMRI-Social Cognition and Emotion Perception
See more of: Brain Structure & Function