Friday, May 21, 2010
Franklin Hall B Level 4 (Philadelphia Marriott Downtown)
3:00 PM
Background:
Repetitive behaviour and inhibitory control deficits are core features of autism; and it has been suggested that they result from differences in the anatomy of striatum; and/or the ‘connectivity’ of subcortical regions to cortex. There are few studies, however, that have measured the micro-structural organisation of white matter tracts connecting striatum and cerebral cortex.
Objectives:
To investigate differences in bulk volume of striatum and microstructural integrity of corticostriatal white matter in people with autism; and their association with repetitive behaviour and inhibitory control.
Methods:
We compared the bulk volume of striatum (caudate nucleus, putamen and nucleus accumbens) and white matter integrity of corticostriatal tracts using (respectively) sMRI and tract specific DTI measures in 21 adults with autism and 22 controls. We also assessed performance on a cognitive inhibition (go/nogo) task.
Results:
Bulk volume of striatal structures did not differ between groups. However, adults with autism had a significantly smaller total brain white matter volume, lower fractional anisotropy of white matter tracts connecting putamen to frontal cortical areas, and worse performance on the go/nogo task. Also, performance on the go/nogo task was significantly related to anatomical variation when both groups were combined; but not within the autism group alone.
Conclusions:
Autism is associated with differences in the anatomy of corticostriatal white matter tracts.
Repetitive behaviour and inhibitory control deficits are core features of autism; and it has been suggested that they result from differences in the anatomy of striatum; and/or the ‘connectivity’ of subcortical regions to cortex. There are few studies, however, that have measured the micro-structural organisation of white matter tracts connecting striatum and cerebral cortex.
Objectives:
To investigate differences in bulk volume of striatum and microstructural integrity of corticostriatal white matter in people with autism; and their association with repetitive behaviour and inhibitory control.
Methods:
We compared the bulk volume of striatum (caudate nucleus, putamen and nucleus accumbens) and white matter integrity of corticostriatal tracts using (respectively) sMRI and tract specific DTI measures in 21 adults with autism and 22 controls. We also assessed performance on a cognitive inhibition (go/nogo) task.
Results:
Bulk volume of striatal structures did not differ between groups. However, adults with autism had a significantly smaller total brain white matter volume, lower fractional anisotropy of white matter tracts connecting putamen to frontal cortical areas, and worse performance on the go/nogo task. Also, performance on the go/nogo task was significantly related to anatomical variation when both groups were combined; but not within the autism group alone.
Conclusions:
Autism is associated with differences in the anatomy of corticostriatal white matter tracts.