White matter integrity in Asperger syndrome: a preliminary diffusion tensor magnetic resonance imaging study in adults.
BACKGROUND
Autistic Spectrum Disorder (ASD), including Asperger syndrome and autism, is a highly genetic neurodevelopmental disorder. There is a consensus that ASD has a biological basis, and it has been proposed that it is a "connectivity" disorder. Diffusion Tensor Magnetic Resonance Imaging (DT-MRI) allows measurement of the microstructural integrity of white matter (a proxy measure of "connectivity"). However, nobody has investigated the microstructural integrity of whole brain white matter in people with Asperger syndrome.


METHODS
We measured the fractional anisotropy (FA), mean diffusivity (MD) and radial diffusivity (RD) of white matter, using DT-MRI, in 13 adults with Asperger syndrome and 13 controls. The groups did not differ significantly in overall intelligence and age. FA, MD and RD were assessed using whole brain voxel-based techniques.


RESULTS
Adults with Asperger syndrome had a significantly lower FA than controls in 13 clusters. These were largely bilateral and included white matter in the internal capsule, frontal, temporal, parietal and occipital lobes, cingulum and corpus callosum.


CONCLUSIONS
Adults with Asperger syndrome have widespread significant differences from controls in white matter microstructural integrity.
Bloemen
Oswald J N
OJ
Section of Brain Maturation, Division of Psychological Medicine, Institute of Psychiatry, King's College London, London, UK. O.J.N.Bloemen@amc.nl
Deeley
Quinton
Q
Sundram
Fred
F
Daly
Eileen M
EM
Barker
Gareth J
GJ
Jones
Derek K
DK
van Amelsvoort
Therese A M J
TA
Schmitz
Nicole
N
Robertson
Dene
D
Murphy
Kieran C
KC
Murphy
Declan G M
DG
D000328:Adult; D016880:Anisotropy; D020817:Asperger Syndrome / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D009186:Myelin Sheath / Q000473:pathology*; D055815:Young Adult