Microstructural connectivity of the arcuate fasciculus in adolescents with high-functioning autism.
The arcuate fasciculus is a white matter fiber bundle of great importance in language. In this study, diffusion tensor imaging (DTI) was used to infer white matter integrity in the arcuate fasciculi of a group of subjects with high-functioning autism and a control group matched for age, handedness, IQ, and head size. The arcuate fasciculus for each subject was automatically extracted from the imaging data using a new volumetric DTI segmentation algorithm. The results showed a significant increase in mean diffusivity (MD) in the autism group, due mostly to an increase in the radial diffusivity (RD). A test of the lateralization of DTI measurements showed that both MD and fractional anisotropy (FA) were less lateralized in the autism group. These results suggest that white matter microstructure in the arcuate fasciculus is affected in autism and that the language specialization apparent in the left arcuate of healthy subjects is not as evident in autism, which may be related to poorer language functioning.
Fletcher
P Thomas
PT
School of Computing, University of Utah, Salt Lake City, UT, USA. fletcher@sci.utah.edu
Whitaker
Ross T
RT
Tao
Ran
R
DuBray
Molly B
MB
Froehlich
Alyson
A
Ravichandran
Caitlin
C
Alexander
Andrew L
AL
Bigler
Erin D
ED
Lange
Nicholas
N
Lainhart
Janet E
JE
D000293:Adolescent; D001111:Arcuate Nucleus of Hypothalamus / Q000473:pathology*; D001321:Autistic Disorder / Q000473:pathology*; D002648:Child; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009434:Neural Pathways / Q000473:pathology*