title: White Matter Diffusion of Major Fiber Tracts Implicated in Autism Spectrum Disorder.
abstract: Autism spectrum disorder (ASD) is a neurodevelopmental disorder found to have widespread alterations in the function and synchrony of brain regions. These differences may underlie alterations in microstructural organization, such as in white matter pathways. To investigate the diffusion of major white matter tracts, the current study examined multiple indices of white matter diffusion in 42 children and adults with ASD and 44 typically developing (TD) age- and IQ-matched peers using diffusion tensor imaging. Diffusivity measures were compared between groups for the following tracts: bilateral cingulum bundle, corpus callosum, inferior longitudinal fasciculus, superior longitudinal fasciculus, and uncinate fasciculus. Results indicate a significant reduction in fractional anisotropy (FA) for the left superior longitudinal fasciculus (LSLF) in ASD children and adults compared with TD peers. A significant increase in radial diffusivity for ASD participants was also found in the same cluster along the LSLF. In addition, a significant positive correlation emerged for all subjects between FA for the LSLF and age, with FA increasing with age. These findings point to a significant alteration in long-distance white matter connectivity in children and adults with ASD, potentially underscoring the relationship between alterations in white matter diffusion and the ASD phenotype. These results also suggest that the white matter alterations in autism may be subtle and related to the developmental trajectory.
authors.affiliation: 1 UC Davis MIND Institute , Sacramento, California.|2 UC Davis Department of Psychiatry & Behavioral Sciences , Sacramento, California.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Libero
authors.affiliation: 3 Department of Psychology, University of Alabama at Birmingham , Birmingham, Alabama.
authors.forename: Wesley K
authors.initials: WK
authors.lastname: Burge
authors.affiliation: 4 Department of Radiology, University of Alabama at Birmingham , Birmingham, Alabama.
authors.forename: Hrishikesh D
authors.initials: HD
authors.lastname: Deshpande
authors.affiliation: 5 Department of Psychological and Brain Sciences, Indiana University , Bloomington, Indiana.
authors.forename: Franco
authors.initials: F
authors.lastname: Pestilli
authors.affiliation: 3 Department of Psychology, University of Alabama at Birmingham , Birmingham, Alabama.
authors.forename: Rajesh K
authors.initials: RK
authors.lastname: Kana
mesh_terms: D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D000067877:Autism Spectrum Disorder / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D002648:Child; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000473:pathology; D066127:White Matter / Q000473:pathology*; D055815:Young Adult
keywords: autism spectrum disorder; diffusion tensor imaging; fractional anisotropy; superior longitudinal fasciculus