title: Diffusion tensor imaging reveals no white matter impairments among adults with autism spectrum disorder.
abstract: Abnormalities within white matter (WM) have been identified in autism spectrum disorder (ASD). Although there is some support for greater neurobiological deficits among females with ASD, there is little research investigating sex differences in WM in ASD. We used diffusion tensor imaging (DTI) to investigate WM aberration in 25 adults with high-functioning ASD and 24 age-, sex- and IQ-matched controls. Tract-based spatial statistics (TBSS) was used to explore differences in WM in major tract bundles. The effects of biological sex were also investigated. TBSS revealed no differences in fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), or axial diffusivity (AD) between groups. There were no effects of biological sex. We consider whether methodological differences between past studies have contributed to the highly heterogeneous findings in the literature. Finally, we suggest that, among a high-functioning sample of adults with ASD, differences in WM microstructure may not be related to clinical impairment.
authors.affiliation: Monash Alfred Psychiatry Research Centre, The Alfred and Central Clinical School, Monash University, Melbourne, Victoria, Australia; Cognitive Neuroscience Unit, School of Psychology, Deakin University, Burwood, Victoria, Australia. Electronic address: melissa.kirkovski@deakin.edu.au.
authors.forename: Melissa
authors.initials: M
authors.lastname: Kirkovski
authors.affiliation: Cognitive Neuroscience Unit, School of Psychology, Deakin University, Burwood, Victoria, Australia; Monash Alfred Psychiatry Research Centre, The Alfred and Central Clinical School, Monash University, Melbourne, Victoria, Australia.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Enticott
authors.affiliation: Monash Alfred Psychiatry Research Centre, The Alfred and Central Clinical School, Monash University, Melbourne, Victoria, Australia.
authors.forename: Jerome J
authors.initials: JJ
authors.lastname: Maller
authors.affiliation: Brain and Psychological Science Research Centre, Faculty Health, Arts and Design, Swinburne University, Hawthorn, Victoria, Australia; Monash Alfred Psychiatry Research Centre, The Alfred and Central Clinical School, Monash University, Melbourne, Victoria, Australia.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Rossell
authors.affiliation: Monash Alfred Psychiatry Research Centre, The Alfred and Central Clinical School, Monash University, Melbourne, Victoria, Australia.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Fitzgerald
mesh_terms: D000328:Adult; D016880:Anisotropy; D000067877:Autism Spectrum Disorder / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D066127:White Matter / Q000503:physiopathology*; D055815:Young Adult
keywords: Autism spectrum disorder; Diffusion tensor imaging; Gender; Magnetic resonance imaging; Tract-based spatial statistics