title: Differences in white matter reflect atypical developmental trajectory in autism: A Tract-based Spatial Statistics study.
abstract: Autism is a neurodevelopmental disorder in which white matter (WM) maturation is affected. We assessed WM integrity in 16 adolescents and 14 adults with high-functioning autism spectrum disorder (ASD) and in matched neurotypical controls (NT) using diffusion weighted imaging and Tract-based Spatial Statistics. Decreased fractional anisotropy (FA) was observed in adolescents with ASD in tracts involved in emotional face processing, language, and executive functioning, including the inferior fronto-occipital fasciculus and the inferior and superior longitudinal fasciculi. Remarkably, no differences in FA were observed between ASD and NT adults. We evaluated the effect of age on WM development across the entire age range. Positive correlations between FA values and age were observed in the right inferior fronto-occipital fasciculus, the left superior longitudinal fasciculus, the corpus callosum, and the cortical spinal tract of ASD participants, but not in NT participants. Our data underscore the dynamic nature of brain development in ASD, showing the presence of an atypical process of WM maturation, that appears to normalize over time and could be at the basis of behavioral improvements often observed in high-functioning autism.
authors.affiliation: Control and Intelligent Processing Center of Excellence, School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, Iran ; Department of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran ; Brain Mind Institute, Ecole Polytechnique Fédérale, Lausanne, Switzerland.
authors.forename: Reyhaneh
authors.initials: R
authors.lastname: Bakhtiari
authors.forename: Nicole R
authors.initials: NR
authors.lastname: Zürcher
authors.forename: Ophélie
authors.initials: O
authors.lastname: Rogier
authors.forename: Britt
authors.initials: B
authors.lastname: Russo
authors.forename: Loyse
authors.initials: L
authors.lastname: Hippolyte
authors.forename: Cristina
authors.initials: C
authors.lastname: Granziera
authors.forename: Babak Nadjar
authors.initials: BN
authors.lastname: Araabi
authors.forename: Majid
authors.initials: M
authors.lastname: Nili Ahmadabadi
authors.forename: Nouchine
authors.initials: N
authors.lastname: Hadjikhani
keywords: ADI-R, Autism Diagnostic Interview-Revised; ADOS, Autism Diagnostic Observation Schedule; AQ, Autism Quotient; ASD, Autism Spectrum Disorders; ATR, anterior thalamic radiations; Autism spectrum disorder; Brain connectivity; Brain development; Brain maturation; CC, corpus callosum; CT, corticospinal tract; DTI, Diffusion Tensor Imaging; DTT, Diffusion Tensor Tractography; Diffusion Tensor Imaging; EF, executive functions; FA, fractional anisotropy; Fractional anisotropy; IFOF, inferior froto-occipital fasciculus; ILF, inferior longitudinal fasciculus; NT, neurotypical; PIQ, Performance Intelligence Quotient; SLF, superior longitudinal fasciculus; TBSS, Tract-based Spatial Statistics; TE, echo time; TFCE, Threshold-free Cluster Enhancement; TR, repetition time; UNC, uncinate fasciculus; VBM, Voxel-Based Morphometry; VBS, Voxel based Statistics of FA Images (VBM-like); WM, white matter