title: Network over-connectivity differentiates autism spectrum disorder from other developmental disorders in toddlers: A diffusion MRI study.
abstract: Advanced connectivity studies in toddlers with Autism Spectrum Disorder (ASD) are increasing and consistently reporting a disruption of brain connectivity. However, most of these studies compare ASD and typically developing subjects, thus providing little information on the specificity of the abnormalities detected in comparison with other developmental disorders (other-DD). We recruited subjects aged below 36 months who received a clinical diagnosis of Neurodevelopmental Disorder (32 ASD and 16 other-DD including intellectual disability and language disorder) according to DSM-IV TR. Structural and diffusion MRI were acquired to perform whole brain probabilistic and anatomically constrained tractography. Network connectivity matrices were built encoding the number of streamlines (DNUM) and the tract-averaged fractional anisotropy (DFA) values connecting each pair of cortical and subcortical regions. Network Based Statistics (NBS) was finally applied on the connectivity matrices to evaluate the network differences between the ASD and other-DD groups. The network differences resulted in an over-connectivity pattern (i.e., higher DNUMand DFAvalues) in the ASD group with a significance of P < 0.05. No contra-comparison results were found. The over-connectivity pattern in ASD occurred in networks primarily involving the fronto-temporal nodes, known to be crucial for social-skill development and basal ganglia, related to restricted and repetitive behaviours in ASD. To our knowledge, this is the first network-based diffusion study comparing toddlers with ASD and those with other-DD. Results indicate the detection of different connectivity patterns in ASD and other-DD at an age when clinical differential diagnosis is often challenging. Hum Brain Mapp 38:2333-2344, 2017. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Conti
authors.affiliation: The Australian eHealth Research Centre, CSIRO, Brisbane, Queensland, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Mitra
authors.affiliation: Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Calderoni
authors.affiliation: The Australian eHealth Research Centre, CSIRO, Brisbane, Queensland, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Pannek
authors.affiliation: The Australian eHealth Research Centre, CSIRO, Brisbane, Queensland, Australia.
authors.forename: K K
authors.initials: KK
authors.lastname: Shen
authors.affiliation: The Australian eHealth Research Centre, CSIRO, Brisbane, Queensland, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Pagnozzi
authors.affiliation: The Australian eHealth Research Centre, CSIRO, Brisbane, Queensland, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Rose
authors.affiliation: Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Mazzotti
authors.affiliation: Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Scelfo
authors.affiliation: Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Tosetti
authors.affiliation: Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy.|Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Muratori
authors.affiliation: Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy.|Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Cioni
authors.affiliation: Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy.|Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Guzzetta
mesh_terms: D016880:Anisotropy; D000067877:Autism Spectrum Disorder / Q000000981:diagnostic imaging*; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002675:Child, Preschool; D039721:Diagnostic and Statistical Manual of Mental Disorders; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008607:Intellectual Disability / Q000209:etiology; D007806:Language Disorders / Q000209:etiology; D008297:Male; D009434:Neural Pathways / Q000000981:diagnostic imaging*; D065886:Neurodevelopmental Disorders / Q000150:complications / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D013223:Statistics as Topic
keywords: autism spectrum disorders; brain connectivity; developmental disorders; overconnectivity; toddlers