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Lateralization of Brain Networks and Clinical Severity in Toddlers with Autism Spectrum Disorder: A HARDI Diffusion MRI Study
Author(s) -
Conti Eugenia,
Calderoni Sara,
Gaglianese Anna,
Pannek Kerstin,
Mazzotti Sara,
Rose Stephen,
Scelfo Danilo,
Tosetti Michela,
Muratori Filippo,
Cioni Giovanni,
Guzzetta Andrea
Publication year - 2016
Publication title -
autism research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.656
H-Index - 66
eISSN - 1939-3806
pISSN - 1939-3792
DOI - 10.1002/aur.1533
Subject(s) - lateralization of brain function , fractional anisotropy , diffusion mri , laterality , autism spectrum disorder , correlation , tractography , audiology , psychology , autism , magnetic resonance imaging , medicine , developmental psychology , radiology , geometry , mathematics
Recent diffusion tensor imaging studies in adolescents and children with Autism Spectrum Disorder (ASD) have reported a loss or an inversion of the typical left–right lateralization in fronto‐temporal regions crucial for sociocommunicative skills. No studies explored atypical lateralization in toddlers and its correlation with clinical severity of ASD. We recruited a cohort of 20 subjects aged 36 months or younger receiving a first clinical diagnosis of ASD (15 males; age range 20–36 months). Patients underwent diffusion MRI (High‐Angular‐Resolution Diffusion Imaging protocol). Data from cortical parcellation were combined with tractography to obtain a connection matrix and diffusion indexes ( D I ) including mean fractional anisotropy ( D FA ), number of tracts ( D NUM ), and total tract length ( D TTL ). A laterality index was generated for each measure, and then correlated with the Autism Diagnostic Observation Schedule‐Generic (ADOS‐G) total score. Laterality indexes of D FA were significantly correlated with ADOS‐G total scores only in two intrafrontal connected areas (correlation was positive in one case and negative in the other). Laterality indexes of D TTL and D NUM showed significant negative correlations ( P < 0.05) in six connected areas, mainly fronto‐temporal. This study provides first evidence of a significant correlation between brain lateralization of diffusion indexes and clinical severity in toddlers with a first diagnosis of ASD. Significant correlations mainly involved regions within the fronto‐temporal circuits, known to be crucial for sociocommunicative skills. It is of interest that all correlations but one were negative, suggesting an inversion of the typical left–right asymmetry in subjects with most severe clinical impairment. Autism Res 2016, 9: 382–392 . © 2015 International Society for Autism Research, Wiley Periodicals, Inc.