title: White Matter Alterations in Infants at Risk for Developmental Dyslexia.
abstract: Developmental dyslexia (DD) is a heritable condition characterized by persistent difficulties in learning to read. White matter alterations in left-lateralized language areas, particularly in the arcuate fasciculus (AF), have been observed in DD, and diffusion properties within the AF correlate with (pre-)reading skills as early as kindergarten. However, it is unclear how early these alterations can be observed. We investigated white matter structure in 14 infants with (FHD+; ages 6.6-17.6 months) and 18 without (FHD-; ages 5.1-17.6 months) familial risk for DD. Diffusion scans were acquired during natural sleep, and early language skills were assessed. Tractography for bilateral AF was reconstructed using manual and automated methods, allowing for independent validation of results. Fractional anisotropy (FA) was calculated at multiple nodes along the tracts for more precise localization of group differences. The analyses revealed significantly lower FA in the left AF for FHD+ compared with FHD- infants, particularly in the central portion of the tract. Moreover, expressive language positively correlated with FA across groups. Our results demonstrate that atypical brain development associated with DD is already present within the first 18 months of life, suggesting that the deficits associated with DD may result from altered structural connectivity in left-hemispheric regions.
authors.affiliation: Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Children's Hospital Boston, Boston, MA, USA.|Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Langer
authors.affiliation: Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Children's Hospital Boston, Boston, MA, USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Peysakhovich
authors.affiliation: Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Children's Hospital Boston, Boston, MA, USA.|Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Zuk
authors.affiliation: Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA 02115, USA.
authors.forename: Marie
authors.initials: M
authors.lastname: Drottar
authors.affiliation: Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Children's Hospital Boston, Boston, MA, USA.|Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA 02115, USA.
authors.forename: Danielle D
authors.initials: DD
authors.lastname: Sliva
authors.affiliation: Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Children's Hospital Boston, Boston, MA, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Smith
authors.affiliation: Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Children's Hospital Boston, Boston, MA, USA.
authors.forename: Bryce L C
authors.initials: BL
authors.lastname: Becker
authors.affiliation: Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA 02115, USA.|Harvard Medical School, Boston, MA 02115, USA.
authors.forename: P Ellen
authors.initials: PE
authors.lastname: Grant
authors.affiliation: Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Children's Hospital Boston, Boston, MA, USA.|Harvard Medical School, Boston, MA 02115, USA.|Harvard Graduate School of Education, Cambridge, MA 02138, USA.
authors.forename: Nadine
authors.initials: N
authors.lastname: Gaab
mesh_terms: D016880:Anisotropy; D056324:Diffusion Tensor Imaging; D004410:Dyslexia / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007802:Language; D007858:Learning; D008297:Male; D009483:Neuropsychological Tests; D011932:Reading; D012306:Risk; D066127:White Matter / Q000000981:diagnostic imaging / Q000254:growth & development / Q000473:pathology*
keywords: arcuate fasciculus; developmental dyslexia; diffusion tensor imaging; infants; reading disabilities