title: Neural systems predicting long-term outcome in dyslexia.
abstract: Individuals with developmental dyslexia vary in their ability to improve reading skills, but the brain basis for improvement remains largely unknown. We performed a prospective, longitudinal study over 2.5 y in children with dyslexia (n = 25) or without dyslexia (n = 20) to discover whether initial behavioral or brain measures, including functional MRI (fMRI) and diffusion tensor imaging (DTI), can predict future long-term reading gains in dyslexia. No behavioral measure, including widely used and standardized reading and language tests, reliably predicted future reading gains in dyslexia. Greater right prefrontal activation during a reading task that demanded phonological awareness and right superior longitudinal fasciculus (including arcuate fasciculus) white-matter organization significantly predicted future reading gains in dyslexia. Multivariate pattern analysis (MVPA) of these two brain measures, using linear support vector machine (SVM) and cross-validation, predicted significantly above chance (72% accuracy) which particular child would or would not improve reading skills (behavioral measures were at chance). MVPA of whole-brain activation pattern during phonological processing predicted which children with dyslexia would improve reading skills 2.5 y later with >90% accuracy. These findings identify right prefrontal brain mechanisms that may be critical for reading improvement in dyslexia and that may differ from typical reading development. Brain measures that predict future behavioral outcomes (neuroprognosis) may be more accurate, in some cases, than available behavioral measures.
authors.affiliation: Center for Interdisciplinary Brain Sciences Research, and Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94129, USA. fumiko@stanford.edu
authors.forename: Fumiko
authors.initials: F
authors.lastname: Hoeft
authors.forename: Bruce D
authors.initials: BD
authors.lastname: McCandliss
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Black
authors.forename: Alexander
authors.initials: A
authors.lastname: Gantman
authors.forename: Nahal
authors.initials: N
authors.lastname: Zakerani
authors.forename: Charles
authors.initials: C
authors.lastname: Hulme
authors.forename: Heikki
authors.initials: H
authors.lastname: Lyytinen
authors.forename: Susan
authors.initials: S
authors.lastname: Whitfield-Gabrieli
authors.forename: Gary H
authors.initials: GH
authors.lastname: Glover
authors.forename: Allan L
authors.initials: AL
authors.lastname: Reiss
authors.forename: John D E
authors.initials: JD
authors.lastname: Gabrieli
mesh_terms: D000293:Adolescent; D001931:Brain Mapping; D002648:Child; D056324:Diffusion Tensor Imaging; D004410:Dyslexia / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007807:Language Tests; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D015999:Multivariate Analysis; D017397:Prefrontal Cortex / Q000502:physiology*; D011379:Prognosis; D011446:Prospective Studies; D011932:Reading