Common Brain Structure Findings Across Children with Varied Reading Disability Profiles

Mark A Eckert,Mulugeta Gebregziabher,Stephanie L Cute,Amanda Maxwell ,Kenneth I Vaden,Virginia W Berninger

doi:10.1038/s41598-017-05691-5

Abstract

Dyslexia is a developmental disorder in reading that exhibits varied patterns of expression across children. Here we examined the degree to which different kinds of reading disabilities (defined as profiles or patterns of reading problems) contribute to brain morphology results in Jacobian determinant images that represent local brain shape and volume. A matched-pair brain morphometry approach was used to control for confounding from brain size and research site effects in this retrospective multi-site study of 134 children from eight different research sites. Parietal operculum, corona radiata, and internal capsule differences between cases and controls were consistently observed across children with evidence of classic dyslexia, specific comprehension deficit, and language learning disability. Thus, there can be common brain morphology findings across children with quite varied reading disability profiles that we hypothesize compound the developmental difficulties of children with unique reading disability profiles and reasons for their reading disability.

Highlights

Random Forest predicted the expert-rater classifications of Poor Decoders, Poor Comprehenders, Generally Poor Readers, and controls with 94% accuracy using the same behavioral and age variables that were used by the expert-raters
The parietal operculum appears to be a target for tracking the effectiveness of interventions46, and may serve as an early marker of reading disability, if present in at-risk children before formal reading instruction47, 48
The subcortical white matter findings within putative descending fiber tracts could be consistent with a procedural learning deficit hypothesis for language disabilities49 and perhaps a cerebellar deficit hypothesis for dyslexia50

Summary

Introduction

Random Forest predicted the expert-rater classifications of Poor Decoders, Poor Comprehenders, Generally Poor Readers, and controls with 94% accuracy using the same behavioral and age variables that were used by the expert-raters. Random Forest misclassified cases were likely to have a Verbal Comprehension or Word Attack score, for example, at a boundary that distinguished the reading disability profiles. These results [1] provide insight into the behavioral variables that were most important for reading disability profile classification and [2] demonstrate that there were unique behavioral profiles in the dataset. The Random Forest classification probabilities for each reading disability profile and controls were used to perform multidimensional scaling for the 134 cases and controls This analysis generated two spatial dimensions to confirm that the profiles were clearly different from each other and from controls

Methods

Results

Conclusion