Predicting early signs of dyslexia at a preliterate age by combining behavioral assessment with structural MRI.
BACKGROUND
Recent studies suggest that neurobiological anomalies are already detectable in pre-school children with a family history of developmental dyslexia (DD). However, there is a lack of longitudinal studies showing a direct link between those differences at a preliterate age and the subsequent literacy difficulties seen in school. It is also not clear whether the prediction of DD in pre-school children can be significantly improved when considering neurobiological predictors, compared to models based on behavioral literacy precursors only.


METHODS
We recruited 53 pre-reading children either with (N=25) or without a family risk of DD (N=28). Quantitative T1 MNI data and literacy precursor abilities were assessed at kindergarten age. A subsample of 35 children was tested for literacy skills either one or two years later, that is, either in first or second grade.


RESULTS
The group comparison of quantitative T1 measures revealed significantly higher T1 intensities in the left anterior arcuate fascicle (AF), suggesting reduced myelin concentration in preliterate children at risk of DD. A logistic regression showed that DD can be predicted significantly better (p=.024) when neuroanatomical differences between groups are used as predictors (80%) compared to a model based on behavioral predictors only (63%). The Wald statistic confirmed that the T1 intensity of the left AF is a statistically significant predictor of DD (p<.05).


CONCLUSIONS
Our longitudinal results provide evidence for the hypothesis that neuroanatomical anomalies in children with a family risk of DD are related to subsequent problems in acquiring literacy. Particularly, solid white matter organization in the left anterior arcuate fascicle seems to play a pivotal role.
Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany. Electronic address: ikraft@cbs.mpg.de.
Indra
I
Kraft
Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany.
Jan
J
Schreiber
Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany.
Riccardo
R
Cafiero
Nuclear Magnetic Resonance Unit, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany.
Riccardo
R
Metere
Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany; Department of Psychology, Humboldt-Universität zu Berlin, Rudower Chaussee 18, 12489 Berlin, Germany.
Gesa
G
Schaadt
Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany.
Jens
J
Brauer
Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany.
Nicole E
NE
Neef
Cognitive Genetics Unit, Department of Cell Therapy, Fraunhofer Institute for Cell Therapy and Immunology, Perlickstraße 1, 04103 Leipzig, Germany.
Bent
B
Müller
Cognitive Genetics Unit, Department of Cell Therapy, Fraunhofer Institute for Cell Therapy and Immunology, Perlickstraße 1, 04103 Leipzig, Germany; Institute for Medical Informatics, Statistics and Epidemiology, and LIFE - Leipzig Research Center for Civilization Diseases, Universität Leipzig, Härtelstraße 16 - 18, 04107 Leipzig, Germany.
Holger
H
Kirsten
Cognitive Genetics Unit, Department of Cell Therapy, Fraunhofer Institute for Cell Therapy and Immunology, Perlickstraße 1, 04103 Leipzig, Germany.
Arndt
A
Wilcke
Cognitive Genetics Unit, Department of Cell Therapy, Fraunhofer Institute for Cell Therapy and Immunology, Perlickstraße 1, 04103 Leipzig, Germany; Fraunhofer Research Institution for Marine Biotechnology, Department of Medical Cell Technology, and Institute for Medical and Marine Biotechnology, Universität Lübeck, Mönkhofer Weg 239a, 23562 Lübeck, Germany.
Johannes
J
Boltze
Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany.
Angela D
AD
Friederici
Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig, Germany.
Michael A
MA
Skeide
D002648:Child; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004410:Dyslexia / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D042241:Early Diagnosis; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D066128:Gray Matter / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011379:Prognosis; D066127:White Matter / Q000000981:diagnostic imaging*
Arcuate fascicle; Cortical thickness; Developmental dyslexia; Diffusion-weighted imaging; Quantitative T1; Reading