TY - JOUR
T1 - White matter microstructural differences linked to left perisylvian language network in children with dyslexia
AU - Rimrodt, Sheryl L.
AU - Peterson, Daniel J.
AU - Denckla, Martha B.
AU - Kaufmann, Walter E.
AU - Cutting, Laurie E.
N1 - Funding Information:
This work was supported by the Johns Hopkins School of Medicine General Clinical Research Center (NIH M01-RR00052); and the Kennedy Krieger Institute Learning Disability Research Center (P50 HD052121); the National Institute for Neurological Disorders (R01 NS049096); the Eunice Kennedy Shriver National Institute of Child Health and Human Development (RO1-HD044073); and the F. M. Kirby Research Center. Sincere thanks to BettyAnn Chodkowski for her contributions to this work.
PY - 2010/6
Y1 - 2010/6
N2 - Studies of dyslexia using diffusion tensor imaging (DTI) have reported fractional anisotropy (FA) differences in left inferior frontal gyrus (LIFG) and left temporo-parietal white matter, suggesting that impaired reading is associated with atypical white matter microstructure in these regions. These anomalies might reflect abnormalities in the left perisylvian language network, long implicated in dyslexia. While DTI investigations frequently report analyses on multiple tensor-derived measures (e.g., FA, orientation, tractography), it is uncommon to integrate analyses to examine the relationships between atypical findings. For the present study, semi-automated techniques were applied to DTI data in an integrated fashion to examine white matter microstructure in 14 children with dyslexia and 17 typically developing readers (ages 7-16 years). Correlations of DTI metrics (FA and fiber orientation) to reading skill (accuracy and speed) and to probabilistic tractography maps of the left perisylvian language tracts were examined. Consistent with previous reports, our findings suggest FA decreases in dyslexia in LIFG and left temporo-parietal white matter. The LIFG FA finding overlaps an area showing differences in fiber orientation in an anterior left perisylvian language pathway. Additionally, a positive correlation of FA to reading speed was found in a posterior circuit previously associated with activation on functional imaging during reading tasks. Overall, integrating results from several complementary semi-automated analyses reveals evidence linking atypical white matter microstructure in dyslexia to atypical fiber orientation in circuits implicated in reading including the left perisylvian language network.
AB - Studies of dyslexia using diffusion tensor imaging (DTI) have reported fractional anisotropy (FA) differences in left inferior frontal gyrus (LIFG) and left temporo-parietal white matter, suggesting that impaired reading is associated with atypical white matter microstructure in these regions. These anomalies might reflect abnormalities in the left perisylvian language network, long implicated in dyslexia. While DTI investigations frequently report analyses on multiple tensor-derived measures (e.g., FA, orientation, tractography), it is uncommon to integrate analyses to examine the relationships between atypical findings. For the present study, semi-automated techniques were applied to DTI data in an integrated fashion to examine white matter microstructure in 14 children with dyslexia and 17 typically developing readers (ages 7-16 years). Correlations of DTI metrics (FA and fiber orientation) to reading skill (accuracy and speed) and to probabilistic tractography maps of the left perisylvian language tracts were examined. Consistent with previous reports, our findings suggest FA decreases in dyslexia in LIFG and left temporo-parietal white matter. The LIFG FA finding overlaps an area showing differences in fiber orientation in an anterior left perisylvian language pathway. Additionally, a positive correlation of FA to reading speed was found in a posterior circuit previously associated with activation on functional imaging during reading tasks. Overall, integrating results from several complementary semi-automated analyses reveals evidence linking atypical white matter microstructure in dyslexia to atypical fiber orientation in circuits implicated in reading including the left perisylvian language network.
KW - Diffusion tensor imaging
KW - Dyslexia
KW - Fractional anisotropy
KW - Left inferior frontal gyrus
KW - Perisylvian language network
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U2 - 10.1016/j.cortex.2009.07.008
DO - 10.1016/j.cortex.2009.07.008
M3 - Article
C2 - 19682675
AN - SCOPUS:77950337794
SN - 0010-9452
VL - 46
SP - 739
EP - 749
JO - Cortex
JF - Cortex
IS - 6
ER -