Using Diffusion Tensor Imaging to Assess White Matter Integrity in Children with Math Difficulties
Lorang, Craig Thomas
USING DIFFUSION TENSOR IMAGING TO ASSESS WHITE MATTER INTEGRITY IN CHILDREN WITH MATH DIFFICULTIES CRAIG THOMAS LORANG Thesis under the direction of Professor Adam Anderson Dyscalculia is a learning disability that interferes with a person’s ability to understand and manipulate numbers. This condition affects up to 6% of all children. Previous studies have shown cortical functional activation in the parietal lobe related to number processing, however no studies have investigated the relationship between white matter integrity and number processing. Thirty-three subjects (mean age: 9.6 years) were imaged using a 3 Tesla Philips Achieva MRI scanner. Anatomical and diffusion weighted datasets were pre-processed and registered to a common space. Fractional anisotropy maps were mapped into the common space. Group t-tests were performed on a voxel-by-voxel basis on the FA maps between control and math difficulty (MD) groups. Linear correlations were performed on a voxel-by-voxel basis between FA and Wide Range Achievement Test – Third Edition (WRAT) performance in the math and reading subtests. Regions in the left parietal and occipital lobes were found to have FA values correlating with math performance. A frontal lobe region was found to correlate with both reading and math performance, suggesting these two complex operations share portions of white matter bundles. These findings suggest white matter disorganization in regions critical for number processing. Further investigation will be needed to determine if intervention can change the developmental trajectory of these white matter pathways.