Diffusion Tensor Imaging Findings in Rett Syndrome Patients

I. Izbudak, L. Farage, D. Bonekamp, W. Zhang, G. Bibat, S. Mori, S. Naidu, A. Horska Radiology, Jonhs Hopkins Medical Institutions, Baltimore, MD, United States, Kennedy Krieger Institute, Baltimore, MD, United States Purpose Rett Syndrome (RTT) is a neurodevelopmental X-linked disease that affects primarily girls. Clinically, these children are normal at birth and then develop progressive autistic-like behavior, neurodevelopmental delay, with loss of motor skills. Cerebral volume loss in RTT was attributed to be due to a decrease in neuronal cell body size and dendritic arborizations, particularly in cortical gray matter with relative preservation of axons and myelin. However recent neuropathologic studies have suggested axonal involvement and our recent magnetic resonance spectroscopic study has also shown more decreased levels of neuronal marker NAA in cortical white matter than gray matter. The purpose of our study is to investigate the involvement of specific cerebral white matter tracts in Rett patients by using diffusion tensor imaging (DTI).