Exploring the Frontal Aslant Tract in Tourette syndrome: a connectivity study

This study investigates for the first time microstructural alteration of the Frontal Aslant Tract (FAT) in nine subjects with TS compared to twelve healthy subjects. FAT was reconstructed trough Spherical Deconvolution (SD) and parameters derived from Diffusion Tensor Imaging (DTI) and Neuritis Orientation Dispersion and Density Imaging (NODDI) were extracted. We observed a Fractional Anisotropy (FA) reduction, indicating a greater disorganization of fibers, and accordingly an increased Orientation Dispersion Index (ODI), which indicates more dispersed fibers. We also highlighted a negative correlation between motor tic severity (quantified by the YGTSS) and neurite density (ND) and free water fraction (FISO).