A voxel-based morphometry study of Tourette syndrome

comparisons, the primary planned analysis showed no statistically significant difference between the TS and control groups. • Our initial choice of spatial filtering was typical for VBM analysis but was chosen in the expectation of differences in cortex, and may not be optimal for comparison of smaller (e.g. subcortical) structures. • A second analysis using less spatial filtering showed a trend (F 1,28 = 46.2, corrected p=0.09, 2-tailed) for a decrease in gray matter concentration in voxels centered in left precentral gyrus (-26, -12, 66) (primary motor cortex).