Areas of decreased regional gray matter volumes in TS patients compared with controls. Areas of decreased regional gray matter volumes in TS patients compared with controls (thresholded at uncorrected P < .005 for display purpose only). The three orthogonal planes on the left side represent a typical maximum intensity projection "glass brain", and the set of images on the right side illustrates results superimposed on averaged and normalized T1-weighted images of the study population in selected planes. The images are shown in neurological convention. The color bar represents the t-score. Significant voxels were found in the left caudate nucleus, cingulate gyrus, primary and premotor cortex bilaterally (corrected P < .05). TS = Tourette syndrome.