Table 1.

Permutation test results for cortical thickness analyses

	All Tourette syndrome versus control, intelligence quotient corrected (n = 70)		Symptom severity within Tourette syndrome group (n = 24)		Simple facial tics within Tourette syndrome group (n = 21)
ROI
Lateral	Left	Right	Left	Right	Left	Right
Dorsal Frontal	ns	0.0800	0.0130	0.0210	ns	ns
Ventral Frontal	0.0039	0.0082	0.0635	ns	ns	0.0304
Parietal	0.0739	0.0291	0.0320	ns	0.0777	0.0096
Occipital	ns	0.0688	0.0132	0.0658	ns	ns
Temporal	0.0953	ns	0.0872	ns	0.0558	0.0360

Permutation test results are shown for all lateral regions of interest that were significant for decreased cortical thickness in the Tourette syndrome group relative to the control group, or at trend-level significance. Also shown are permutation test results for correlations between cortical thickness and overall symptom severity, and facial tics. The P values shown reflect the likelihood of observing the number of significant (at P = 0.05) surface points in each region of interest (ROI) by chance on 10,000 randomizations. Permutation results for medial ROIs were significant only for the left medial dorsal frontal region in the symptom severity versus thickness analyses (P = 0.0117) and are thus not shown for the other nonsignificant medial ROIs. ns, nonsignificant.