Short-term Effect of Splint on Tic ScoresIn addition to the analysis using TSSR, we also made more objective assessment of splint-induced short-term effects (estimated at the first hospital visit while wearing the splint) on motor tics by counting the actual number of tics for 3 minutes before and during splint application in 8 patients (No. 9-13, 15, 19, and 22; Supporting Fig. 1). We found that the immediate splint effects were observed on head/neck/face part (Wilcoxon signed-rank test, P = 0.039) and arm/hand/chest part (Wilcoxon signed-rank test, P = 0.031). However, no statistically significant effect was observed on leg/foot part (Wilcoxon signed-rank test, P = 0.250). Long-term Effect of Splint on Tic Scores In terms of long-term effects (up to the latest hospital visit after more than 100 days of treatment), 14 patients (excluding No. 4–6, 9, 12, 16, 17, and 21) who had continued to wear the splint more than for 291 days were analyzed (Supporting Tables 3, 4). The motor tic scores in eight (No. 2, 3, 10, 11, 13–15, and 19) of these 14 patients further decreased compared with their first visit while wearing the splint, whereas three patients showed increased scores, and the scores of three were unchanged (Supporting Fig. 2, left). The phonic tic scores further decreased in four patients, whereas they increased in four patients and remained unchanged in six patients (Supporting Fig. 2, right). Overall, there were significant decreases in splint-induced change between pre-splint condition and the latest hospital-visit condition (Wilcoxon signed-rank test; motor tic, P = 0.011; phonic tic, P = 0.004), while no difference between the first hospital-visit condition and the late hospital-visit condition (Wilcoxon signed-rank test; motor tic, P = 0.286; phonic tic, P = 0.758). Both the age at first hospital visit and the age at tic onset were negatively correlated with the reduction rate (i.e., clinical improvements) of motor tic scores (Fig. 1E; Spearman's rank correlation coefficient, P = 0.011 and P = 0.025, respectively).