Functional connectivity of the precuneus and posterior cingulate cortex moderates the relationship between tic symptoms and premonitory urge in tourette syndrome.

This study explores the roles of the precuneus and posterior cingulate cortex (pCunPCC) in the relationship between premonitory urge (PU) and tic severity in Tourette syndrome (TS). We recruited 58 children diagnosed with TS (age mean ± SD = 11.12 ± 2.56, F/M = 11/47). Tic and PU severity were measured using the Yale Global Tic Severity Scale (YGTSS) and the Premonitory Urge for Tics Scale (PUTS), respectively. We constructed brain functional networks for each subject based on resting-state fMRI and further calculated the degree centrality (DC), global efficiency (GE), and local efficiency (LE) of each pCunPCC region. A significant positive correlation was found between PUTS and YGTSS scores (t = 4.75, p < 0.001). The DC and GE of the right pCunPCC ROI 3 (Schaefer Atlas) showed significant negative correlations with YGTSS (t = -2.63, FDR-corrected p = 0.03 for DC; t = -2.85, FDR-corrected p = 0.04 for GE) and PUTS scores (t = -3.35, FDR-corrected p = 0.01 for DC; t = -2.95, FDR-corrected p = 0.03 for GE). Moderation analysis indicated that higher DC in the right pCunPCC ROI 3 reduced the effect of PU on tic severity. These moderation effects were also observed with PU and vocal tics, but not motor tics. The right pCunPCC serves as critical moderator in the relationship between PU and tic severity. This study highlighted the potential neural mechanisms underlying the relationship between PU and tic severity, providing potential targets for future intervention and treatment of TS.