Parietal signatures of urge control in paediatric tic disorders: Hyperactivation and salience-biased coupling.

Premonitory urges (PU) are central to tic expression and guide behavioural treatment yet are difficult to measure in children using self-report because urge awareness often lags tic onset. We therefore examined neural correlates of urge control in paediatric tic disorders (TS) across natural urge conditions (blink, yawn) and tics, using an fMRI release-suppression task in 25 medication-naïve children and adolescents with TS (76% male; 7-16 years) and 25 matched typically developing control participants (76% male; 6-17 years). We compared natural urge suppression between the TS group and controls at behavioural and neural levels. In participants with TS, we identified neural correlates of voluntary tic suppression, and examined task-evoked connectivity during tic suppression using psychophysiological interaction (PPI) analyses with parietal seeds derived from natural urge effects to assess coupling with control/monitoring and interoceptive-salience networks. Across blink and yawn, TS participants showed greater suppression-related activation than controls in left posterior parietal association cortex, with additional right parietal and frontal engagement for yawn. Behavioural impairment was selective to blink. Tic suppression did not yield uniform group-level activation, but suppression success was positively associated with engagement of executive, salience, and default-mode hubs. PPI analyses showed that stronger parietal-cingulo-opercular coupling was negatively associated with suppression success, whereas fronto-parietal coupling showed no positive association. These network-level associations provide a framework for refining models of urge control in youth and motivate future studies with larger samples to evaluate their robustness and potential translational relevance.