Brain Functional Connectivity and Inhibitory Control in Tourette Syndrome with and without Comorbid Attention-Deficit/Hyperactivity Disorder.

Objective: Tourette syndrome (TS) is often comorbid with attention-deficit/hyperactivity disorder (ADHD) and is associated with inhibitory control deficits. However, the differences in whole-brain functional connectivity (FC) between TS with and without ADHD and their neural basis for inhibitory control remain unclear. This study examines FC differences between these groups and their association with inhibitory control.

Methods: We recruited 52 children with TS (30 pure TS, 22 TS+ADHD) from Beijing Children's Hospital. Resting-state functional magnetic resonance imaging was used to construct individual FC networks, and inhibitory control was assessed using the Go/No-Go task. Group differences in whole-brain FC were analyzed using the network-based statistic (NBS) approach, which identifies connected subnetworks showing significant differences between groups while controlling for multiple comparisons. Multivariate linear regression models examined associations between FC and inhibitory control, adjusting for ADHD comorbidity.

Results: Compared to the pure TS group, the TS+ADHD group showed decreased FC involving the default mode, somatomotor, and limbic networks. In both groups, inhibitory control had a positive correlation with FCs, predominantly involving the default mode, frontoparietal, somatomotor and attention networks. There were no significant group differences in FC related to inhibitory control.

Conclusion: Although differences in FC were observed between the TS and TS+ADHD groups, both groups exhibited similar FC associated with inhibitory control. These findings highlight the neural impact of ADHD in TS and provide insights for future clinical interventions.