Brain functional connectivity and inhibitory control in Tourette syndrome with and without comorbid attention-deficit/hyperactivity disorder.

OBJECTIVE

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

METHODS

We recruited 52 children with Tourette syndrome (30 with Tourette syndrome only and 22 with Tourette syndrome + attention-deficit/hyperactivity disorder) from Beijing Children's Hospital. Resting-state functional magnetic resonance imaging was used to construct individual functional connectivity networks, and inhibitory control was assessed using the Go/No-Go task. Group differences in whole-brain functional connectivity were analyzed using the network-based statistic approach, which identifies connected subnetworks showing significant differences between groups while controlling for multiple comparisons. Multivariate linear regression models were used to examine associations between functional connectivity and inhibitory control, adjusting for comorbid attention-deficit/hyperactivity disorder.

RESULTS

Compared to the Tourette syndrome only group, the Tourette syndrome + attention-deficit/hyperactivity disorder group showed decreased functional connectivity involving the default mode, somatomotor, and limbic networks. In both groups, inhibitory control was positively correlated with functional connectivity, predominantly involving the default mode, frontoparietal, somatomotor, and attention networks. The groups did not differ significantly in functional connectivity related to inhibitory control.

CONCLUSIONS

Although differences in functional connectivity were observed between the Tourette syndrome and Tourette syndrome + attention-deficit/hyperactivity disorder groups, both had similar functional connectivity associated with inhibitory control. These findings highlight the neural impact of attention-deficit/hyperactivity disorder in Tourette syndrome and provide insights for future clinical interventions.