Study of Sensorimotor Network Connectivity in ADHD Children and Its Correlations with Executive Function

Background: The sensorimotor network (SMN) is a crucial functional network in the brain that integrates and regulates somatosensory and motor functions. It plays a key role in converting sensory information into motor behavior and executing motor control. In children with Attention deficit/hyperactivity disorder (ADHD), the SMN is closely related to the regulation of sensory‒motor functions and higher-order executive functions (EFs) However, several questions remain unanswered: (1) What are the characteristics of the SMN in children with ADHD, and how does this functional network influence sensory‒motor functions in patients? (2) How do the interactions between the SMN itself and other important networks related to EFs affect the regulation of EFs in children with ADHD? This study uses resting-state functional magnetic resonance imaging (rs-fMRI) to investigate the internal and external functional connectivity (FC) of the SMN in children with ADHD and its correlation with clinical behaviors and EFs, aiming to elucidate the role of the SMN in ADHD neuropathology. Methods: The study included 73 patients with ADHD and 49 healthy controls (HCs) matched for age, sex, and IQ. fMRI was used to acquire structural brain data and resting-state FC parameters from the participants. Multiple seed regions within the SMN, salience network (SN), default mode network (DMN), and frontoparietal network (FPN) were selected as regions of interest (ROIs) on the basis of the Dosenbach atlas. FC values were extracted from these ROIs and analysed via network connectivity analysis. Additionally, partial correlation analyses were conducted in the ADHD group to explore the relationships between clinical characteristics, EF data, and neuroimaging results. Results: Within the SMN, the ADHD group presented significantly greater FCs. FC between the SMN and the DMN, as well as the SN was also significantly greater in the ADHD group than in the HCs. The increased FC within the SMN and between the SMN and the DMN in the ADHD group was negatively correlated with the Conners Scale. The enhanced FC between the SMN and the DMN in the ADHD group was positively correlated with the IVA-CPT. The increased FC between the SMN and the SN in the ADHD group was negatively correlated with the EF disturbance. Conclusion: Abnormal FC in the SMN may be a neurobiological indicator of ADHD, and its internal and external functional activities play an important role in the clinical symptoms of ADHD and the development of cognitive EF disorders.