Disrupted Functional Rich-Club Organization of the Brain Networks in Children with Attention-Deficit/Hyperactivity Disorder, a Resting-State EEG Study

• Main Authors: Maliheh Ahmadi, Kamran Kazemi, Katarzyna Kuc, Anita Cybulska-Klosowicz, Mohammad Sadegh Helfroush, Ardalan Aarabi
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Brain Sciences
• Subjects: EEG; cortical source imaging; eLORETA; rich-club organization; graph analysis; connectivity analysis
• Online Access: https://www.mdpi.com/2076-3425/11/7/938

Growing evidence indicates that disruptions in the brain’s functional connectivity play an important role in the pathophysiology of ADHD. The present study investigates alterations in resting-state EEG source connectivity and rich-club organization in children with inattentive (ADHD_I) and combined (ADHD_C) ADHD compared with typically developing children (TD) under the eyes-closed condition. EEG source analysis was performed by eLORETA in different frequency bands. The lagged phase synchronization (LPS) and graph theoretical metrics were then used to examine group differences in the topological properties and rich-club organization of functional networks. Compared with the TD children, the ADHD_I children were characterized by a widespread significant decrease in delta and beta LPS, as well as increased theta and alpha LPS in the left frontal and right occipital regions. The ADHD_C children displayed significant increases in LPS in the central, temporal and posterior areas. Both ADHD groups showed small-worldness properties with significant increases and decreases in the network degree in the θ and β bands, respectively. Both subtypes also displayed reduced levels of network segregation. Group differences in rich-club distribution were found in the central and posterior areas. Our findings suggest that resting-state EEG source connectivity analysis can better characterize alterations in the rich-club organization of functional brain networks in ADHD patients.