Alterations of static and dynamic brain functional network connectivity in preschool children with autism spectrum disorder

Abstract

Objective: To investigate alterations in both static and dynamic brain functional network connectivity (FNC) in preschool children with autism spectrum disorder (ASD) and their correlation with clinical symptoms, thereby providing neuroimaging evidence for understanding the potential pathogenesis of ASD.

Methods: Clinical and resting-state functional magnetic resonance imaging (rs-fMRI) data were collected from 47 preschool children with ASD and 56 matched typically developing children (TDC). Independent component analysis (ICA) and dynamic FNC analysis were employed to compare differences in static FNC and dynamic FNC metrics between the groups. Correlations between altered FNC measures and clinical scale scores were specifically examined within the ASD group.

Results: In the static FNC analysis, the ASD group showed decreased connectivity between the left frontoparietal network (lFPN) and the sensorimotor network (SMN), lateral visual network (lVN), and auditory network (AN) respectively. Connectivity was also reduced between the lVN and the posterior default mode network (pDMN), and between the right frontoparietal network (rFPN) and the posterior visual network (pVN). Conversely, the ASD group showed increased connectivity between the rFPN and both the pDMN and the dorsal attention network (DAN). Scores for repetitive behaviors and restricted interests in the Autism Diagnostic Observation Schedule (ADOS) were positively correlated with the strength of the rFPN-pDMN and rFPN-DAN connections. In the dynamic FNC analysis, the ASD group showed increased functional connectivity variability within the pVN and AN, and decreased variability within the lVN and lFPN. Furthermore, the fraction time spent in state 5 was positively correlated with the communication score in the ADOS.

Conclusion: The brain functional networks of preschool ASD children exhibit a dual characteristic pattern: static dysconnectivity and dynamic rigidity. These alterations may be closely related to the core symptoms of ASD in this age group, including social communication impairments, repetitive behaviors, and restricted interests.

Keywords: Autism spectrum disorder; Dynamic functional network connectivity; Independent component analysis; Static functional network connectivity.