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

Researchers used brain scans to study how different brain regions communicate in young children with autism (ages 3-6) compared to typically developing children. They found that autistic children's brains showed two main differences: some brain networks were less connected than usual, while others were more rigidly connected. Importantly, children with stronger connections in certain brain areas had more repetitive behaviors and restricted interests. This research helps us understand how brain differences in autism may relate to the behaviors and challenges we observe.

This neuroimaging study examined brain connectivity patterns in 47 preschool children with autism spectrum disorder compared to 56 typically developing children using resting-state fMRI. The research investigated both static (unchanging) and dynamic (time-varying) functional network connectivity. Results revealed a dual pattern in autism: 'static dysconnectivity' with reduced connections between frontoparietal and sensory networks, alongside increased connections between frontoparietal and attention networks; and 'dynamic rigidity' with altered variability in network flexibility. Notably, stronger connections between right frontoparietal and default mode/attention networks correlated with more severe repetitive behaviors and restricted interests on the ADOS assessment, suggesting these connectivity patterns may underlie core autism symptoms.

Findings suggest early brain connectivity differences may serve as potential biomarkers for autism diagnosis and symptom severity. The relationship between specific connectivity patterns and repetitive behaviors could inform targeted interventions focusing on network flexibility and sensory integration during critical early developmental periods.

Single study with moderate sample size. Cross-sectional design prevents determination of causality or developmental trajectories. Unclear if findings generalize beyond preschool age group or to different autism severity levels. Technical limitations of fMRI in young children may affect data quality.

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. 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.

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. 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.