Network over-connectivity differentiates autism spectrum disorder from other developmental disorders in toddlers: A...

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Pediatric Neurology

Background:

• Autism Spectrum Disorder (ASD) diagnosis in toddlers is challenging.
• Existing brain connectivity studies in ASD often lack specificity by not comparing with other developmental disorders (other-DD).
• Early identification of specific neurobiological markers is crucial for timely intervention.

Purpose of the Study:

• To investigate distinct brain connectivity patterns in toddlers with ASD versus other-DD.
• To identify early neuroimaging markers differentiating ASD from other neurodevelopmental conditions.
• To advance understanding of the neural underpinnings of ASD in early childhood.

Main Methods:

• Recruited toddlers (<36 months) diagnosed with ASD (n=32) or other-DD (n=16) per DSM-IV TR.
• Acquired structural and diffusion MRI data for whole-brain tractography.
• Utilized Network Based Statistics (NBS) on connectivity matrices (DNUM, DFA) to compare ASD and other-DD groups.

Main Results:

• Toddlers with ASD exhibited a significant pattern of over-connectivity (higher DNUM and DFA) compared to the other-DD group (P < 0.05).
• This over-connectivity was prominent in fronto-temporal networks and basal ganglia.
• No significant differences were found when comparing other-DD to ASD.

Conclusions:

• This study provides the first network-based diffusion MRI evidence differentiating brain connectivity in toddlers with ASD from those with other-DD.
• Distinct connectivity patterns, specifically over-connectivity in ASD, are detectable in early development.
• Findings suggest potential neuroimaging biomarkers for early ASD diagnosis when clinical presentation is ambiguous.