Specific tractography differences in autism compared to developmental coordination disorder.

Area of Science:

• Neuroimaging
• Developmental Neuroscience
• Autism Research

Background:

• Autism spectrum disorder (ASD) often co-occurs with motor impairments (85% of cases).
• Previous white matter abnormalities in ASD raise questions about their link to social deficits versus motor issues.

Purpose of the Study:

• To identify specific white matter signatures in ASD independent of motor impairments.
• To differentiate white matter differences between ASD, developmental coordination disorder (DCD), and typically developing (TD) youth.

Main Methods:

• Diffusion weighted imaging (DWI) was used to analyze white matter microstructure.
• Quantitative anisotropy, radial diffusivity, mean diffusivity, and axial diffusivity were compared across three groups: ASD (n=22), DCD (n=16), and TD (n=22).
• DWI metrics were correlated with social and motor assessments.

Main Results:

• ASD group showed distinct white matter diffusivity differences in the mid-cingulum, corpus callosum forceps minor/anterior commissure, and left middle cerebellar peduncle compared to DCD and TD groups.
• ASD group exhibited diffusivity differences in the right inferior frontal occipital/extreme capsule and genu of the corpus callosum compared to the TD group.
• These diffusion abnormalities in ASD correlated with emotional deficits and/or autism severity.
• Children with DCD displayed unique white matter abnormalities in the left cortico-spinal and cortico-pontine tracts.

Conclusions:

• White matter abnormalities in ASD are specifically associated with core social-communication deficits, not comorbid motor impairments.
• Distinct white matter signatures differentiate ASD from DCD.
• Neuroimaging findings provide insights into the neural basis of ASD and its associated challenges.