Diffusion Tensor Imaging And Tractography In Autistic, Dysphasic, And Healthy Control Children

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Neuroimaging

Background:

• Autism spectrum disorder (ASD) and developmental dysphasia (DD) are neurodevelopmental conditions impacting communication and social interaction.
• Investigating white matter connectivity differences is crucial for understanding these conditions.
• Diffusion tensor imaging (DTI) offers a non-invasive method to assess brain's white matter microstructure.

Purpose of the Study:

• To compare brain anatomical connectivity using DTI in children diagnosed with ASD, DD, and healthy controls (HC).
• To examine specific white matter tracts including the arcuate fasciculus (AF), inferior frontal occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), and uncinate fasciculus (UF).

Main Methods:

• A cohort of 113 children (mean age 8.7±2.2 years) was divided into three groups: ASD (n=39), DD (n=36), and HC (n=38).
• Clinical diagnoses were confirmed using the International Classification of Diseases, 10th ed.
• DTI data were acquired using a 1.5 T Phillips Achieva MR imaging system.

Main Results:

• Significant fractional anisotropy (FA) differences were observed among ASD, DD, and HC groups in the left and right AF, left and right IFOF, and left and right ILF (p<0.014).
• The uncinate fasciculus (UF) did not show significant group differences in FA.
• Post-hoc analyses revealed distinct patterns of FA reduction in ASD compared to DD and HC groups across several tracts, with the left ILF showing the most similar FA impairment between ASD and DD groups.

Conclusions:

• Microstructural white matter properties, as measured by FA, significantly differ between children with ASD and DD compared to HC.
• The left ILF represents a key tract where white matter alterations are comparable between ASD and DD, suggesting potential shared neuropathological mechanisms.