Age-related differences in white matter diffusion measures in autism spectrum condition

Area of Science:

• Neuroscience
• Developmental Psychology
• Medical Imaging

Background:

• Autism spectrum condition (ASC) is associated with brain anatomy and connectivity differences.
• White matter studies in ASC using diffusion imaging show heterogeneous results.
• Characterizing white matter maturation requires broad age ranges and age × group interaction analyses.

Purpose of the Study:

• To investigate age-related differences in white matter connectivity in autistic males and typically developing controls.
• To examine the neurodevelopmental trajectory of white matter maturation in autism spectrum condition.
• To identify age × group interactions in white matter properties.

Main Methods:

• Utilized a spatially unbiased tract-based spatial statistics (TBSS) approach.
• Analyzed a sample of 41 individuals with ASC and 41 matched controls (ages 7-17).
• Examined age-related differences in white matter connectivity using diffusion imaging metrics.

Main Results:

• Significant age-related differences in white matter connectivity were found in widespread brain regions for individuals with ASC compared to controls.
• Fractional anisotropy (FA) and radial diffusivity (RD) showed significantly stronger age-related associations in the ASC group.
• Specific white matter tracts including the corticospinal tract and superior longitudinal fasciculus exhibited these differences.

Conclusions:

• Autistic males exhibit an altered trajectory of white matter maturation compared to controls.
• Findings suggest differences in the developmental timing and rate of white matter maturation in ASC.
• Longitudinal studies are necessary to fully elucidate the time course of these neurodevelopmental differences.