Differences in white matter fiber tract development present from 6 to 24 months in infants with autism

Area of Science:

• Neuroscience
• Developmental Psychology
• Medical Imaging

Background:

• Early symptoms of autism spectrum disorders (ASDs) typically emerge in the late first or early second year of life.
• A period of relatively typical development often precedes the onset of these early autistic symptoms.

Purpose of the Study:

• To prospectively examine white matter fiber tract organization in high-risk infants from 6 to 24 months of age.
• To identify early neuroimaging markers associated with the later development of autism spectrum disorders (ASDs).

Main Methods:

• Utilized diffusion tensor imaging (DTI) to assess white matter microstructure in 92 high-risk infant siblings.
• Collected imaging data at 6 months, with additional data at 12 and/or 24 months.
• Characterized fractional anisotropy (FA) and diffusivity measures in key white matter tracts.

Main Results:

• Significant differences in fractional anisotropy (FA) trajectories were observed in 12 of 15 analyzed white matter tracts between infants who developed ASDs and those who did not.
• Infants who developed ASDs exhibited higher FA values at 6 months, followed by slower developmental changes, resulting in lower FA by 24 months.
• These findings suggest altered white matter maturation trajectories in early development for infants later diagnosed with ASDs.

Conclusions:

• Aberrant development of white matter pathways in infancy may precede the clinical manifestation of autistic symptoms.
• Longitudinal neuroimaging data are crucial for understanding the dynamic, age-related brain changes associated with autism spectrum disorders.
• Early identification of white matter alterations could inform future diagnostic and intervention strategies for ASDs.