White matter microstructural alterations in children with prenatal methamphetamine/polydrug exposure

Area of Science:

• Neuroscience
• Developmental Psychology
• Radiology

Background:

• Prenatal substance exposure impacts neurodevelopment.
• Effects of prenatal methamphetamine and alcohol on white matter are not well understood.

Purpose of the Study:

• To investigate white matter microstructure differences in children with prenatal methamphetamine exposure, with or without alcohol co-exposure.
• To compare these findings with children exposed only to alcohol prenatally.

Main Methods:

• Diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS) were used to analyze whole-brain fractional anisotropy (FA).
• Neurocognitive testing assessed executive functioning and visuomotor integration.
• Three groups were studied: prenatal methamphetamine exposure (n=21), prenatal alcohol exposure (n=19), and typically developing controls (n=27).

Main Results:

• Children with prenatal methamphetamine exposure showed higher FA in left-sided white matter regions (e.g., left anterior corona radiata, corticospinal tract), primarily due to lower radial diffusivity.
• Children with prenatal alcohol exposure exhibited lower FA in frontotemporal regions (e.g., right external capsule) compared to the methamphetamine-exposed group.
• No group-performance interaction was found, but FA in the right external capsule correlated with visuomotor integration performance across all groups.

Conclusions:

• Prenatal methamphetamine exposure leads to distinct white matter diffusion abnormalities compared to alcohol exposure alone.
• These microstructural brain differences persist into childhood and adolescence.
• Findings highlight the unique and lasting impact of prenatal methamphetamine/polydrug exposure on brain development.