Microstructure of white matter fiber tracts in infants with positional plagiocephaly.

BACKGROUND

Diffusion magnetic resonance imaging has emerged as an opportunity to explore brain white matter fiber tracts (WMFTs) through 3D digital reconstruction. This method could be useful in investigating the relationship between positional plagiocephaly and developmental problems; however, this has not been fully explored.

OBJECTIVE

Evaluate WMFTs of healthy infants in two age groups with a range of positional plagiocephaly from normal to severe.

MATERIALS AND

METHODS

This exploratory study, conducted at a free-standing, quaternary pediatric hospital in the Northeastern United States, utilized an existing database of healthy infants' MRIs obtained between 1 month and 4 months of age. MRIs were included if deemed good quality and had complete T1- and diffusion-weighted sequences and excluded if there were measurement disagreements or MRI data processing problems. Positional plagiocephaly severity was calculated using the Cranial Vault Asymmetry Index (CVAI). A repeated-measures regression model was constructed to assess the association of positional plagiocephaly severity with WMFTs fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD).

RESULTS

Median age of 18 infants was 64.5 (IQR 71) days at the time of MRI. FA had a negative association with CVAI overall (β±SE=-0.53±0.51% per unit CVAI, P=0.32) and in both age groups. MD and RD had a positive association with CVAI overall (β±SE=1.31±0.46% per unit CVAI, P=0.013; β±SE=1.54±0.54% per unit CVAI, P=0.012) and in both age groups and all pathways.

CONCLUSION

As the severity of positional plagiocephaly increases, differences in WMFT formation are observed, suggesting the need for longitudinal studies with cognitive and behavioral assessments.