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Updated: Jun 27, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Early White Matter Microstructure Alterations in Infants with Down Syndrome
Omar Azrak1, Dea Garic2, Aleeshah Nasir1
1Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA.
Insights
Infants with Down syndrome (DS) show reduced white matter integrity and disrupted myelination early in life. These findings reveal widespread brain development alterations in DS, informing potential early interventions.
Area of Science:
- Neuroscience
- Genetics
- Developmental Biology
Background:
- Down syndrome (DS), caused by Trisomy 21, is the most common chromosomal disorder and a primary cause of intellectual disability.
- While its impact on brain development is known, early white matter (WM) microstructure in infants with DS is under-researched.
- Previous studies show reduced WM integrity in older individuals with DS, but not in infancy.
Purpose of the Study:
- To investigate early white matter (WM) microstructure in infants with Down syndrome (DS).
- To utilize advanced neuroimaging techniques, Diffusion Tensor Imaging (DTI) and Neurite Orientation Dispersion and Density Imaging (NODDI), for detailed analysis.
- To identify specific patterns of WM alterations in infants with DS.
Main Methods:
- Recruited 49 infants with DS and 36 typically developing controls, all scanned at 6 months of age.
- Employed Diffusion Tensor Imaging (DTI) to assess white matter integrity.
- Utilized Neurite Orientation Dispersion and Density Imaging (NODDI) to examine neurite density and dispersion.
Main Results:
- Infants with DS exhibited significantly reduced fractional anisotropy and neurite density index in key association tracts like the inferior fronto-occipital fasciculus and superior longitudinal fasciculus II.
- Increased radial diffusivity, indicative of disrupted myelination, was observed in these tracts.
- Elevated orientation dispersion index in several tracts suggested increased neurite dispersion and fanning in infants with DS.
Conclusions:
- Early infancy reveals widespread white matter (WM) microstructural developmental alterations in Down syndrome (DS).
- Findings highlight reduced structural integrity, neurite density, and altered myelination in infants with DS.
- These insights into early neurodevelopment in DS may guide the timing of therapeutic interventions.
Abstract:
Down syndrome (DS), resulting from Trisomy 21, is the most prevalent chromosomal disorder and a leading cause of intellectual disability. Despite the significant impact of Trisomy 21 on brain development, research on white matter (WM) microstructure in infants with DS remains limited. While widespread reductions in WM integrity have been identified in children and young adults with DS, no study has examined WM microstructure in infancy. This study investigates early WM microstructure in infants with DS using diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI). Forty-nine infants with DS (28 [57.14%] female) and 36 control (18 [48.65%] female) infants were scanned at 6 months of age. Infants with DS showed significant reductions in fractional anisotropy and neurite density index across multiple association tracts, particularly in the inferior fronto-occipital fasciculus and superior longitudinal fasciculus II, consistent with reduced structural integrity and neurite density. Increased radial diffusivity was observed in these tracts, a feature associated with disrupted myelination. In the inferior fronto-occipital fasciculus, superior longitudinal fasciculus II, and uncinate fasciculus, an elevated orientation dispersion index suggested increased neurite dispersion and fanning in infants with DS. These findings reveal widespread WM developmental alterations in DS, providing new insights into the early neurodevelopment of DS, which may inform timing of early therapeutic interventions.
