Microstructural Alterations in Tract Development in College Football and Volleyball Players: A Longitudinal Diffusion...

Area of Science:

• Neuroscience
• Radiology
• Sports Medicine

Background:

• Repeated head impacts in sports can alter brain microstructure.
• Existing studies often lack longitudinal data, low-contact controls, or advanced metrics.
• Diffusion MRI is crucial for studying these microstructural changes.

Purpose of the Study:

• To investigate longitudinal brain microstructural changes in high-contact (football) vs. low-contact (volleyball) athletes.
• To compare advanced diffusion MRI metrics and automated fiber quantification between groups.
• To assess acute and chronic effects of impacts and their association with clinical measures.

Main Methods:

• Longitudinal study of collegiate football and volleyball players over 4 years.
• Advanced diffusion MRI and automated fiber quantification used.
• Nested linear mixed-effects models analyzed tract-specific diffusion metrics.

Main Results:

• Football players showed divergent microstructural trajectories compared to volleyball players.
• Concussed football players exhibited more prominent longitudinal differences in white matter tracts.
• High-impact risk positions in football correlated with increased intracellular volume fraction.

Conclusions:

• Football's impact profile leads to distinct white matter development trajectories compared to low-contact sports.
• Observed changes may indicate altered myelination, axonal caliber, or pruning processes.
• This study highlights potential long-term microstructural alterations from concussive and subconcussive impacts.