Concussion Associated with Brain Microstructure Alterations
REPETITIVE head impacts and prior concussion can alter cortical microstructure in young athletes, indicating early brain changes that may precede neurodegenerative disease.
Early Structural Markers of Neurotrauma
Concussion and contact sports have been linked with long term brain health concerns. This study evaluated MRI data from 207 collegiate aged athletes to investigate whether cortical macrostructure or microstructure was associated with concussion history. Researchers examined cortical thickness, cortical surface area, and cortical mean diffusivity, which may provide an earlier indicator of subtle gray matter disruption.
The primary finding was a strong positive association between the number of prior concussions and elevated cortical mean diffusivity across most cortical regions. Increased diffusivity suggests microstructural changes that could reflect early tissue alterations prior to widespread cortical atrophy.
Cortical Microstructure More Sensitive Than Thickness or Volume
Concussion history was also associated with increased cortical surface area in specific brain regions. In contrast, reduced cortical thickness was restricted to anterior and medial temporal regions, highlighting a more localized macrostructural effect. These observations suggest that cortical mean diffusivity may reveal earlier shifts in tissue integrity compared with thickness measurements.
Contact sport exposure alone, measured as cumulative years of participation, showed weak or no association with any cortical metric. This distinction indicates concussion itself rather than routine exposure to repetitive head impacts may be a more important contributor to early neurobiological changes.
Clinical Implications for Athlete Monitoring
These results underscore the relevance of cortical microstructure as a potentially sensitive biomarker of early neurotrauma in younger athletes who appear otherwise healthy. The authors emphasize the importance of continued concussion risk reduction strategies in sport and encourage further research to understand long term neurological implications.
Reference: Meier TB et al. The Relationship of Prior Concussion and Contact Sport Exposure with Cortical Macro and Microstructure. Hum Brain Mapp. 2025;46(16):e70392.
