Repetitive head impacts — blows to the head that do not lead to symptoms that do not meet criteria for concussion — are now recognized as an independent risk factor for neurodegeneration. Our research established that exposure to repetitive head impacts can change brain microstructure in the absence of clinically apparent injury, a finding that has reshaped how risk is conceptualized in contact sports and youth athletics and contributed to policy changes in sports.

Our work investigates the biological consequences of repetitive head impacts across the lifespan, from youth athletes to former professional players and individuals at risk of chronic traumatic encephalopathy. We combine advanced multimodal neuroimaging with fluid biomarkers, exposure quantification, and longitudinal cohort designs with deep phenotyping to identify early signatures of injury, characterize the trajectory of neurobiological change, and develop diagnostic tools for neurodegeneration.

The core focus of our program is mechanism. We investigate the biological pathways that link repetitive exposure to long-term brain alterations — including disruption of brain clearance pathways such as glymphatic and perivascular function, neuroinflammation, and microstructural injury to white matter and neurovasculature. Identifying these mechanisms is essential for moving from descriptive risk to tractable targets for intervention.

Two questions cut across our research program: how biological sex shapes vulnerability and response to repetitive head impacts, and how cumulative exposure interacts with modulating factors (e.g., genetics) to determine who develops long-term neurological consequences. Answering these questions is essential for moving from population-level risk estimates toward individual prediction and for designing prevention strategies grounded in mechanism.