51³Ô¹Ï

This website stores cookies on your computer. These cookies are used to collect information about how you interact with our website and allow us to remember your browser. We use this information to improve and customize your browsing experience, for analytics and metrics about our visitors both on this website and other media, and for marketing purposes. By using this website, you accept and agree to be bound by UVic’s Terms of Use and Protection of Privacy Policy. If you do not agree to the above, you must not use this website.

Skip to main content
People Departments Maps Buildings Rooms A-Z
University
of 51³Ô¹Ï
51³Ô¹Ï Library
Sign in Online tools Sign out
Faculty of Graduate Studies

Taylor Snowden-Richardson

  • BSc (51³Ô¹Ï, 2019)
Notice of the Final Oral Examination for the Degree of Doctor of Philosophy

Topic

A Multimodal Assessment of the Long-Term Effects of Concussions in Adults over age Fifty

School of Medical Sciences

Date & location

  • Friday, July 4, 2025
  • 2:00 P.M.
  • Medical Sciences Building, Room 150

Examining Committee

Supervisory Committee

  • Dr. Brian Christie, School of Medical Sciences, 51³Ô¹Ï (Supervisor)
  • Dr. Jodie Gawryluk, School of Medical Sciences, UVic (Member)
  • Dr. Sandy Shultz, School of Medical Sciences, UVic (Member)
  • Dr. Stuart McDonald, Department of Neuroscience, Monash University (Outside Member)

External Examiner

  • Dr. Carolyn Emery, Faculty of Kinesiology, University of Calgary

Chair of Oral Examination

  • Dr. Lisa Reynolds, Department of Biochemistry and Microbiology, UVic

Abstract

Concussion, a form of mild traumatic brain injury (mTBI), is often viewed as a transient event with limited long-term impact. However, growing evidence suggests that concussions may carry lasting neurobiological consequences, particularly in older adults. This dissertation explores the long-term effects of concussion in adults over the age of fifty using a multimodal research framework that includes a systematic review and meta-analysis, a cross-sectional observational study, and a cognitive training intervention. The chapter two presents a comprehensive meta-analysis examining whether a history of mTBI is associated with an increased risk of developing dementia. The analysis included over 18,000 mTBI cases and revealed that individuals with prior mTBI are nearly twice as likely to develop dementia compared to those without, supporting the classification of concussion as a significant environmental risk factor for neurodegeneration. Chapter three investigated cognitive performance, brain structure, and serum biomarkers in older adults with and without a history of concussion. While traditional cognitive testing did not show significant group-level differences, participants with concussion histories exhibited relationships between levels of neurofilament light chain and decreased white matter integrity, suggesting ongoing or residual neural vulnerability that may not yet be behaviorally apparent. Chapter four evaluated whether a 12-week cognitive training intervention could support brain health and plasticity in aging adults. The program led to a significant increase in brain-derived neurotrophic factor, although cognitive and structural outcomes remained unchanged. These findings highlight the potential for targeted neuroplasticity interventions in at-risk individuals. Together, these studies provide converging evidence that having a history of concussion is associated with both increased dementia risk and subtle, persistent changes in brain health. The results underscore the importance of early identification, ongoing monitoring, and the development of preventative strategies to support cognitive aging in individuals with a history of concussion.

Back to oral exams