1. Dalla Lana School of Public Health, University of Toronto, Toronto, M5T 3M7, Ontario, Canada
2. Division of Neurology, University of Toronto, Toronto, M5S 3H2, Ontario, Canada
3. Head Injury Clinic, St. Michael's Hospital, Unity Health, Toronto, M5B 1W8, Ontario, Canada
4. Concussion Ontario Network, Ontario Brain Institute, Toronto, M5H 3W4, Ontario, Canada
5. Department of Anesthesia & Surgery, University of Toronto, Toronto, M5G 1E2, Ontario, Canada