Linda E. Clarke is a writer and professional performance storyteller who has taught at Dalhousie University Faculty of Medicine, Columbia Medical School, the University of Toronto, and the Yale School of Medicine. Michael D. Cusimano, MD, PhD, has been a staff neurosurgeon at St. Michael's Hospital in Toronto since 1992. His work on traumatic brain injury and concussions was an important component in the national change in Canadian hockey policy.