Dave Mirra, one of the biggest stars in extreme sports, committed suicide in February. Months later, an examination confirmed that Mirra, a BMX rider, had the degenerative brain injury called chronic traumatic encephalopathy, or CTE. That has moved the conversation on head trauma to amateur athletes and to recreational activities like biking and skiing.
A 2015 study analyzed more than 4 million emergency room visits in the U.S. from 2000-2011, and was published last year in the Orthopaedic Journal of Sports Medicine. It reported a steadily rising number of concussion injuries in seven sports: surfing, mountain biking, motocross, skateboarding, snowboarding, snowmobiling and skiing. Snowboarding was the most concussive activity, with 42,811 concussions over that 10-year period.
Read more at: http://www.cpr.org/news/story/not-just-the-nfl-traumatic-brain-injury-a-growing-concern-in-extreme-sports