One hit ended Paige Decker's hockey career. The misdiagnoses and long, painful road back to normalcy led her to educate other players about the effects of concussions.

It’s impossible to definitively say that his recent series of concussions will leave Broncos wide receiver Wes Welker with any lasting medical issues. Everyone responds to concussions differently, and every hit leaves its own impression. Fifteen years from now, Welker may be a happy father, tossing the football with his future kids, without a hint of a health issue. Or his brain might be fried.