As an American, I am proud of Olympic Gold medalist Claressa Shields' feat in women's boxing at the Olympics -- but as a woman who has suffered traumatic brain injury, I am deeply concerned that her win will encourage other young women to pursue this dangerous, potentially life-altering sport. There is no question that repeated blows to the head cause changes in the brain -- even when the head is protected by gear meant to soften the blows. The NFL has come under fire recently because of the link between football-incurred concussions and greatly increased risk of Alzheimer's and other...