This is a hot topic here in the US in all sports, especially football. Lots of new rules about players having to come out of games and get checked by an independent (i.e., not team paid) doctor. It is so serious that many parents won't let their sons play football, which is seen as threat to the future of the game here. Even in Texas, where they have a long tradition of serious high school football. Several US pro players have donated their brains to labs after they die, to be checked for CTE (concussions). They are finding some links too.
Having recently had brain surgery for a spontaneous hematoma, I can relate to how serious this is. I can't imagine having a concussion. Or even more than one, like many NFL and AFL players get. Very Scary.