To Gojirason,
Thanks for that exeellent reply! Yes, I think you are right. It really depends on the prior injuries, but I do think the jostling seems to be the issue. My son seems to be O.K with cross country right now and has not had a problem yet but he will not go back to wrestling. We are painfully aware that the next injury will further set him back. It does not seem to matter whether it is years later or not, the brain is still vulnerable. All input from others helps us make a wise decision.
Nancy