Dementia can strike for many reasons, for them to say this was from concussions is not exactly accurate. However, I would think that, as my first guess. The science of proving this condition is not proven methodologically yet. I do believe concussions are damaging though. That's why, I think it's crazy to become a boxer or octagon fighter, not sure the payoff is with the punishment to Ur brain. Exercise can produce new connections in the brain till the day you die, do I think he needs to work on that, then maybe memory exercises to try and counter this if at all possible.