Thank you for your warm welcome and response!

He doesn't play hockey competitively anymore--sometimes he'll play pond hockey, but it's far less physical than on the rink. The only sport he does now is weight lifting/body building, and he's aware of the cumulative effect--it's one of the reasons we think this most recent concussion is so bad.

Thanks for the advice about Aricept. I've been reading that ADHD drugs like Ritalin and Adderall can also help. I just hope we can get him into a concussion clinic. His previous PCP never referred him to a neurologist or anything. She was basically just like "eh, it'll go away on its own." His biggest problem is that he can't work right now because of all this, which leaves him on medicaid, and it seems like doctors don't have an interest in helping medicaid patients. :/