Hmm...yeah, you have to wonder sometimes if lingering football injuries can cause problems in their children. I doubt it matters; it's probably just a coincidence. There are over 1500 players in the NFL, so you're going to have some disabled children in a sample size like that. Some people get hit harder than QB's.
That is really sad to think that he was only 8 years old, and I've already lived nearly 20 years longer. Condolences to Jim (Northwestern PA product) and his family.