I can't buy that as a legitimate theory based on everything I know about ALS. The cause of ALS seams to continue to be a mystery and I would think something as relatively simple as head trauma would have shown a stronger correlation by now. There is lots of research out there about it. Apparently ALS is unusually high among boxers, football players, soccer players and other contact sports. Can you point me towards anything you've read? I am pretty interested in the disease and have never heard of this. Here is a story on the NFL site, but there are studies all over the place. http://www.nfl.com/news/story/09000d5d819d12df/article/scientists-link-athletes-head-injuries-alslike-disease If you weren't aware of the Steve Gleason story, he founded what really is an amazing foundation for the research of ALS and the treatment and care of patients with the disease. The logo for his foundation is my sig, and he is a huge inspiration for me, our city and really anyone for that matter. I honestly am in awe of him, and his wife. Here's his story behind the foundation: