Pretty interesting reading up about some of this stuff. Looks like one study from August 2010 initially made some link, but more recent stuff says its actually more likely brain trauma related issues being mis-diagnosed as ALS (even Lou Gehrig himself maybe). And the distinction being a specific protein that is unique to those who show the symptoms with a history of brain trauma, verse those without the trauma. So it is likely a related though technically different disorder. But for all normal intents and purposes, there does seem to be a link (because who cares if theres the existence of a certain protein or not when your body just slowly degrades on itself) My uncle died of a disease pretty similar to ALS although I don't think they ever actually were able to diagnose him with anything, watching him, it was a pretty similar degradation of his body. Not sure what his concussion history, but he was a college football player. Just awful to experience that slow transformation though.