The NFL helped fund a study that has led scientists to make a connection between head injuries in athletes and Lou Gehrig’s disease (ALS). In research conducted on the bodies of former athletes, the study results indicate that the new disease is similar to but not the same as ALS.

Dr. Ann McKee, a neurology professor at Boston University, who conducted the study, calls the new disease chronic traumatic encephalopathy (CTEM). She says it is likely caused by repetitive head trauma that athletes can be exposed to in sports.

To reach her conclusions, she studied the brains and spinal cords of three deceased professional sports figures and found the same toxic proteins in all three. The proteins were not present in the spines of athletes with CTE and who didn’t have Lou Gehrig’s disease. Nor had she seen them in non-athletes who died of ALS.

The study raises the question of whether the New York Yankees first baseman really died from the disease bearing his name or CTEM.