Ex-NFL Player, 25, With CTE Highlights How Dangerous Disease Can Develop Early

The degenerative disease involves a buildup of the abnormal protein called tao, which is also found in Alzheimer's patients and is associated with a breakdown of brain tissue. It's believed to be caused by repetitive trauma to the brain, according to the CTE Center at Boston University, and symptoms include memory loss, confusion, impulse control problems, aggression, depression anxiety and progressive dementia.