Above left is an image of healthy brain tissue. Above right is brain tissue of a middle-aged football player. It reveals the intense damage from repeated concussions received on the field. According to Dr. Ann McKee, co-director of the Center for the Study of Traumatic Encephalopathy (CSTE), the damage looks similar to that of an 80-year-old with dementia caused by Alzheimer's disease. The CSTE have found the condition, called chronic traumatic encephalopathy (CTE), in the donated brains of dead NFL players John Grimsley, Mike Webster, Andre Waters, Justin Strzelczyk and Terry Long. From CNN:
"What's been surprising is that (the damage is) so extensive," said Dr. Ann McKee, a neuropathologist at the Veterans Administration Hospital in Bedford, Massachusetts, and co-director of the CSTE. "It's throughout the brain, not just on the superficial aspects of the brain, but it's deep inside."
The damage affects the parts of the brain that control emotion, rage, hypersexuality, even breathing, and recent studies find that CTE is a progressive disease that eventually kills brain cells.