You may have seen Chris Harvard's work as a pro wrestler or the work he did on the college gridiron. But he never saw the head shot that ended his career.
His real name is Chris Nowinski and he's suffered six concussions in all. He teamed up with the Boston University School of Medicine to identify head trauma's deepest impact.
"I had headaches for five years. I had memory problems for about a year-and-a-half," said Nowinski.
Lab work on the brains of deceased athletes reveals new information on chronic traumatic encephalopathy (CTE). Doctors say it's caused by repetitive trauma like concussions, and symptoms include memory loss and impulse control issues.
"CTE is another cause of dementia; it's another brain disease like Alzheimer's disease," said Dr. Robert Stern, associate professor of neurology at Boston University School of Medicine.
Post-mortem brain scans of former linebacker John Grimsley, who suffered nine concussions, show buildup of a harmful protein called tau.
"It starts kind of clumping together and develops into these tangled fibers," said Stern.
That protein triggers brain cell death and dementia. Big news to the 50,000 child athletes diagnosed with concussions each year. This work may help doctors unravel the mystery of Lou Gehrig's disease, too.
"A bunch of athletes who developed ALS clinically actually had essentially CTE that had gone in their spine," said Nowinski.
Not all head traumas mean CTE.
Right now, the only way to detect CTE is to dissect the brain after death. Still, researchers are hoping to find a way to diagnose the disease during life. Additional investigations include whether some people are genetically predisposed to developing CTE.