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Brain Injury Strikes 40 Percent of Former NFL Players: Study

The more years a player grinds in the game, the higher the likelihood of brain injury once he leaves it.

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Professional football players put their bodies on the line every time they step out on the field. But how much damage carries over long after the whistle is blown and pros transition to life away from the game? Emerging studies on brain trauma are painting a picture of what it means to carry the scars of playing football at the highest level.

More than 40 percent of retired NFL players participating in a study that will be presented at the upcoming American Academy of Neurology's annual meeting showed signs of traumatic brain injury.

For the research, 40 NFL veterans participated in cognitive and memory tests. They also underwent MRI scans for physical signs of damage to the brain's white matter, which connects different neural regions.

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Among those who participated, the average age of the player was just 36 years old, though they ranged from 27 to 56. The average player's professional career lasted seven years, with a range of two to 17 years in the game as a pro. Most of the veterans in this study waved goodbye to the game less than five years ago.

As a group, the rate of traumatic brain injury was significantly higher in the players compared with the general population, according to study author Francis X. Conidi of the Florida Center for Headache and Sports Neurology and Florida State University College of Medicine.

The MRI scans demonstrated within a 1 percent margin of error that 43 percent of the players studied showed signs of traumatic brain injury, based on the movement of water molecules in their brain tissue. Twelve of the athletes, or 30 percent, showed evidence of disruption to the connections between nerve cells and brain cells.

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The tests results weren't any more encouraging. Twenty-four percent of players had issues with spatial reasoning; 42 percent displayed trouble with focus and concentration. Forty-five percent had trouble with learning or memory, and almost half struggled with executive function skills.

Players with the longest careers were more likely to show signs of traumatic brain injury. The average player suffered 8.1 concussions over the course of a career, but others reported experiencing sub-concussive events, hard hits that don't quite meet the criteria for a concussion. The number of concussions, however, did not seem to affect the results in this particular study.

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Earlier this year, neurological researchers at the University of California, Los Angeles, published a study on a formula that they assert can predict which NFL players suffer brain damage in their retirement, based on their concussion history and other factors, Discovery News' Eric Niiler reported in February. The most important variable the researcher for that study found was whether a player had post-concussive amnesia, in other words remembering what he even did on game day.

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