A study based on MRI scans called diffusion tensor imaging and performed on living retired National Football League (NFL) players suggests that more than 40% of them showed signs of traumatic brain injury (TBI).
“The rate of traumatic brain injury was significantly higher in the players than that found in the general population,” notes study author Francis X. Conidi, MD, DO, of the Florida Center for Headache and Sports Neurology and Florida State University College of Medicine in Tallahassee, in a media release from the American Academy of Neurology.
The study is being presented during the American Academy of Neurology’s 68th Annual Meeting in Vancouver.
In the study, Conidi and colleagues conducted thinking and memory tests in 40 retired NFL players, along with the brain scans. The players were an average age of 36, ranging from 27 to 56. A majority of the players had been out of the NFL for less than 5 years. They played an average of 7 years in the NFL, with a range of 2 to 17 years. They reported an average of 8.1 concussions. Twelve players, or 31%, said they had several sub-concussive hits, or hits considered below the threshold of a diagnosed concussion, according to the release.
The MRI scans measured the amount of damage to the brain’s white matter based on the movement of water molecules in the brain tissue. Seventeen players, or 43%, had levels of movement 2.5 standard deviations below those of healthy people of the same age, which is considered evidence of TBI with a less than 1% error rate.
Twelve of the former athletes, or 30%, showed evidence on traditional MRI of brain injury due to disruption of the nerve axons. On the tests of thinking skills, about 50% had significant problems on executive function, 45% on learning or memory, 42% on attention and concentration, and 24% on spatial and perceptual function, per the release.
The more years a player spent in the NFL, the more likely he was to show signs of TBI on the advanced MRI scans. However, there was no relationship between the number of concussions a player experienced and whether he had TBI based on the advanced MRI. There was also no relationship between the number of years a player spent in the NFL and whether he had signs of brain damage on the traditional MRI.
“We found that longer careers placed the athletes at a higher risk of TBI,” Conidi states in the release. “This research in living players sheds light on the possible pathological changes consistent with chronic traumatic encephalopathy that may be taking place.”
[Source(s): American Academy of Neurology, PR Newswire]