Brain impact of football affected by career length, player's position

The lasting effects of football on the brain continue to make headlines, with plenty of attention focused on chronic traumatic encephalopathy (CTE), a progressive neurodegeneration associated with repetitive head trauma.

New research, funded by the National Football League Charities and the NFL Players Association, examined former football players, examined career duration and playing position in the white matter structure and neural recruitment of former college and professional athletes.

The team used diffusion tensor imaging and functional MRI to examine 61 former players between the age of 52 and 65. Half of the players reported experiencing more than three concussions, while the other half reported zero or one.

“Career duration and primary playing position seem to modify the effects of concussion history on white matter structure and neural recruitment,” wrote Michael Clark, a medical student at the University of North Carolina in Chapel Hill, et al., in the study, published Oct. 31 in Radiology. “The differences in brain structure and function were observed in the absence of clinical impairment, which suggested that multimodal imaging may provide early markers of onset of traumatic neurodegenerative disease.”

The team found former college players with three or more concussions had lower integrity in a white matter compared to those with fewer concussions. However, the opposite was true for former professional players, which the researchers hypothesized was due to the sample of those in the study.

Injuries also varied by position. The high proportion of frontal impacts experienced by

Non-speed players may result in more localized damage to frontal white matter tracts from repeated frontal impacts. Speed players experienced more variable impact locations.

"These findings suggest the playing position of an athlete may change the effects of concussions on the brain," said study author Kevin Guskiewicz, PhD, research director for the Center for the Study of Retired Athletes at UNC. "The mechanisms of concussions in non-speed players are fundamentally different from those of speed position players, suggesting that perhaps position-specific helmets are warranted."

The full study is available for free at Radiology.