Researchers at Johns Hopkins have discovered signs of accumulated brain damage in former NFL players that may be connected to specific memory problems experienced decades after they stopped playing football.
The study involved nine former NFL players who underwent a variety of imaging and cognitive tests. The findings strengthen the argument for better helmet protection by showing the long-term neurological risks to football players who have experienced repeated concussions.
“We’re hoping that our findings are going to further inform the game,” said Jennifer Coughlin, M.D., assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine.
“That may mean individuals are able to make more educated decisions about whether they’re susceptible to brain injury, advise how helmets are structured, or inform guidelines for the game to better protect players.”
Anecdotal accounts and studies have long suggested that athletes exposed to repeat concussions could suffer permanent brain damage and deficits. Until now, however, the mechanism of damage and the source of these deficits have remained unclear.
For the study, the researchers recruited nine former NFL players (ages 57-74) who had retired decades ago. The participants had played a variety of positions and had experienced a wide range of concussions, varying from none for a running back to 40 for a defensive tackle. The researchers also recruited nine healthy age-matched “controls.”
Each participant underwent a positron emission tomography (PET) scan. The researchers focused on the translocator protein, a marker of damage and repair in the brain. While healthy people exhibit low levels of this protein, those with brain injuries tend to have concentrated zones with high levels wherever an injury has occurred.
The volunteers also underwent magnetic resonance imaging (MRI) tests. This allowed the researchers to match up the PET scan findings with anatomical locations in the brain and to also check for structural abnormalities. Finally, the participants took a variety of memory tests.
PET scans showed that on average, the NFL players had evidence of brain injury in several temporal medial lobe regions, including the amygdala, a region that plays a significant role in regulating mood. Imaging also identified injuries in many players’ supramarginal gyrus, which is linked to verbal memory.
MRIs of the former players’ brains also revealed atrophy on the right-side of the hippocampus (an area that plays a role in several aspects of memory), suggesting that this region may have shrunk in size due to previous damage. Furthermore, many of the NFL players scored low on memory testing, particularly in areas of verbal learning and memory.
Though the researchers emphasize that this pilot study is small in size, they note that the evidence suggests that there are molecular and structural changes in the brains of athletes with a history of repeated hits to the head, and that these changes persist for decades, long after their playing careers have ended.
Currently, the researchers are looking for translocator protein hotspots in both active and recently retired players. They want to find out whether these changes develop rapidly or if they’re the result of a more delayed response to injury.
If the results of this study are replicated in larger studies, they say, it may lead to changes in the way players are treated post-concussion or perhaps in how contact sports are played.
The findings are published in the journal Neurobiology of Disease.
Source: Johns Hopkins