Retired NFL players with concussion history at high risk of brain atrophy

Playing professional football in the NFL has always posed physical risks to the willing athletes lucky enough to find a spot on a roster. With more attention than ever now focused on examining and predicting those risks, researchers—and the players themselves—are discovering more information about just how dangerous the sport can be.

A newly published MRI-based study has found that retired NFL players who suffered concussion and loss of consciousness on the field during their careers may be at high risk for brain atrophy, including problems associated with memory storage and impaired memory performance. The results of the study were published online May 18 in JAMA Neurology.

“One of the most common deficits following traumatic brain injury is a disturbance in episodic memory, which may persist years after injury, although the potential mechanism for this is poorly understood,” writes lead author Jeremy Strain, a researcher at The University of Texas at Dallas, and his colleagues. “Traumatic brain injury has also been reported as a risk factor for dementia, including Alzheimer disease and chronic traumatic encephalopathy later in life.”

Strain and his team wanted to ascertain the relationship between memory performance and concussion history in retired NFL athletes. To do so, they analyzed each player’s concussion history, duration of time in the NFL, and measures of hippocampal volume as determined by MRI, and compared the results against a control group and among athletes with and without mild cognitive impairment (MCI).

Their results showed that retired athletes with a history of concussion without cognitive impairment had normal but significantly lower test scores than control participants. Athletes with both a concussion history and MCI performed worse on tests when compared with both control participants and athletes without memory impairment. They also found that athletes aged 63 or older with a history of G3 concussion were more likely to have MCI (7 of 7) than retired athletes without a history of G3 concussion (1 of 5).

“Prior concussion that results in loss of consciousness is a risk factor for increased hippocampal atrophy and the development of MCI,” wrote Strain et al. “In individuals with MCI, hippocampal volume loss appears greater among those with a history of concussion.”

Despite issues surrounding the accuracy of concussion reporting and, specifically, self-reporting, during the players’ careers, Strain and his colleagues believe their results can help better inform athletes about the risks of concussion and spur additional research. “Our findings suggest that a remote history of concussion with loss of consciousness is associated with both later-in-life decreases in hippocampal volume and memory performance in retired NFL football players,” the researchers concluded. “Prospective longitudinal studies after a G3 concussion would add further insight to the mechanism of MCI development in these populations.”