Concussion Effects May Linger More Than a Year After Return to Play

New research published inNeurology has found athletes’ brains may still not be fully recovered 1 year after being allowed to return to play. The study involved 24 college athletes with concussion college athletes and 122 athletes without concussions. Men and women were equally represented in both groups. Participants competed in the following sports: volleyball, hockey, soccer, football, rugby, basketball, lacrosse, and water polo. 

When compared to athletes without concussions, those returned to play after a concussion had significantly reduced blood flow in the brain 1 year later. Specifically, athletes with concussions had an average decrease in blood flow of 10 mL/100 g of blood per minute compared to athletes without concussions. When examining diffusion weighted imaging (DTI) of white matter tracts, researchers also found the brains of athletes with concussions still showed possible signs of tissue swelling 1 year after return to play. No changes in resting brain activity in grey matter or white matter tractography differences were seen, however.

 “There is growing evidence that recovery from a concussion may not be complete when symptoms such as headache and dizziness are gone and the athlete is allowed to return to play, so it is important to determine if various aspects of the brain injury resolve over time or are perhaps permanent,” said study author Nathan W. Churchill, PhD, of St. Michael’s Hospital in Toronto, Canada. “Our research looked at the brain one year after return to play in a group of college athletes and found that evidence of brain injury from concussion remained in some parts of the brain.”

“The principal finding of this study was that different aspects of brain physiology have different patterns of long-term recovery,” said Dr. Churchill. “These findings significantly enhance our understanding of the natural course of brain recovery after a concussion. Future studies are needed to look beyond one year after return to play to see if these longer-term brain injuries eventually heal or remain permanent.”

For athletes with concussions, the first brain MRI was performed an average of 4 days after injury. The second occurred when the athlete was cleared to return to play. The third scan was performed 1 year after return to play. Athletes who did not have concussion also had a brain MRI at the start of their seasons. Brain scans of the athletes with concussions were then compared to the brain scans of the healthy athletes.

A limitation of the study is no athletes had baseline brain MRI done before injury and comparisons were age-, sex-, and concussion-history matched instead.
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