Most concussions seem to last just a few days or weeks before symptoms are absent. However, recent research has suggested symptoms may disappear before the brain is fully healed. While symptoms may be gone, the brain may still be vulnerable and healing.
Researchers from the Medical College of Wisconsin in Milwaukee say damage in the brain is observable for months after the injury and long after symptoms have faded.
In the small study, Melissa Lancaster, Ph.D., and a team of researchers examined 17 high school and college football players who had experienced sports-related concussions.
The football players underwent MRI scans and rated their concussions symptoms. The team of researchers also recorded other factors like cognitive deficits, balance problems, and memory issues. These tests were conducted 24 hours, 6 days, and 6 months after the injury and compared to results from 18 matched athletes who had not experienced a brain injury.
The participants were also given advanced brain scans using diffusion tensor imaging and diffusion kurtosis tensor imaging. These tests measure the amount of water moving through brain tissue to measure short- and long-term changes in the white matter.
The white matter in the brain helps connect regions of the brain and relay information. Damage to it could cause difficulties processing information and lead to impairments in many areas like vision and memory.
The findings showed that injured athletes had a reduction in water diffusion throughout the white matter that could be seen at all stages of testing. The team also noted that those with the most severe brain injuries were the most likely to exhibit these abnormalities after 6 months.
Despite these changes to the brains, the athletes who experienced brain injuries showed no difference from healthy athletes when self-reporting symptoms, balance, or cognition issues.
“In other words, athletes may still experience long-term brain changes even after they feel they have recovered from the injury,” said Lancaster. “These findings have important implications for managing concussions and determining recovery in athletes who have experienced a sports-related concussion.”
With a study this size, it is hard to draw concrete conclusions from the findings. But, when viewed in the context of other recent reports, it seems clear that the brain may take much longer to heal from a concussion than we initially thought.