Concussions alter brains well past point of full-function regain

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Amplifying research from earlier this year showing that the anatomic effects of traumatic brain injury persist long after observable symptoms subside— potentially long enough to increase risk for Alzheimer’s—a new diffusion MRI study has shown white matter changes in the brains of athletes six months after a concussion event.  

The findings were presented July 8 at the 2016 Sports Concussion Conference in Chicago, according to a news release sent from the meeting by the American Academy of Neurology (AAN).

AAN says Melissa Lancaster, PhD, of the Medical College of Wisconsin in Milwaukee, and colleagues looked at 17 concussed football players and 18 carefully matched control athletes. All were playing at the high school or college level when the study started.

The participants underwent diffusion MRI brain scans of two types—conventional diffusion tensor imaging and emerging diffusion kurtosis tensor imaging—and were assessed for concussion signs and symptoms at 24 hours, eight days and six months following the injury.

Both diffusion MRI techniques capture the movement of water molecules in brain tissue and measure microstructural changes in white matter.

The researchers found that the concussed athletes had less water diffusion in the acute stages following concussion (24 hours, six days) compared to those who did not have concussions.

These microstructural changes remained six months after the injury, and the most severely symptomatic subjects were the most likely to have alterations in the brain’s white matter six months later.

AAN notes that, despite these findings, there was no difference between the two groups in terms of self-reported concussion symptoms, cognition or balance at six months post-injury.

“In other words, athletes may still experience long-term brain changes even after they feel they have recovered from the injury,” Lancaster says in the release. “These findings have important implications for managing concussions and determining recovery in athletes who have experienced a sports-related concussion.”

Lancaster calls for additional research to explore how the structural brain changes relate to long-term outcomes.