After Concussion, Rest Is Best

Recent research at Georgetown suggests that several days of rest should be prescribed after a concussion.

Georgetown University Medical Center neuroscientists say rest—for more than a day—is critical for the brain to reset neural networks and repair any short-term injury. The new study in mice also shows that repeated mild concussions with only a day to recover between injuries leads to mounting damage and brain inflammation that remains evident a year after injury.

"It is good news that the brain can recover from a hit if given enough time to rest and recover," says the study's lead researcher, Mark P. Burns, associate professor of neuroscience at GUMC and director of the Laboratory for Brain Injury and Dementia. "But on the flip side, we find that the brain does not undertake this rebalancing when impacts come too close together."

Published in the March 2016 issue of American Journal of Pathology, this Georgetown study, the first of its kind, modeled repeated mild head trauma to investigate brain damage that occurs after such an injury.

Investigators developed a mouse model of repetitive, extremely mild concussive impacts conducted while the mouse is anesthetized. They compared the brain's response to a single concussion with an injury received daily for 30 days and one received weekly over 30 weeks. Mice with a single insult temporarily lose 10-15 percent of the neuronal connections in their brains, but no inflammation or cell death resulted. With three days of rest, all neuronal connections were restored. This neuronal response is not seen in mice with daily concussions, but the pattern is restored when a week of rest is given between each impact.

"The findings mirror what has been observed about such damage in humans years after a brain injury, especially among athletes," Burns says. "Studies have shown that almost all people with single concussions spontaneously recover, but athletes who play contact sports are much more susceptible to lasting brain damage. These findings help fill in the picture of how and when concussions and mild head trauma can lead to sustained brain damage."

In addition to its Georgetown co-authors, colleagues from the Centre Hospitalier de l'Université Laval, Neurosciences, Québec, Canada, also contributed.