When your doctor tells you to rest for several days after a concussion, better follow that advice.
Researchers at the Georgetown University Medical Center (GUMC) found more than one day's rest is required after a head injury.
The study of mice indicated that shortening the rest period increased brain inflammation up to a year after injury. Repeated mild concussions with only one day's rest between injuries led to mounting damage.
Repeated mild concussions are common in many contact sports, like football and hockey. Military service and physical domestic abuse may also result in repeated concussions.
Lead author Mark P. Burns, PhD, commented in a press release, “It is good news that the brain can recover from a hit if given enough time to rest and recover. But on the flip side, we find that the brain does not undertake this rebalancing when impacts come too close together.”
Dr. Burns is an assistant professor of neuroscience at GUMC and director of the Laboratory for Brain Injury and Dementia.
Dr. Burns and colleagues studied mice that had repeated mild head trauma similar to what humans would experience after a concussion.
The mice were divided into two groups. The first group sustained a mild head injury once daily for 30 days. The second group sustained a mild head injury once a week for 30 weeks.
A mouse with a single mild head injury temporarily lost 10 to 15 percent of nerve connections in the brain. After three days' rest, the brain had healed.
Mice with daily concussions never healed completely. The brain became inflamed and damage to the brain occurred. “This damage became progressively worse for two months and remained apparent one year after the last impact,” Dr. Burns noted.
Mice with a week of rest between injuries healed without damage.
“The findings mirror what has been observed about such damage in humans years after a brain injury, especially among athletes,” Dr. Burns commented. “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.”
The study was published in the February issue of the American Journal of Pathology.
Funding for the study was provided by Georgetown University’s Neural Injury and Plasticity Training Program, the National Institute for Neurological Disorders and Stroke, the Canadian Institute of Health Research, the Natural Sciences and Engineering Research Council of Canada, among others.
Information on conflict of interest was not available.
