Athletes who wait to report a concussion may experience longer recovery times, say University of Florida researchers who found that college players who delayed treatment or removal from play missed an average of five more days of play than athletes who immediately reported concussion symptoms.

The study appears in the Journal of Athletic Training.

The findings suggest that athletes who don't receive immediate treatment for concussion risk further insult to the brain and may take longer to recover, said Breton Asken, the study's lead author and a student in the neuropsychology track of the clinical psychology doctoral program at the College of Public Health and Health Professions, part of UF Health. While other studies have described a "window of vulnerability" in animals immediately after brain injury, the UF study is one of the first to examine how it may translate to humans.

Previous research indicates that during this period after a concussion, intense physical activity, not just direct hits to the head, can be detrimental, Asken said.

"We believe exertion or increasing blood flow to the brain when it's not quite ready to handle that, even in the absence of more impacts to the brain, could also interfere with recovery in this window," said Asken, also a clinical and research coordinator for the Sports Concussion Center at the UF Student Health Care Center.

For the UF study, researchers examined data from the University of Florida Concussion Databank, which contains concussion-related medical history and injury details for athletes in UF's varsity sports programs. The study included 97 male and female athletes participating in basketball, football, gymnastics, lacrosse, soccer, swimming and diving, track and field and volleyball who were diagnosed with a sport-related concussion between 2008 and 2015. Of those, 50 did not immediately report concussion symptoms.

When controlling for other factors shown to prolong recovery time, such as a history of concussion or previous diagnosis of a learning disability, attention deficit hyperactivity disorder or depression, the researchers found that athletes who delayed reporting a concussion still took an average of five more days to receive medical clearance to return to play.

"I think many athletes naively believe that concussion symptoms will go away, or if they report a concussion it will keep them out of play for a lot longer," said senior author Russell Bauer, Ph.D., Asken's mentor and a professor in the department of clinical and health psychology. "These data show that if you do have signs of concussion and you wait to report it, you may actually have a longer road back to the playing field."

Future research should examine larger groups of athletes and different ages, including high school players, the researchers say. Because this was a retrospective study of medical records and notes by team physicians and athletic trainers, the research team wasn't able to quantify the specific amount of time athletes kept playing before reporting a concussion, whether that was immediately after finishing the game or days later, to determine how the length of a reporting delay contributed to recovery time.

The researchers hope the information will become part of athletic trainers and team physicians' pre-season education of athletes.

"The acute effects of concussion and what it does to the brain are becoming better understood at this point, but in some cases it is still not enough to convince athletes that it is important to report an injury or remove themselves immediately from play," Asken said. "What this study might add is context the athlete can relate to, and that is how much time they may miss from their sport. Immediate reporting of concussion symptoms allows for proper management at the point of injury and gives athletes the best opportunity to return to their sport more quickly."

In addition to Asken and Bauer, the study team included James Clugston, M.D., a University Athletic Association team physician at UF and an associate professor of community health and family medicine in the College of Medicine; Michael McCrea, Ph.D., a professor of neurosurgery and neurology and director of brain injury research at the Medical College of Wisconsin; and Aliyah Snyder and Zac Houck, both doctoral students in the UF department of clinical and health psychology.

Article: "Playing Through It": Delayed Reporting and Removal From Athletic Activity After Concussion Predicts Prolonged Recovery, Breton M. Asken, Russell M. Bauer, et al., Journal of Athletic Training, doi: 10.4085/1062-6050-51.5.02, published online May 2016.