Cognitive Deficits Can Linger After Concussions
January 7, 2013

Cognitive Deficits From Concussions Still Present After 2 Months

Alan McStravick for — Your Universe Online

Concussions and their negative effects have been in the news a lot lately. From professional athletes who have, in bizarre acts of suicide meant to leave their brains to study for posterity, to the most recent noteworthy incident involving a certain high-ranking government official at the State Department, the attention that concussions or traumatic brain injuries (TBI) have been receiving seems very much to be on the rise. And for good reason. We really don´t know the long-term effects of a TBI. That is doubly true when they are experienced by high school athletes.

A new study out of the University of Oregon (UO) is hoping to shed a bright light on this topic. In their research they have found the ability to focus and switch tasks readily amid distractions was lessened for a period of up to 2 months following a brain concussion by a high school athlete.

According to the Centers for Disease Control (CDC), a concussion is a type of TBI that is caused by a bump, blow or jolt to the head that affects the way your brain would normally work. Other possible causes of concussions can come after a fall or blow to the body that allows the head and brain to move quickly back and forth.

The CDC also states that health care professionals will typically describe a concussion as a “mild” brain injury because they are not usually life-threatening. Their effects, however, can be very serious.

The research team, headed by lead author David Howell, a graduate student in the UO Department of Human Physiology, states that the current conventional wisdom for concussion recovery of 7-10 days may be missing the mark by quite a lot. Their research suggests some athletes may require far more time to recover than previously thought. This extended recovery time could be a significant factor in preventing subsequent concussions.

"The differences we detected may be a matter of milliseconds between a concussed person and a control subject, but as far as brain time goes that difference for a linebacker returning to competition too soon could mean the difference between another injury or successfully preparing to safely tackle an oncoming running back," Howell said.

The team utilized two different cognitive exercise testing methods to arrive at their findings. The sensitive computer-based measuring tools — the attentional network test and the task-switching test — were administered five times over the two month study period. The goal was to focus on the effects of the concussion as it related specifically to the frontal region of the brain. It is this region, according to Li-Shan Chou, professor of human physiology and director of the UO Motion Analysis Laboratory, which is responsible for working, or short-term, memory and executive function.

Symptoms associated with damage, even minor damage, to this area can include difficulty thinking clearly or remembering new information. Victims of concussion often will suffer headache, blurred or fuzzy vision, dizziness often accompanied by nausea or vomiting, and lack of energy. The insidiousness of concussion lies in the fact that these symptoms may or may not appear right away, while still others may only become apparent several days or even months after the injury. This lapse in time often makes it difficult for the victim of the concussion, and even health care professionals, to draw the parallels between the symptoms and the inciting injury.

It is when the symptoms go undiagnosed that the real problems can begin to occur. “If a person goes back to the playing field without a full recovery, that person is put into great danger of being re-injured,” Chou said. “In any given season, if you suffer a concussion, the chances of your suffering a second one is 3 to 6 times higher and suffering a third is 8 times higher. There are accumulations in this kind of injury. It doesn´t go away easily.”

The researchers have published their study online ahead of print in Medicine & Science in Sports & Exercise, the official journal of the American College of Sports Medicine. One concession the team makes is the great unknown of just how serious concussion injuries are for adolescents. Because their brains are still in development, it is uncertain as to whether the brain can recover more easily or suffer from deficits produced by the injury for the remainder of their lives. “We just don´t know,” Chou said. Almost all previous research on the subject has laid its focus on college-aged athletes and older adults.

The team cites figures from a 2011 report from the CDC, which stated these sports-related concussions in youths have seen a 60 percent increase over the last decade. Yearly, there are approximately 300,000 to 500,000 mild TBI´s with approximately 100,000 tied directly to the sport of football, Chou stated. Another source of concussion is also via close proximity to improvised explosive devices in the battle theater.

Researchers established an arrangement with Eugene, Oregon area schools for the execution of their study. The team worked with 20 high school athletes who had suffered concussion. While they were primarily football players, other athletes came from the sports of soccer, volleyball and wrestling. Each athlete was able to be assessed within 72 hours of their injury and then again after a week, two weeks, one month and again at the second month. Diagnosis of each concussion victim was performed by either a certified athletic trainer or a physician. Each victim was then paired with a healthy control subject of the same sex, approximate body size, age and sport.

"After two months following the concussions, these individuals were still significantly impaired in their executive function, compared to age-matched, activity-matched and gender-matched control populations," said co-author Louis Osternig, professor emeritus of human physiology and a fellow of the American College of Sports Medicine.

One of the challenges of the research team, according to Osternig, himself a certified athletic trainer, was how self-reports by the subjects with regard to how they were feeling were often at odds with the test results obtained. This, according to Osternig, showed a continuation of the subtle deficits in the cognitive function of the subjects. Additionally, anecdotal reports by both the concussed athletes and their parents purported a decline in overall academic performance during the two-month period.

The study, which has multiple funding sources, including the Department of Defense Telemedicine & Advanced Technology Research Center, the National Athletic Trainers Association, the Veterans Administration, as well as a translational research award from a joint UO-PeachHealth Oregon Region collaboration program, is also reviewing additional data that links the cognitive testing deficits to the gait of the subject. The purpose is to review the subjects´ task shifting abilities while they are walking.

"By using tools from cognitive psychology, neuroscience and human physiology, this interdisciplinary team of scientists is improving our understanding of how brain trauma affects reaction time, and they are helping to create better outcomes for athletes, soldiers and others who are affected by concussions," said Kimberly Andrews Espy, vice president for research and innovation and dean of the graduate school. "UO researchers are working to improve the health and well-being of people in our local communities and throughout the world."

"The brain is the controller of our body movement," Chou said. "If you have a brain injury, are there any differences that we can pick up in the way a subject moves the body? In this lab, we are using motion analysis as a way to detect any deficiencies or abnormalities of body movement."

Chou, along with additional co-authors of the study, Ulrich Mayr, a UO psychology professor and Paul van Donkelaar, a former UO human physiology professor now with the University of British Columbia, states that the goal of his lab, at this time, is to share their findings with the public by engaging with parents, athletic trainers and coaches directly. The idea is to say, according to Chou, “These are the facts. We may not be able to draw any line on what clinically should or shouldn´t be done. However, these are our observations based on our scientific testing.”