“A dislocated ankle is easy to see, and we have a fairly systematic way of treating it,” said Kevin M. Guskiewicz, PhD, ATC-L, speaking during the AAOS Annual Meeting symposium on “New Concepts Regarding Athletic Induced Mild Traumatic (Concussion) and Catastrophic Brain Injuries.” “But concussion is not so obvious, and we need to take that into account when dealing with it.”

Dr. Guskiewicz explained that the medical community’s understanding of concussion—and what steps to take in response to the injury—has evolved in recent years, and research is ongoing.

“Concussions are diverse and unique injuries,” he said, “and we should treat them individually. We’ve moved away from grading concussions because grading scales have traditionally been based on two parameters: loss of consciousness and amnesia. Loss of consciousness is involved in less than 10 percent of all concussions, and amnesia in probably less than about 30 percent. So we’ve begun to focus more on objective tools to measure and track symptoms in cognitive function and balance.”

How many concussions?
A blow to the head—whether the result of a football tackle or a hockey check—triggers a series of reactions. “Upon impact, the brain sloshes around inside the skull,” said Dr. Guskiewicz. “The brain is a semi-gelatinous structure, and even though a helmet might mitigate movement to some extent, it won’t completely manage the energy inside the cranial cavity.

“The brain has about 86 billion neurons, and with each head impact, those neurons stretch, recoil, and start to swell. Without proper rest time, they can begin to disintegrate. And then we’re likely to see some impairment, depending on the region of the brain in which the pathology takes place,” he continued.

Mismanaging concussion can have a long-term impact on athletes, noted Dr. Guskiewicz. “Recent media reports have focused on the decreased quality of life among former professional athletes with a history of concussion. Student athletes may face academic issues, and published data show that a player who has had three or more diagnosed concussions is at an increased risk for many neuropsychologic factors and neuropsychiatric factors such as depression, cognitive impairment, and chronic traumatic encephalopathy (CTE), which researchers are just beginning to investigate.”

Although the scientific community has done a good job addressing what Dr. Guskiewicz calls “the right-hand side of the concussion equation”—looking at symptoms, neurocognitive function, and chronic effects—research is lacking on the “left-hand side” of the equation—identifying those at risk and preventive measures.

“How can we better identify players who might be predisposed to this injury?” he asked.

He suggested that simple approaches such as watching video footage of games could be used to help identify players with high-risk profiles. Similarly, video footage may provide clues to help design better protective gear.

“At every youth football, hockey, or lacrosse game, several parents will have video cameras,” he said. “We can learn from these basic technologies. If we can identify predispositions, we can work with organizing bodies to change rules and modify behavior and help guide equipment manufacturers.”

Structural effects
Dr. Guskiewicz explained that concussion has long been described as a functional injury, but new data suggest potentially visible structural factors as well.

“We need to think in terms of acute diagnostic biomarkers,” he said. “The military is very interested in this, particularly blood biomarkers that may be able to identify neuro trauma. In addition, some researchers are looking into diffusion tensor imaging, which shows the white matter tracks and the way in which water perfuses across those membranes. After brain injury, water does not perfuse in an organized manner. We may soon be able to use that technology to image concussion.”

Developing baseline studies of players’ responses is another area that should be explored, Dr. Guskiewicz suggested.

“We probably image one in 15 suspected concussions at my center,” he said. “We can begin to piece this puzzle together with a sound physical exam; tracking the players’ symptoms; looking at balance, postural stability, and vestibular problems; and testing cognition. But a baseline is really helpful because it enables us to track recovery over time and make more informed decisions about the player’s condition and ability to return to play.”

Evaluation tools
Those who work the sidelines need a good evaluation tool for concussion management.

“Have a protocol for disqualifying players from returning to play,” Dr. Guskiewicz advised. “The Sport Concussion Assessment Tool—3rd Edition (SCAT3) assesses for orientation, concentration, and memory. It has been found to be sensitive during the initial 24 to 48 hours after injury. Also, the new Zurich guidelines call for using a brief tandem walk to assess balance.”

Dr. Guskiewicz explained that no two concussions are alike, and athletes will display a variety of symptoms and recover at varying rates. In addition, male and female athletes tend to respond differently to concussion.

“In general, women’s and girls’ symptom scores will remain higher for a longer period of time, relative to males,” he said. “But on the brief mental status exam, men and boys tend to score worse at the time of injury and for 1 to 3 hours postinjury. The bottom line is that all patients should be managed individually.”

Team physicians also need to be prepared for high-risk scenarios that may be related to concussion. Dr. Guskiewicz outlined recommendations from the National Athletic Trainers’ Association for the prevention of catastrophic sports injuries.

“We wrote these recommendations based on the latest science,” he said. “Be prepared to perform manual ventilation if a player’s Glasgow Coma Scale score is less than 8 or if an athlete who has sustained an impact is posturing and not oxygenating well. If paramedics are available and can get the player to the hospital quickly, they may need to intubate.

“Think about reducing intracranial pressure,” he continued. “Sometimes there can be an associated cervical spine injury. If there’s any doubt, use a board, and elevate the head end of the board by 30 degrees, which can help ensure that neutral alignment is maintained in the head and neck, while optimizing venous outflow.”

Importance of education
One of the most important factors in preventing and treating concussion is educating the parents, the coaches, and the players themselves.

“Doctors on the sideline are going to face athletes who say, ‘It really wasn’t a concussion…I was just stunned,’” Dr. Guskiewicz explained. “I’ve even heard someone describe what happened as a ‘transient neurological condition.’ That sounds like a concussion to me.

“And I regularly receive phone calls from parents saying that their kid had a second concussion in the last 6 months and asking me about a new concussion-proof helmet they heard about. I explain that no such thing exists. We need to advise our patients, explain the long-term risks, and educate them regarding equipment.”

Disclosure: Dr. Guskiewicz reports no conflicts.

Peter Pollack is a staff writer for AAOS Now. He can be reached at ppollack@aaos.org

Bottom Line

• Concussion is a serious issue that must be addressed to prevent long-term impairment.
• Athletes with a history of concussion may have a decreased quality of life and an increased risk for many neuropsychologic and neuropsychiatric conditions.
• Identification of a biomarker or imaging test to measure concussion may help identify those at risk.
• Baseline measurements are important in tracking recovery.

Additional Information

• Zurich Guidelines
• SCAT3 Assessment Tool
• Child Scat3
• Pocket Concussion Recognition Tool