Heads in the Game

When it comes to evaluating and treating concussions, there's a lot we don't know. A bonanza of new research is trying to change that.

By R.J. Anderson
R.J. Anderson is an Assistant Editor at Training & Conditioning.

Brandon Manning, a junior linebacker at Virginia Tech, is known for being in the right place at the right time. But during the team's loss to West Virginia this past fall, Manning seemed to be in a different stratosphere.

While reviewing video of the second half of the game, a member of the coaching staff turned to Manning and asked, "Brandon, what in the heck were you doing on that play?" After careful consideration, Manning answered that he didn't know--in fact, he didn't even remember being on the field for that play. A few minutes later, he realized that he was seeing many parts of the game for the first time.

After getting over their surprise, coaches relayed word of Manning's amnesia to the sports medical staff, who quickly went to their computers. During the game, Manning wore one of the team's eight helmets outfitted with the Head Impact Telemetry System (HITS) technology, a wireless, impact-measuring device. The special helmet contains six tiny accelerometers similar to the sensors used in automobiles to trigger air bag deployment during a collision. The sensors gather information about the force and directionality of each blow to the helmet and transfer the data to a microchip imbedded inside the crown of the helmet. A small antenna is attached to the microchip and transmits the data to a receiver connected to a laptop computer on the sideline, where the information is stored and monitored.

HITS technology was used at Virginia Tech last season to study the types of blows football players receive and what types cause concussions. In Manning's case, it also helped the sports medicine staff uncover a concussion they otherwise would have missed.

Examining the readings from Manning's helmet, the medical staff discovered that a relatively high load had been delivered in the first half of the game. They were then able to time-synch the game video with the HITS data and view the play which led to Manning's concussion: a helmet-to-helmet collision with West Virginia tailback Quincy Wilson, followed by Manning's head hitting the turf. To Manning, the Hokies leading tackler, the hit seemed no different than any other of the hundreds of blows he had dished out during his career. He didn't leave the field following the play and he never reported anything to the coaches during or after the game. But unbeknownst to him, Manning was the first person to ever have a concussion recorded by HITS technology.

"The technology is spectacular, because for the first time it allows us to evaluate these hits in real time," says, Gunnar Brolinson, DO, Team Physician for Virginia Tech football. "It's an opportunity to prevent players from sustaining additional blows to the head after having sustained a concussive load to the brain."

Hits measured in real time? Accelerometer sensors? Microchips in helmets? Concussion-reading computers? Welcome to the wave of the future in concussion research.

Only five years ago, most athletic trainers assessed concussions according to whether or not a player lost consciousness, and determined if they were ready to return to play based on one of the many arbitrary grading scales available. Today, a rapid succession of research has shed new light on assessing these injuries and has even broken new ground on treatment ideas. In this article, we'll update you on the most recent research and review how it can help you, right now, better assess concussions.



Latest Research

"Before last year there wasn't a single published study looking at concussions in high school athletes," says Michael Collins, PhD, Assistant Director of the Sports Concussion Program at the University of Pittsburgh Medical Center. "But in 2003 alone, we published seven studies looking at high school kids."

Among the UPMC findings was information that high school athletes take longer to recover from initial concussions than do college athletes. The researchers found that even seven days after suffering a concussion, high school athletes still reported significant symptoms, such as headaches and nausea, and also performed worse on neurocognitive tests than those who were uninjured. In the study, published in the May 2003 Journal of Pediatrics, college athletes typically returned to near-normal levels within three days, despite suffering more serious injuries.

The UPMC research also calls into question traditional concussion evaluation for athletes of all ages. In a study published in the July 2003 issue of the Clinical Journal of Sports Medicine, UPMC researchers determined that amnesia--as opposed to loss of consciousness--was the most important symptom for measuring severity. "Our study showed that many athletes with mild concussions whose symptoms disappeared within 15 minutes still showed significant decline in memory processing and other symptoms within one week post-injury, which means they weren't healed," says Mark Lovell, PhD, Director of the Sports Concussion Program at UPMC.

Based on the research, Lovell and his colleagues encourage athletic trainers to revisit the way they judge the severity of a concussion. "You want to find out if the player remembers what happened during the first five or 10 minutes before and after the injury," he says. "Ask the athlete to remember three words. Ask them to recount details of what happened to them. We think it's very, very important to evaluate that on the field, at the time of the injury. If we can detect any amnesia on the field, if there's any detectable mental status change, if they have a significant headache, or if their balance is off, then we hold them out for the rest of the contest."

The reason assessing concussions is so critical was underscored in an article in the Nov. 19, 2003 issue of the Journal of the American Medical Association. It indicates that once an athlete is concussed, the probability that he or she will experience a second concussion during the same season is greatly increased. Conducted by Kevin Guskiewicz, PhD, ATC, Director of the Sports Medicine Research Laboratory at the University of North Carolina, the study also indicates that recovery is slower in players with a history of concussions, and that players who reported a history of three or more concussions are three times more likely to experience the injury again compared to players with no concussion history.

Guskiewicz notes that 30 percent of the players with three or more previous concussions had symptoms lasting longer than a week, compared with only about seven percent of those with no history of concussion. Researchers found that 92 percent of repeat concussions occurred within 10 days of the initial injury, and 75 percent occurred within seven days.

"This underscores the critical importance of making certain that athletes are without symptoms before they are allowed to return to participation," says Guskiewicz. "Concussed players often will still be vulnerable during the first few days following the injury, but they are unlikely to sit out unless a physician or athletic trainer holds them out."

The study, which is part of the NCAA Concussion Study, is currently the largest multi-site study on recovery and outcome following sports-related concussion. The investigation took place at 25 colleges over a three-year span ending in 2001. During that time, 200 concussive injuries were reported in 2,905 football players. Guskiewicz and his colleagues reported 184 players (6.3 percent) experienced a concussion during that period, and 12 players suffered at least two. Positions that incurred the most concussions were linebackers, offensive linemen, and defensive backs.

While many of the recently published studies examine the effects of concussion-induced collisions, the next wave of research concentrates on the biomechanics involved with concussion-causing impacts. The first of these studies was introduced in the October 2003 issue of Neurosurgery and was commissioned by the National Football League along with NFL Charities and directed by Elliot Pellman, MD, Chair of the NFL Committee on Mild Traumatic Brain Injury (MTBI) and Team Physician for the New York Jets. The purpose of the research was to break down the impacts that caused significant head injuries and concussion by utilizing NFL game footage. The researchers obtained 182 cases on video for analysis that took place between 1996 and 2001. A cinematographic analysis was developed to determine the speed at which the players were moving prior to the concussion-causing collision. For 31 of the incidents, footage containing multiple camera angles of the impact was available. These viewings allowed the researchers to perform three-dimensional laboratory reconstructions using helmeted crash-test dummies.

The results indicated that concussions are more likely to result from translational acceleration where impact causes the head to move in a straight line, rather than from the neck twisting from side to side. The footage also revealed that most concussions occurred when players were hit on the side of the helmet, on the facemask, or when the back of the helmet absorbed the impact.

The Pellman study was considered to be a milestone for concussion research, as it was the first to look at the speed of impact and the amount of head acceleration that occurred on impact. With a precedent now set, other groups are set to carry that research a step or two further. One such group is at Virginia Tech, where Manning and his teammates are helping researchers gauge the speed and directionality of the blows they receive. While Pellman and the MTBI Committee painstakingly worked to estimate and re-enact the impact in a laboratory, the medical staff and engineers at Virginia Tech aim to measure the impacts in real time as they occur on the playing field.



Capturing the Data

The Virginia Tech project, which is funded by the Center for Injury Biometrics at the Virginia Tech College of Engineering in conjunction with the Edward Via Virginia College of Osteopathic Medicine and the Virginia Tech Sports Medicine Department, was implemented at the beginning of the 2003 football season. Every two weeks the team rotated eight sets of sensors to eight helmets belonging to different players. By the end of the season, 38 players had worn helmets equipped with HITS sensors during games and practices.

The sensors are designed to track a range of blows, which are measured in gravitational forces (g's) with ranges from 15 to 150 g's. "An impact of 120 g's would be like a severe car accident, which you could survive while wearing a seat belt," says Stefan Duma, PhD, Director of the Virginia Tech-Wake Forest Center for Injury Biomechanics. Half of the blows registered by HITS measured more than 30 g's, while blows exceeding 150 g's were rare, but did occur.

"We rotated the sensors to get a valid assessment of which position is taking what kind of blows," says Brolinson, adding that the system captured data from over 3,300 high-impact blows during the season. "One of the things I think is going to come out of this study is the need for position-specific helmets. I think we're seeing that linemen sustain certain kinds of loads compared with defensive backs, running backs, and so on. We already have position-specific shoulder pads, why not position-specific helmets too?"

One particular finding that surprised Brolinson and his colleagues was the abnormally high number of hits that offensive and defensive linemen experience during a game. "It was not unusual for our linemen to sustain 50 or 60 significant blows to the head during a game," he says.

In follow-up studies, Brolinson says he would like to find the clinical significance of repeated nonconcussive blows. "We see multiple loads occurring with linemen," he says. "They are below the level of concussion, but almost any lineman that you talk to--high school, college, or professional--will tell you that a lot of them have headaches following games. We have previously thought these headaches were simple muscle tension headaches, and that may in fact be the case, but at this point given the number of blows and amount of g-loading sustained over the course of a game, we've identified an area we want to investigate more thoroughly."

Brolinson also wants to continue to investigate the type of hits that cause concussions. "Ultimately what we want to do, using regression equations, is predict risk of concussion based on the directionality of the blow and the load that is sustained, and then evaluate the athlete accordingly," he says. "We want to identify what level of blow we need to be concerned about, even in a player that retains consciousness. If a player sustains a 120-g hit, what is his risk of significant brain injury? Is it 25 percent, is it 50 percent, is it 75 percent? We want to identify the at-risk player based on the magnitude of the blow and we would also like to identify the at-risk player based on the cumulative blows."

The directionality of the blow, Brolinson stresses, is just as important to causing a concussion as the force of the impact. A player who sustains a 130-g frontal impact might walk away from the play without a concussion, while the same player could take a 70- or 80-g lateral or posterior blow that could leave them with concussion symptoms. It is one of the variables their study is exploring--using risk modeling to decode concussion-causing impacts.

"Once we accumulate enough data to build these logistic models, we'll have the ability to look at an 80- or 90-g blow, see where it comes from, and keeping in mind who it's happening to, have an idea of what their risk of concussion is," says Brolinson. "If that's somebody with, for example, a 75 percent risk of concussion, then we can immediately get him to the sideline. And if their sideline evaluation indicates they have a concussion then that is somebody we can take out of the game and avoid subjecting to further risks."

Last season the system was part of a pilot study and used strictly as a research gathering tool, but by next season, Virginia Tech plans to outfit 64 helmets with accelerometers and begin using the system to help diagnose concussions. "Our goal is for this to be another tool in the athletic training staff's arsenal," says Rick Greenwald, PhD, President and co-founder of Simbex, the company that manufactures HITS. "This would alert them that an impact above the threshold that has been determined for that player or that group has been exceeded. Therefore they might want to trigger their other steps."

While the current cost of the HITS technology is prohibitive for smaller colleges and high schools--to equip a team of 50 to 75 players would cost $165,000 to $195,000, says Greenwald--Brolinson is confident that over time, HITS will be accessible for more mainstream use. Brolinson also hypothesizes that perhaps one day, hospital emergency rooms will be outfitted with the software to read the accelerometer chips, making it unnecessary for high schools to purchase the diagnostic technology. Then, if a player takes a hit that the athletic trainer believes could be concussive, the player's helmet can be taken to the ER to have the impact tested. Brolinson feels this scenario is feasible for a variety of helmeted activities such as hockey, cycling, and skateboarding, because the sensors and chips are relatively inexpensive to produce.



What's Next

Researchers on many fronts are excited about the implications of HITS technology. "We've got a grant out and are proposing to do the same sort of project next year," says Guskiewicz. "But we're going to take a little different angle."

Instead of focusing on the thresholds of concussions, Guskiewicz will be investigating how biomechanical measures correlate to the follow-up assessments of postural stability and cognitive function, and whether there is a threshold for tissue damage. "We're going to be doing MRI's on all of our subjects," he says. "We're looking to see what the correlation is between biomechanical measures and clinical measures.

"We need to somehow hone in on what the cause is, and try to prevent concussion," he adds. "And I'm not convinced it's going to be through improving helmets or changing the rules of the game--for whatever sport."

One of Brolinson's goals for the study at Virginia Tech is to eventually develop a more sophisticated paradigm for treating concussion. "We can see a scenario that would develop based on an enhanced understanding of what's going on with the brain that might result in some kind of pharmacological treatment to enhance healing," he says. "We have a multitude of pharmacological treatments for people who suffer migraines, strokes, and other neurological disorders. Why can't we develop something to treat concussion?"

Lovell also believes that there is a lot of work to be done in terms of developing medication to treat the neurochemical imbalance that occurs following a concussion. "Some of the work we've done with medications for post-traumatic migraines might be very useful for developing something to treat concussions," he says. "We're starting to get into that, but first, we need to make sure people are diagnosed properly."



Take Home Message

The best news about all this exciting research is that many of its findings can be translated into new assessment techniques right now. The most important piece of advice from the researchers is to throw away your grading scales. Although Lovell played a big part in developing some of the early concussion grading scales, he no longer endorses their use.

"Those scales were based on arbitrary criteria. They weren't based on any science," says Lovell. "They were a best guess of everybody out there at the time as far as if you could go back in the game after 15 minutes, or whether you should stay out longer."

Instead, researchers suggest focusing more on individualized testing and using as many tools as possible. Those tools include balance testing, awareness testing, and knowing the athletes.

Virginia Tech currently uses a stabilogram, which measures a player's balance and physical stability, and a Web-based neuropsychological exam called HeadMinder, which measures neurocognitive skills such as reaction time and memory retention. "All of that can be done on a sideline or in a locker room which allows the medical staff to make a well-calculated decision on whether or not to return that player to the game," says Brolinson.

Virginia Tech athletic trainers also make sure they have personalized knowledge of the athletes themselves. "At this level, the bottom line is, you have to know the athlete and how they respond to certain situations, because there are subtleties that will tip you off," says Mike Goforth, MS, ATC, Head Athletic Trainer at Virginia Tech. "They might pass a neuropsyche test, they might pass a balance test, but you'll notice that there is something that just isn't right about them and you have to hold them out. You don't notice those kind of things unless you know the athlete."

For athletic trainers who don't have the luxury of getting to know all of the athletes under their care, computer-based neuropsychological testing may be most important. There are a variety of computer-based neuropsychological examinations available, but the basic premise of each is for the athlete to develop a baseline score based on neurocognitive factors that become vulnerable during a concussion, such as an athlete's reaction time, processing speed, problem solving, and memory. If an athlete is suspected of having a concussion, he or she re-takes the exam and the results are measured against their baseline score. These types of exams are helpful in that they allow a clinician to evaluate the athlete based on more objective criteria before making a decision on whether or not it is safe for the athlete to play again.

"In the high school setting, where there are more athletes per athletic trainer, I think the computer-based testing will become more and more important," says Timothy Neal, MS, ATC, Head Athletic Trainer at Syracuse University. "In the college setting, I think the use of neuropsychological testing will be more of an adjunct to what people are already doing."

Neal, whose program currently uses the pencil and paper-based Standardized Assessment of Concussion (SAC) evaluation, is in the process of implementing the HeadMinder system with the Syracuse football team and plans to use both systems simultaneously in 2004. The school's men's and women's soccer team began using the HeadMinder system during their 2003 seasons.

Another benefit of computer-based neuropsychological testing is the message it sends athletes about the seriousness of reporting their symptoms when they are injured. "They sit down and take a baseline test that goes over all the symptoms of concussion," Collins says. "And at that point [the coach or athletic trainer] can say, ÔLook guys, this is why we're taking this test. If you have any symptoms let me know and we'll manage this sensibly.'"

Lovell, who along with Collins, developed a neuropsychological test called ImPACT, says that such tests are a useful tool, but they are not the only tool. "We aren't suggesting that it be the only criteria by which return-to-play issues are settled," he says. "But it can be very helpful because athletes are notorious for lying about their symptoms--and they aren't able to do that with this kind of testing."

With new information being released all the time, Guskiewicz advises clinicians to keep up to date on the subject and make return-to-play decisions based on the resources they have in their particular setting. He also stresses the importance of instituting some kind of baseline assessment, whether it be computer-based or pen-and-paper, as well as a postural stability testing program to objectively assess each individual athlete. "I describe it as a concussion puzzle," says Guskiewicz. "And in order to piece it all together, you have to be educated."