Over a million persons suffer from concussions in the United States every year -- including many young athletes whose diagnosis depends on someone on the sidelines who may, or may not, be capable of getting it right. If the diagnosis is wrong, and the player returns to the field and is hit in the head again, the second concussion will probably be far more serious, and possibly even fatal.
Now, a team of research engineers at the Georgia Tech Research Institute is developing the technology that will enable nearly anyone, with just a few minutes training, to make a reliable diagnosis, possibly saving many lives every year.
And the cornerstone of the new technology is a simple radar system like the one used by a cop to nail a motorist for speeding.
The goal is to make the system so simple that the person using it "doesn't even have to think about it," Kristin Bing, a member of the team, said in a telephone interview. The system will spit out easily-read data that will give the user "high certainty that the person is healthy or concussed or kind of in between and maybe needs further diagnosis."
If the technology wins approval from the Food and Drug Administration, it could be used in many different applications, from sporting events to the battlefield. So far, it has only been tested in the laboratory, using volunteers who were conditioned to perform as if they'd had a concussion, but field tests will get underway soon to see if it works as well in the real world as it does in the lab.
Signatures of Concussion: Slower Walk, Inability to Perform Simple Cognitive Tests
How do you simulate a concussion? It's not that difficult, according to the researchers. Studies by others have shown that a person with a concussion performs physically about like a person who has had a bit too much alcohol. The clear signature is in the walk, which is slower than normal, and the inability to perform simple cognitive tests.
"When a person with a concussion performs cognitive and motor skill tasks simultaneously, they have a different gait pattern than a healthy individual, and we can identify those anomalies in a person's walk with radar," said research engineer Jennifer Palmer, lead author of a study presented Tuesday at a science conference in Orlando, Florida.
The sooner the concussion is detected the better, because early diagnosis "improves the prognosis," Bing noted. It also reduces the chances that a person with a concussion will be immediately redeployed, raising the risk of a second and more serious brain injury.
Here's the way it works:
Previous research has shown that a person with a concussion performs about the same as someone with a blood alcohol level of 0.05 percent. Researchers have also found that special goggles can cause the same effect. So participants in the study were tested four ways, with and without the goggles, and performing, or not performing, the simple mental challenge of reciting the months of the year backwards.
It turns out that it took both the goggles and the cognitive test for the radar to show that the participant had a concussion.
"The gait for our visually impaired or concussed individuals is less periodic than for healthy individuals," Bing said. "They tend to walk a little slower."
There is also a difference in the velocity of different parts of the body. When a normal, healthy person walks, the foot "kicks" forward at about six meters per second, she said. "When they are wearing the visual impairment goggles the kicks decrease in velocity and they become less regular."
Those differences might be too subtle to be detected by a coach, or even a trained medical specialist, but they can't fool the radar, the researchers said. At least, not all the time.
It would be helpful to have both before and after data on every athlete, or soldier, but that isn't practical. But the researchers say they can compile data bases showing the characteristics of average healthy individuals and concussed persons, and the system should be able to determine which category a person belongs in.
As with any medical diagnostic tool, there will always be some false positives, and the system can be fine tuned to different thresholds of sensitivity. A high school football coach, for example, may want to err on the side of caution, even if it means more athletes will be sidelined to reduce the possibility of a second concussion. A battlefield commander whose troops are facing life or death, by contrast, may be less inclined to pull someone from the field because he or she may have a concussion, and thus would want a very high threshold of proof.
Researchers: Athlete with Concussion Could Show Decline More Than 30 Years Later
Most concussions can be described as mild brain injuries, but the effect can be long lasting.
Researchers in Canada found that an athlete who suffers a concussion will probably show a decline in mental and physical processes more than 30 years later.
The gridiron is particularly dangerous. Scientists at the University of North Carolina at Chapel Hill found that football players who suffer a concussion are three times more likely than other players to suffer a second concussion in the same season.
In many cases, the athlete is a poor judge of his or her own condition, according to studies at the University of Pittsburgh Medical Center. For whatever reason, the victim will often understate the symptoms, returning to the field far too soon.
Radar, of course, is not going to solve all those problems. But any tool that increases the chances of early detection of a concussion could prove valuable. That diagnosis should be followed up with a clinical evaluation, and the sooner that happens, the better.