Space-Age Concussion Assessment Tool Has a Long Way to Go

BOSTON, Aug. 2, 2005 -- As NFL training camps opened this weekend, Ted Johnson, the veteran linebacker for Super Bowl champions New England Patriots, announced his retirement at age 32, citing the effects of multiple concussions.

Wide receiver Wayne Chrebet, who has also had several concussions, was mulling over his future with the New York Jets.

The widely publicized fate of both players drew attention to the difficult question of when a player can return to action after a head injury. This holds true for players at any level of football, from junior high school to the pros.

One proposed solution is a sideline assessment tool using a space-age headset and laptop to save athletes from the consequences of a serious head injury. Others, however, suggest that questions typed on an index card and stuffed into a shirt pocket do just as well or better at no cost.

Low-tech assessment tools, though far from perfect, are probably just as good as pricey, high-tech ones -- and likely better, say some experts. But there is little evidence to show that any sideline assessment tool -- including the new interactive helmet -- do what researchers and clinicians wish they did.

"I think they're putting the cart before the horse here," said Robert E. Sallis, M.D., vice president of the American College of Sports Medicine and editor of the journal Current Sports Medicine Reports. "You want to prevent death and disability. But there's no evidence that any of these tools are going to prevent the things they've set out to prevent," he said in an interview.

"The bottom line is: Do you need this tool to make the diagnosis?" said John P. DiFiori, M.D., chief of sports medicine at UCLA. "Probably not in most cases."

The prospect of rare but devastating head injuries colors the entire management of concussion in sports. Researchers from the Georgia Institute of Technology and Emory University recently provided journalists with a preview of an innovative device designed to help identify those athletes who should be withheld from competition in order to minimize such injuries.

The computer-driven, interactive headset of oversized goggles and earmuffs -- dubbed DETECT (Display Enhanced Testing for Concussions and Mild Traumatic Brain System) -- would envelop the player's ears and eyes, shutting out most noise and all light.

Immersed in a virtual environment, the athlete would take a seven-minute mini-neuropsychological exam by pressing one of two buttons on a handset. (A full pen-and-paper neuropsychological exam takes about an hour and a half and is administered by a trained clinician.) The results of the sideline exam would be compared with pre-season baseline scores for signs of cognitive impairment.

The researchers say the device could help physicians, athletic trainers, parents, or coaches decide when it is safe to send an athlete back into the game. The device can "detect brain injuries right on the sidelines of a football game, on a battlefield, or in the emergency room," according to a press release.

"We're trying to pick out the players who seem okay? who have problems that you can't pick up in the heat of the battle," says Emory University's David Wright, M.D., one of the researchers investigating the device. "They're the ones we're most worried about."

DETECT attempts to do this through three tests -- one that assesses memory and two that assess cognition (through recognition of increasingly complex patterns, colors, shapes, and designs).

The device has yet to be field-tested in athletes. Researchers have so far studied it in healthy volunteers in the laboratory, in patients with early Alzheimer's disease, and in the emergency room. It has not yet undergone rigorous testing for validity and reliability. Still in development, DETECT is projected to come to market some time in the next few years at a price of to ,000.

The goal of sideline assessment tools is a lofty one: to prevent the forbidding "second-impact" and post-concussive syndromes. This has proved elusive.

A concussion is defined as a diffuse reversible brain injury that occurs at the time of trauma. It is characterized by a change in mental status, which may include loss of consciousness. Loss of consciousness usually resolves quickly, although it may extend up to six hours in more severe cases.

A concussion is caused by inertial forces from the traumatic injury that lead to shear strain. This strain results in increased energy demands of the brain and transient diffuse cerebral dysfunction, which involves the reticular formation in the brain stem.

Typical signs of concussion are confusion and amnesia. Headache, nausea, vomiting, dizziness, and lack of awareness of surroundings frequently are associated findings.

In the second-impact syndrome, incidental contact to the head of an athlete who has not fully recovered from a head injury can lead to rapid brain edema and death.

Post-concussive syndrome is characterized by debilitating and long-lasting after-effects of mild traumatic brain injury, including persistent symptoms (e.g. headache, dizziness, diminished concentration, slow reaction time) and permanent cognitive deficits that impair an individual's ability to work and function normally.

To minimize such injuries, the so-called Prague concussion guidelines issued in March would make moot any assessment tool designed to ever return a dinged player to the same game.

"Athletes should not be returned to play the same day of injury," the guidelines states in bold red letters in its accompanying Sport Concussion Assessment Tool (SCAT). "Any athlete suspected of having a concussion should be removed from play, and then seek medical evaluation."

A proliferation of guidelines has sprung up over the years to help minimize and manage concussions -- to little avail. There is little ironclad evidence to lead the way. There is disagreement about which factors (e.g. amnesia, loss of consciousness) predict a better or worse outcome. There is little agreement on a concussion classification or grading system.

Unfortunately, there is also no consensus on a "best" sideline assessment tool to evaluate severity, predict prognosis, and determine return to play. "The ones that have been suggested have been shown to be of limited value," said Dr. DiFiori.

On a broader question, however, there seems to be some agreement. Most experts today say that the assessment of concussion involves a complex, multi-system evaluation -- far more than the yield of the neuropsychological exam which forms the foundation for the DETECT system.

The new Prague guidelines suggested that sideline assessment should cover a lot of ground.

The guidelines recommended that a clinician assess loss of consciousness, seizure/convulsive activity, and impaired balance; ask a handful of memory questions. These include what stadium are you in or who scored last, determine cognitive impairment (using tests of delayed five-word recall, listing months in reverse order, and repeating nonsequential digits backwards); check symptoms and physical signs (headache, dizziness, nausea, feelings of "fogginess," vision problems, emotional changes, as well as sluggishness, fatigue, and others); and perform a neurologic exam to pick up problems with speech, eye motion, pronator drift (hands out, palms up, eyes closed), and gait.

What's more, the guidelines explicitly downgrade the value of the neuropsychological exam in the evaluation of the most common athletic head injuries, pointing up the failure of neuropsychological testing to reduce the incidence of second-impact syndrome or post-concussive syndrome.

"It must be emphasized ? that neuropsychological assessment should not be the sole basis of a return to play decision but rather be seen as an aid to the clinical decision making," according to guideline authors Paul McGrory, M.D., and colleagues.

Neuropsychological assessment "is not currently regarded as important in the evaluation of simple concussion [the most common form of injury, resolving without complication over seven to 10 days]," they wrote.

Moreover, added the guideline authors, "Neuropsychological testing should not be done while the athlete is symptomatic since it adds nothing to return-to-play decisions and it may contaminate the testing process by allowing for practice effects to confound the results." It may be helpful in the evaluation of complex concussion marked by persistent symptoms and prolonged impairments, they added.

Instead of returning a dinged player to the same game, the guideline advised clinicians to guide the athlete through a cautious, stepped rehabilitation -- usually lasting several days -- before returning an athlete to play.

The two-sided SCAT includes an index card-sized section for the athlete to self score 18 symptoms and a brief medical evaluation for clinicians on the reverse side. It is freely available at the web sites of the Clinical Journal of Sport Medicine and three other major journals.

One of the more provocative claims being made by the developers of the DETECT device is that it can help parents and coaches make the return-to-play determination in the absence of a trained clinician.

"The reality is that these decisions are being made every day all the time without any help," said Emory's Dr. Wright. He anticipates the device will be targeted at high school level and younger athletes. "This test will help support those groups that don't have any medical people on the sideline."

Dr. Wright also said that DETECT is not intended to be used on its own. "This is a tool that provides some information about the cognitive impairment of the athlete or patient? The disclaimer is that it does not supplant a neurological exam on the sideline," he said. "There's not a magic bullet."

Players who score poorly should be withheld from the game and see a doctor for further evaluation, said Dr. Wright. If a player's score appears normal, "the information has to be used in relation to everything else, not necessarily used by itself" to make the return-to-play decision, he said.

By this logic, said Dr. Sallis, it would not be prudent for a parent or coach to make the return-to-play decision based on data from DETECT.

UCLA's Dr. DiFiori agrees. "I would have concerns" about a parent or coach making the return-to-play decision, he said.

"You will err on the side of being conservative when you use the SCAT card" in a bright, noisy arena, said Dr. Sallis. A retreat to the locker room is not necessarily a bad thing, he suggested. It can remove the physician and the player from the pressure of the arena.

"Relax and talk and sit down," advised Dr. Sallis. "Take their pads off. This shows the player the potential seriousness of the situation."

Cost could prove to be a hurdle once DETECT becomes available. In an era of steep athletic user fees in schools that lack funds to pay for buses and uniforms, schools may consider it pricey.

"Why should schools spend a thousand dollars when they can pull the SCAT card out of a journal for free?" asks Dr. Sallis. "I don't see this as being a good use of a school's limited resources. They're better off spending their money on athletic tape."