A simple, two-minute test given athletes on the sports sideline provides an accurate and reliable method for quick assessment of concussion in college athletes, according to a new study by researchers at the University of Pennsylvania and published online in the Journal of the Neurological Sciences.1
The test has shown such promise for sideline assessment of concussion that consumer advocate Ralph Nader is now calling for its mandatory use at all levels of sports, from the pros down to youth leagues.2
A visual recognition and reaction time test utilized for over 25 years to track rapid eye movements called saccades, and detect reading difficulties such as dylexia, the K-D test requires a test-taker to read from left to right eight rows of unevenly spaced, single digit numbers on three test cards as quickly and accurately as possible.
It not only measures the speed of rapid number naming, thus capturing impairment of eye movements, but the test-taker's balance, attention, language and visual recognition skills and other correlates of suboptimal brain function.
A baseline test score is obtained before the start of the season (40 seconds is about normal). Any increase (worsening) in the time needed to complete the test suggests a concussion has occurred, particularly if the delay is greater than five seconds compared to the individual's baseline test time.
In the new study, athletes at the University of Pennsylvania underwent baseline K-D testing prior to the start of the 2010-11 playing season and again after the season was over. For athletes who had concussions during the season, K-D testing was administered immediately on the sidelines and changes in score from baseline were determined.
Researchers found that scores for athletes who did not suffer concussion improved slightly from baseline to post-season, reflecting mild learning effects in the absence of concussion. But for the 10 athletes who had concussions, K-D testing on the sidelines showed significant worsening from baseline, with an average of 5.9 seconds slower than their best baseline scores in healthy controls on the timed test.
The results provide additional support for viewing the K-D test as a strong candidate as a rapid sideline visual screening tool for concussion. Some experts are even going so far as to call it the "missing link" in concussion management.
An earlier 2011 study3 reported in the journal Neurology by the same Penn researchers of boxers and mixed martial arts (MMA) founding that the K-D test had a high degree of test-retest and inter-rater reliability and to be an accurate method for rapidly identifying boxers and mixed martial arts fighters with concussion.
Mandatory use urged
In announcing the support of his group, A League of Fans, for mandatory use of the K-D test on sports sidelines from youth through high school, Nader stated that, "Too many sports organizations, from the little leagues to the professional level, continue to have their heads in the sand when it comes to concussion safety and prevention measures. The growing mound of research showing the often devastating long-term effects of sports-related brain trauma demands that we take proactive measures to protect our young athletes' brains. The King-Devick test is a simple and objective sideline screening test that can be administered by coaches, trainers and parents."
"There are other quality concussion screening tests out there," added Ken Reed, Sports Director of a League of Fans and author of the report4 advocating for mandatory use of the K-D test. "However, most of those tests need to be administered by professional healthcare providers. The King-Devick test is easy to learn, understand and administer for virtually anybody."
"General awareness and understanding of brain injuries is still lacking at all levels of sports," said Reed. "Torn up knees and shoulders are one thing, but brain injuries are an entirely different matter. An easy-to-learn, inexpensive and highly-accurate concussion screening tool like the King-Devick test could prevent thousands of devastating brain injuries in high school and youth sports programs. As such, it should be implemented across the nation immediately."
Quick, easy to use, objective
While other sideline exams test cognitive or memory skills and rely on the administrator to make subjective decisions, the K-D Test is objective and it reveals impairments of eye movement, attention, language and other symptoms of impaired brain function that are frequently abnormal following a concussion. "It is reliable, valid, and cannot lie," noted Eric Laudano, M.H.S., ATC, head athletic trainer at the University of Pennyslvania, MomsTeam expert, and one of the authors of the Penn studies in a recent interview with MomsTeam. "The test does not allow players to cheat."
At a recent presentation in Boston at Patrick Kennedy's "One Mind For Research Symposium", Drs. Laura Balcer and Steve Galletta, two of the co-authors of the Penn studies, emphasized just how easy the KD test is to use: all that is needed is the athlete's baseline, a King-Devick Test score sheet, and a stopwatch (timer or smartphone).
It may have particular value in sideline screening for concussion at the youth level, where immediate evaluation for head trauma by a trained professional is often not possible. Once an athlete's baseline score has been established, re-testing can then be performed right on the sports sideline, as the "test stands up in an active setting", Dr. Balcer, MD, MSCE, professor of Neurology and senior author on the paper, told MomsTeam. Because the test takes less than two minutes to perform, it could be performed during a single football or basketball time out. Any worsening of scores could then investigated further using other clinical tests for concussion.
To facilitate ease of use in a variety of sports settings, the K-D Test is available in three different formats: hard copy test score sheets, on-line, and as an iPad application ($44.99). Using the new iPad application, the K-D test can be administered even when an internet connection is not available. All offline user data is synchronized to a secure account once an internet connection is available. The secure browser-based King-Devick Test Online allows administration of the test from a computer, laptop or iPad that is connected to the internet and conveniently stores up to 1000 athletes' baseline data.
This is not to say that all other testing, assessment and protocols are unnecessary, as Dr. Balcer told MomsTeam at the time of the first Penn study of boxers and MMA fighters. She emphasized that King-Devick is only meant for use as an initial screen to identify athletes who should not be allowed to return to the game or practice and who should be referred for further, more comprehensive evaluation by a trained professional as part of a Comprehensive Concussion Management Program, which should include:
- a pre-participation physical exam (PPE), including the completion of a head injury/concussion symptom questionnaire along with a Standardized Assessment of Concussion (SAC);
- a baseline assessment from one of the following every year:
- a preseason balance test (BESS)
- baseline K-D Test; and
- an educational session with athletes, coaches and parents/guardians.
"Most of these tests need to be administered by a sports healthcare provider," notes Dr. Enrico Esposito in his blog, The Sports Digest.5 "But what makes The K-D Test so useful is that it's easy to understand, easy to learn and simple to administer. It can be a very valuable part of a sideline/screening assessment for concussions that everyone can learn just like CPR/AED and Sports First Aid. The K-D Test can become a part of the Standard of Care for all who are involved with the healthcare of young athletes."
"This test has demonstrated its ability to provide objective evidence to aid medical professionals and trainers in determining which athletes need to come out of games after a blow to the head," said Dr. Balcer. "We'll continue to measure the test's effectiveness in different groups - players who play the same position who have and have not suffered concussions, for instance. It is our hope that the new test, once validated, can be folded into the current sideline battery of tests for concussion, as no single test at this time can be used to diagnose or manage concussion."
"Though the King-Devick test may prove to be a great addition to the sideline tool set," writes sports concussion neuropsychologist and MomsTEAM expert Rosemarie Scolaro Moser, PhD in her new book, Ahead of the Game, it's important to remember that the best way to measure and diagnose a concussion is by testing a variety of skills. For example, I might see a concussed athlete demonstrate strong reaction time on post-concussion testing but show weak verbal or design memory. It's also possible for symptoms of concussion to appear days after impact. So no matter how 'well' your child performs on a sideline assessment test - no matter what type of test is being used - he or she should not be returned to play until examined by a licensed health care professional."
1. Galetta K, Brandes L, Maki K, Dziemiannowicz M, Laudano E., Allen M, Lawler K, Sennett B, Wiebe D, Devick S, Messner L, Galetta S, Balcer L. The King-Devick test and sports-related concussion: Study of a rapid visual screening tool in a collegiate cohort. J. Neur'l Sci. 2011; 309(1):34-39.
2. "Ralph Nader Calls For Mandatory Implementation of King-Devick Concussion Test in High School and Youth Sports" (http://leagueoffans.org/2011/08/25/ralph-nader-calls-for-mandatory-imple...) (accessed August 25, 2011)
3. Galetta KM, Barret J, Allen M, et. al. The King-Devick test as a determinant of head trauma and concussion in boxers and MMA fighters. Neurology (2011); 76:1456-1462.
4. Reed K. "Concussion Research Can't Be Ignored," (http://leagueoffans.org/pdf/Manifesto5.pdf) (accessed August 30, 2011)
5. http://thesportdigest.com/2011/06/the-king-devick-test-the-missing-link-... (accessed August 30, 2011)
Posted August 30, 2011; revised July 10, 2012 to include Dr. Moser's comment.