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Posted by on Feb 4, 2011 in Neurology, Neuropsychiatry, Sports medicine

Old Number-Reading Test May Aid Rapid Assessment of Head Injury

Old Number-Reading Test May Aid Rapid Assessment of Head Injury


Although I would argue that any athlete who is suspected of sustaining a brain injury should be eliminated from further play, regardless of the outcome of any sideline assessment, a new, brief test may provide a practical way of assessing sports-related head injuries on the fly.

Writing in this week’s Neurology, researchers from the University of Pennsylvania and various Illinois facilities report on the utility of the 2-minute King-Devick test, which requires a brief series of rapid left-to-right number readings. In a study population of 39 boxers and other “mixed martial arts” fighters (nearly all of which were male), K-D test performance, measured in seconds, deteriorated significantly from baseline after some kind of head trauma (~11-second worsening) and even moreso after loss of consciousness (18-second worsening) during bouts. (Fighters without injury actually showed minor post-play improvement in their test scores.)

K-D tests results, importantly, also appeared to correlate well with outcomes of another validated, but more extensive, sideline test for head injury: the SAC portion of the Military Acute Concussion Evaluation (MACE).* The K-D authors report that prospective studies of athletes at the University of Pennsylvania are ongoing, to establish, among other things, norms of testing.

One ethical concern that I have with this intriguing study, however, is the use of boxers as subjects, an act that ostensibly endorsesor at least, turns a blind eye toa sport that outrightly promotes head injury. I would’ve had fewer qualms about a study of a sport that doesn’t intend head injury as an object of so-called play.

Another note: One of the coauthors, optometrist and entrepreneur Steve Devick, has a patent pending on the K-D test, which can be bought online in various plan packages (from “family” to “organizational”) for $50-$1000. According to a 2004 profile piece in the Magazine of the University College of Optometry, Devick and Alan King invented the K-D test when they were fourth-year students at optometry school in 1976. As the story goes, they flipped a coin to determine whose surname would come first in the test’s label. 

The K-D test has a long history of being administered to early grade-school kids to assess rapid eye movements and their potential relationship to reading performance; however, the reliability of test results in this setting has been called into question.

SAC = Standardized Assessment of Concussion.

* My understanding is that the NFL uses the much-more complex and computerized Immediate Post-Concussion and Cognitive Testing [ImPACT] assessment off the field in its vulnerable players.

bmartin (1127 Posts)

A native East Tennessean, Barbara Martin is a formerly practicing, board-certified neurologist who received her BS (psychology, summa cum laude) and MD from Duke University before completing her postgraduate training (internship, residency, fellowship) at the Hospital of the University of Pennsylvania in Philadelphia. She has worked in academia, private practice, medical publishing, drug market research, and continuing medical education (CME). For the last 3 years, she has worked in a freelance capacity as a medical writer, analyst, and consultant. Follow Dr. Barbara Martin on and Twitter.