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 endorses—or at least, turns a blind eye to—a 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.