Study indicates accuracy of King-Devick test in detecting concussion

SEATTLE – In a study of 127 athletes, those with concussion tested worse on the King-Devick test compared to baseline, and those tested merely after physical fatigue showed no worsening, according to a study presented here at the American Academy of Optometry meeting.

Co-author Danielle Leong, OD, told attendees at an academy-sponsored press conference that a link has been suggested in repetitive head trauma and Alzheimer’s disease. One study showed that 20% to 30% of Alzheimer’s patients reported head trauma vs. 8% to 10% of controls, she said.

“Boys’ football and girls’ soccer have the highest incidence rates,” Leong said, “with nearly 4 million injuries in the U.S. per year. The need exists to identify concussed athletes and remove them from play.”

The King-Devick test (King-Devick LLC), which can be administered on the sidelines, requires eye movements, language function and attention for performance, according to the study abstract.

“It is a rapid number naming test that captures eye movements,” Leong said.

Athletes from a men’s college football and men’s and women’s basketball teams were tested at their pre-season physical to establish a baseline, she said.

“Sideline testing was administered as needed, and post-season testing was performed on athletes who had not sustained concussion,” Leong said. “The basketball team was also tested after a 2.5-hour strenuous workout to determine the effects of physical fatigue.”

Upon sideline re-testing, “if there’s an increase in time to complete the test or any numerical errors, that’s been correlated with concussion,” she said.

Eleven athletes sustained concussion, and they performed significantly worse on the King-Devick in terms of time, Leong reported.

“Those athletes showed no other signs or symptoms of concussion, and their King-Devick results were the only sign of concussion,” she said.

Those who did not sustain concussion tested significantly better than their baseline scores in the post-season testing, Leong added.

“The fatigue trial with the basketball players did not show any worsening and, in fact, showed improved testing time,” she said.

“The King-Devick test is a quick assessment of rapid eye movement and number naming,” Leong concluded. “Our study shows that King-Devick scores were worse after concussion and no worse after physical fatigue, and results support the King-Devick test as an accurate, rapid and reliable tool for concussion detection.”

Disclosures: None of the authors has a financial interest in the King-Devick test, and the work was not funded by King-Devick Test LLC. Leong is director of research for King-Devick Test LLC.