Objectives: The Department of Defense reported that 344,030 cases of traumatic brain injury (TBI) were clinically confirmed from 2000 to 2015, with mild TBI (mTBI) accounting for 82.3 percent of all cases. Unfortunately, warfighters with TBI are often identified only when moderate or severe head injuries have occurred, leaving more subtle mTBI cases undiagnosed. This study aims to identify and validate an eye-movement visual test for screening acute mTBI.
Methods: Two-hundred active duty military personnel were recruited to perform the King-Devick® (K-D) test. Subjects were equally divided into two groups: those with diagnosed acute mTBI (≤72 hours) and age-matched controls. The K-D test was administered twice for test-retest reliability, and the outcome measure was total cumulative time to complete each test.
Results: The mTBI group had approximately 36 percent mean slower performance time with significant differences between the groups (p < 0.001) in both tests. There were significant differences between the two K-D test administrations in each group, however, a strong correlation was observed between each test administration.
Conclusions: Significant differences in K-D test performance were seen between the acute mTBI and control groups. The results suggest the K-D test can be utilized for screening acute mTBI. A validated and rapidly administered mTBI screening test with results that are easily interpreted by providers is essential in making return-to-duty decisions in the injured warfighter.
Summary Points:
- King-Devick (K-D) test was studied as screening tool in 200 Army warfighters.
- Significant K-D cumulative time differences between acute mTBI and control groups. The K-D Test showed a little more than one-third slower reading time in the mTBI group.
- There was strong test-retest reliability in both groups.
- Results suggest acquiring K-D baseline tests prior to deployment/training.
- Having a validated, rapid, easy-to-assess mTBI brain screening test can assist frontline providers in making the return-to-duty (RTD) decision to send the warfighter back to the “fight”, or to a higher echelon of care for more comprehensive tests.