Assessment of mild traumatic brain injury with the King-Devick Test in an emergency department sample

The King-Devick Test (K-D) is a brief measure of cognitive processing speed and rapid gaze shifting that appears sensitive to the effects of sport-related concussion. This study evaluated its diagnostic and incremental validity in civilian patients with mild traumatic brain injury (MTBI).

Participants with MTBI (n = 26) and controls with non-head injuries (n = 33) were prospectively recruited from an Emergency Department (ED). They underwent a clinical evaluation including the K-D test and the Sport Concussion Assessment Tool 2 (SCAT2). Magnetic resonance imaging (MRI) was conducted within 10 days post-injury.

The patients with MTBI differed from those without MTBI on components of the SCAT2, including the Symptom Scale (Cohen's d = 1.02-1.15, p < 0.001) and Standardized Assessment of Concussion (d = 0.81, p = 0.004), but not the K-D test (d = 0.40, p = 0.148). In a logistic regression analysis, the K-D Test did not contribute over and above these two measures in predicting group membership (MTBI vs. control), p = 0.191. Low K-D Test scores in the MTBI group (<1 SD below controls) were not associated with poor SCAT2 performance, loss of consciousness or traumatic abnormalities on MRI, suggesting these cases may have been false positives.

The present findings do not support the K-D Test for the assessment of civilian MTBI in an ED setting.