To determine if change in King-Devick test (K-D) score from baseline in acutely concussed collegiate Division I athletes predicts time to return to play (RTP).
Efferent visual pathways are vulnerable to impairment during the acute stages of concussion; these pathways can be assessed through visual performance measurements such as the K-D test. K-D requires rapid eye movements (horizontal saccades), attentional focus, and language function, requiring the integration of the brainstem, cerebral cortex, and the cerebellum. K-D performance is impaired acutely post-concussion; however, the association between degree of impairment and recovery duration has not been established.
Thirty-one NCAA Division I student-athletes (1.7 ± 0.1 m, 69.9 ± 12.6 kg, 21 female) performed K-D at baseline (prior to sports participation) and then again within 24-48 hours post-concussion. A linear regression was modeled with change in K-D score between baseline and acute as the independent variable, and days until RTP as the dependent variable.
Average baseline and post-injury K-D scores were 39.9 ± 5.9 and 46.0 ± 20.6 s respectively. The average change in K-D score was 6.12 ± 18.6 s (range: -7.3-97.3 s) and mean days until RTP was 20.0 ± 20.4 days (range: 8-119 days). The overall regression model was not significant for K-D change as a predictor of RTP time, F(1, 29) = .002, p = .961, R2 = .00.
Visuomotor performance, as measured by the K-D test, acutely post-concussion did not predict the amount of days until RTP in collegiate student athletes. These results suggest that K-D performance alterations following concussion may not be indicative of recovery time.
- Post-injury K-D Test scores were 6.12 ± 18.6 seconds slower compared to baseline measures, and mean days until return-to-play was 20.0 ± 20.4 days.
- Post-injury K-D Test performance did not predict the amount of days until return-to-play for these collegiate student athletes.