King-Devick Test Identifies Symptomatic Concussion in Real-time and Asymptomatic Concussion Over Time. (S11.003)

Abstract

OBJECTIVE To evaluate the effects of head injury in adolescents on long-term cognitive and visuospatial performance and determine if similar impairment (subclinical concussion) exists in athletes without obvious head injury. BACKGROUND Sports concussion has an annual incidence of approximately 3.8 million. Over half go unreported and a substantial number may be asymptomatic. Repeat concussion is associated with serious consequences in long-term neurological function, to which adolescents may be more vulnerable. A rapid, cost-effective and reliable tool that facilitates diagnosis of concussion is needed. The King-Devick (K-D) test is a promising tool for real-time assessment of concussion. An increase in score from baseline suggests possible concussion. This is the first study to use K-D testing in adolescents for the detection of symptomatic and subclinical concussion. METHODS High school hockey players underwent K-D testing pre-season, post-season and immediately after suspected concussion. All were assessed pre- and post-season with a computerized cognitive assessment test (Axon Sports®). Additional testing was performed in a subgroup of non-concussed athletes before and after a game to determine impacts of fatigue and subconcussive hits on KD scores. RESULTS 141 players were tested, of which 20 reported head injury. All 20 had immediate post-concussion K-D times >5s from baseline (average 7.3s) and all but 2 had worse post-season scores (46.4s vs. 52.4s p<0.05 Wilcoxon signed rank test). 11 non-concussed players had worse post-season times from baseline (37.6s vs. 43.8s). 110 players saw minimal improvement post-season (43.9s vs. 42.1s p<0.05) and 51 non-concussed players assessed before and after a game revealed no significant time change (43.4s vs. 42.0s post-game p<0.05). Pre- and post-season CCAT results will be correlated with K-D results and presented. CONCLUSION King-Devick testing accurately identifies real-time, symptomatic concussion in adolescents. Scores in concussed players may remain abnormal over time. The K-D test may additionally detect asymptomatic concussion. Athletes should undergo pre- and post-season K-D testing, with additional evaluation real-time to inform the assessment of suspected concussion.

Disclosure: Dr. Dhawan has nothing to disclose. Dr. Starling has nothing to disclose. Dr. Tapsell has nothing to disclose. Dr. Adler has nothing to disclose. Dr. Galetta has received personal compensation for activities with Biogen Idec, Questcor, and Teva Neuroscience. Dr. Balcer has received personal compensation for activities with Biogen Idec, Questcor, Novartis, and Vaccinex. Dr. Dodick has received personal compensation for activities with Allergan, Inc., Pfizer Inc., Merck & Co., Inc., ENeura NuPathe, Colucid, Alder, Artaeus, Eli Lilly & Company, Amgen Inc., WL Gore, Bristol-Myers Squibb Company, Ethicon J&J, ATI, Zogenix, Cognimed, Intramed, Scientiae, Syndergy, Curatio CME, and Pfizer Inc. Dr. Dodick has received personal compensation in an editorial capacity for Sage Publishing, Lippincott, Oxford University Press, Cambridge University Press, UpToDate, and Web MD.