The King–Devick test was useful in management of concussion in amateur rugby union and rugby league in New Zealand D. King a,c, ⁎, C. Gissane b , P.A. Hume a , M. Flaws c a Sports Performance Research Institute New Zealand (SPRINZ) at AUT Millennium Campus, Faculty of Health and Environmental Science, Auckland University of Technology, New Zealand b School of Sport, Health and Applied Science, St Mary's University, Twickenham, Middlesex, United Kingdom c Emergency Department, Hutt Valley District Health Board, Lower Hutt, New Zealand abstract article info Article history: Received 15 November 2014 Received in revised form 18 February 2015 Accepted 19 February 2015 Available online xxxx Keywords: Brain injury Sport-related concussion King–Devick SCAT3 Vision Saccadic Aim: To use the King–Devick (K–D) test in senior amateur rugby union and rugby league players over a domestic competition season to see if it could identify witnessed and unwitnessed episodes of concussion that occurred from participation in competition matches over three years. Methods: A prospective observational cohort study was conducted on a club level senior amateur rugby union team (n = 36 players in 2012 and 35 players in 2013) and a rugby league team (n = 33 players in 2014) during competition seasons in New Zealand. All 104 players completed two trials 10 min apart of the K–D at the beginning of their competition season. Concussions (witnessed or unwitnessed) were only recorded if they were formally diagnosed by a health practitioner. Results: A total of 52 (8 witnessed; 44 unwitnessed) concussive events were identified over the duration of the study resulting in a concussion injury incidence of 44 (95% CI: 32 to 56) per 1000 match participation hours. There was a six-fold difference between witnessed and unwitnessed concussions recorded. There were observ- able learning effects observed between the first and the second K–D test baseline testing (50 vs. 45 s; z = -8.81; p b 0.001). For every 1 point reduction in each of the post-injury SAC components there was a corresponding increase (worsening) of K–D test times post-match for changes in orientation (2.9 s), immediate memory (1.8 s) concentration (2.8 s), delayed recall (2.0 s) and SAC total score (1.7 s). Discussion: The rate of undetected concussion was higher than detected concussions by using the K–D test routinely following matches. Worsening of the K–D test post-match was associated with reduction in compo- nents of the SAC. The appeal of the K–D test is in the rapid, easy manner of its administration and the reliable, objective results it provides to the administrator. The K–D test helped identify cognitive impairment in players without clinically observable symptoms. © 2015 Elsevier B.V. All rights reserved. 1. Introduction The number of sport-related concussions has raised concern in the public, media and clinical arenas in recent years [1]. The incidence of sport-related concussion has increased over the past decade but the actual incidence is likely higher than documented as there is a tendency for sport participants to under-report their symptoms [2]. Concussion has become one of the most troublesome injuries facing the sport medicine professional [3], especially in regard to early identification of concussive signs and symptoms, and appropriate concussive manage- ment facilitation [4]. A sport-related concussion is a unique and individ- ualized injury that can present with a myriad of physical, emotional, somatic, cognitive and sleep-related symptoms and impairments [5]. Due to the nature and variability of concussions, these injuries should have a multifaceted approach in the assessment and management of these injuries. In the upper levels of sport on-site health professionals are available to assess players on the sideline for the signs and symptoms of concus- sion. Yet symptoms may not manifest for several hours post-event, so many participants may not produce symptoms that meet the clinical criteria for concussion [6]. More recently interest has increased in the impacts to the head that do not result in clinically-observed symptoms associated with concussion [7]. Termed ‘subconcussive’, these impacts are often not recognised as a concussion, but may result in a rapid acceleration–deceleration of the body or head, moving the brain within the cranium creating a “slosh” phenomenon [8]. The number of impacts that can occur varies, but over time there are repetitive occurrences of these impacts and the cumulative exposure of these may become deleterious [8]. Players not reporting or showing any signs or symptoms of concussion can still have neurophysiological changes [6]. Following any brain trauma eye function movements may become impaired [9,10]. In acute traumatic brain injuries there are reported Journal of the Neurological Sciences xxx (2015) xxx–xxx ⁎ Corresponding author at: Emergency Department, Hutt Valley District Health Board, Private Bag 31-907, Lower Hutt, New Zealand. Tel.: +64 22 477 7285 (mobile). E-mail address: dking@aut.ac.nz (D. King). JNS-13663; No of Pages 7 http://dx.doi.org/10.1016/j.jns.2015.02.035 0022-510X/© 2015 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Journal of the Neurological Sciences journal homepage: www.elsevier.com/locate/jns Please cite this article as: King D, et al, The King–Devick test was useful in management of concussion in amateur rugby union and rugby league in New Zealand, J Neurol Sci (2015), http://dx.doi.org/10.1016/j.jns.2015.02.035