Dysfunctions of ocular motor and binocular vision are some of the most commonly observed problems in patients with severe traumatic brain injury. Secondarily, subjective complaints of compromised vision and ocular motor functions are also sometimes reported in mild traumatic brain injuries (mTBI). Simple ocular/vision assessments such as near point of convergence (NPC), the King-Devick Test (KDT), and stereoacuity can be performed to identify and assess these deficits, but their diagnostic accuracy has yet to be thoroughly investigated. The purpose of this study was to determine if differences exist in NPC, KDT, and stereoacuity test scores between concussed and control athletes, and to determine the diagnostic accuracy of these tests. A multicenter control group design was utilized. The independent variable was group (control vs. concussed). The dependent variables were the ocular test scores from the NPC, KDT, and stereoacuity tests. Participants were recruited from several collegiate athletic programs. In total 34 healthy, non-concussed controls (21 male, 13 female) aged 19 + 1.5 years and 19 concussions (11 male, 8 female) aged 20.42 + 1.5 years participated in the study. A concussion was operationally defined as a complex pathophysiological process affecting the brain, induced by biomechanical forces, that was diagnosed by a health care professional through the use of signs and symptoms scales, balance and neurocognitive testing. Data were analyzed using descriptive and inferential statistics. T-tests and chi-squares were performed to ensure there were no significant differences between groups on specific demographic or relevant prognostic variables (sport, sex, and concussion history). T-tests were employed to identify significant differences between groups on ocular test scores. Then clinical and statistical cutoffs for all three tests were determined. Based off of these cutoffs sensitivity, specificity, and likelihood ratios were determined for each assessment. Furthermore, receiver operating characteristic (ROC) curves were calculated to help determine the diagnostic accuracy of these assessments. The alpha level was set at p < .05 and the SPSS for Windows, Version 21.0, statistical program (IBM, Inc., Armonk, NY) was used for all data analysis. Significant differences were found between groups for all three ocular assessments. NPC demonstrated a statistical cutoff of 5.5 cm, which provided a sensitivity of 79% and specificity of 76% and an AUC of 0.827. For the KDT, a statistical cutoff time of 49.5s demonstrated a sensitivity of 58% and specificity of 72% with an AUC of 0.658. Lastly, for stereoacuity a statistical cutoff point of 28.50 arc sec was found which produced a sensitivity of 65% and specificity of 54% with a maximum AUC of 0.706. All three tests demonstrated their potential to positively contribute to the diagnosis of a concussion. / Kinesiology

In the United States, an annual estimate of 1.36 million traumatic brain injuries present to the emergency department (ED), of which approximately 75% are concussions. Proper and timely treatment of concussion is especially important in pediatrics as children and adolescents under the age of 19 are at a higher risk for sustaining more severe and longer-lasting consequences. However, due to the wide range of symptoms at presentation, or to the potential lack of obvious symptoms, concussion can be especially difficult to diagnose in the ED setting. Neurocognitive tests provide a valuable supplement to the clinical diagnosis of concussion by objectively identifying aberrant brain activity. However, many of these tests are often too lengthy and impractical for use in the ED setting. The Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) is a 20-minute computer test that is considered to be one of the gold-standard neurocognitive tests used to diagnose concussion and track recovery. The King-Devick test (KD) is a 1-2 minute test that uses saccadic eye movements to detect suboptimal brain impairment associated with concussion. To date, there have not been any studies that analyzed the relative usability of the KD and the ImPACT in the pediatric ED (PED). The present prospective pilot study investigates the use of the KD as a neurocognitive tool for concussion assessment in the PED and at a post-ED visit, relative to the ImPACT, the gold standard tool for concussion diagnosis. We hypothesize that the change in performance in the KD will correlate with the change in the ImPACT results. To date, 20 subjects between the ages of 11-18 years old presenting to the PED within 72 hours of sustaining a head injury have completed the study. The mean age of our study population was 13.6 years. The average change in test scores between PED and follow-up were: 7.2 seconds in the KD, 0.03 points in the ImPACT reaction time, 1.8 points in verbal memory, 8.3 points in visual memory, 0.8 points in visual motor speed, and 14.9 points in post-concussion symptom scale. Analysis of the correlation of the change in the KD scores to the change in the ImPACT measures revealed that the change in the KD was significantly correlated with the change in the ImPACT reaction time (p < 0.01), and with the change in the ImPACT verbal memory (p < 0.05) in the subjects that presented with LOC, 80% of whom were male. In conclusion, our findings report that the correlation between the results of the KD and the ImPACT is more pronounced in patients presenting with more severe head trauma, such as those leading to LOC. The usability of the KD as a reliable concussion assessment tool in the PED would require further investigation with a larger sample of participants. / 2017-04-30T00:00:00Z

Objective: To determine the extent to which aspects of the Sport Concussion Assessment Tool 3 (SCAT3) or Child SCAT3 (C-SCAT3), and the King-Devick Test (KDT) predict Three-Dimensional Multiple Object Tracking (3D-MOT) speed. Participants: A sample of 304 healthy, non-concussed participants with a sporting history (101 females, 203 males) ranging in age from 7-29 years (mean age = 16.05 +/- 4.36) were included in the analysis. Methods: Participants completed the SCAT3, KDT and 3D-MOT in a single visit. Data Analysis: A regression analysis was performed to determine the extent to which aspects of the SCAT3 (immediate memory (IM), coordination (COOR), delayed recall (DR)), and the KDT predicted 3D-MOT speed. Results: Using the stepwise method, it was found that KDT, DR and COOR explain a significant amount of the variance in the speed of the 3D-MOT (F(3, 256)) = 11.82, p < .000 with an R2 = .12. The analysis shows that KDT (Beta = -0.01, p < .000), DR (Beta = 0.07, p < .02), and COOR (Beta = .23, p < .03), were significant predictors of 3D-MOT speed. Conclusions: This study suggests that the KDT, DR, and COOR significantly account for 12% of the 3D-MOT scores, however, there is a large portion of variability unaccounted for by the SCAT3 or C-SCAT3 and KDT. This shows that 3D-MOT likely accounts for central cognitive functions above and beyond the SCAT3 or C-SCAT3 and KDT. Future studies should examine this relationship at baseline, post-injury, and through concussion recovery. This could provide valuable information to better inform clinicians responsible for making return to play determinations. Keywords: Concussion, Mild Traumatic Brain Injury, 3D-MOT, King-Devick Test, Sport Concussion Assessment Tool 3, Child Sport Concussion Assessment Tool 3. / Graduate / 0769 / 0633 / 0566 / oslundk@uvic.ca