Relationship Between Neurocognitive Testing and Saccadic Eye Movements in Symptom Free Division I Athletes

Abstract

Saccadic eye movements are produced from several frontal and parietal cortical regions of the brain that also aid in the execution of cognitive functions. However, no known research has examined the relationship between a sport-like antisaccade task and standard neurocognitive exams. PURPOSE: To evaluate the relationship between the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) cognitive domains and a sport-like antisaccade task (SLT) of Division I athletes on symptom free-day of post- sport like concussion. METHODS: 10 concussed individuals (8 males; 2 females; age: 20 ± 2 years) were assessed on the ImPACT test and the SLT on a symptom free day post- sport related concussion. A monocular eye tracker (240Hz, Argus Science) synced with the Vicon Motion Capture System (Vicon Motion Ltd., Version 1.85, Oxford, England) was employed to track raw ocular coordinates and further analyzed to obtain resultant distance (RD), mean horizontal velocity (MHV), and prosaccade errors (PE) during the athlete’s participation in the SLT. ImPACT variables included verbal and visual memory composite, visual motor speed, reaction time composite (RT), and impulse control. All eye variables were run through a custom MatLab code (MATLAB 2017, Mathworks, Inc., Matick, MA). Spearman rho correlations were used to assess the relationship between ImPACT variables and ocular metrics. RESULTS: Significant negative moderate relationships (r = -0.70, p = 0.02) between MHV (5.78 ± 1.28 pixels/second) and reaction time composite score (0.57 ± 0.07) were observed. Similarly, there was a significant negative moderate relationship (r= -0.65, p = 0.03) between RD (2.73 ± 1.03 pixels) and Impulse control composite score (6.4 ± 3.75). No other significant relationships were noted. CONCLUSION: These significant relationships suggest that as eye velocities increase, RT decreases which is possibly due to a decrease in accuracy on overall cognitive efficiency. As impulse control decreases, the eye movement resultant distances are minimal. This may be due to more cognitive errors that lead to an inability to properly control antisaccadic eye movements. Due to the relationships exhibited between the ImPACT and SLT, it can be suggested that antisaccade eye movements contain a neurocognitive component.