Assessing the capability of the corneal blink reflex to display neurological changes following subconcussive head impacts

Osamudiamen S Ogbeide¹Madeleine K Nowak^1,2Lillian Klemsz¹Dena Garner³Keisuke Kawata^1*

• ¹Indiana University Bloomington, Bloomington, United States
• ²Chobanian & Avedisian School of Medicine, Boston University, Boston, Massachusetts, United States
• ³Citadel, Charleston, South Carolina, United States

This study examines the capability of detecting neurological changes caused by subconcussive head impacts by analyzing the blink reflex of an individual when they encounter puffs of air as a stimulus. Following attrition and technical issues, 26 participants (15 females, 11 males: age ± SD; 21.3 ± 2.11 years) with at least 5 years of soccer heading experience were included in the final analysis. Participants performed 10 soccer headers with soccer balls projected at a speed of 30 mph. Parameters related to blink reflex, including blink latency, differential latency, number of oscillations, delta 30, and excursions, were assessed by the EyeStat device at pre-heading baseline, and 2-hours and 24-hours post-heading. Significant declines in blink reflex parameters were observed at specific post-heading timepoints compared to baseline. At 24-hours post-heading, significant reductions were detected in the overall blink latency (p=0.0255), the blink latencies of the right eye (p=0.0411), ipsilateral latency (p=0.0314) and contralateral latency (p=0.0434). At 2-hours postheading, significant declines were observed in the overall delta 30 value (p=0.0053) and delta 30 of the right eye (p=0.0260). Both delta 30 values returned to baseline by the 24-hour post-heading timepoint. No significant changes in the differential latency, number of oscillations, and excursion of the eye were found. These findings suggest changes in the latency and delta 30 of a blink reflex is a viable measure of detection for neurological changes when monitoring subconcussive head impacts.