Changes in the blink reflex after a sport-related concussion: Test-retest reliability of a blink reflexometer in high school athletes.

INTRODUCTION

Sport-related concussion (SRC) is a traumatic brain injury affecting approximately 20 % of high school athletes annually. Recent investigations propose the blink reflex as a potential diagnostic measure for SRC, with studies showing significant changes in the reflex post-concussion. The current study aims to assess the baseline test-retest reliability of the EyeStat device, a handheld blink reflexometer, in a cohort of healthy high school athletes.

METHODS

A prospective cohort study of healthy youth athletes at a local high school was conducted. The EyeStat device, an FDA-approved blink reflexometer, was utilized to capture blink reflex responses from each participant. Participants underwent two 20-second baseline measurements separated by a 15-minute gap. Pearson's/Spearman's r and Intraclass Correlation Coefficient (ICC) tests were performed to determine the test-retest reliability of the device between the two baseline measurements.

RESULTS

Forty-eight athletes (mean age: 15.3 ± 1.3; 65.2 % male) were included for our analyses. All 10 Eyestat parameters demonstrated significant positive relationships between the two baseline assessments (p < 0.001), with intraclass correlation confirming test-retest reliability across measures (oscillations: 0.87; total blink time: 0.82; time to open: 0.82; time under threshold: 0.80; lid excursion: 0.77; lid velocity: 0.77; time to close: 0.76; latency: 0.57; differential latency: 0.49). Moderate to strong positive relationships were observed for latency, differential latency, and time under threshold, while parameters like delta 30, time to close, lid excursion, lid velocity, total blink time, and time to open showed strong correlation, and oscillations displayed a very strong positive relationship. None of the EyeStat parameters differed significantly based on sex, hours of sleep, or concussion history.

CONCLUSIONS

Our study demonstrates the consistent test-retest reliability of the EyeStat device across various blink reflex parameters in a cohort of non-concussed, healthy high school athletes. The findings support the potential utility of the EyeStat device as a reliable baseline measure for assessing the blink reflex in the context of SRC among young athletes. Further research and validation studies are warranted to confirm its effectiveness in diagnosing SRC and its applicability in diverse athlete populations.