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

## TL;DR

This study shows that changes in the blink reflex can detect neurological effects from subconcussive head impacts, such as those experienced in soccer heading.

## Contribution

The study introduces blink reflex parameters as a potential tool for detecting neurological changes caused by subconcussive impacts.

## Key findings

- Significant reductions in blink latency and delta 30 values were observed 2-h and 24-h post-heading.
- Delta 30 values returned to baseline by 24-h post-heading, while blink latency remained reduced.
- No significant changes were found in differential latency, number of oscillations, or excursion.

## Abstract

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-h and 24-h post-heading.

Significant declines in blink reflex parameters were observed at specific post-heading timepoints compared to baseline. At 24-h 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-h post-heading, 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-h 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.