Steady-State Visual-Evoked Potentials as a Biomarker for Concussion: A Pilot Study.

Objective This study aims to utilize a portable system capable of measuring steady-state visual evoked potentials (SSVEP) to investigate their use as an objective electrophysiologic biomarker for concussion. Background The most pressing issues in relation to sports related concussion (SRC) involves accurate and timely diagnosis, for a safe return to play criteria. Despite the vast range of tools available to help clinicians assess concussion, most are subjective, non-portable, and therefore non-ideal for unbiased application at the site and time of a suspected injury. Design/Methods This system applied a smartphone housed in a VR-frame delivering a 15-Hz flickering stimulus while a wireless electroencephalography (EEG) headset recorded EEG signals. Sixty-five male amateur rugby athletes (20.9 ± 2.3 years-old) were tested throughout a season and were stratified into healthy, concussed, and recovered groups based on clinical examinations pre- and post-competitive games. Players SSVEP responses was quantified into a signal-to-noise ratio (SNR) and summarized into respective study-groups for comparison of medians with 25th–75th interquartile range. Results All sixty-five participants completed a baseline evaluation preseason. Twelve participants sustained a diagnosed concussion during the season and were retested within 72 h of injury. Eight concussed players received additional SSVEP testing following a 2-week recovery period. Concussed participants had a significantly lower SNR [2.20 (2.04–2.38)] when compared to their baseline [4.54 (3.79–5.10)]. When clinically recovered, participant SNR [4.82 (4.13–5.18)] was not significantly different to their baseline. Baseline SNR of concussed and non-concussed participants [4.80 (4.07–5.68)] did not significantly differ. Conclusions This is the first study to show that SSVEPs are significantly attenuated in the presence of concussion in male athletes. Concussed individuals9 ability to generate SSVEP appear to recover following clinical recovery. The observations of this study indicate SSVEP have the potential to be a supplemental aid for the assessment and management of concussion at point-of-care.