Abstract

INTRODUCTION Traumatic brain injury (TBI) is a significant health concern, particularly in military and sports settings. This study investigated the use of functional near-infrared spectroscopy (fNIRS) to identify TBI in Role of Care (ROC) 1 and 2 environments. This initial study aimed to begin the development of a rapid, noninvasive neuroimaging technique for assessing brain injuries in field settings.

MATERIAL AND METHODS Twelve participants, who were all Division 1 athletes, volunteered for this study (age: 21.1 ± 2.7 years). A 4 × 1 optode to receiver fNIRS grid was placed over the injured and un-injured region of the brain (control) while performing a 60-second simple reaction time test. These assessments were collected within the first 24  hours of injury, when the team's physician cleared the participant for return to activity (RTA) and return to play (RTP). All testing were performed in ROC 1 or 2 environments. A Morlet wavelet fNIRS analysis approach was then used to rapidly interpret data in field-based environments.

RESULTS The Morlet wavelet fNIRS analysis identified the injured brain region. The injured region exhibited 72% greater tHb (P = .013), 2.6-fold increase in O2Hb (P = .018), and 1.3-fold increase in hHb compared to the control region (P = .006). The average time from the initial point of injury to being cleared for RTP was 4.3 ± 2.7 weeks. The average of the simple reaction time test exhibited a decrease in reaction time from initial and RTA at the RTP timepoint (P = .016).

CONCLUSION The Morlet wavelet fNIRS analysis identified the injured region of the brain at initial, RTA, and RTP timepoints in ROC 1 and 2 environments. It did not detect differences in recovery, but there was an improvement in simple reaction time. Thus, the fNIRS analysis detected TBI's in ROC 1 and 2, but further development is needed to increase its sensitivity to tracking TBI's over time.