Applicability of brain oxygenation measurement in the assessment of post-concussion outcomes in combat sport

Purpose: Investigate the association in semi and professional boxers (mTBI), who experienced previous multiple sports concussions, between brain oxygenation, balance, maximal aerobic capacity and power, in comparison to non concussed (NC) subjects. Methods: We tested 6 mTBI age 20-43 years (1 female and 5 males) and 7 NC age 24-38 (3 females, 4 males) subjects. Cerebral changes in DO2Hb, DHHb and total hemoglobin were measured using a protocol of three steps (Rest before max VO2 test, Hypercapnia, and recovery after max VO2 test, 5 minutes each) with a Nimo Nirs system (Nirox, Brescia) and 02 measurement with a Cosmed Quark CPET (Cosmed, Roma). CVR (cerebral vascular reactivity) in mTBI and NC subjects and respiratory parameters were calculated. Aerobic fitness outcome was quantified by mean of VO2max with a Bruce test on a bike. A Romberg Test was performed on a force platform (Kistler 9281, Switzerland) and software Sway (BTS Eng., Milan). Analysis of transversal (ML) and Longitudinal (AP) range of oscillation was performed. A Fitt’s test, was performed on a pc and scoring was obtained. Statistical analysis was performed with SPSS-v.23 (IBM Inc. Chicago) using the Mann-Whitney U test. Results: Any difference mTBI/NC was found in Fitt’s test. Any differences were found between males and females in any of the parameters measured, except anthropometry with a weight of 0.29 for sex (GLM test, SPSS). VO2max for mTBI was 49.58 ± 5.19 and for NC was 47.47 ± 4.91 ml/kg/min-1 without any significant difference. mTBI (17.65 ± 4.79 mm) show a significant differences with NC (25.35 ± 4.11 mm) in medio-lateral sway with eyes open (sig. 0.008). At GLM test, major predictor was the medio-lateral sway with eyes open with a weight of 0.71. Also a significant was found difference of FetO2 average in hypercapnia (sig. 0.008). Conclusions: Concussion seems to be evidenced by medio-lateral sway values (eyes open) and FetO2 in hypercapnia. Reference 1. Amen DG et al. (2011) Reversing brain damage in former NFL players: implications for traumatic brain injury and substance abuse rehabilitation. Journal of Psychoactive Drugs 43: 1-