Selective head-and-neck cooling on biomarker levels and symptom rating following a boxing bout- protocol for an exploratory randomized trial

Abstract

Background Head impacts are common in contact sports such as boxing and occur at times of elevated core body and brain temperatures induced by the exercise. Following impact, elevated brain temperature may lead to the development of exacerbated brain injury that can be monitored by blood biomarkers. We hypothesized that acute head-and-neck cooling, recently shown to shorten return-to-play in concussed ice hockey players, applied acutely following a boxing bout is associated with an attenuated release of blood biomarkers and improved symptom rating. Methods The trial is academically driven and funded by external and hospital research funds. Young, healthy elite boxers ≥ 18 years old are recruited. Prior to, and immediately after a competitive boxing bout over 3x2 or 3x3 minutes, blood samples are drawn. Boxers are randomized to intervention or control management by 1:1 allocation prior to baseline testing. After the initial post-fight blood sample is drawn and symptom rating using the sports concussion assessment tool-5 (SCAT-5) has been collected, the boxers receive either acute selective head-and-neck cooling for 45 min, or routine post-fight management. The number of head impacts are counted in all boxers on match video recordings. In both groups, blood samples are drawn 45 minutes after the initial post-bout blood sample, as well as 3 and 6 days post-fight. At all time points for blood sampling, the number of symptoms (NOS) and symptom severity score (SSS) are assessed using the symptom rating part of the SCAT-5. The primary endpoint is the difference in biomarker levels (GFAP, NF-L, tau, UCH-L1, neuronal-specific enolase) between immediately post-fight and pre-intervention levels, to those obtained at 6 days post-fight. The post-fight SCAT-5 NOS and SSS are secondary endpoints. Discussion There is no treatment available for boxing-induced brain injury. Biomarkers are surrogate yet objective marker of brain injury, and the head-and-neck cooling treatment may attenuate the release of brain injury-related biomarkers as well as reduce symptoms induced by head impacts attained during a boxing fight. Potentially, head-and-neck cooling is a treatment option acutely following a boxing bout. Trials registration ClinicalTrials.gov, ClinicalTrials.gov Identifier NCT06386484. Registered April 23, 2024.