Effect of Selective Head-neck Cooling on Signs and Symptoms of Sport Originated Brain Injury in Amateur Sports: A Pilot Study

Background: During contact sports, body temperature can elevate to between 38.9°C and 40.0°C at the peak of activity, and the temperature increase may be more long-lasting in hot environments. Mild traumatic brain injury (mTBI) occurring during exercise-induced hyperthermia may result in a cumulatively worse brain injury. Aim: To investigate the effect of a portable head-neck cooling cap on people with sport originated brain injury (SOBI) and to record changes in the signs and symptoms of SOBI after a period of cooling (i.e. intervention) compared to people with SOBI and no cooling (i.e. control). Methods: Thirty-five players with an identified SOBI were offered use of a head-neck cooling cap. Following assessment with the Concussion Symptom Scale (CSS) 13 players selected to rest and 22 players selected to wear the cooling cap for up to 30 minutes following the SOBI. Post CSS assessments were made following the rest or cooling cap period. Results: Differences between cooling and non-cooling, irrespective of sex were a lower post Global Severity Index (14.6 ±4.8 vs. 18.9 ±4.4; χ2(1)=0.3; p=0.6091; t(12)=3.3; p=0.0063; d=0.93), Positive Symptom Total (1.4 ±1.0 vs. 2.9 ±0.8; χ2(1)=0.1; p=0.7041; t(12)=3.8; p=0.0026; d=1.66), CSS (29.6 ±21.7 vs. 64.5 ±17.6; χ2(1)=0.2; p=0.7032; t(12)=3.7; p=0.0026; d=1.77), and Positive Symptom Distress Index (1.9 ±0.9 vs. 3.2 ±0.6; χ2(1)=0.2; p=0.6682; t(12)=3.6; p=0.0033; d=1.70) for the cooling participants. Conclusion: Despite limited participants, this pilot study showed initial positive support for the use of cooling in the management of SOBI to reduce the total symptom score and severity of the CSS when compared with rest alone. Highlights a) Brain temperature is slightly higher but correlates well with body temperature. b) Brain hypothermia, with its broad and pleiotropic effects, presents as the most potent neuroprotection technique available to date. c) Short duration, active head-neck cooling immediately after a SOBI may aid in acute phase recovery. d) SOBI players described an improvement in feelings of wellbeing when using the Cryohelmet, and that their head instantly felt calmer and cooler