1. Vanderbilt Sports Concussion Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
2. Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
3. Department of Neurology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
4. Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA
5. Department of Exercise & Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27154, USA
6. Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, University of North Carolina, Chapel Hill, NC 27154, USA
7. Injury Prevention Research Center, University of North Carolina, Chapel Hill, NC, USA