1. Sports Concussion Research Group, Department of Kinesiology, Texas Christian University, Fort Worth, Texas.
2. Division of Health and Human Performance, George Mason University, Manassas, Virginia.
3. Department of Sport Medicine, Texas Christian University, Fort Worth, Texas.
4. Department of Sport Medicine, John Peter Smith Hospital, Fort Worth, Texas.
5. Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at University of Gothenburg, Mölndal, Sweden.
6. UmanDiagnostics, Umeå, Sweden.
7. Department of Molecular Neuroscience, University College London Institute of Neurology, Queen Square, London, United Kingdom.