1. The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia;
2. Hotchkiss Brain Institute, Faculty of Medicine, and Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, AB, Canada;
3. International Ice Hockey Federation, Zurich, Switzerland, International Olympic Committee Medical Commission Games Group, Lausanne, Switzerland, and Ottawa Sport Medicine Centre, ON, Canada;
4. Department of Neurosurgery and Center for the Study of Traumatic Encephalopathy, Boston University Medical Center, MA;
5. Department of Neurology, University of Zurich, Schulthess Clinic, and Fédération Internationale de Football Association Medical Assessment and Research Center, Zurich, Switzerland;
6. Psychological and Neurobehavioral Associates, Inc, State College, PA, and University of Missouri–Kansas City;
7. Department of Orthopaedic Surgery, Oslo University Hospital, and Faculty of Medicine, University of Oslo, Norway, Oslo Sports Trauma Research Center, Norway, and International Olympic Committee, Lausanne, Switzerland;
8. *Division of Neurosurgery, University of Toronto, and Concussion Management Program, Athletic Edge Sports Medicine, Toronto, ON, Canada;
9. †Michigan NeuroSport, Department of Neurology, University of Michigan, Ann Arbor;
10. ‡International Rugby Board, Dublin, Ireland;
11. §Departments of Neurosurgery, Orthopaedic Surgery, and Rehabilitation, Vanderbilt Sports Concussion Center, Vanderbilt University Medical Center, Nashville, TN;
12. Department of Clinical Neurosciences, Faculty of Medicine, Department of Family Medicine, and Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, AB, Canada;
13. ¶Department of Neurosurgery, Austin and Cabrini Hospitals, and The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia;
14. #Theodore S. Roberts Endowed Chair, Department of Neurological Surgery, University of Washington, Seattle, and National Football League Head, Neck and Spine Medical Committee, New York, NY;
15. **Kenan Distinguished Professor, Department of Exercise and Sport Science, and Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, University of North Carolina at Chapel Hill;
16. ††Departments of Rehabilitation Medicine, Orthopaedics and Sports Medicine, and Neurological Surgery, University of Washington, Seattle Sports Concussion Program, Seattle Seahawks, and Seattle Mariners;
17. ‡‡Neuropsychology Outcome Assessment Laboratory and Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada;
18. §§Department of Clinical Neurology, Weill Medical College of Cornell University, New York, NY, Burke Rehabilitation Hospital, White Plains, NY, and New York State Athletic Commission, New York;
19. Ottawa Sport Medicine Centre, Department of Family Medicine, University of Ottawa, Canadian National Men's Sledge Hockey Team, Ottawa, ON, Canada;
20. ¶¶Brain Injury Research, Departments of Neurosurgery and Neurology, Medical College of Wisconsin, Madison;
21. ##Australian Centre for Research into Injury in Sports and its Prevention, Monash Injury Research Institute, Monash University, Melbourne, Transport and Road Safety Research, Faculty of Science, the University of New South Wales, Sydney, and McIntosh Consultancy and Research Pty Ltd, Sydney, Australia;
22. ***Perry Maddocks Trollope Lawyers and Melbourne Neuropsychology Services, Australia;
23. †††The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, and Centre For Health Exercise and Sports Medicine, Melbourne Physiotherapy Department, University of Melbourne, Australia;
24. ‡‡‡Department of Pediatrics and David Braley Sport Medicine and Rehabilitation Centre, McMaster University, Hamilton, ON, Canada;
25. §§§Athletic Medicine, Princeton University, NJ, and Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick;
26. Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, AB, Canada
27. ¶¶¶Department of Neurosurgery, Toronto Western Hospital and University of Toronto, ON, Canada, Krembil Neuroscience Centre, Toronto, ThinkFirst Canada, Toronto, and Parachute Canada, Toronto, ON;
28. British Horseracing Authority, London, United Kingdom