*Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, Massachusetts;

†Spaulding Rehabilitation Hospital and Spaulding Rehabilitation Institute, Charlestown, Massachusetts;

‡MassGeneral Hospital for Children Sport Concussion Program, Boston, Massachusetts;

§Home Base, A Red Sox Foundation and Massachusetts General Hospital Program, Charlestown, Massachusetts;

¶Department of Orthopedics, University of Colorado School of Medicine, Sports Medicine Center, Children's Hospital Colorado, Aurora, Colorado;

║Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada;

**British Columbia Mental Health and Addictions Research Institute, Vancouver, BC, Canada;

††Seafair Minor Hockey Association, Richmond, BC, Canada;

‡‡Evolution Sport Therapy, Richmond, BC, Canada;

§§Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada;

¶¶Djavad Mowafaghian Centre for Brain Health, Vancouver, BC, Canada; and

║║British Columbia Provincial Neuropsychiatry Program, Vancouver Coastal Health, University of British Columbia, Vancouver, BC, Canada.

Corresponding Author: William J. Panenka, MD, BC Children's Hospital Research Building, 938 W. 28th Ave, Room A3-123, 3rd Floor, Vancouver, BC V5Z-4H4, Canada ([email protected]).

G. L. Iverson has a clinical and consulting practice in forensic neuropsychology involving individuals who have sustained mild TBIs (including athletes). He has received research funding from several test publishing companies, including ImPACT Applications, Inc, CNS Vital Signs, and Psychological Assessment Resources (PAR, Inc). He has received salary support from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. He serves as a scientific advisor for BioDirection, Inc, Sway Operations, LLC, and Highmark, Inc. He acknowledges grant support from the National Football League. He acknowledges unrestricted philanthropic support from the Mooney-Reed Charitable Foundation, Heinz Family Foundation, Boston Bolts, Spaulding Research Institute, and ImPACT Applications, Inc. W. J. Panenka is the founder and CEO of Translational Life Sciences, an early stage biotechnology company. He is also on the scientific advisory board of Medipure Pharmaceuticals and Vitality Biopharma, and in the past, he has been on the board of directors for Abattis Bioceuticals and on the advisory board of Vinergy Resources. All of these companies are early stage biotechnology enterprises with no relation to concussion or brain injury. The remaining authors report no conflicts of interest.