1. Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, Massachusetts, USA.
2. MassGeneral Hospital for Children Sports Concussion Program, Waltham, Massachusetts, USA.
3. Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Charlestown, Massachusetts, USA.
4. Department of Psychology, University of British Columbia, Vancouver, British Columbia, Canada.
5. Department of Psychiatry, UC San Diego School of Medicine, San Diego, California, USA.
6. Department of Physical Medicine and Rehabilitation, Shoen Adams Research Institute at Spaulding Rehabilitation, Charlestown, Massachusetts, USA.