1. From the Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital and Spaulding Research Institute, Harvard Medical School, Boston, Mass. (Iverson, Terry, Luz, Zafonte); Massachusetts General Hospital for Children Sports Concussion Program (Iverson, Terry, Zafonte); Home Base, A Red Sox Foundation and Massachusetts General Hospital Program, Boston, Mass. (Iverson, Terry, Zafonte); the Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital,...