1. From Vanderbilt Sports Concussion Center, Vanderbilt University School of Medicine, Nashville (BLB, NM, AWK, AMY-K, SLZ); the Department of Neurology, Medical College of Wisconsin, Milwaukee (BLB); the Department of Neurosurgery, Medical College of Wisconsin, Milwaukee (BLB); and the Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville (AMY-K, SLZ).