[1] Boston Univ, Sch Med, Dept Neurol, Ctr Study Traumat Encephalopathy, Boston, MA 02118 USA
[2] Sports Legacy Inst, Waltham, MA USA
[3] Bedford Vet Affairs Med Ctr, Dept Neuropathol, Bedford, MA 01730 USA
[4] Boston Univ, Sch Med, Dept Pathol, Boston, MA 02118 USA
[5] Boston Univ, Sch Med, Dept Neurosurg, Boston, MA 02118 USA
[6] Emerson Hosp, Dept Neurosurg, Concord, MA 01742 USA
[7] Emerson Hosp, Dept Surg, Concord, MA 01742 USA
[8] Brigham & Womens Hosp, Dept Neurosurg, Neurol Sports Injury Ctr, Boston, MA 02115 USA