[1] Univ Pittsburgh, Med Ctr, Sports Med Concuss Program, Dept Orthopaed Surg, Pittsburgh, PA 15203 USA
[2] Univ Pittsburgh, Med Ctr, Dept Neurol Surg, Pittsburgh, PA 15203 USA
[3] Univ British Columbia, Dept Psychiat, Vancouver, BC V5Z 1M9, Canada
[4] Emerson Hosp, Dept Neurol Surg, Concord, MA USA
[5] Henry Ford Hlth Syst, Div Neuropsychol, Detroit, MI USA
[6] Michigan State Univ, Dept Phys Educ & Exercise Sci, E Lansing, MI 48824 USA
[7] Orthoped & Neurosurg Ctr Cascades, Dept Neurosurg, Bend, OR USA