[1] Duke Univ, Sch Med, Dept Neurosurg, Durham, NC USA
[2] Kentucky Spinal Cord Injury Res Ctr, Louisville, KY USA
[3] Houston Methodist Hosp, Dept Neurosurg, Houston, TX USA
[4] Univ Miami, Miami Project Cure Paralysis, Miami, FL USA
[5] Med Coll Wisconsin, Dept Neurosurg, Milwaukee, WI USA
[6] Univ Maryland, Sch Med, Baltimore, MD USA
[7] Thomas Jefferson Univ, Dept Neurosurg, Philadelphia, PA USA
[8] Miami Valley Hosp, Dept Orthoped Surg, Centerville, OH USA
[9] Univ Toronto, Dept Surg, Div Neurosurg & Spine Program, Toronto, ON, Canada
[10] Walter Reed Natl Mil Med Ctr, Div Neurosurg, Bethesda, MD USA
[11] Massachusetts Gen Hosp, Dept Neurosurg, Boston, MA USA
[12] Harvard Med Sch, Boston, MA USA
[13] Massachusetts Gen Hosp, Harvard Med Sch, Dept Neurosurg, 55 Fruit St, Wang 745, Boston, MA 02114 USA