[1] Univ Utah, Clin Neurosci Ctr, Dept Neurosurg, Salt Lake City, UT 84112 USA
[2] Mayo Clin, Dept Neurosurg, Rochester, MN USA
[3] Carolinas HealthCare Syst, Dept Neurosurg, Carolina Neurosurg & Spine Associates & Neurosci, Charlotte, NC USA
[4] Weill Cornell Med Coll, Dept Neurosurg, New York, NY USA
[5] Univ Tennessee, Dept Neurosurg, Memphis, TN USA
[6] Semmes Murphy Clin, Memphis, TN USA
[7] Univ Michigan, Dept Neurosurg, Ann Arbor, MI 48109 USA
[8] St Lukes Neurol & Spine Surg, Kansas City, MO USA
[9] Atlantic Neurosurg Specialists, Morristown, NJ USA
[10] Univ Virginia Hlth Syst, Dept Neurosurg, Charlottesville, VA USA
[11] Indiana Univ, Dept Neurosurg, Indianapolis, IN 46204 USA
[12] Goodman Campbell Brain & Spine, Indianapolis, IN USA
[13] Duke Univ, Dept Neurosurg, Durham, NC USA
[14] Univ Miami, Dept Neurosurg, Miami, FL USA
[15] Univ Calif San Francisco, Dept Neurosurg, San Francisco, CA USA
[16] Barrow Brain & Spine, Phoenix, AZ USA