[1] Mayo Clin, 200 First St SW, Alfred Bldg 9-446, Rochester, MN 55905 USA
[2] Mayo Clin, Dept Neurosurg, Rochester, MN USA
[3] Mayo Clin, Dept Radiol, Rochester, MN USA
[4] Univ Nebraska, Dept Neurol Sci, Med Ctr, Omaha, NE USA
[5] Mayo Clin, Evidence Based Practice Ctr, Kern Ctr Sci Healthcare Delivery, Rochester, MN USA
[6] Yale New Haven Hlth Bridgeport Hosp, Dept Internal Med, Bridgeport, CT USA
[7] Mayo Clin, Dept Neurol, Rochester, MN USA