[1] Geisel Sch Med Dartmouth, Hanover, NH USA
[2] Univ Copenhagen, Dept Neurol, Danish Headache Ctr, Copenhagen, Denmark
[3] Charite Univ Med Berlin, Dept Neurol, Berlin, Germany
[4] Vanderbilt Univ, Nashville Neurosci Grp, 221 Kirkland Hall, Nashville, TN 37235 USA
[5] DADO Med Sro, Prague Headache Ctr, Prague, Czech Republic
[6] Thomas Jefferson Univ, Jefferson Headache Ctr, Philadelphia, PA 19107 USA
[7] Nova Southeastern Univ, Premiere Res Inst, W Palm Beach, FL USA
[8] Amgen Inc, Thousand Oaks, CA 91320 USA