[1] Brigham & Womens Hosp, Boston, MA USA
[2] Thomas Jefferson Univ, Dept Neurol, Jefferson Headache Ctr, Philadelphia, PA 19107 USA
[3] Barrow Neurol Inst, Phoenix, AZ 85013 USA
[4] Dent Neurol Inst, Amherst, NY USA
[5] Carolinas Headache Clin, Matthews, NC USA
[6] AbbVie Inc, Madison, NJ USA
[7] Univ Copenhagen, Danish Headache Ctr, Rigshosp Glostrup, Glostrup, Denmark