[1] Kings Coll London, NIHR Kings Clin Res Fac, London WC2R 2LS, England
[2] Univ Calif Los Angeles, Dept Neurol, Los Angeles, CA USA
[3] Univ Texas SouthWestern Med Ctr, Dept Neurol & Ophthalmol, Dallas, TX USA
[4] Univ Essen Gesamthsch, Dept Neurol, Westgerman Headache & Vertigo Ctr Essen, Essen, Germany
[5] Hospices Civils Lyon, Dept Neurol, Lyon, France
[6] Lyon Neurosci Res Ctr, Lyon, France
[7] Beth Israel Deaconess Med Ctr, BIDMC Comprehens Headache Ctr, Boston, MA USA
[8] Harvard Med Sch, Dept Neurol & Dept Anesthesia, Crit Care & Pain Med, Boston, MA USA
[9] AbbVie, Madison, NJ USA
[10] AbbVie, N Chicago, IL USA