[1] Kings Coll London, Headache Grp, NIHR Kings Clin Res Facil, London, England
[2] Guys & St ThomasNHS Fdn Trust, Neurol Dept, London, England
[3] IRCCS San Raffaele Roma, Headache & Pain Unit, Rome, Italy
[4] San Raffaele Univ, Rome, Italy
[5] Univ Duisburg Essen, Inst Med Informat Biometry & Epidemiol IMIBE, Dept Neuroepidemiol, Med Fac, Essen, Germany
[6] KMG Klinikum Gustrow, Neurol Zent, Neurol Klin, Gustrow, Germany
[7] Kopfschmerzzentrum Nord Ost, Klinik & Poliklin Neurol, Rostock, Germany
[8] Univ Cote Azur, CHU Nice, Pain Dept, Nice, France
[9] Univ Cote Azur, FHU Inov Pain, Nice, France
[10] Univ Clermont Auvergne, Inserm U1107, Neurodol Trigeminal Pain & Migraine, Clermont Ferrand, France
[11] CHU Lille, Hop Salengro, Serv Neurochirurg, Pain Clin, Lille, France
[12] Assistance Publ Hop Paris, Lariboisiere Hosp, Emergency Headache Ctr, Dept Neurol JM, Paris, France
[13] Univ Clermont Auvergne, Serv neurol, CHU Clermont Ferrand, Inserm,Neurodol, Clermont Ferrand, France
[14] Univ Campania Luigi Vanvitelli, Headache Ctr, Dept Adv Med & Surg Sci, Naples, Italy
[15] Univ Aquila, Dept Biotechnol & Appl Clin Sci, Laquila, Italy
[16] Univ Birmingham, Inst Metab & Syst Res, Birmingham, England
[17] Univ Hosp Birmingham NHS Fdn Trust, Queen Elizabeth Hosp Birmingham, Dept Neurol, Birmingham, England
[18] Univ Tampere, Fac Med & Hlth Technol, Tampere, Finland
[19] Univ Pavia, Dept Brain & Behav Sci, Pavia, Italy
[20] IRCCS Mondino Fdn, Headache Sci & Neurorehabil Ctr, Pavia, Italy
[21] Univ Calif Los Angeles, Dept Neurol, Los Angeles, CA USA