[1] Univ Pavia, Dept Brain & Behav Sci, Pavia, Italy
[2] IRCCS Mondino Fdn, Pavia, Italy
[3] Natl & Kapodistrian Univ Athens, Aeginit Hosp, Dept Neurol 1, Athens, Greece
[4] Copenhagen Univ Hosp Rigshosp Glostrup, Dept Neurol, Danish Headache Ctr, Copenhagen, Denmark
[5] Univ Copenhagen, Dept Neurorehabilitat Traumat Brain Injury, Rigshosp Glostrup, Copenhagen, Denmark
[6] Teva Netherlands BV, Amsterdam, Netherlands
[7] Univ Bern, Univ Hosp Bern, Dept Neurol, Inselspital, Bern, Switzerland
[8] Lund Univ, Dept Clin Sci Lund, Skaneuro Neurol Clin, Lund, Sweden
[9] Univ Autonoma Barcelona, Headache Unit, Barcelona, Spain
[10] Univ Autonoma Barcelona, Vall dHebron Hosp & Res Inst, Res Grp, Barcelona, Spain
[11] Newcastle Upon Tyne Hosp NHS Fdn Trust, Newcastle, England
[12] Charles Univ Prague, Inst Neuropsychiat Care, Sch Med 1, Prague, Czech Republic
[13] Oslo Headache Ctr, Oslo, Norway
[14] Univ Lisbon, Ctr Estudos Egas Moniz, Fac Med, Lisbon, Portugal
[15] Univ Tampere, Fac Med & Hlth Technol, Tampere, Finland
[16] Teva Branded Pharmaceut Prod R&D Inc, W Chester, PA USA
[17] Copenhagen Univ Hosp Rigshosp Glostrup, Danish Headache Ctr, Dept Neurol, Copenhagen, Denmark
[18] Univ Copenhagen, Dept Clin Med, Copenhagen, Denmark