[1] Univ Copenhagen, Danish Headache Ctr, Rigshosp Glostrup, Copenhagen, Denmark
[2] Ctr Hosp Univ Nice, Pain Dept, Nice, France
[3] Ctr Hosp Univ Nice, FHU InovPain, Nice, France
[4] Univ Cote Azur, Nice, France
[5] Univ Autonoma Barcelona, Headache Unit, Vall dHebron Univ Hosp, Barcelona, Spain
[6] Univ Autonoma Barcelona, Res Grp, Vall dHebron Univ Hosp, Barcelona, Spain
[7] Univ Autonoma Barcelona, Res Inst, Barcelona, Spain
[8] H Lundbeck & Co AS, Copenhagen, Denmark