[1] Hosp Univ Vall dHebron, Headache Unit, Dept Neurol, Barcelona, Spain
[2] Univ Autonoma Barcelona, Vall dHebron Res Inst VHIR, Headache Res Grp, Barcelona, Spain
[3] Miguel Hernandez Univ, Calite Res Grp, Elche, Spain
[4] Marques Valdecilla Hosp, Santander, Spain
[5] Valdecilla Biomed Res Inst IDIVAL, Santander, Spain
[6] Cadiz Univ, Cadiz, Spain
[7] Univ Hosp Valladolid, Dept Neurol, Headache Unit, Valladolid, Spain
[8] Inst Biomed Res Salamanca IBSAL, Salamanca, Spain
[9] Univ Hosp Getafe, Dept Neurol, Getafe, Spain
[10] San Carlos Hosp, Dept Neurol, Headache Unit, Madrid, Spain
[11] Univ Hosp Fuenlabrada, Dept Neurol, Madrid, Spain
[12] Univ Hosp Albacete, Dept Neurol, Albacete, Spain
[13] Virgen de la Arrixaca Univ Hosp, Dept Neurol, Murcia, Spain
[14] Alicante St Joan Hlth Dist, Alicante, Spain
[15] REDISSEC, Hlth Serv Res Chron Illnesses Network, Alicante, Spain