[1] Hosp Univ Marques Valdecilla, Serv Neurol, Santander 39008, Spain
[2] Hosp Clin Univ, Serv Neurol, Valencia, Spain
[3] Hosp Clin Univ, Serv Neurol, Santiago De Compostela, Spain
[4] Hosp Gen Valle Hebron, Serv Neurol, Barcelona, Spain
[5] Univ Oviedo, Hosp Cent Asturias, Serv Neurol 2, E-33080 Oviedo, Spain
[6] Almirall Prodestfarma Sa, Dept Med, Barcelona, Spain