[1] Univ Cantabria, Marques Valdecilla Univ Hosp, Neurol Serv, Santander 39008, Spain
[2] Univ Cantabria, Marques Valdecilla Univ Hosp, Ctr Invest Biomed Red Enfermedades Neurodegenerat, Santander 39008, Spain
[3] Fdn Marques de Valdecilla IFIMAV, Inst Format & Res, Santander, Spain
[4] Univ Cantabria, Marques Valdecilla Univ Hosp, Dept Internal Med, E-39005 Santander, Spain