[1] Complejo Asistencial Universitario Salamanca, Dept Neurol, CAUSA, Paseo San Vicente 58-182, E-37007 Salamanca, Spain
[2] Dept Internal Med, Div Neurol, Complejo Asistencial avila, Avila, Avila, Spain
[3] Univ Salamanca, Instituto Investigac Biomedica Salamanca, IBSAL, Salamanca, Spain
[4] Hosp Clin Universitario Santiago, Dept Neurol, CHUS, La Coruna, Spain
[5] Hosp Bierzo Ponferrada, Dept Internal Med, Div Neurol, Leon, Leon, Spain
[6] Univ Salamanca, Dept Med, Mol Med Unit, Salamanca, Spain