[1] Univ Siena, Dept Med Surg & Neurosci, Viale Bracci 2, I-53100 Siena, Italy
[2] Vall dHebron Univ Hosp, Neurol Neuroimmunol Dept, Barcelona, Spain
[3] Univ Florence, Sect Neurosci, Dept NEUROFARBA, Florence, Italy
[4] Kantonsspital, Univ Hosp, Dept Neurol, Basel, Switzerland
[5] Univ Oxford, Nuffield Dept Clin Neurosci, Oxford, England
[6] UCL, Inst Neurol, London, England
[7] Univ Vita Salute San Raffaele, San Raffaele Sci Inst, Div Neurosci, Neuroimaging Res Unit,Inst Expt Neurol, Milan, Italy
[8] Med Univ Graz, Dept Neurol, Graz, Austria
[9] Med Univ Graz, Div Neuroradiol Vasc & Intervent Radiol, Dept Radiol, Graz, Austria
[10] Rigshosp Glostrup, Dept Neurol, Glostrup, Denmark
[11] Vrije Univ Amsterdam Med Ctr, Dept Radiol & Nucl Med, Amsterdam, Netherlands
[12] Vrije Univ Amsterdam Med Ctr, Dept Phys & Med Technol, Amsterdam, Netherlands
[13] Vall dHebron Univ Hosp, Neuroradiol Sect, Barcelona, Spain