[1] Med Univ Graz, Dept Neurol, Auenbruggerpl 22, A-8036 Graz, Austria
[2] Med Univ Graz, Div Neuroradiol Vasc & Intervent Radiol, Graz, Austria
[3] Univ Basel, Univ Hosp Basel, Dept Med, Neurol Clin & Policlin, Basel, Switzerland
[4] Univ Basel, Univ Hosp Basel, Dept Biomed, Neurol Clin & Policlin, Basel, Switzerland
[5] Univ Basel, Univ Hosp Basel, Dept Clin Res, Neurol Clin & Policlin, Basel, Switzerland
[6] Med Univ Graz, Inst Med Informat Stat & Documentat, Graz, Austria
[7] Univ Edinburgh, Brain Res Imaging Ctr, Ctr Clin Brain Sci, Edinburgh, Midlothian, Scotland
[8] Univ Edinburgh, UK Dementia Res Inst, Edinburgh, Midlothian, Scotland