Note: Starting from 01.01.2014 this study is expanded to a multi-centric design funded by the German Center for Neurodegenerative Diseases (The DZNE - Mechanisms of Dementia After Stroke (DEMDAS) Study). This includes the following study sites: DZNE/München - Institute for Stroke and Dementia Research, Klinikum der Universität München (Coordinator); DZNE/Berlin - Neuroscience Research Center - Campus Mitte Charité; DZNE/Bonn - Klinik und Poliklinik für Neurologie, Universitätsklinikum Bonn; DZNE/Göttingen - University Medical Center Göttingen; DZNE/Magdeburg - Universitätsklinikum Magdeburg.