1. Department of Neurology University of Helsinki and Helsinki University Hospital Helsinki Finland
2. Department of Neurology Medical University of Graz Graz Austria
3. Department of Neurology University Medicine Greifswald Greifswald Germany
4. Department of Radiology University of Helsinki and Helsinki University Hospital Helsinki Finland
5. Division of Neuroradiology, Vascular and Interventional Radiology, Department of Radiology Medical University of Graz Graz Austria
6. Department of Clinical Neuroscience, Institute of Neurosciences and Physiology, Sahlgrenska Academy at University of Gothenburg & Department of Neurology Sahlgrenska University Hospital Gothenburg Sweden