1. University of Eastern Finland, Institute of Clinical Medicine/Neurology, Kuopio, Finland
2. Department of Radiology, Kuopio University Hospital, Kuopio, Finland
3. Department of Neurology, Kuopio University Hospital, Kuopio, Finland
4. Research Unit of Clinical Neuroscience, Neurology, University of Oulu, Oulu, Finland
5. MRC, Oulu University Hospital, Oulu, Finland