1. Institute of Clinical Medicine – Neurology, University of Eastern Finland, Kuopio, Finland
2. Department of Anesthesia and Operative Services, Kuopio University Hospital, Kuopio, Finland
3. Department of Neurology, Kuopio University Hospital, Kuopio, Finland
4. Institute of Clinical Medicine, Anesthesiology and Intensive Care, University of Eastern Finland, Kuopio, Finland
5. Research and Service Centre for Occupational Health, Finnish Institute of Occupational Health, Helsinki, Finland
6. Medical Research Center, Oulu University Hospital, Oulu, Finland
7. Research Unit of Clinical Neuroscience, Neurology, University of Oulu, Oulu, Finland