1. Department of Neurology, Oslo University Hospital and University of Oslo , 0424 Oslo , Norway
2. Institute of Clinical Medicine, University of Oslo , 0316 Oslo , Norway
3. Department of Research, Innovation and Education, Division of Clinical Neuroscience, Oslo University Hospital , 0424 Oslo , Norway
4. National Institute of Occupational Health , 0304 O slo , Norway
5. Oslo Metropolitan University , 0130 Oslo , Norway
6. National Institute of Occupational Health , 0304 Oslo , Norway