1. Section of Neurology, Department of Internal Medicine, Ryhov County Hospital, Jönköping, Sweden
2. Division of Cellular Biology, Department of Biomedicine and Surgery, Linköping University, Linköping, Sweden
3. Department of Occupational and Environmental Medicine, University Hospital, Linköping, Sweden
4. Department of Occupational and Environmental Medicine, Faculty of Medicine, University of Tehran, Tehran, Iran
5. Occupational and Environmental Medicine, Department of Public Health and Community Medicine, University of Gothenburg, Gothenburg, Sweden
6. Departments of Neurology and Neurophysiology, University Hospital of Linköping, Linköping, Sweden