1. Department of Neurology, Faculty of Medicine, Safarik University and L. Pasteur University Hospital, Kosice, Slovak Republic
2. Graduate School Kosice Institute for Society and Health, Safarik University, Kosice, Slovak Republic
3. Department of Social Medicine, Faculty of Medicine, Institute of Public Health, Safarik University, Slovak Republic
4. Department of Community and Occupational Health, University Medical Center Groningen, University of Groningen, the Netherlands