1. Department of Neurology, University of Kuopio, P.O. Kuopio, Finland
2. Aging Research Center (ARC), Karolinska Institutet, Stockholm, Sweden
3. Department of Epidemiology and Health Promotion, National Public Health Institute, Helsinki, Finland
4. Department of Public Health, University of Helsinki, Helsinki, Finland
5. South Ostrobothnia Central Hospital, Seinäjoki, Finland
6. Department of Neurology, Kuopio University Hospital, Kuopio, Finland