1. Department of Neurology , Satakunta Central Hospital , Pori , Finland
2. Department of Clinical Neurosciences , University of Turku , Turku , Finland
3. Turku University Hospital, Hospital District of Southwest Finland, Neurocenter , Turku , Finland
4. Department of General Practice , University of Turku and Turku University Hospital , Turku , Finland
5. Unit of Primary Health Care, Kuopio University Hospital , Kuopio , Finland
6. Folkhälsan Research Centre , Helsinki , Finland
7. Department of Neurosurgery , Helsinki University Central Hospital , Helsinki , Finland
8. Mutual Insurance Company Ilmarinen , Helsinki , Finland