1. Department of Neurology and Neurosurgery, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
2. Department of Neurology and Neurosurgery, Neurology Clinic, Tartu University Hospital, Tartu, Estonia
3. Faculty of Medicine, University of Tartu, Tartu, Estonia
4. Neurosurgery Centre, North Estonia Medical Centre, Tallinn, Estonia