1. Department of Neurosurgery, Faculty of Medicine, Canakkale 18 March University, Canakkale;
2. Departments of Neurosurgery and
3. Department of Neurosurgery, Pendik State Hospital, Istanbul; and
4. Anesthesiology, VKV American Hospital, Istanbul;
5. Department of Orthopedics, Faculty of Medicine, Kocatepe University, Afyonkarahisar, Turkey