1. Department of Neurosurgery, Gazi University Faculty of Medicine, Ankara;
2. Department of Neurosurgery, Kars Harakani State Hospital, Kars;
3. Department of Radiology, Kars Harakani State Hospital, Kars; and
4. Department of Neurosurgery, University of Health Sciences, Gulhane Education and Research Hospital, Ankara, Turkey