1. Department of Neurosurgery, Turgut Ozal University Faculty of Medicine, Emek, Ankara, Turkey.
2. Department of Neurosurgery, Ministry of Health Kirikkale Yuksek Ihtisas State Hospital, Kirikkale, Turkey.
3. Department of Pathology, Ministry of Health, Diskapi Yildirim Beyazit Education and Research Hospital, Ankara, Turkey.
4. Department of Biochemistry, Faculty of Medicine, Kirikkale University, Kirikkale, Turkey.
5. Department of Anatomy, Hacettepe University Faculty of Medicine, Ankara, Turkey.
6. Department of Anesthesiology, Turgut Ozal University Faculty of Medicine, Emek, Ankara, Turkey.