1. Department of Neurosurgery, Ministry of Health, Training and Research Hospital, Kayseri, Turkey.
2. Department of Neurosurgery, Çankırı State Hospital, Çankırı, Turkey.
3. Department of Neurosurgery, Gazi University Faculty of Medicine, Ankara, Turkey.
4. Department of Histology and Embryology, Hacettepe University Faculty of Medicine, Ankara, Turkey.