1. Department of Neurosurgery, University of Süleyman Demirel, Isparta, Turkey, and Department of Neurological Surgery, University of Wisconsin, Madison, Wisconsin
2. Department of Pathology, University of Uludağ, Bursa, Turkey
3. Department of Physiology, University of Uludağ, Bursa, Turkey
4. Department of Neurosurgery, University of Uludağ, Bursa, Turkey