1. Department of Neurological Sciences, Division of Neurosurgery, Università degli Studi di Napoli Federico II, Naples, Italy
2. Department of Neurosurgery, Faculty of Medicine, Istanbul University, Istanbul, Turkey
3. Department of Neurosurgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
4. Microsurgical and Endoscopic Anatomy Study Group, Center of Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria