1. Division of Neurosurgery, Department of Surgery, King Saud University, Riyadh, Riyadh Province, Saudi Arabia
2. Neurosurgery Department, Stanford University, Stanford, California, United States
3. Department of Otolaryngology-Head and Neck Surgery, College of Medicine, King Saud University, Riyadh, Saudi Arabia
4. Department of Pathology, College of Medicine, King Saud University, Riyadh, Saudi Arabia