1. Division of Neurosurgery, Surgery Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
2. Division of Neurosurgery, Surgery Department, Security Forces Hospital, Riyadh, Saudi Arabia
3. Department of Neurosurgery, King Abdulaziz Specialist Hospital, Taif, Saudi Arabia
4. Department of Otorhinolaryngology – Head & Neck Surgery, College of Medicine, King Saud University, Riyadh, Saudi Arabia
5. Department of Otorhinolaryngology – Head & Neck Surgery, The James Cancer Hospital, Wexner Medical Center, The Ohio State University, Columbus, Ohio, United States