1. Division of Rhinology, Department of Otolaryngology–Head and Neck Surgery, School of Medicine, Stanford University, Stanford, California, USA
2. Department of Otolaryngology–Head and Neck Surgery, Faculty of Medicine, Mansoura University, Mansoura, Egypt
3. Department of Diagnostic and Interventional Radiology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
4. Department of Neurosurgery, Faculty of Medicine, Mansoura University, Mansoura, Egypt
5. Department of Neurosurgery, Prince Mohamed Bin Abdul-Aziz Hospital, Riyadh, Saudi Arabia