1. Division of Neurological Surgery, Neurosciences Department, King Faisal Specialist Hospital and Research Center, P.O. Box 3354, Riyadh 11211, Saudi Arabia
2. College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
3. Department of Otolaryngology, King Faisal Specialist Hospital and Research Center, P.O. Box 3354, Riyadh 11211, Saudi Arabia