1. Department of Neurosurgery, King Faisal Specialist Hospital and Research Centre,
2. Department of Neurosurgery, King Abdulaziz Medical City, Ministry of National Guard – Health Affairs,
3. Departments of Otolaryngology, King Khalid University Hospital, King Saud University, Riyadh, Central Province, Saudi Arabia.
4. Departments of Neurosurgery, King Khalid University Hospital, King Saud University, Riyadh, Central Province, Saudi Arabia.