1. Department of Adult Neurosurgery, National Neuroscience Institute, King Fahed Medical City, Riyadh, Saudi Arabia,
2. Division of Neurosurgery, Department of Surgery, King Abdulaziz Medical City, Ministry of the National Guard - Health Affairs, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia,
3. Department of Neurosciences, Division of Neurosurgery, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.