1. Department of Neurosurgery, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
2. College of Medicine, Almothana Bin Haretha, Ar Rass, Saudi Arabia
3. Department of Medicine, Qu, Alqassim, Saudi Arabia
4. College of Medicine, King Abdulaziz University,Jeddah, Saudi Arabia
5. Department of Pathology, King Abdul-Aziz Medical City, National Guard Health Affairs, Jeddah, Saudi Arabia
6. Department of Neurosurgery, King Abdulaziz Medical City, Jeddah, Saudi Arabia.