1. King Saud medical city, Riyadh, Saudi Arabia,
2. College of Medicine, King Saud University, Riyadh, Saudi Arabia
3. College of dentistry King Saud University, Riyadh, Saudi Arabia,
4. Neuroscience Center, King Fahad Specialist Hospital, Dammam, Saudi Arabia.
5. College of Applied Medical Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.