1. Department of Internal Medicine, College of Medicine, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
2. Department of Neuroscience, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
3. Department of neuroscience, King Fahd Military Medical Complex, Dhahran, Saudi Arabia
4. Departmentof Family Medicine, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia