1. Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia
2. Department of Medicine, Geriatric Division, University of British Columbia, Vancouver, Canada
3. Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
4. Imam Abdulrahman Bin Faisal University, Dammam, Medicine Department Geriatrics Division, Dammam, Saudi Arabia
5. Ain Shams University, Geriatrics Department, Cairo, Egypt
6. King Fahad Specialist Hospital, Department of Neurology, Dammam, Saudi Arabia
7. Neurology Unit, Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia
8. School of Psychological Science & School of Population and Global Health, University of Western Australia, Perth, Australia