1. Neurology Department, King Fahad Medical City, Riyadh, Saudi Arabia
2. College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
3. Division of Neurology, King Abdulaziz Medical City (National Guard Health Affairs), Riyadh, Saudi Arabia
4. College of Medicine, King Saud University, Riyadh, Saudi Arabia
5. Division of Neurology, King Saud University Medical City, Riyadh, Saudi Arabia
6. Neurology Department, King Abdullah Bin Abdulaziz University Hospital, Riyadh, Saudi Arabia
7. Neurology Department, King Fahad Military Medical Complex Dhahran, Dammam Eastern Region, Saudi Arabia
8. Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
9. Neurology Department, King Fahad Specialist Hospital Dammam, Dammam Eastern Region, Saudi Arabia
10. Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
11. Merck KGaA, Riyadh, Saudi Arabia
12. Clinical and Biological Sciences Department, University of Torino, Orbassano, Italy