1. Neurology Section, Department of Medicine, King Abdulaziz Medical City, Jeddah, Saudi Arabia
2. Research Office, King Abdullah International Medical Research Center, Jeddah, Saudi Arabia
3. College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
4. Department of Neuroscience, King Faisal Specialist Hospital & Research Centre, Jeddah, Saudi Arabia
5. Division of Neurology, University of Alberta, Alberta, Canada