1. Department of Internal Medicine, Prince Sattam Bin Abdulaziz University, College of Medicine, Al-Kharj, Kingdom of Saudi Arabia
2. Neurology Department, Faculty of Medicine, Minia University, Minia, Egypt
3. Department of Medicine, College of Medicine, Al Imam Mohammed Ibn Saud Islamic University, Riyadh, Saudi Arabia
4. Division of Musculoskeletal Radiology, Department of Radiology, University of Michigan, Ann Arbor, MI
5. Neurosurgery Department, Faculty of Medicine, Minia University, Minia, Egypt.