[1] King Saud Univ, Coll Med, King Khalid Univ Hosp, Neurol Sect, Riyadh 11461, Saudi Arabia
[2] King Saud Bin Abdulaziz Univ Hlth Sci, King Abdullah Int Med Res Ctr, Riyadh, Saudi Arabia
[3] King Faisal Specialist Hosp & Res Ctr, Dept Neurosci, Riyadh 11211, Saudi Arabia
[4] Kuwait Univ, Fac Med, Dept Med, Div Neurol, Kuwait, Kuwait
[5] Neurol Unit, Manama, Bahrain
[6] Arab Med Ctr, Dept Neurol, Amman, Jordan
[7] Cairo Univ, Fac Med, Dept Med, Cairo, Egypt
[8] Amer Univ Beirut Med Ctr, Div Neurol, Dept Internal Med, Beirut, Lebanon