[1] Cairo Univ, Sch Med, Dept Rheumatol & Rehabil, Cairo, Egypt
[2] Stanford Univ, Stanford Headache Ctr, Ctr Innovat Global Hlth, Dept Neurol & Neurol Sci,Sch Med, Stanford, CA USA
[3] Cairo Univ, Kasr Alainy Sch Med, Dept Rheumatol & Rehabil, Al Saray St, Cairo 11956, Egypt