[1] Univ Hosp North Staffordshire, Neurol Res Dept, Stoke On Trent, Staffs, England
[2] Keele Univ, Keele ST5 5BG, Staffs, England
[3] Cent Manchester Univ Hosp, Manchester, Lancs, England
[4] Bilim Univ, Dept Neurol, Istanbul, Turkey
[5] King Faisal Specialist Hosp & Res Ctr, Dept Neurosci, Saudi Neurol Soc, Riyadh 11211, Saudi Arabia
[6] Shiraz Univ Med Sci, Ctr Hlth Policy Res, Shiraz, Iran
[7] Shiraz Univ Med Sci, Dept Neurol, Shiraz, Iran
[8] Univ Nottingham, Queens Med Ctr, Acad Div Clin Neurol, Nottingham NG7 2RD, England
[9] Univ El Manar 2 Tunis, Fac Med Tunis, Hosp La Rabta, Dept Internal Med, Tunis, Tunisia
[10] Univ Paris 07, Dept Internal Med, Hosp St Louis, Paris, France
[11] IRCCS Reggio Emilia, Azienda Osped, Dept Internal Med, Rheumatol Unit, I-42123 Reggio Emilia, Italy
[12] Univ Athens, Sch Med, Dept Propedeut Internal Med 1, GR-11527 Athens, Greece
[13] Istanbul Univ, Dept Neurol, Istanbul, Turkey