[1] Univ Belgrade, Fac Med, CCS, Clin Neurol, Belgrade, Serbia
[2] Clin Ctr Zvezdara, Dept Neurol, Belgrade, Serbia
[3] Univ Zagreb, Sch Med, Zagreb, Croatia
[4] Univ Belgrade, Inst Epidemiol, Fac Med, Belgrade, Serbia
[5] Univ Hosp Ctr Zagreb, Dept Neurol, Referral Ctr Auton Nervous Syst Disorders, Zagreb, Croatia