[1] NINDS, Clin Trials Unit, Off Clin Director, NIH, Bldg 36,Rm 4D04, Bethesda, MD 20892 USA
[2] DINOGMI Univ Genoa, Genoa, Italy
[3] Imperial Coll London, Charing Cross Hosp, Dept Neurol, London, England
[4] Nottingham Univ Hosp NHS Trust, Dept Neurol, Nottingham, England
[5] Univ Hosp 12 Octubre, Dept Neurol, Madrid, Spain
[6] Ctr Invest Biomed Red Enfermedades Neurodegenerat, Madrid, Spain
[7] Univ Complutense, Dept Med, Madrid, Spain
[8] UCL, Inst Neurol, Sobell Dept Movement Neurosci, Queen Sq, London, England
[9] Univ Kiel, Dept Neurol, Kiel, Germany
[10] Carlos III Inst Hlth, Natl Sch Publ Hlth, Madrid, Spain
[11] Carlos III Inst Hlth, Red Invest Serv Sanitarios & Enfermedades Cron RE, Madrid, Spain
[12] NINDS, Human Motor Control Sect, NIH, Bldg 36,Rm 4D04, Bethesda, MD 20892 USA
[13] Yale Sch Med, Dept Neurol, New Haven, CT USA
[14] Yale Sch Med, Dept Chron Dis Epidemiol, New Haven, CT USA
[15] Yale Univ, Yale Sch Publ Hlth, New Haven, CT USA
[16] Univ Kansas, Med Ctr, Kansas City, KS 66103 USA
[17] Univ Ottawa, Parkinsons Dis & Movement Disorders Ctr, Ottawa Brain & Mind Res Inst, Div Neurol,Dept Med,Ottawa Hosp,Res Inst, Ottawa, ON, Canada
[18] Univ Athens, Dept Dept, GR-10679 Athens, Greece
[19] Philipps Univ, Dept Neurol, Marburg, Germany
[20] Singapore Gen Hosp, Duke NUS Med Sch, Dept Neurol, Natl Inst Neurosci, SGH Campus, Singapore, Singapore
[21] Virginia Commonwealth Univ, Parkinsons & Movement Disorders Ctr, Richmond, VA USA
[22] Southern Illinois Univ, Sch Med, Dept Neurol, Springfield, IL USA