[1] Carlos III Inst Hlth, Natl Ctr Epidemiol, Av Monforte Lemos 5, Madrid 28029, Spain
[2] Carlos III Inst Hlth, CIBERNED, Madrid 28029, Spain
[3] Alzheimer Ctr Reina Sofia Fdn, Carlos III Inst Hlth, CIEN Fdn Reina Sofia Fdn, Alzheimer Dis Res Unit, Madrid, Spain
[4] Univ Amsterdam, Acad Med Ctr, Dept Rehabil, NL-1105 AZ Amsterdam, Netherlands
[5] Univ Kansas, Med Ctr, Parkinsons Dis & Movement Disorder Ctr, Kansas City, KS 66103 USA
[6] UCL, Natl Hosp Neurol & Neurosurg, Inst Neurol, Sobell Dept Motor Neurosci & Movement Disorders, London, England
[7] Univ Penn, Sch Med, Dept Neurol, Philadelphia, PA 19104 USA
[8] Univ So Calif, Keck Sch Med, Div Movement Disorders, Los Angeles, CA 90033 USA
[9] Univ Innsbruck Hosp, Dept Neurol, A-6020 Innsbruck, Austria
[10] Lab Pharmacol Med & Clin, Toulouse, France
[11] Lisbon Sch Med, Lab Clin Pharmacol & Therapeut, Lisbon, Portugal
[12] Rush Univ, Med Ctr, Dept Neurol Serv, Chicago, IL 60612 USA
[13] UCL, Royal Free Hosp, Dept Clin Neurosci, London, England