[1] Carlos III Inst Hlth, Natl Ctr Epidemiol, Madrid 28029, Spain
[2] Carlos III Inst Hlth, CIBERNED, Madrid 28029, Spain
[3] Konan Womens Univ, Dept Neurol & Rehabil, Kobe, Hyogo, Japan
[4] Burdwan Med Coll & Hosp, Bangur Inst Neurosci & Psychiat, Dept Neuromed, Kolkata, W Bengal, India
[5] Radboud Univ Nijmegen, Med Ctr, Donders Inst Brain Cognit & Behav, Dept Neurol, NL-6525 ED Nijmegen, Netherlands
[6] Sarah Hosp, Dept Neurol, Brasilia, DF, Brazil
[7] Med Coll Georgia, Dept Neurol, Augusta, GA 30912 USA
[8] Transilvania Univ, Dept Neurol, Brasov, Romania
[9] Hosp Domingo Dr Luciani, Movement Disorders Unit, Caracas, Venezuela
[10] Hosp Univ Virgen Rocio CSIC U Sevilla, Inst Biomed Sevilla, Dept Neurol, Movement Disorders Unit, Seville, Spain
[11] Univ Hosp, Dept Neurol, London, England
[12] Univ Catania, Dept Neurosci, I-95124 Catania, Italy
[13] Fukuoka Univ Hosp, Dept Neurol, Fukuoka, Japan
[14] Leiden Univ, Med Ctr, Dept Neurol, NL-2300 RA Leiden, Netherlands
[15] Kings Coll Hosp London, Natl Parkinson Fdn Ctr Excellence, London, England