[1] Kings Coll Hosp London, Natl Parkinson Fdn Ctr Excellence, London, England
[2] Carlos III Inst Hlth, Alzheimers Dis Res Unit, Madrid, Spain
[3] Infanta Elena Hosp Valdemoro, Dept Neurol, Madrid, Spain
[4] Univ Hosp Lewisham, Dept Neurol, London, England
[5] Guys Kings & St Thomas Sch Med, Dept Neurosci, London, England
[6] Carlos III Inst Hlth, Natl Ctr Epidemiol, Alzheimer Dis Res Unit, Madrid, Spain
[7] Carlos III Inst Hlth, C1BERNED, Madrid, Spain
[8] Klinikum Bremerhaven Reinkenheide, Dept Neurol, Bremerhaven, Germany
[9] So Gen Hosp, Dept Med Elderly, Glasgow G51 4TF, Lanark, Scotland
[10] IRCCS San Raffaele, Dept Neurol, Rome, Italy
[11] Baylor Coll Med, Dept Neurol, Houston, TX 77030 USA
[12] Med Coll Georgia, Dept Neurol, Athens, GA USA
[13] UCL, Inst Neurol, Dept Clin Neurosci, London, England