[1] Kings Coll London, Kings Coll Hosp, Natl Parkinson Fdn, Ctr Excellence, London SE5 9RS, England
[2] Cent Hosp, Dept Neurol, Bremerhaven, Germany
[3] Univ Hosp, Dept Neurol, Lund, Sweden
[4] Venice & Univ Padua, IRCCS San Camillo, Padua, Italy
[5] Alzheimer Ctr Reina Sofia Fdn, AD Res Unit, Madrid, Spain
[6] Alzheimer Ctr Reina Sofia Fdn, CIBERNED, CIEN Fdn, Carlos III Inst Hlth, Madrid, Spain