[1] Royal Cornwall Hosp Trust, Res & Dev Unit Neurol, Truro TR1 3HD, England
[2] Kings Coll London, Kings Coll Hosp, Parkinsons Fdn Ctr Excellence, London WC2R 2LS, England
[3] Kings Coll London, Inst Psychiat Psychol & Neurosci, NIHR Biomed Res Ctr, London WC2R 2LS, England
[4] Univ Plymouth, Fac Hlth, Plymouth PL6 8BX, Devon, England
[5] Univ Lincoln, Lincoln Cty Hosp, Lincoln LN2 5QY, England
[6] Newcastle Univ, Clin Ageing Res Unit, Newcastle Upon Tyne NE4 5PL, Tyne & Wear, England
[7] Nottingham Univ NHS Trust, Dept Neurol, Nottingham NG7 2UH, England
[8] Natl Hosp Neurol & Neurosurg, Unit Funct Neurosurg, London WC1N 3BG, England
[9] Univ Dresden, Dept Neurol, D-01069 Dresden, Germany
[10] BIAL Pharma UK Ltd, Med Affairs Dept, Windsor SL4 3BL, England
[11] BIAL Portela & CaSA, P-4745457 Coronado, Portugal
[12] Univ Porto, Ctr Drug Discovery & Innovat Med, MedInUP, P-4099002 Porto, Portugal
[13] UCL, Reta Lila Weston Inst & Natl Hosp, Queen Sq, London WC1N 1PJ, England