[1] UCL Inst Neurol, Stroke Res Grp, London WC1N 3BG, England
[2] Natl Hosp Neurol & Neurosurg, London WC1N 3BG, England
[3] UCL Inst Neurol, Biomed Res Ctr, London WC1N 3BG, England
[4] UCL Inst Neurol, Educ Unit, London WC1N 3BG, England
[5] Clin Univ UCL St Luc, Dept Neurol, Brussels, Belgium
[6] Catholic Univ Louvain, CHU Mt Godinne, Dept Neurol, B-1200 Brussels, Belgium
[7] Catholic Univ Louvain, Inst Neurosci, B-1200 Brussels, Belgium
[8] Univ Cambridge, Addenbrookes Hosp, Dept Clin Neurosci, Cambridge CB2 2QQ, England
[9] Univ Paris 05, UMR INSERM 894, Paris, France
[10] UCL Inst Neurol, Lysholm Dept Neuroradiol, London WC1N 3BG, England
[11] UCL Inst Neurol, Dept Brain Repair & Rehabil, London WC1N 3BG, England