[1] Natl Hosp Neurol & Neurosurg, Lysholm Dept Neuroradiol, Queen Sq, London WC1N 3BG, England
[2] Natl Hosp Neurol & Neurosurg, Victor Horsley Dept Neurosurg, Queen Sq, London WC1N 3BG, England
[3] Natl Hosp Neurol & Neurosurg, Dept Neurol, Queen Sq, London WC1N 3BG, England
[4] Natl Hosp Neurol & Neurosurg, Dept Neurooncol, Queen Sq, London WC1N 3BG, England
[5] Natl Hosp Neurol & Neurosurg, Dept Neurodegenerat Dis, London WC1N 3BG, England
[6] UCL, Div Neuropathol, Inst Neurol, London WC1N 3BG, England
[7] UCL, Inst Neurol, Neuroradiol Acad Unit, Dept Brain Rehabil & Repair, Queen Sq, London WC1N 3BG, England
[8] Univ Coll Hosp, Imaging Dept, London WC1N 3BG, England