[1] Kings Coll Hosp NHS Fdn Trust, Dept Neurol, London, England
[2] Queen Elizabeth Hosp Woolwich Lewisham & Greenwic, London, England
[3] Univ Milan, IRCCS Fdn Ca Granda Osped Maggiore Policlin, Dino Ferrari Ctr, Neurosci Sect,Dept Pathophysiol & Transplantat, Milan, Italy
[4] Kings Coll Hosp NHS Fdn Trust, Dept Neuroradiol, London, England