[1] Univ Coll London Hosp NHS Fdn Trust, Natl Hosp Neurol & Neurosurg, Comprehens Stroke Serv, London, England
[2] Univ Coll London Hosp NHS Fdn Trust, Dept Haematol, London, England
[3] UCL Queen Sq Inst Neurol, Stroke Res Ctr, London, England
[4] Sandwell & West Birmingham Hosp NHS Trust, Stroke Serv, Birmingham, W Midlands, England
[5] UCL Queen Sq Inst Neurol, Acad Neuroradiol Unit, London, England