1 Preventive Neurology Unit, Queen Mary University of London, London E1 4NS, UK.
2 Barts Health NHS Trust, The Royal London Hospital, London, UK.
3 Preventive Neurology Unit, Queen Mary University of London, London E1 4NS, UK; Barts Health NHS Trust, The Royal London Hospital, London, UK. Electronic address: a.noyce@qmul.ac.uk.