1 Department of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK. piri.anant@ucl.ac.uk.
2 Department of Neuroinflammation, Institute of Neurology, University College London, 1st Floor, Russell Square House, 10-12 Russell Square, London, WC1B 5EH, UK. piri.anant@ucl.ac.uk.
3 Department of Neurology, Queen's Hospital, Romford, Essex, UK.
4 Department of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.