1. UCL Institute of Neurology, University College London, London, UK
2. Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
3. Department of Neurology, Guy’s and St Thomas’ NHS Foundation Trust, London, UK
4. Department of Clinical Neuroscience, King’s College London, London, UK
5. Wessex Neurological Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK