1. School of Clinical Medicine, University of Cambridge, Cambridge, UK
2. Department of Clinical Neurosciences, Division of Neurosurgery, Addenbrooke’s Hospital, University of Cambridge, Cambridge, UK
3. Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
4. Myelopathy.org, Cambridge, UK
5. Department of Clinical Neurosciences, Neurology Unit, University of Cambridge, Cambridge, UK