1. Department of Clinical Neuroscience, Western General Hospital, Edinburgh, United Kingdom.
2. Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom.
3. Department of Haematology, Eastbourne District General Hospital, Eastbourne, United Kingdom.
4. Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge and Addenbrooke's Hospital, Cambridge, United Kingdom.
5. Surgery Theme, Cambridge Clinical Trials Unit, Cambridge Biomedical Campus, Cambridge, United Kingdom.