1. Department of Neurosurgery, Jena University Hospital, Jena, Germany;
2. Department of Clinical Neuroscience, Western General Hospital, NHS Lothian, Edinburgh;
3. Usher Institute, University of Edinburgh;
4. Department of Neurosurgery, Wessex Neurological Centre, Southampton General Hospital, University Hospital Southampton NHS Foundation Trust, Southampton;
5. Department of Neurosurgery, Royal Preston Hospital, Lancashire Teaching Hospitals NHS Foundation Trust, Preston;
6. Department of Neurosurgery, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne;
7. Department of Neurosurgery, Derriford Hospital, University Hospitals Plymouth NHS Trust, Plymouth;
8. Department of Neurosurgery, Southmead Hospital, North Bristol NHS Trust, Bristol; and
9. Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, United Kingdom