1 Birmingham Neuro-Ophthalmology (SPM), Queen Elizabeth Hospital, Birmingham, United Kingdom; Cancer Research UK Clinical Trials Unit (CRCTU) (VH, SG, KB), University of Birmingham, Birmingham, United Kingdom; Metabolic Neurology (AJS), Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom; Centre for Endocrinology (AJS), Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom; and Department of Neurology (AJS), Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom.