3 Department of Neuromuscular Diseases, University College London, London, UK.
4 Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK.
5 Department of Radiology & Nuclear Medicine, Amsterdam UMC, Amsterdam, Netherlands.
6 Charles Dent Metabolic Unit, University College London Hospitals NHS Foundation Trust National Hospital for Neurology and Neurosurgery, London, UK.
7 National Institute for Health Research, University College London Hospitals, Biomedical Research Centre, London, UK.
8 Department of Neuromuscular Diseases, University College London, London, UK david.lynch.13@ucl.ac.uk.