1 From the Queen Square MS Centre (Y.H.), UCL Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London; Department of Neurology (Y.H.), Great Ormond Street Hospital for Children, London, UK; Department of Neurology (W.K.), David Geffen School of Medicine at UCLA, Los Angeles, CA; and Nuffield Department of Clinical Neurosciences (P.W.), John Radcliffe Hospital, Oxford, UK. y.hacohen@ucl.ac.uk.
2 From the Queen Square MS Centre (Y.H.), UCL Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London; Department of Neurology (Y.H.), Great Ormond Street Hospital for Children, London, UK; Department of Neurology (W.K.), David Geffen School of Medicine at UCLA, Los Angeles, CA; and Nuffield Department of Clinical Neurosciences (P.W.), John Radcliffe Hospital, Oxford, UK.