1. Institute of Neurology; NMR Unit; Queen Square London UK WC1N 3BG
2. Queen Mary University of London; Forensic Psychiatry Research Unit; 61 Bartholomew Close St Bartholomew's Hospital, William Harvey House London UK EC1A 7BE
3. National Hospital for Neurology and Neurosurgery; Department of Neurology and MRC Centre for Neuromuscular Diseases; Queen Square London UK WC1N 3BG
4. University of Utah School of Medicine; 30 North 1900 East, SOM 3R242 Salt Lake City Utah USA UT 84132