1 Department of Pediatrics (Neurology), Hospital for Sick Children, Division of Neurosciences and Mental Health, SickKids Research Institute, University of Toronto, Canada. Electronic address: ann.yeh@sickkids.ca.
2 Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
3 Dept of Neurology, John Hunter Hospital, University Newcastle, UK.
4 Department of Neurology, Massachusetts General Hospital and Harvard Medical School, USA.