1. Department of Neurology and Neurosurgery, McGill University, Montréal, Québec;
2. Department of Medicine, Université de Montréal, Montréal, Québec;
3. Department of Surgery, Montréal General Hospital, McGill University, Montréal, Québec;
4. Division of Neurology, Hospital for Sick Children, Department of Pediatrics, University of Toronto, Ontario;
5. Division of Neurosurgery, Department of Surgery, Hospital for Sick Children, University of Toronto, Ontario, Canada;
6. Department of Neurosurgery, National Neuroscience Institute, King Fahad Medical City and College of Medicine, Alfaisal University, Riyadh, Saudi Arabia;
7. Division of Neurosurgery, Sainte Justine Hospital, Montréal, Québec, Canada; and
8. Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, California