1. Division of Genetics and Development, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada.
2. Division of Neurosurgery and Spine Program, Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
3. Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
4. Division of Neurosurgery, Walter Reed National Military Medical Center, Bethesda, Maryland, USA.
5. Department of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
6. Department of Neurosurgery, Houston Methodist Hospital, Houston, Texas, USA.
7. Neurological Surgery and the Miami Project to Cure Paralysis, University of Miami, Miami, Florida, USA.