1. Interventional Neuroradiology, The Ottawa Hospital—Ottawa Hospital Research Institute and University of Ottawa, Ottawa, Ontario, Canada
2. Division of Neurosurgery, Department of Surgery, St Michael's Hospital, University of Toronto, Toronto, ON, Canada
3. Division of Neurosurgery, Department of Surgery, The Ottawa Hospital—Ottawa Hospital Research Institute and University of Ottawa, Ottawa, Ontario, Canada
4. Division of Neurology, Department of Medicine, The Ottawa Hospital—Ottawa Hospital Research Institute and University of Ottawa, Ottawa, Ontario, Canada