1. Department of Medicine and
2. Division of Neurosurgery, Department of Surgery, University of Toronto;
3. Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto;
4. Department of Neurosurgery, Health Sciences North, Northern Ontario School of Medicine, Sudbury;
5. Division of Neurosurgery, Windsor Regional Hospital, Windsor; and
6. Division of Neuroradiology, Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada