1. Division of Clinical Sciences, Health Sciences North, Northern Ontario School of Medicine University, Sudbury, ON P3E 2C6, Canada
2. Division of Neurosurgery, Health Sciences North, Northern Ontario School of Medicine University, Sudbury, ON P3E 2C6, Canada
3. Division of Neurology, Hamilton General Hospital, McMaster University, Hamilton, ON L8S 4L8, Canada
4. Department of Neurosurgery, Highly Specialized Hospital of National Importance “Garibaldi”, 95126 Catania, Italy
5. Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON M5S 1A1, Canada