1 Department of Emergency Medicine, The Ottawa Hospital, University of Ottawa, 1053 Carling Avenue, F-Main, Room EM-206, Box 227, Ottawa, ON, Canada. dodrew@toh.ca.
2 Department of Medicine (Neurology), The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
3 The Ottawa Hospital Research Institute, Ottawa, ON, Canada.
4 Department of Emergency Medicine, The Ottawa Hospital, University of Ottawa, 1053 Carling Avenue, F-Main, Room EM-206, Box 227, Ottawa, ON, Canada.