[1] Univ Hlth Network, Toronto Western Hosp, Dept Anesthesia, Toronto, ON, Canada
[2] Univ Hlth Network, Stroke Program, Dept Neurol, Toronto, ON, Canada
[3] Univ Hlth Network, Dept Med Imaging, Div Neuroradiol, Toronto, ON, Canada
[4] Univ Hlth Network, Dept Surg, Div Neurosurg, Toronto, ON, Canada
[5] Univ Hlth Network, Div Cardiol, Toronto, ON, Canada
[6] Western Univ, Schulich Sch Med & Dent, Dept Anesthesia & Perioperat Med, London, ON, Canada