[1] Univ Manitoba, Neurosurg Sect, Dept Surg, GB-1 820 Sherbrook St, Winnipeg, MB R3A 1R9, Canada
[2] Misericordia Hlth Ctr, Winnipeg, MB, Canada
[3] McGill, Montreal Neurol Inst, Sect Neurocrit Care, Montreal, PQ, Canada
[4] McGill, Montreal Neurol Inst, Neurol Sect, Montreal, PQ, Canada
[5] Univ Manitoba, Dept Med, Sect Crit Care Med, Winnipeg, MB R3A 1R9, Canada
[6] Univ Manitoba, Dept Surg, Sect Gen Surg, Winnipeg, MB R3A 1R9, Canada