[1] Univ British Columbia, Dept Med, Div Neurol, Vancouver, BC, Canada
[2] BC Childrens Hosp, Ambulatory Care Bldg,K3-179,4480 Oak St, Vancouver, BC V6H 3V4, Canada
[3] Univ British Columbia, Dept Pediat, Div Emergency Med, Vancouver, BC, Canada
[4] Univ British Columbia, Dept Pediat, Div Pediat Neurol, Vancouver, BC, Canada