[1] Univ British Columbia, Dept Med, Div Neurol, Vancouver, BC, Canada
[2] BC Childrens & Womens Hosp, Vancouver, BC, Canada
[3] BC Childrens Hosp, Vancouver, BC, Canada
[4] BC Childrens Hosp, Dept Procedure & Surg Serv, Vancouver, BC, Canada
[5] Dalhousie Univ, Dept Pediat, Halifax, NS, Canada
[6] IWK Hlth Ctr, Ctr Pediat Pain Res, Halifax, NS, Canada