[1] Univ British Columbia, Dept Med, Div Neurol, Vancouver, BC, Canada
[2] Univ British Columbia, Fac Med, Dept Surg, Div Neurosurg, Vancouver, BC, Canada
[3] BC Childrens Hosp, Dept Pediat, Div Neurol, Vancouver, BC, Canada
[4] Univ British Columbia, Fac Pharmaceut Sci, Vancouver, BC, Canada
[5] St Pauls Hosp, Ctr Hlth Evaluat & Outcome Sci, Vancouver, BC, Canada
[6] Hosp Sick Children, Div Neurosurg, Toronto, ON, Canada
[7] Toronto Western Hosp, Toronto, ON, Canada
[8] Vanderbilt Univ, Med Ctr, Dept Neurosurg, Nashville, TN USA
[9] Univ Calif San Francisco, Memory & Aging Ctr, Dept Neurol, Weill Inst Neurosci, San Francisco, CA 94143 USA
[10] Simon Fraser Univ, Behav & Cognit Neurosci Inst, Burnaby, BC, Canada