[1] Univ British Columbia, Div Neurol, BC Canc, Vancouver, BC, Canada
[2] Univ Texas MD Anderson Canc Ctr, Dept Palliat Care Rehabil & Integrat Med, Houston, TX USA
[3] Univ Maryland, Dept Neurol, Sch Med, Baltimore, MD USA
[4] Univ Texas MD Anderson Canc Ctr, Dept Neurooncol, Houston, TX USA
[5] Univ Texas MD Anderson Canc Ctr, Dept Biostat, Houston, TX USA