[1] Washington Univ, Sch Med, Dept Neurol, St Louis, MO 63110 USA
[2] Washington Univ, Sch Med, Dept Radiol, St Louis, MO 63110 USA
[3] Childrens Hosp Philadelphia, Div Oncol, Philadelphia, PA 19104 USA
[4] Childrens Natl Med Ctr, Ctr Neurosci Behav Med, Washington, DC 20010 USA
[5] Northwestern Univ, Ann & Robert H Lurie Childrens Hosp Chicago, Feinberg Sch Med, Div Acad Gen Pediat, Evanston, IL 60208 USA
[6] Univ Penn, Dept Pediat, Perelman Sch Med, Philadelphia, PA 19104 USA