[1] Washington Univ, Sch Med, Dept Neurosurg, St Louis, MO 63110 USA
[2] Washington Univ, Sch Med, Dept Pediat, St Louis, MO 63110 USA
[3] Washington Univ, Sch Med, Dept Otolaryngol, St Louis, MO 63110 USA
[4] Washington Univ, Sch Med, Dept Neurol, St Louis, MO 63110 USA
[5] Washington Univ, Sch Med, Dept Anat & Neurobiol, St Louis, MO 63110 USA
[6] Washington Univ, Sch Med, Dept Med, Div Oncol, St Louis, MO 63110 USA
[7] JB & Greeta B Arthur Canc Ctr, Mexico, MO USA