[1] Univ Pittsburgh, Dept Neurol Surg, Pittsburgh, PA 15201 USA
[2] Univ Pittsburgh, Sch Med, Pittsburgh, PA 15201 USA
[3] Duke Univ, Med Ctr, Dept Neurosurg, Durham, NC USA
[4] Tel Aviv Sourasky Med Ctr, Dept Neurol, Tel Aviv, Israel
[5] Univ Pittsburgh, Dept Pediat, Pittsburgh, PA 15224 USA
[6] Univ Minnesota, Dept Pediat, Minneapolis, MN USA
[7] Childrens Natl Med Ctr, Div Oncol, Washington, DC USA
[8] Univ Pittsburgh, Dept Immunol, Pittsburgh, PA 15201 USA