[1] Univ Washington, Dept Neurol Surg, Seattle, WA 98104 USA
[2] Santa Clara Univ, Sch Engn, Santa Clara, CA USA
[3] Baylor Coll Med, Dept Neurosurg, Houston, TX USA
[4] Baylor Coll Med, Dept Otolaryngol Head & Neck Surg, Houston, TX USA
[5] Texas Childrens Hosp, Jan & Dan Duncan Neurol Res Inst, Houston, TX USA
[6] Seattle Childrens Hosp, Div Neurosurg, Seattle, WA USA
[7] Puget Sound Vet Affairs Hosp, Neurosurg, Seattle, WA 98108 USA