[1] Univ Washington, Div Pediat Neurol, Seattle, WA 98105 USA
[2] Univ Washington, Dept Anesthesiol & Pain Med, Seattle, WA 98105 USA
[3] Univ Washington, Dept Pediat, Seattle, WA 98105 USA
[4] Univ Washington, Dept Rehabil Med, Seattle, WA 98105 USA
[5] Univ Washington, Dept Epidemiol, Seattle, WA 98105 USA
[6] Univ Washington, Dept Neurol Surg, Seattle, WA 98105 USA
[7] Univ Washington, Dept Biostat, Seattle, WA 98105 USA
[8] Univ Washington, Harborview Injury Prevent & Res Ctr, Seattle, WA 98105 USA
[9] Seattle Childrens Res Inst, Seattle, WA USA
[10] Childrens Hosp Philadelphia, Div Emergency Med, Philadelphia, PA 19104 USA
[11] Mary Bridge Childrens Hosp, Div Pediat Psychol, Tacoma, WA USA