[1] Univ Colorado, Dept Pediat, Sect Neurol, Anschutz Sch Med, Aurora, CO 80045 USA
[2] Univ Colorado, Dept Pediat, Anschutz Sch Med, Aurora, CO USA
[3] Univ Colorado, Sect Emergency Med, Anschutz Sch Med, Aurora, CO USA
[4] Univ Penn Perelman Sch Med, Dept Pediat & Neurol, Philadelphia, PA USA