[1] Univ Calif Los Angeles, David Geffen Sch Med, Div Pediat Neurol, Los Angeles, CA 90095 USA
[2] Univ Calif Los Angeles, David Geffen Sch Med, Dept Neurol, Los Angeles, CA 90095 USA
[3] Univ Calif Los Angeles, Mattel Childrens Hosp, 10833 Le Conte Ave, Los Angeles, CA 90095 USA
[4] Univ Colorado, Dept Neurol, Sch Med, Aurora, CO USA