[1] Vanderbilt Univ, Med Ctr, Dept Pediat, Div Pediat Neurol, Nashville, TN 37232 USA
[2] Univ Calif San Francisco, Dept Neurol, San Francisco, CA 94143 USA
[3] Univ Calif San Francisco, Dept Biostat & Epidemiol, San Francisco, CA 94143 USA
[4] Univ Calif San Francisco, Dept Pediat, San Francisco, CA 94143 USA
[5] Childrens Hosp Philadelphia, Dept Neurol, Philadelphia, PA 19104 USA
[6] Childrens Natl Med Ctr, Dept Neurol, 111 Michigan Ave NW, Washington, DC 20010 USA
[7] Hosp Sick Children, Dept Neurol, Toronto, ON, Canada
[8] Nationwide Childrens Hosp, Dept Neurol, Columbus, OH USA