[1] Univ Calif San Francisco, San Francisco, CA 94143 USA
[2] Vanderbilt Univ, Div Pediat Neurol, 221 Kirkland Hall, Nashville, TN 37235 USA
[3] Royal Childrens Hosp, Neurol Dept, Melbourne, Vic, Australia
[4] Hosp Sick Children, Dept Pediat, Neurol Div, San Francisco, CA USA