1 Keck School of Medicine at the University of Southern California, Los Angeles, California.
2 Division of Neurology, Children's Hospital Los Angeles, Los Angeles, California; Department of Neurology, Keck School of Medicine at the University of Southern California, Los Angeles, California.
3 Division of Neurology, Children's Hospital Los Angeles, Los Angeles, California.
4 Division of Neurology, Children's Hospital Los Angeles, Los Angeles, California; Department of Neurology, Keck School of Medicine at the University of Southern California, Los Angeles, California. Electronic address: santoroj@usc.edu.