Department of Neurological Surgery, University of California, Irvine, Irvine, CA. Department of Neurological Surgery, University of California, Los Angeles, CA. John A. Burns School of Medicine, University of Hawaii, Honolulu HI. Department of Biomedical Engineering, Johns Hopkins Whiting School of Engineering, Baltimore, MD. Electronic address: jgendre1@jhu.edu. Keck School of Medicine of USC, Los Angeles, CA; Medical Scientist Training Program, California Institute of Technology, Pasadena, CA. Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL. Kentucky College of Osteopathic Medicine, University of Pikeville, Pikeville, KY. Department of Neuroscience, University of Pittsburgh, PA. Department of Neurological Surgery, University of California, San Diego, La Jolla, California.