1 From the National Institute of Neurological Disorders and Stroke (N.F.S.), National Institute of Health, Bethesda, MD; and School of Medicine (A.B.), University of California, Davis, Sacramento. nina.schor@nih.gov.
2 From the National Institute of Neurological Disorders and Stroke (N.F.S.), National Institute of Health, Bethesda, MD; and School of Medicine (A.B.), University of California, Davis, Sacramento.