Drexel University College of Medicine, Hahnemann Campus, Philadelphia, Pennsylvania, United States
University of Vermont, Burlington, Vermont, United States
Methodist Hospital, Houston, Texas, United States
Washington Hospital Center, Washington, D.C., District of Columbia, United States
Suburban Hospital, Bethesda, Maryland, United States
National Institutes of Health Clinical Center, 9000 Rockville Pike, Bethesda, Maryland, United States
Washington Hospital Center, Washington, D.C., District of Columbia, United States
National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, Maryland, United States
National Institutes of Health Clinical Center, 9000 Rockville Pike, Bethesda, Maryland, United States
National Institutes of Health Clinical Center, 9000 Rockville Pike, Bethesda, Maryland, United States
Institute of Child Health, London, United Kingdom
National Institutes of Health Clinical Center, 9000 Rockville Pike, Bethesda, Maryland, United States
University of Minnesota, Division of Epidemiology, School of Public Health, Epidemiology Clinic Research Center, Suite 201, 1100 Washington Avenue South, Minneapolis, Minnesota, United States
University of Cincinnati, Cincinnati, Ohio, United States
University of Texas-Houston, Houston, Texas, United States
St. Louis University, St. Louis, Missouri, United States
National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, Maryland, United States