Authors:Michael Farrell, Georgetown UniversityBarbara I. Karp, National Institutes of Neurological Disorders and StrokePanagiotis Kassavetis, National Institutes of Neurological Disorders and StrokeWilliam Berrigan, Emory UniversitySimge Yonter, National Institutes of HealthDebra Ehrlich, National Institutes of Neurological Disorders and StrokeKatherine E. Alter, National Institutes of Health