Phase I/II Study of Safety and Preliminary Efficacy of Intravenous Allogeneic Mesenchymal Stem Cells in Chronic Stroke Michael L. Levy, MD, PhD; John R. Crawford, MD; Nabil Dib, MD; Lev Verkh, PhD; Nikolai Tankovich, MD, PhD; Steven C. Cramer, MD   Background and Purpose—Stroke is a leading cause of long-term disability. Limited treatment options exist