Steven M Greenberg1, Eric E Smith2. 1. From Massachusetts General Hospital Stroke Research Center and Harvard Medical School (S.M.G.), Boston, MA; and Department of Clinical Neurosciences and Hotchkiss Brain Institute (E.E.S.), University of Calgary, Canada. sgreenberg@partners.org. 2. From Massachusetts General Hospital Stroke Research Center and Harvard Medical School (S.M.G.), Boston, MA; and Department of Clinical Neurosciences and Hotchkiss Brain Institute (E.E.S.), University of Calgary, Canada.