1. Departments of Emergency Medicine (K.S.Z), Massachusetts General Hospital, Boston.
2. Neurology (L.H.S.), Massachusetts General Hospital, Boston.
3. Duke Clinical Research Institute (H.X., R.M.), Duke University School of Medicine, Durham, NC.
4. Departments of Neurology (S.S.), Duke University School of Medicine, Durham, NC.
5. Department of Neurology, University of Calgary, AB (E.E.S.).
6. Medicine (Y.X.), Duke University School of Medicine, Durham, NC.
7. Division of Cardiology (G.C.F.), University of California Los Angeles.
8. Department of Neurology (J.S.), University of California Los Angeles.