1. From the Department of Neurology, University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh (J.J.L.); and the Departments of Radiology (O.R.), Neurology (M.A.W.), and Pathology (M.M.-L.), Massachusetts General Hospital, and the Departments of Radiology (O.R.), Neurology (M.A.W.), and Pathology (M.M.-L.), Harvard Medical School — both in Boston.