1. From the Department of Neurology, McLean Hospital, Belmont, MA (B.H.P.); and the Departments of Neurology (B.H.P., D.L.P.), Psychiatry (D.L.P.), Radiology (O.R.), and Pathology (D.H.O.), Massachusetts General Hospital, and the Departments of Neurology (B.H.P., D.L.P.), Radiology (O.R.), and Pathology (D.H.O.), Harvard Medical School — both in Boston.