Case records of the Massachusetts General Hospital. Case 12-2009. A 46-year-old man with migraine, aphasia, and hemiparesis and similarly affected family members.

From the Departments of Neurology (S.D.B.), Radiology (W.A.C.), and Pathology (M.P.F.), Massachusetts General Hospital, Boston; the Department of Neurology, Foothills Hospital, and the Department of Clinical Neurosciences, University of Calgary — both in Calgary, AB, Canada (E.E.S.); and the Departments of Neurology (S.D.B.), Cell Biology (J.F.A.-V.), Radiology (W.A.C.), and Pathology (M.P.F.), Harvard Medical School, Boston.