From the Department of Neurology (D.S.K., P.V., B.J.B., R.C.P.), Mayo Clinic Alzheimer's Disease Research Center (D.S.K., C.R.J., R.J.I., B.J.B., R.C.P.), Department of Radiology (C.R.J., V.L., K.K., J.L.G., M.L.S.), Department of Health Sciences Research (H.J.W., S.D.W.), Department of Psychiatry and Psychology (R.J.I.), Division of Epidemiology, Department of Health Sciences Research (R.O.R., R.C.P.), Mayo Clinic and Foundation, Rochester, MN. (At 2012-05-15)