1. From the Department of Neurology (M.S., M.V.P., D.D., T.O., J.H.U., A.S., N.P.S., P.J.B.D., C.E.R., C.J.K.), Mayo Clinic, Rochester, MN; Department of Neurology (S.S.), Rambam Health Care Clinic, Haifa, Israel; Department of Neurosurgery (R.J.S.); and Department of Laboratory Medicine and Pathology (C.J.K.), Mayo Clinic, Rochester, MN.