1 Neuroimmunology Group (SR), Institute for Neuroscience and Muscle Research, The Kids Research Institute at the Children's Hospital at Westmead, Sydney Medical School, University of Sydney, Sydney, Australia; Department of Neurology (SR, VSCF), Westmead Hospital, Sydney, Australia; A.B.Surgery (AB), Kempsey, Australia; Brain and Mind Research Institution (LM, MEB), University of Sydney, Sydney, Australia; Department of Nuclear Medicine (RRR), Concord Hospital, Concord, Australia; Department of Neuropathology (MEB), Royal Prince Alfred Hospital, Camperdown, Australia; Australian National Creutzfeldt-Jakob Disease Registry (SS, GMJAK, SC), Department of Pathology, The University of Melbourne, Parkville, Australia; and Department of Neurology (SWR), Concord Repatriation General Hospital, Concord, Australia.