1. From the Division of Neurology (R.M., B.G., L.G., M.K., T.J., B.B., K.B.) and Department of Diagnostic Imaging (D.E.), University of Alberta, Edmonton, Canada; Division of Neurology, University of British Columbia, Vancouver, Canada (N.A.); Division of Neurology, University of Ottawa, Ottawa, Canada (D.D.); and Department of Clinical Neurosciences, University of Calgary, Calgary, Canada (S.B.C., M.D.H., A.M.D.).