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