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