1 Department of Pediatric Neurology (Z.L.), 2nd Faculty of Medicine, Charles University in Prague, University Hospital Motol, Prague, Czech Republic; Division of Neurology (O.M., B.M., E.A.Y.), Division of Pathology (W.H.), and Division of Neuroradiology (H.B.), Hospital for Sick Children, Toronto, Ontario, Canada; and Department of Pediatrics (O.M., B.M., E.A.Y.), Department of Internal Medicine (J.T.), Department of Laboratory Medicine & Pathobiology (W.H.), and Department of Medical Imaging (H.B.), University of Toronto, Ontario, Canada.