1. Division of Neurosurgery, Department of Surgery (A.C.O.T., F.C.P.T., W.M.L.), The University of Hong Kong
2. Division of Neuroradiology, Joint Department of Medical Imaging (A.C.O.T., E.O., J.M.K., I.-H.Y., V.M.P., T.K.), Toronto Western Hospital, University of Toronto, Canada.
3. Division of Neurology, Department of Medicine (K.K.L.), The University of Hong Kong
4. Division of Neurosurgery, Department of Surgery, University Health Network (V.M.P.), Toronto Western Hospital, University of Toronto, Canada.