1. From the Department of Neurology (A.S.L.N., E.K.T., L.C.S.T.), Department of Neuroradiology (Y.Y.S.), National Neuroscience Institute, Tan Tock Seng Hospital Campus, Jalan Tan Tock Seng, Singapore; Department of Clinical Research (Y.Z.), Molecular Genetics Laboratory (E.W.L.T.), Department of Clinical Research, Singapore General Hospital, Singapore.