Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 1 E Kent Ridge Road, Singapore, 119228, Singapore. Department of Medicine, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore. Department of Neurology, Detroit Medical Centre, Detroit, MI, USA. Department of Cardiology, National University Heart Centre, Singapore, Singapore. Department of Neurology, National Neuroscience Institute, Singapore, Singapore. Division of Neurology, Department of Medicine, National University Health System, Singapore, Singapore. Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 1 E Kent Ridge Road, Singapore, 119228, Singapore. benjamin_yq_tan@nuhs.edu.sg. Division of Neurology, Department of Medicine, National University Health System, Singapore, Singapore. benjamin_yq_tan@nuhs.edu.sg.