1 Division of Neurology, Department of Medicine, National University Hospital, Singapore.
2 Department of Medicine, National University Hospital, Singapore.
3 Yong Loo Lin School of Medicine, National University of Singapore; Department of Pathology, National University Hospital, Singapore.
4 Yong Loo Lin School of Medicine, National University of Singapore; Department of Cardiology, National University Heart Centre, Singapore.
5 Division of Neurology, Department of Medicine, National University Hospital; Yong Loo Lin School of Medicine, National University of Singapore, Singapore.