1 Department of Neurology, National Neuroscience Institute (Tan Tock Seng Hospital campus), Singapore.
2 Department of Neurology, National Neuroscience Institute (Singapore General Hospital campus), Singapore.
3 Division of Neurology, Department of Medicine, National University Health System, Singapore.
4 Department of Neurology, National Neuroscience Institute (Tan Tock Seng Hospital campus), Singapore; Division of Neurology, Department of General Medicine, Changi General Hospital, Singapore.
5 Division of Neurology, Department of Medicine, Ng Teng Fong General Hospital, Singapore.
6 Department of General Medicine, Khoo Teck Puat Hospital, Singapore.
7 Department of Neurosurgery, National Neuroscience Institute, Singapore.
8 Department of Neuroradiology, National Neuroscience Institute, Singapore.
9 Department of Neurology, National Neuroscience Institute (Singapore General Hospital campus), Singapore; Division of Neurology, Department of General Medicine, Changi General Hospital, Singapore.
10 Department of Neurology, National Neuroscience Institute (Singapore General Hospital campus), Singapore; Department of Neurology, Sengkang General Hospital, Singapore.
11 Department of Paediatrics, Neurology Service, KK Women's and Children's Hospital, Singapore.
12 National Centre for Infectious Diseases, Tan Tock Seng Hospital, Singapore.
13 Department of Neurology, National Neuroscience Institute (Tan Tock Seng Hospital campus), Singapore. Electronic address: umapathi@nni.com.sg.