S W Cheo1, Q J Low2, Y A Tan3, Y K Chia4. 1. Department of Internal Medicine, Hospital Lahad Datu, Peti Bersurat 60065, Lahad Datu, Sabah 91110, Malaysia. 2. Department of Internal Medicine, Hospital Sultanah Nora Ismail, Jalan Korma, Taman Soga, Batu Pahat, Johor 83000, Malaysia. 3. Department of Internal Medicine, Hospital Queen Elizabeth, Kota Kinabalu, Sabah 88200, Malaysia. 4. Neurology Unit, Department of Internal Medicine, Hospital Queen Elizabeth, Kota Kinabalu, Sabah 88200, Malaysia.