Kongkiat Kulkantrakorn1,2, Tumtip Sangruchi3. 1. Division of Neurology, Department of Internal Medicine, Faculty of Medicine, Thammasat University, Pathumthani, Thailand. 2. Neuroscience Center, Bangkok Hospital Medical Center, Bangkok Hospital Group, Bangkok, Thailand. 3. Department of Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.