[1] Natl Univ Singapore, Dept Microbiol, Singapore 117597, Singapore
[2] Natl Univ Singapore, Dept Med, Singapore 117597, Singapore
[3] Dokkyo Med Univ, Dept Neurol, Mibu, Tochigi, Japan
[4] Chiba Univ, Dept Neurol, Grad Sch Med, Chiba, Japan
[5] Univ G DAnnunzio, Dept Neurosci & Imaging, Chieti, Italy
[6] Neuroctr So Switzerland EOC, Lugano, Switzerland