[1] Natl Univ Singapore, Yong Loo Lin Sch Med, Singapore, Singapore
[2] Univ Auckland, Fac Med & Hlth Sci, Auckland, New Zealand
[3] Natl Univ Singapore Hosp, Dept Diagnost Imaging, Singapore, Singapore
[4] Singapore Gen Hosp, Dept Otorhinolaryngol Head & Neck Surg, Singapore, Singapore
[5] Natl Univ Hlth Syst, Alexandra Hosp, Dept Med, Singapore, Singapore
[6] Natl Univ Hlth Syst, Alexandra Hosp, Dept Med, Div Geriatr Med, Singapore, Singapore
[7] Natl Univ Hlth Syst, Natl Univ Hosp, Dept Med, Div Neurol, Singapore, Singapore