1. Neuroscience Research Center, Healthy Ageing Research Center, and Department of Neurology; Chang Gung Memorial Hospital and Chang Gung University College of Medicine; Taoyuan 33305 Taiwan
2. Institute of Cognitive Neuroscience; National Central University; Taoyuan 32001 Taiwan
3. Sobell Department of Motor Neuroscience and Movement Disorders; Institute of Neurology, University College London; Queen Square London WC1N 3BG UK
4. Department of Neurology; Cheng Ching Hospital; Taichung 40764 Taiwan
5. Department of Neurology; Landseed Hospital; Taoyuan 32449 Taiwan