1. Human Motor Control Section; National Institute of Neurological Disorders and Stroke; National Institutes of Health; Bethesda MD USA
2. Department of Medicine; Faculty of Medicine; Chulalongkorn Centre of Excellence on Parkinson Disease and Related Disorders; Chulalongkorn University and King Chulalongkorn Memorial Hospital; Thai Red Cross Society; Bangkok Thailand
3. Division of Neurology; Department of Medicine; Faculty of Medicine; Siriraj Hospital; Mahidol University; Bangkok Thailand
4. Clinical Neurosciences Program; National Institute of Neurological Disorders and Stroke; National Institutes of Health; Bethesda MD USA