1. Mary S. Easton Center for Alzheimer's Disease Research at UCLA, Los Angeles, CA, USA
2. Department of Neurology, Behavioural Neurology and Movement Disorders Unit, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
3. Norwegian Centre for Movement Disorders, Psychiatric Clinic, Stavanger University Hospital, Stavanger, Norway
4. Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA