1. The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
2. McGaw Bioethics Scholars Program, Center for Bioethics and Humanities, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
3. Division of Palliative Medicine, Department of Medicine, University of California, San Francisco, San Francisco, California, USA.
4. Struthers Parkinson's Center, Golden Valley, Minnesota, USA.
5. Hennepin County Medical Center, Minneapolis, Minnesota, USA.
6. Departments of Neurology and Medicine, University of Rochester Medical Center, Rochester, New York, USA.
7. Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
8. Department of Neurology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
9. Division of Geriatrics, Department of Medicine, University of California, San Francisco, San Francisco, California, USA.
10. Division of Movement Disorders, The Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.