1. Rush University Medical Center; Chicago Illinois USA
2. Washington University School of Medicine; St. Louis Missouri USA
3. Emory University; Atlanta Georgia USA
4. National Institute of Neurological Disorders and Stroke; National Institutes of Health; Bethesda Maryland USA
5. Mayo Clinic; Scottsdale Arizona USA
6. University of Rochester; Rochester New York USA
7. Baylor College of Medicine; Houston Texas USA
8. University of Maryland School of Medicine; Baltimore Maryland USA
9. University of Florida Movement Disorders Center; Gainesville Florida USA
10. Beth Israel Medical Center; New York New York USA
11. University of Toronto, University Health Network; Toronto Ontario Canada