1. Larner College of Medicine; University of Vermont, 1 South Prospect Street; Burlington Vermont 05401 USA
2. Department of Neurology, Duke University School of Medicine; Durham North Carolina USA
3. Department of Neurology, University of Miami Health System; Miami Florida USA
4. Department of Neurology, University of Virginia School of Medicine; Charlottesville Virginia USA
5. Department of Neurology, University of Toronto School of Medicine; Toronto Ontario Canada
6. Department of Neurology, University at Buffalo Jacobs School of Medicine & Biomedical Sciences; Buffalo New York USA
7. Department of Neurology, University of North Carolina School of Medicine; Chapel Hill North Carolina USA
8. Department of Neurology, Oregon Health & Science University; Portland Oregon USA
9. Department of Neurology, Mayo Clinic; Rochester Minnesota USA
10. Department of Neurology, Yale School of Medicine; New Haven Connecticut USA
11. Department of Neurology, Medical University of South Carolina; Charleston South Carolina USA
12. Department of Neurology, University of Florida; Jacksonville Florida USA
13. Department of Neurology, University of Kansas Medical Center; Kansas City Kansas USA