1. Department of Neurology, The Johns Hopkins University, Baltimore, Maryland2Department of Epidemiology, The Johns Hopkins University, Baltimore, Maryland
2. Department of Neurology, The Johns Hopkins University, Baltimore, Maryland
3. Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia
4. Division of Public Health Sciences, Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston-Salem, North Carolina
5. Department of Epidemiology, The Johns Hopkins University, Baltimore, Maryland
6. Department of Biostatistics, The University of North Carolina at Chapel Hill
7. Department of Medicine, University of Mississippi Medical Center, Jackson
8. Duke Clinical Research Institute, Duke University, Durham, North Carolina
9. Department of Neurology, Mayo Clinic, Rochester, Minnesota