1. Struthers Parkinson’s Center, Golden Valley, Minnesota
2. Division of Biostatistics, University of Texas at Houston
3. Department of Neurology, University of Rochester, Rochester, New York
4. State University of New York, Downstate Medical Center, Brooklyn
5. The Parkinson’s Institute and Clinical Center, Sunnyvale, California
6. VA Pacific Islands Health Care System, Honolulu, Hawaii
7. Department of Neurology, University of Maryland School of Medicine, Baltimore