1. Department of Neurosciences, Forbes Norris ALS Research Center, Sutter Pacific Medical Foundation, USA
2. Department of Psychiatry, New York State Psychiatric Institute, Columbia University Medical Center (CUMC), USA
3. Department of Epidemiology, CUMC, Mailman School of Public Health, USA
4. Department of Neurology, University of California, San Francisco (UCSF), USA
5. Department of Neurology, Eleanor and Lou Gehrig MD/ALS Research Center, CUMC, USA
6. Department of Neurology, UCSF, USA
7. Departments of Biostatistics and Psychiatry, CUMC, Mailman School of Medicine, USA
8. Texas Neurology, PA, USA
9. Duke University, USA
10. Department of Neurology, University of Kansas, USA
11. Mayo Clinic, Rochester, USA
12. University of California, Davis, Mayo Clinic, Jacksonville, USA
13. University of Nebraska Medical Center, USA
14. University of Kentucky, Lexington, USA
15. University of California, Irvine, USA
16. University of Texas, Southwestern, USA
17. University of Iowa, USA
18. Hospital for Special Care, USA