1. Department of Neurology; University of North Carolina; 2200 Physicians Office Building, CB 7025, 170 Manning Drive, Chapel Hill North Carolina 27599-7025 USA
2. Department of Neurology; University of Kansas; Lawrence Kansas USA
3. Department of Biostatistics; University of Alabama at Birmingham School of Public Health; Birmingham Alabama USA
4. Department of Neurology; Ohio State University; Columbus Ohio USA
5. Department of Medicine; Duke University; Durham North Carolina USA
6. ALS and Neuromuscular Center; University of California; Irvine California USA
7. Department of Neurology; Warren Alpert Medical School of Brown University; Providence Rhode Island USA
8. Department of Neurology; University of Miami; Miami Florida USA
9. Department of Neurology; Institute of Neurological Sciences; Glasgow UK
10. Clinical Research and Global Medical Affairs Departments; Alexion Pharmaceuticals; Cheshire Connecticut USA