1. Neurology Associates P.C Lincoln NE U.S.A.
2. Department of Speech, Language and Hearing SciencesUniversity of Florida Gainesville FL U.S.A.
3. Department of Speech Pathology and AudiologyUniversity of South Alabama Mobile AL U.S.A.
4. Speech and Feeding Disorders Lab, MGH Institute of Health Professions, Charlestown, MA, U.S.A., ALS Augmentative Communication ProgramBoston Children's Hospital Boston MA U.S.A.
5. Carolinas Medical Center Charlotte NC U.S.A.
6. MGH Department of Neurology Boston MA U.S.A.
7. Center for Neurologic Study San Diego CA U.S.A.
8. Department of Speech‐Language PathologyUniversity of Toronto Toronto ON CANADA
9. Beth Israel Deaconess Medical Center Boston MA U.S.A.
10. State University of New YorkDepartment of Neurology Syracuse NY U.S.A.
11. MGH Biostatistics Center Boston MA U.S.A.
12. Holy Cross HospitalDepartment of Neurology Fort Lauderdale FL U.S.A.
13. Istituto Auxologico Italiano, IRCCS, Department of Neurology and Laboratory of Neuroscience, Department of Pathophysiology and Transplantation, “Dino Ferrari” CenterUniversità degli studi di Milano Milan 20122 Italy
14. Texas Neurology, P.A Dallas TX U.S.A.
15. University of Florida, Rehabilitation Science Gainesville FL U.S.A.
16. University of MichiganDepartment of Neurology Ann Arbor MI U.S.A.
17. UNC Health Care Chapel Hill NC U.S.A.
18. MGH Speech Language Pathology Boston MA U.S.A.
19. Cleveland ClinicDepartment of Neurology Cleveland OH U.S.A.
20. National Scientific and Technical Research Council Buenos Aires Argentina