1. Agency for Toxic Substances and Disease Registry/Centers for Disease Control and Prevention, Atlanta, GA, USA
2. Sean M Healey & AMG Center for ALS, Massachusetts General Hospital, Boston, MA, USA
3. Carolinas Medical Center, Atrium Health, University of North Carolina School of Medicine – Charlotte Campus, Charlotte, NC, USA
4. Department of Neurology, Mayo Clinic, Jacksonville, FL, USA and
5. Department of Neurology, University of Michigan, Ann Arbor, MI, USA