1. Johns Hopkins University School of Medicine, Baltimore, MD, USA,
2. Massachusetts General Hospital, Boston, MA, USA,
3. Faculty of Medicine, IMM, University of Lisbon, Department of Neurosciences-CHLN, Lisbon, Portugal,
4. Montreal Neurological Institute, Montreal, Canada,
5. Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland,
6. Eleanor and Lou Gehrig ALS Center, The Neurological Institute, Columbia University, New York, NY, USA,
7. Unidad de ELA-Hospital Universitario La Paz-Hospital Carlos III, Madrid, Spain,
8. Department of Neurology, Barrow Neurological Institute, Phoenix, AZ, USA,
9. Department of Neurology, Brain Centre Rudolf Magnus, University Medical Centre Utrecht, Utrecht, The Netherlands