1. Neuromuscular Diseases Unit; Department of Neurology; Hospital de la Santa Creu i Sant Pau; Universitat Autònoma de Barcelona; Barcelona Spain
2. Centre for Biomedical Network Research on Rare Diseases (CIBERER); Madrid Spain
3. Neuromuscular Diseases Unit; Department of Neurology; Hospital Universitari de Bellvitge - IDIBELL; L'Hospitalet de Llobregat; Barcelona Spain
4. Neuromuscular Diseases Unit; Departament of Neurology; Hospital Universitario Clínico San Carlos; Madrid Spain
5. ALS-Neuromuscular Unit; Department of Neurology; Hospital General Universitario Gregorio Marañón; IISGM; Madrid Spain
6. Department of Neurology; Hospital Universitario Cruces; Baracaldo Spain
7. Neuromuscular Diseases Unit; Departament of Neurology and Neurophysiology; Hospital Universitario Virgen del Rocío; Sevilla Spain
8. Department of Neurology; Hospital Clínico; Santiago de Compostela Spain
9. Department of Neurology; Hospital Juan Ramón Jiménez; Huelva Spain
10. Department of Neurology; Hospital Son Llàtzer; Palma de Mallorca Spain
11. Department of Neurology; Hospital Universitario Central de Asturias; Oviedo Spain
12. Neuromuscular Unit; Department of Neurology; Hospital Universitari i Politècnic La Fe; Valencia Spain
13. Department of Medicine; University of Valencia; Valencia Spain