1 Neuromuscular Pathology Unit, Service of Neurology, Hospital "Sant Joan de Déu," Esplugues de Llobregat, Barcelona, Spain.
2 Service of Neurology, University Hospital "Marqués de Valdecilla (IDIVAL)," University of Cantabria (UC), "Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED)," Santander, Spain.
3 Service of Clinical Neurophysiology, University Hospital "Marqués de Valdecilla (IDIVAL)," University of Cantabria (UC), "Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED)," Santander, Spain.
4 Service of Radiology, University Hospital "Marqués de Valdecilla (IDIVAL)," University of Cantabria (UC), "Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED)," Santander, Spain.