1. Department of Neurology, Columbia University Medical Center, New York, New York2Unidad de Enfermedades Neuromusculares, Servicio de Neurología, Hospital Universitario Virgen del Rocío, Instituto de Biomédicina de Sevilla, Consejo Superior de Investigación
2. Department of Neurology, Columbia University Medical Center, New York, New York
3. Department of Neurology, University of Massachusetts Memorial Medical Center, Worcester
4. Rusk Institute of Rehabilitation, NYU Langone Medical Center, New York, New York
5. Department of Pathology, University of Massachusetts Memorial Medical Center, Worcester