1 Department of Neurology, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, Brazil ; MRC Centre for Neuromuscular Diseases and Division of Neuropathology, Institute of Neurology, University College London, London, UK.
2 MRC Centre for Neuromuscular Diseases and Division of Neuropathology, Institute of Neurology, University College London, London, UK.
3 Department of Neurology, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.
4 Department of Rheumatology, PUCRS, Porto Alegre, Brazil.