J Neurol (2012) 259:1814–1823 treated with natalizumab. Poster P494, 26th congress of the European committee for treatment and research in multiple sclerosis, Gothenburg, Sweden, 13–16 October 2010 19. O’Connor PW, Goodman AD, Kappos L, Lublin FD, Polman CH, Rudick RA et al (2010) Updated efﬁcacy and safety of natal- izumab in patients who participated in the STRATA study. Poster P483, 26th congress of the European committee for treatment and research in multiple sclerosis, Gothenburg, Sweden, 13–16 October 2010 20. Yousry TA, Major EO, Ryschkewitsch C, Fahle G, Fischer S, Hou J et al (2006) Evaluation of patients treated with natalizumab for progressive multifocal leukoencephalopathy. N Engl J Med 354:924–933 21. Sandrock A, Hotermans C, Richman S, Natarajan A, Lee S, Plavina T et al (2011) Risk stratiﬁcation for progressive multi- focal leukoencephalopathy (PML) in MS patients: role of prior immunosuppressant use, natalizumab-treatment duration, and anti-JCV antibody status. 63rd annual meeting of the American Academy of Neurology, Honolulu, Hawaii, 9–16 April 2011 1823 22. Bozic C, Hyde R, Natarajan A, Kooijmans-Coutinho M (2010) Utilization and safety of natalizumab in patients with relapsing multiple sclerosis. Poster P893, 26th congress of the European committee for treatment and research in multiple sclerosis, Gothenburg, Sweden, 13–16 October 2010 23. Clifford DB, De Luca A, DeLuca A, Arendt G, Giovannoni G, Nath A (2010) Natalizumab-associated progressive multifocal leukoencephalopathy in patients with multiple sclerosis: lessons from 28 cases. Lancet Neurol 9:438–446 24. Pasquini MC, Grifﬁth LM, Arnold DL, Atkins HL, Bowen JD, Chen JT (2010) Hematopoietic stem cell transplantation for multiple sclerosis: collaboration of the CIBMTR and EBMT to facilitate international clinical studies. Biol Blood Marrow Transplant 16:1076–1083 25. Coppo P, Laporte JP, Aoudjhane M, Lebon P, Isnard F, Lesage S et al (1999) Progressive multifocal leucoencephalopathy with peripheral demyelinating neuropathy after autologous bone marrow transplantation for acute myeloblastic leukemia (FAB5). Bone Marrow Transplant 23:401–403 123