Table of Contents Author Guidelines Submit a Manuscript
Multiple Sclerosis International
Volume 2015, Article ID 809252, 14 pages
http://dx.doi.org/10.1155/2015/809252
Review Article

Neuroimaging of Natalizumab Complications in Multiple Sclerosis: PML and Other Associated Entities

Division of Neuroradiology, University of Colorado School of Medicine, 12700 E 19th Avenue Mail Stop C278, Aurora, CO 80045, USA

Received 12 June 2015; Revised 14 August 2015; Accepted 31 August 2015

Academic Editor: Martin Stangel

Copyright © 2015 Justin M. Honce et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Linked References

  1. A. Lutterotti and R. Martin, “Getting specific: monoclonal antibodies in multiple sclerosis,” The Lancet Neurology, vol. 7, no. 6, pp. 538–547, 2008. View at Publisher · View at Google Scholar · View at Scopus
  2. J. R. Berger, “Natalizumab,” Drugs of Today, vol. 42, no. 10, pp. 639–655, 2006. View at Publisher · View at Google Scholar · View at Scopus
  3. C. H. Polman, P. W. O'Connor, E. Havrdova et al., “A randomized, placebo-controlled trial of natalizumab for relapsing multiple sclerosis,” The New England Journal of Medicine, vol. 354, no. 9, pp. 899–910, 2006. View at Publisher · View at Google Scholar · View at Scopus
  4. D. H. Miller, D. Soon, K. T. Fernando et al., “MRI outcomes in a placebo-controlled trial of natalizumab in relapsing MS,” Neurology, vol. 68, no. 17, pp. 1390–1401, 2007. View at Publisher · View at Google Scholar · View at Scopus
  5. R. A. Rudick, W. H. Stuart, P. A. Calabresi et al., “Natalizumab plus interferon beta-1a for relapsing multiple sclerosis,” The New England Journal of Medicine, vol. 354, no. 9, pp. 911–923, 2006. View at Publisher · View at Google Scholar · View at Scopus
  6. E. Havrdova, S. Galetta, M. Hutchinson et al., “Effect of natalizumab on clinical and radiological disease activity in multiple sclerosis: a retrospective analysis of the natalizumab safety and efficacy in relapsing-remitting multiple sclerosis (AFFIRM) study,” The Lancet Neurology, vol. 8, no. 3, pp. 254–260, 2009. View at Publisher · View at Google Scholar · View at Scopus
  7. K. Hellwig, S. Schimrigk, M. Fischer et al., “Allergic and nonallergic delayed infusion reactions during natalizumab therapy,” Archives of Neurology, vol. 65, no. 5, pp. 656–658, 2008. View at Publisher · View at Google Scholar · View at Scopus
  8. A. Lisotti, F. Azzaroli, S. Brillanti, and G. Mazzella, “Severe acute autoimmune hepatitis after natalizumab treatment,” Digestive and Liver Disease, vol. 44, no. 4, pp. 356–357, 2012. View at Publisher · View at Google Scholar · View at Scopus
  9. S. Bezabeh, C. M. Flowers, C. Kortepeter, and M. Avigan, “Clinically significant liver injury in patients treated with natalizumab,” Alimentary Pharmacology and Therapeutics, vol. 31, no. 9, pp. 1028–1035, 2010. View at Publisher · View at Google Scholar · View at Scopus
  10. J. T. Mullen, T. K. Vartanian, and M. B. Atkins, “Melanoma complicating treatment with natalizumab for multiple sclerosis,” The New England Journal of Medicine, vol. 358, no. 6, pp. 647–648, 2008. View at Google Scholar · View at Scopus
  11. R. Bergamaschi and C. Montomoli, “Melanoma in multiple sclerosis treated with natalizumab: causal association or coincidence?” Multiple Sclerosis, vol. 15, no. 12, pp. 1532–1533, 2009. View at Publisher · View at Google Scholar · View at Scopus
  12. A. Ismail, J. Kemp, and B. Sharrack, “Melanoma complicating treatment with Natalizumab (Tysabri) for multiple sclerosis,” Journal of Neurology, vol. 256, no. 10, pp. 1771–1772, 2009. View at Publisher · View at Google Scholar · View at Scopus
  13. A. Laroni, M. Bedognetti, A. Uccelli, E. Capello, and G. L. Mancardi, “Association of melanoma and natalizumab therapy in the Italian MS population: a second case report,” Neurological Sciences, vol. 32, no. 1, pp. 181–182, 2011. View at Publisher · View at Google Scholar · View at Scopus
  14. M. A. Panzara, C. Bozic, and A. W. Sandrock, “More on melanoma with transdifferentiation,” The New England Journal of Medicine, vol. 359, no. 1, pp. 99–100, 2008. View at Publisher · View at Google Scholar · View at Scopus
  15. A. Schweikert, M. Kremer, F. Ringel et al., “Primary central nervous system lymphoma in a patient treated with natalizumab,” Annals of Neurology, vol. 66, no. 3, pp. 403–406, 2009. View at Publisher · View at Google Scholar · View at Scopus
  16. C. Bozic, J. LaGuette, M. A. Panzara, and A. W. Sandrock, “Natalizumab and central nervous system lymphoma: no clear association,” Annals of Neurology, vol. 66, no. 3, pp. 261–262, 2009. View at Publisher · View at Google Scholar · View at Scopus
  17. R. Phan-Ba, B. Bisig, M. Deprez et al., “Primary central nervous system lymphoma in a patient treated with natalizumab,” Annals of Neurology, vol. 69, no. 6, pp. 1060–1062, 2011. View at Publisher · View at Google Scholar · View at Scopus
  18. M. Matzke, S. Schreiber, E. Elolf et al., “Natalizumab-associated central nervous system lymphoma?—another patient,” Multiple Sclerosis, vol. 18, no. 11, pp. 1653–1654, 2012. View at Publisher · View at Google Scholar · View at Scopus
  19. A. Na, N. Hall, B. Kavar, and J. King, “Central nervous system lymphoma associated with natalizumab,” Journal of Clinical Neuroscience, vol. 21, no. 6, pp. 1068–1070, 2014. View at Publisher · View at Google Scholar · View at Scopus
  20. N. Goebels and L. Kappos, “Another complication of natalizumab treatment? Taking the challenge,” Annals of Neurology, vol. 66, no. 3, pp. 264–266, 2009. View at Publisher · View at Google Scholar · View at Scopus
  21. D. B. Clifford, A. DeLuca, D. M. Simpson, G. Arendt, G. Giovannoni, and A. Nath, “Natalizumab-associated progressive multifocal leukoencephalopathy in patients with multiple sclerosis: lessons from 28 cases,” The Lancet Neurology, vol. 9, no. 4, pp. 438–446, 2010. View at Publisher · View at Google Scholar · View at Scopus
  22. S. Dahlhaus, R. Hoepner, A. Chan et al., “Disease course and outcome of 15 monocentrically treated natalizumab-associated progressive multifocal leukoencephalopathy patients,” Journal of Neurology, Neurosurgery and Psychiatry, vol. 84, no. 10, pp. 1068–1074, 2013. View at Publisher · View at Google Scholar · View at Scopus
  23. P. Vermersch, L. Kappos, R. Gold et al., “Clinical outcomes of natalizumab-associated progressive multifocal leukoencephalopathy,” Neurology, vol. 76, no. 20, pp. 1697–1704, 2011. View at Publisher · View at Google Scholar · View at Scopus
  24. C. S. Tan and I. J. Koralnik, “Progressive multifocal leukoencephalopathy and other disorders caused by JC virus: clinical features and pathogenesis,” The Lancet Neurology, vol. 9, no. 4, pp. 425–437, 2010. View at Publisher · View at Google Scholar · View at Scopus
  25. J. R. Berger and E. O. Major, “Progressive multifocal leukoencephalopathy,” Seminars in Neurology, vol. 19, no. 2, pp. 193–200, 1999. View at Publisher · View at Google Scholar · View at Scopus
  26. B. F. Sabath and E. O. Major, “Traffic of JC virus from sites of initial infection to the brain: the path to progressive multifocal leukoencephalopathy,” The Journal of Infectious Diseases, vol. 186, supplement 2, pp. S180–S186, 2002. View at Publisher · View at Google Scholar · View at Scopus
  27. S. Ledoux, I. Libman, F. Robert, and N. Just, “Progressive multifocal leukoencephalopathy with gray matter involvement,” Canadian Journal of Neurological Sciences, vol. 16, no. 2, pp. 200–202, 1989. View at Google Scholar · View at Scopus
  28. E. P. Richardson Jr. and H. D. Webster, “Progressive multifocal leukoencephalopathy: its pathological features,” Progress in Clinical and Biological Research, vol. 105, pp. 191–203, 1983. View at Google Scholar · View at Scopus
  29. R. A. Du Pasquier, S. Corey, D. H. Margolin et al., “Productive infection of cerebellar granule cell neurons by JC virus in an HIV+ individual,” Neurology, vol. 61, no. 6, pp. 775–775, 2003. View at Publisher · View at Google Scholar · View at Scopus
  30. C. Wüthrich, X. Dang, S. Westmoreland et al., “Fulminant JC virus encephalopathy with productive infection of cortical pyramidal neurons,” Annals of Neurology, vol. 65, no. 6, pp. 742–748, 2009. View at Publisher · View at Google Scholar · View at Scopus
  31. C. Tornatore, K. Amemiya, W. Atwood, K. Conant, E. O. Major, and J. Berger, “JC virus: current concepts and controversies in the molecular virology and pathogenesis of progressive multifocal leucoencephalopathy,” Reviews in Medical Virology, vol. 4, no. 3, pp. 197–219, 1994. View at Publisher · View at Google Scholar · View at Scopus
  32. P. M. Chesters, J. Heritage, and D. J. McCance, “Persistence of DNA sequences of BK virus and JC virus in normal human tissues and in diseased tissues,” Journal of Infectious Diseases, vol. 147, no. 4, pp. 676–684, 1983. View at Publisher · View at Google Scholar · View at Scopus
  33. M. C. G. Monaco, W. J. Atwood, M. Gravell, C. S. Tornatore, and E. O. Major, “JC virus infection of hematopoietic progenitor cells, primary B lymphocytes, and tonsillar stromal cells: Implications for viral latency,” Journal of Virology, vol. 70, no. 10, pp. 7004–7012, 1996. View at Google Scholar · View at Scopus
  34. C. Power, J. G. B. Gladden, W. Halliday et al., “AIDS- and non-AIDS-related PML association with distinct p53 polymorphism,” Neurology, vol. 54, no. 3, pp. 743–746, 2000. View at Publisher · View at Google Scholar · View at Scopus
  35. L. Kappos, D. Bates, G. Edan et al., “Natalizumab treatment for multiple sclerosis: updated recommendations for patient selection and monitoring,” The Lancet Neurology, vol. 10, no. 8, pp. 745–758, 2011. View at Publisher · View at Google Scholar · View at Scopus
  36. US Food and Drug Administration, “Drug Safety and Availability—FDA Drug Safety Communication: FDA warns about cases of rare brain infection with MS drug Gilenya (fingolimod) in two patients with no prior exposure to immunosuppressant drugs,” http://www.fda.gov/Drugs/DrugSafety/ucm456919.htm.
  37. US Food and Drug Administration, “Drug Safety and Availability—FDA Drug Safety Communication: FDA warns about case of rare brain infection PML with MS drug Tecfidera (dimethyl fumarate),” http://www.fda.gov/Drugs/DrugSafety/ucm424625.htm.
  38. B. W. Van Oosten, J. Killestein, F. Barkhof, C. H. Polman, and M. P. Wattjes, “PML in a patient treated with dimethyl fumarate from a compounding pharmacy,” The New England Journal of Medicine, vol. 368, no. 17, pp. 1658–1659, 2013. View at Publisher · View at Google Scholar · View at Scopus
  39. U. Ermis, J. Weis, and J. B. Schulz, “PML in a patient treated with fumaric acid,” The New England Journal of Medicine, vol. 368, no. 17, pp. 1657–1658, 2013. View at Publisher · View at Google Scholar · View at Scopus
  40. D. J. Nieuwkamp, J. Murk, C. H. Cremers et al., “PML in a patient without severe lymphocytopenia receiving dimethyl fumarate,” The New England Journal of Medicine, vol. 372, no. 15, pp. 1474–1476, 2015. View at Publisher · View at Google Scholar
  41. A. Langer-Gould, S. W. Atlas, A. J. Green, A. W. Bollen, and D. Pelletier, “Progressive multifocal leukoencephalopathy in a patient treated with natalizumab,” The New England Journal of Medicine, vol. 353, no. 4, pp. 375–381, 2005. View at Publisher · View at Google Scholar · View at Scopus
  42. B. K. Kleinschmidt-DeMasters and K. L. Tyler, “Progressive multifocal leukoencephalopathy complicating treatment with natalizumab and interferon beta-1a for multiple sclerosis,” The New England Journal of Medicine, vol. 353, no. 4, pp. 369–374, 2005. View at Publisher · View at Google Scholar · View at Scopus
  43. G. Van Assche, M. Van Ranst, R. Sciot et al., “Progressive multifocal leukoencephalopathy after natalizumab therapy for Crohn's disease,” The New England Journal of Medicine, vol. 353, no. 4, pp. 362–368, 2005. View at Publisher · View at Google Scholar · View at Scopus
  44. T. A. Yousry, E. O. Major, C. Ryschkewitsch et al., “Evaluation of patients treated with natalizumab for progressive multifocal leukoencephalopathy,” The New England Journal of Medicine, vol. 354, no. 9, pp. 924–933, 2006. View at Publisher · View at Google Scholar · View at Scopus
  45. T. Plavina, M. Subramanyam, G. Bloomgren et al., “Anti–JC virus antibody levels in serum or plasma further define risk of natalizumab-associated progressive multifocal leukoencephalopathy,” Annals of Neurology, vol. 76, no. 6, pp. 802–812, 2014. View at Publisher · View at Google Scholar · View at Scopus
  46. P. O'Connor, “Natalizumab risk stratification: role of a two- step anti-JCV antibody assay,” Canadian Journal of Neurological Sciences, vol. 39, no. 5, pp. 670–675, 2012. View at Publisher · View at Google Scholar · View at Scopus
  47. T. Dong-Si, S. Richman, M. P. Wattjes et al., “Outcome and survival of asymptomatic PML in natalizumab-treated MS patients,” Annals of Clinical and Translational Neurology, vol. 1, no. 10, pp. 755–764, 2014. View at Publisher · View at Google Scholar
  48. A. Boster, S. Hreha, J. R. Berger et al., “Progressive multifocal leukoencephalopathy and relapsing-remitting multiple sclerosis: a comparative study,” Archives of Neurology, vol. 66, no. 5, pp. 593–599, 2009. View at Publisher · View at Google Scholar · View at Scopus
  49. R. Phan-Ba, E. Lommers, L. Tshibanda et al., “MRI preclinical detection and asymptomatic course of a progressive multifocal leucoencephalopathy (PML) under natalizumab therapy,” Journal of Neurology, Neurosurgery & Psychiatry, vol. 83, no. 2, pp. 224–226, 2012. View at Publisher · View at Google Scholar · View at Scopus
  50. P. K. Coyle, J. F. Foley, E. J. Fox, D. R. Jeffery, F. E. Munschauer III, and C. Tornatore, “Best practice recommendations for the selection and management of patients with multiple sclerosis receiving natalizumab therapy,” Multiple Sclerosis, vol. 15, no. 4, pp. S26–S36, 2009. View at Publisher · View at Google Scholar
  51. M. A. Lima, F. W. Drislane, and I. J. Koralnik, “Seizures and their outcome in progressive multifocal leukoencephalopathy,” Neurology, vol. 66, no. 2, pp. 262–264, 2006. View at Publisher · View at Google Scholar · View at Scopus
  52. J. R. Berger, A. J. Aksamit, D. B. Clifford et al., “PML diagnostic criteria: consensus statement from the AAN neuroinfectious disease section,” Neurology, vol. 80, no. 15, pp. 1430–1438, 2013. View at Publisher · View at Google Scholar · View at Scopus
  53. D. Mentzer, J. Prestel, O. Adams et al., “Case definition for progressive multifocal leukoencephalopathy following treatment with monoclonal antibodies,” Journal of Neurology, Neurosurgery and Psychiatry, vol. 83, no. 9, pp. 927–933, 2012. View at Publisher · View at Google Scholar · View at Scopus
  54. R. Phan-Ba, S. Belachew, O. Outteryck et al., “The earlier, the smaller, the better for natalizumab-associated PML: in MRI vigilance veritas?” Neurology, vol. 79, no. 10, pp. 1067–1069, 2012. View at Publisher · View at Google Scholar · View at Scopus
  55. T. Weber, “Progressive multifocal leukoencephalopathy,” Neurologic Clinics, vol. 26, no. 3, pp. 833–854, 2008. View at Publisher · View at Google Scholar · View at Scopus
  56. C. Warnke, G. Von Geldern, P. Markwerth et al., “Cerebrospinal fluid JC virus antibody index for diagnosis of natalizumab-associated progressive multifocal leukoencephalopathy,” Annals of Neurology, vol. 76, no. 6, pp. 792–801, 2014. View at Publisher · View at Google Scholar · View at Scopus
  57. J. Kuhle, R. Gosert, R. Bühler et al., “Management and outcome of CSF-JC virus PCR-negative PML in a natalizumab-treated patient with MS,” Neurology, vol. 77, no. 23, pp. 2010–2016, 2011. View at Publisher · View at Google Scholar · View at Scopus
  58. B. A. Carroll, B. Lane, D. Norman, and D. Enzmann, “Diagnosis of progressive multifocal leukoencephalopathy by computed tomography,” Radiology, vol. 122, no. 1, pp. 137–141, 1977. View at Publisher · View at Google Scholar · View at Scopus
  59. T. A. Yousry, D. Pelletier, D. Cadavid et al., “Magnetic resonance imaging pattern in natalizumab-associated progressive multifocal leukoencephalopathy,” Annals of Neurology, vol. 72, no. 5, pp. 779–787, 2012. View at Publisher · View at Google Scholar · View at Scopus
  60. M. Piola, F. Di Palma, N. Mascoli, S. Binda, M. Arnaboldi, and M. Rezzonico, “Atypical MRI features at early onset natalizumab-associated progressive multifocal leukoencephalopathy: a case report,” Journal of the Neurological Sciences, vol. 340, no. 1-2, pp. 213–214, 2014. View at Publisher · View at Google Scholar · View at Scopus
  61. S. Gheuens, C. Wüthrich, and I. J. Koralnik, “Progressive multifocal leukoencephalopathy: why gray and white matter,” Annual Review of Pathology: Mechanisms of Disease, vol. 8, pp. 189–215, 2013. View at Publisher · View at Google Scholar · View at Scopus
  62. I. J. Koralnik, “Progressive multifocal leukoencephalopathy revisited: has the disease outgrown its name?” Annals of Neurology, vol. 60, no. 2, pp. 162–173, 2006. View at Publisher · View at Google Scholar · View at Scopus
  63. M. P. Wattjes and F. Barkhof, “Diagnosis of natalizumab-associated progressive multifocal leukoencephalopathy using MRI,” Current Opinion in Neurology, vol. 27, no. 3, pp. 260–270, 2014. View at Publisher · View at Google Scholar · View at Scopus
  64. N. F. Blair, B. J. Brew, and J.-P. Halpern, “Natalizumab-associated PML identified in the presymptomatic phase using MRI surveillance,” Neurology, vol. 78, no. 7, pp. 507–508, 2012. View at Publisher · View at Google Scholar · View at Scopus
  65. I. Ayzenberg, C. Lukas, N. Trampe, R. Gold, and K. Hellwig, “Value of MRI as a surrogate marker for PML in natalizumab long-term therapy,” Journal of Neurology, vol. 259, no. 8, pp. 1732–1733, 2012. View at Publisher · View at Google Scholar · View at Scopus
  66. B. K. Kleinschmidt-Demasters, A. Miravalle, J. Schowinsky, J. Corboy, and T. Vollmer, “Update on PML and PML-IRIS occurring in multiple sclerosis patients treated with natalizumab,” Journal of Neuropathology and Experimental Neurology, vol. 71, no. 7, pp. 604–617, 2012. View at Publisher · View at Google Scholar · View at Scopus
  67. M. P. Wattjes, A. Vennegoor, M. D. Steenwijk et al., “MRI pattern in asymptomatic natalizumab-associated PML,” Journal of Neurology, Neurosurgery & Psychiatry, vol. 86, pp. 793–798, 2015. View at Publisher · View at Google Scholar
  68. N. Richert, G. Bloomgren, D. Cadavid, T. Dong-Si, S. Richman, and B. Ticho, “Imaging findings for PML in natalizumab-trated MS patients,” Multiple Sclerosis Journal, vol. 27, 2012. View at Google Scholar
  69. M. P. Wattjes, N. D. Richert, J. Killestein et al., “The chameleon of neuroinflammation: magnetic resonance imaging characteristics of natalizumab-associated progressive multifocal leukoencephalopathy,” Multiple Sclerosis, vol. 19, no. 14, pp. 1826–1840, 2013. View at Publisher · View at Google Scholar · View at Scopus
  70. O. Kastrup, M. Maschke, H. C. Diener, and I. Wanke, “Progressive multifocal leukoencephalopathy limited to the brain stem,” Neuroradiology, vol. 44, no. 3, pp. 227–229, 2002. View at Publisher · View at Google Scholar · View at Scopus
  71. R. M. Mathew and M. Murnane, “MRI in PML: bilateral medullary lesions,” Neurology, vol. 63, no. 12, article 2380, 2004. View at Publisher · View at Google Scholar · View at Scopus
  72. P.-Å. Svensson and E.-M. Larsson, “Infratentorial progressive multifocal leucoencephalopathy (PML) in a patient with SLE (2008: 4b),” European Radiology, vol. 18, no. 7, pp. 1526–1528, 2008. View at Publisher · View at Google Scholar · View at Scopus
  73. A. Semmler, H. Urbach, T. Klockgether, and M. Linnebank, “Progressive multifocal leukoencephalopathy with selective involvement of the pyramidal tracts,” Neurology, vol. 68, no. 11, article 871, 2007. View at Publisher · View at Google Scholar · View at Scopus
  74. J. L. Sarrazin, D. Soulié, C. Derosier, J. Lescop, H. Schill, and Y. S. Cordoliani, “MRI aspects of progressive multifocal leukoencephalopathy,” Journal of Neuroradiology, vol. 22, no. 3, pp. 172–179, 1995. View at Google Scholar
  75. M. P. Wattjes, L. Verhoeff, W. Zentjens et al., “Punctate lesion pattern suggestive of perivascular inflammation in acute natalizumab-associated progressive multifocal leukoencephalopathy: productive JC virus infection or preclinical PML-IRIS manifestation?” Journal of Neurology, Neurosurgery and Psychiatry, vol. 84, no. 10, pp. 1176–1177, 2013. View at Publisher · View at Google Scholar · View at Scopus
  76. I. L. Tan, J. C. McArthur, D. B. Clifford, E. O. Major, and A. Nath, “Immune reconstitution inflammatory syndrome in natalizumab-associated PML,” Neurology, vol. 77, no. 11, pp. 1061–1067, 2011. View at Publisher · View at Google Scholar · View at Scopus
  77. T. P. L. Roberts and D. Mikulis, “Neuro MR: principles,” Journal of Magnetic Resonance Imaging, vol. 26, no. 4, pp. 823–837, 2007. View at Publisher · View at Google Scholar · View at Scopus
  78. M. Bergui, G. B. Bradac, K. K. Oguz et al., “Progressive multifocal leukoencephalopathy: diffusion-weighted imaging and pathological correlations,” Neuroradiology, vol. 46, no. 1, pp. 22–25, 2004. View at Publisher · View at Google Scholar · View at Scopus
  79. W. Küker, I. Mader, T. Nägele et al., “Progressive multifocal leukoencephalopathy: value of diffusion-weighted and contrast-enhanced magnetic resonance imaging for diagnosis and treatment control,” European Journal of Neurology, vol. 13, no. 8, pp. 819–826, 2006. View at Publisher · View at Google Scholar · View at Scopus
  80. M. Cosottini, C. Tavarelli, L. Del Bono et al., “Diffusion-weighted imaging in patients with progressive multifocal leukoencephalopathy,” European Radiology, vol. 18, no. 5, pp. 1024–1030, 2008. View at Publisher · View at Google Scholar · View at Scopus
  81. I. Mader, U. Herrlinger, U. Klose, F. Schmidt, and W. Küker, “Progressive multifocal leukoencephalopathy: analysis of lesion development with diffusion-weighted MRI,” Neuroradiology, vol. 45, no. 10, pp. 717–721, 2003. View at Publisher · View at Google Scholar · View at Scopus
  82. R. Shah, A. K. Bag, P. R. Chapman, and J. K. Curé, “Imaging manifestations of progressive multifocal leukoencephalopathy,” Clinical Radiology, vol. 65, no. 6, pp. 431–439, 2010. View at Publisher · View at Google Scholar · View at Scopus
  83. M. A. Sahraian, E.-W. Radue, A. Eshaghi, S. Besliu, and A. Minagar, “Progressive multifocal leukoencephalopathy: a review of the neuroimaging features and differential diagnosis,” European Journal of Neurology, vol. 19, no. 8, pp. 1060–1069, 2012. View at Publisher · View at Google Scholar · View at Scopus
  84. S. I. Usiskin, A. Bainbridge, R. F. Miller, and H. R. Jäger, “Progressive multifocal leukoencephalopathy: serial high-b-value diffusion-weighted MR imaging and apparent diffusion coefficient measurements to assess response to highly active antiretroviral therapy,” American Journal of Neuroradiology, vol. 28, no. 2, pp. 285–286, 2007. View at Google Scholar · View at Scopus
  85. S. Da Pozzo, R. Manara, S. Tonello, and C. Carollo, “Conventional and diffusion-weighted MRI in progressive multifocal leukoencephalopathy: new elements for identification and follow-up,” Radiologia Medica, vol. 111, no. 7, pp. 971–977, 2006. View at Publisher · View at Google Scholar · View at Scopus
  86. K. Ohta, K. Obara, M. Sakauchi, K. Obara, H. Takane, and Y. Yogo, “Lesion extension detected by diffusion-weighted magnetic resonance imaging in progressive multifocal leukoencephalopathy,” Journal of Neurology, vol. 248, no. 9, pp. 809–811, 2001. View at Publisher · View at Google Scholar · View at Scopus
  87. J. H. Yoon, O. Y. Bang, and H. S. Kim, “Progressive multifocal leukoencephalopathy in AIDS: proton MR spectroscopy patterns of asynchronous lesions confirmed by serial diffusion-weighted imaging and apparent diffusion coefficient mapping,” Journal of Clinical Neurology, vol. 3, no. 4, pp. 200–203, 2007. View at Publisher · View at Google Scholar
  88. L. Chang, T. Ernst, C. Tornatore et al., “Metabolite abnormalities in progressive multifocal leukoencephalopathy by proton magnetic resonance spectroscopy,” Neurology, vol. 48, no. 4, pp. 836–845, 1997. View at Publisher · View at Google Scholar · View at Scopus
  89. A. Iranzo, A. Moreno, J. Pujol et al., “Proton magnetic resonance spectroscopy pattern of progressive multifocal leukoencephalopathy in AIDS,” Journal of Neurology, Neurosurgery & Psychiatry, vol. 66, no. 4, pp. 520–523, 1999. View at Publisher · View at Google Scholar · View at Scopus
  90. A. J. Fine, A. Sorbello, C. Kortepeter, and L. Scarazzini, “Central nervous system herpes simplex and varicella zoster virus infections in natalizumab-treated patients,” Clinical Infectious Diseases, vol. 57, no. 6, pp. 849–852, 2013. View at Publisher · View at Google Scholar · View at Scopus
  91. J. Yeung, C. Cauquil, G. Saliou et al., “Varicella-zoster virus acute myelitis in a patient with MS treated with natalizumab,” Neurology, vol. 80, no. 19, pp. 1812–1813, 2013. View at Publisher · View at Google Scholar · View at Scopus
  92. A. Kwiatkowski, J. Gallois, N. Bilbault, G. Calais, A. MacKowiak, and P. Hautecoeur, “Herpes encephalitis during natalizumab treatment in multiple sclerosis,” Multiple Sclerosis, vol. 18, no. 6, pp. 909–911, 2012. View at Publisher · View at Google Scholar · View at Scopus
  93. P. Eisele, K. Szabo, M. Griebe et al., “Reduced diffusion in a subset of acute MS lesions: a serial multiparametric MRI study,” American Journal of Neuroradiology, vol. 33, no. 7, pp. 1369–1373, 2012. View at Publisher · View at Google Scholar · View at Scopus
  94. S. Jander, B. Turowski, B. C. Kieseier, and H.-P. Hartung, “Emerging tumefactive multiple sclerosis after switching therapy from natalizumab to fingolimod,” Multiple Sclerosis, vol. 18, no. 11, pp. 1650–1652, 2012. View at Publisher · View at Google Scholar · View at Scopus
  95. A. Seewann, C. Enzinger, M. Filippi et al., “MRI characteristics of atypical idiopathic inflammatory demyelinating lesions of the brain: a review of reported findings,” Journal of Neurology, vol. 255, no. 1, pp. 1–10, 2008. View at Publisher · View at Google Scholar · View at Scopus
  96. F. Visser, M. P. Wattjes, P. J. W. Pouwels, W. H. J. P. Linssen, and B. W. van Oosten, “Tumefactive multiple sclerosis lesions under fingolimod treatment,” Neurology, vol. 79, no. 19, pp. 2000–2003, 2012. View at Publisher · View at Google Scholar · View at Scopus
  97. S. Tenembaum, T. Chitnis, J. Ness, and J. S. Hahn, “Acute disseminated encephalomyelitis,” Neurology, vol. 68, no. 16, pp. S23–S36, 2007. View at Publisher · View at Google Scholar · View at Scopus
  98. C. Lamy, C. Oppenheim, J. F. Méder, and J. L. Mas, “Neuroimaging in posterior reversible encephalopathy syndrome,” Journal of Neuroimaging, vol. 14, no. 2, pp. 89–96, 2004. View at Publisher · View at Google Scholar · View at Scopus
  99. B. O. Khatri, S. Man, G. Giovannoni et al., “Effect of plasma exchange in accelerating natalizumab clearance and restoring leukocyte function,” Neurology, vol. 72, no. 5, pp. 402–409, 2009. View at Publisher · View at Google Scholar · View at Scopus
  100. A. Vennegoor, T. Rispens, B. W. Van Oosten et al., “Application of serum natalizumab levels during plasma exchange in MS patients with progressive multifocal leukoencephalopathy,” Multiple Sclerosis Journal, vol. 21, no. 4, pp. 481–484, 2014. View at Publisher · View at Google Scholar
  101. S. A. Shelburne III, R. J. Hamill, M. C. Rodriguez-Barradas et al., “Immune reconstitution inflammatory syndrome: emergence of a unique syndrome during highly active antiretroviral therapy,” Medicine, vol. 81, no. 3, pp. 213–227, 2002. View at Publisher · View at Google Scholar · View at Scopus
  102. M. P. Wattjes and J. Killestein, “Progressive multifocal leukoencephalopathy after natalizumab discontinuation: few and true?” Annals of Neurology, vol. 75, no. 3, article 462, 2014. View at Publisher · View at Google Scholar · View at Scopus
  103. S. Salhofer-Polanyi, A. Baumgartner, J. Kraus, E. Maida, M. Schmied, and F. Leutmezer, “What to expect after natalizumab cessation in a real-life setting,” Acta Neurologica Scandinavica, vol. 130, no. 2, pp. 97–102, 2014. View at Publisher · View at Google Scholar · View at Scopus
  104. T. W. West and B. A. C. Cree, “Natalizumab dosage suspension: are we helping or hurting?” Annals of Neurology, vol. 68, no. 3, pp. 395–399, 2010. View at Publisher · View at Google Scholar · View at Scopus
  105. T. W. West, J. Killestein, and R. J. Fox, “Natalizumab discontinuation: an increasingly tricky proposition,” European Journal of Neurology, vol. 19, no. 5, pp. 663–664, 2012. View at Publisher · View at Google Scholar · View at Scopus
  106. A. Kerbrat, E. Le Page, E. Leray et al., “Natalizumab and drug holiday in clinical practice: an observational study in very active relapsing remitting Multiple Sclerosis patients,” Journal of the Neurological Sciences, vol. 308, no. 1-2, pp. 98–102, 2011. View at Publisher · View at Google Scholar · View at Scopus
  107. V. Rigau, A. Mania, P. Befort et al., “Lethal multiple sclerosis relapse after natalizumab withdrawal,” Neurology, vol. 79, no. 22, pp. 2214–2216, 2012. View at Publisher · View at Google Scholar
  108. P. S. Sorensen, N. Koch-Henriksen, T. Petersen, M. Ravnborg, A. Oturai, and F. Sellebjerg, “Recurrence or rebound of clinical relapses after discontinuation of natalizumab therapy in highly active MS patients,” Journal of Neurology, vol. 261, no. 6, pp. 1170–1177, 2014. View at Publisher · View at Google Scholar · View at Scopus
  109. A. Miravalle, R. Jensen, and R. P. Kinkel, “Immune reconstitution inflammatory syndrome in patients with multiple sclerosis following cessation of natalizumab therapy,” Archives of Neurology, vol. 68, no. 2, pp. 186–191, 2011. View at Publisher · View at Google Scholar · View at Scopus
  110. L.-A. Beume, R. Dersch, H. Fuhrer, O. Stich, S. Rauer, and W. D. Niesen, “Massive exacerbation of multiple sclerosis after withdrawal and early restart of treatment with natalizumab,” Journal of Clinical Neuroscience, vol. 22, no. 2, pp. 400–401, 2015. View at Publisher · View at Google Scholar · View at Scopus
  111. M. M. Vellinga, J. A. Castelijns, F. Barkhof, B. M. J. Uitdehaag, and C. H. Polman, “Postwithdrawal rebound increase in T2 lesional activity in natalizumab-treated MS patients,” Neurology, vol. 70, no. 13, pp. 1150–1151, 2008. View at Publisher · View at Google Scholar · View at Scopus
  112. F. Sangalli, L. Moiola, L. Ferrè et al., “Long-term management of natalizumab discontinuation in a large monocentric cohort of multiple sclerosis patients,” Multiple Sclerosis and Related Disorders, vol. 3, no. 4, pp. 520–526, 2014. View at Publisher · View at Google Scholar · View at Scopus
  113. P. W. O'Connor, A. Goodman, L. Kappos et al., “Disease activity return during natalizumab treatment interruption in patients with multiple sclerosis,” Neurology, vol. 76, no. 22, pp. 1858–1865, 2011. View at Publisher · View at Google Scholar · View at Scopus
  114. V. G. Jokubaitis, V. Li, T. Kalincik et al., “Fingolimod after natalizumab and the risk of short-term relapse,” Neurology, vol. 82, no. 14, pp. 1204–1211, 2014. View at Publisher · View at Google Scholar · View at Scopus
  115. R. J. Fox, B. A. C. Cree, J. De Séze et al., “MS disease activity in RESTORE: a randomized 24-week natalizumab treatment interruption study,” Neurology, vol. 82, no. 17, pp. 1491–1498, 2014. View at Publisher · View at Google Scholar · View at Scopus
  116. C. Chaves, R. Ganguly, C. Dionne, and A. Camac, “Relapse and rebound risks after natalizumab discontinuation in patients with multiple sclerosis. (P3.294),” Neurology, vol. 84, P3.294, no. 14, 2015. View at Google Scholar
  117. R. H. Clares, R. C. Torres, E. Carreon, E. Andreu, J. M. La Llana, and M. Fernandez, “Risk of rebound in multiple sclerosis after a switch from natalizumab to fingolimod. Early onset versus delayed onset. (P3.291),” Neurology, vol. 84, no. 14, supplement P3.291, 2015. View at Google Scholar