Magnetic resonance imaging pattern in natalizumab‐associated progressive multifocal leukoencephalopathy

Abstract

Attention to characteristic MRI patterns, especially the presence of contrast enhancement, and the subcortical location may have utility in screening and early diagnosis of PML in natalizumab-treated MS patients.

MAGNIMS consensus guidelines on the use of MRI in multiple sclerosis—establishing disease prognosis and monitoring patients

“…Imaging find ings of natalizumab associated PML are heterogeneous and can, therefore, be difficult to interpret. However, experienced readers who are fully informed of patient backgrounds can reliably detect natalizumab associated PML via MRI, [95][96][97] even before patients manifest symp toms. 98 Detection of PML lesions at this asymptomatic or presymptomatic stage is associated with improved survival and functional outcome.…”

“…In patients with MRI lesions suggestive of PML, the MRI protocol should be extended to include contrast enhanced T1 weighted imaging to detect inflammatory features and the possible coincidence of PML and PML immune reconstitution inflammatory syndrome (IRIS), particularly during follow up. 95,105 MRI based monitoring for early PML detection is appropriate not only for patients taking natalizumab, but also for other DMDs, including alemtuzumab, 106 rituximab 107 and dimethyl fumarate. [108][109][110] The value of MRI for treatment monitoring goes beyond PML detection.…”

“…Statements and recommendations ■ MRI should be included in drug surveillance pro grammes to screen for opportunistic infections, 103,114 unexpected disease activity (including paradoxical reactions), 82,115,116 and comorbidities 7,93 ■ For natalizumab treated patients with MS who are at high risk of PML (JCV seropositive, treatment dura tion ≥18 months), we recommend brain MRI screen ing every 3-4 months using an MRI protocol that includes FLAIR, T2 weighted and diffusion weighted imaging [95][96][97][98][99]101,104 ■ In patients at low risk of PML (JCV seronegative), we recommend brain MRI assessment once a year using the same MRI protocol [95][96][97][98][99]101,104 ■ In patients at high risk of developing opportunis tic infections who are switching DMDs, we reco mmend brain MRI at the time that the current treatment is discontinued and after the new treatment is started 117-119 ■ Enhanced pharmacovigilance, including brain MRI every 3-4 months for up to 12 months, is required in patients who switch from natalizumab to other thera peutics (including fingolimod, alemtuzumab and dimethyl fumarate) [117][118][119] Standardized follow-up MRI protocol…”

Clinical and Radiological Characterization of Progressive Multifocal Leukoencephalopathy in HIV-Infected Patients: A Retrospective Analysis and Review of the Literature

“…3) in 56-86% of patients, with associated edema and mass effect. [69][70][71][72] Nonetheless, non-enhancement of a PML lesion with clinical deterioration does not preclude the diagnosis. To date, there is no biomarker that confirms IRIS.…”

Use of Natalizumab in Patients with Multiple Sclerosis: 2015 Update

“…Tables 3 and 4 outline clinical and MRI features that help to distinguish PML from MS relapses. 28,29 An algorithm for evaluating possible PML cases has been proposed by the International Multiple Sclerosis Expert Forum and adapted by this panel (Figure 1). 30 If there is suspicion of PML, dosing should be suspended, an MRI with Gd enhancement and diffusion-weighted imaging should be obtained as soon as possible, and the drug manufacturer should be contacted.…”