PML-IRIS during Fingolimod Diagnosed after Natalizumab Discontinuation

Figure 1

Axial T2-weighted (top row) and contrast-enhanced T1-weighted images (bottom row) obtained during Natalizumab treatment (3 December 2012), at the time of Natalizumab discontinuation (22 April 2013), at the time of PML-IRIS occurrence (16 September 2013), and after PML-IRIS treatment (21 October 2013). A small lesion suggestive of PML was already visible at the time of Natalizumab discontinuation (arrow). During Fingolimod treatment, this lesion progressed and changed to a PML-IRIS manifestation with slight mass effect and contrast enhancement (arrows) leading to posttreatment sequelae (arrow).