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

Figure 2

25-year-old woman with RRMS who developed worsening symptoms including weakness and inability to ambulate after beginning natalizumab. MRI FLAIR image demonstrates classic appearance of PML including a sharply demarcated peripheral border along the subcortical U-fibers (arrow) and a hazy, ill-defined central border (dashed arrow).