Fellows’ Journal Club
Editor’s Comment
These authors retrospectively evaluated 12 patients with natalizumab–progressive multifocal leukoencephalopathy (PML), 5 with PML from other causes, and 55 patients with MS without progressive PML for comparison. They observed T2* or SWI signal abnormalities at the chronic stage in all patients with PML, but in patients without PML no areas of low SWI signal intensity were detected. PML—related to natalizumab or not—induces brain susceptibility changes within U-fibers or deep gray matter that are visible on T2* or SWI and potentially explained by iron deposition.
Summary
We investigated the brain magnetic susceptibility changes induced by natalizumab-associated progressive multifocal leukoencephalopathy. We retrospectively included 12 patients with natalizumab–progressive multifocal leukoencephalopathy, 5 with progressive multifocal leukoencephalopathy from other causes, and 55 patients with MS without progressive multifocal leukoencephalopathy for comparison. MR imaging examinations included T2* or SWI sequences in patients with progressive multifocal leukoencephalopathy (86 examinations) and SWI in all patients with MS without progressive multifocal leukoencephalopathy. Signal abnormalities on T2* and SWI were defined as low signal intensity within the cortex and/or U-fibers and the basal ganglia. We observed T2* or SWI signal abnormalities at the chronic stage in all patients with progressive multifocal leukoencephalopathy, whereas no area of low SWI signal intensity was detected in patients without progressive multifocal leukoencephalopathy. Among the 8 patients with asymptomatic natalizumab–progressive multifocal leukoencephalopathy, susceptibility changes were observed in 6 (75%). The basal ganglia adjacent to progressive multifocal leukoencephalopathy lesions systematically appeared hypointense by using T2* and/or SWI. Brain magnetic susceptibility changes may be explained by the increased iron deposition and constitute a useful tool for the diagnosis of progressive multifocal leukoencephalopathy.
Read this article: http://bit.ly/Natalizumab-Leukoencephalopathy
