Neurological complications in HIV patients – a case of PML-IRIS

Background Progressive multifocal leukoencephalopathy (PML) is a rare but frequently fatal demyelinating disease caused by the JC polyomavirus (JCV). It has been traditionally associated to severe immunosuppression and described mainly in HIV patients with a low CD4 count. On neuroimaging, PML is classically seen as diffuse, often multifocal, white matter lesions involving the U-fibers without associated contrast enhancement, vasogenic edema or mass effect. If untreated, PML is usually fatal within 1 year. Treatment with highly active antiretroviral therapy (HAART) may prolong survival. Nevertheless, in the recent decade, the availability of HAART can also be responsible for some PML cases attributed to the reconstitution of the immune system known as PML-IRIS.