Spinal cord progressive multifocal leukoencephalopathy detected premortem by MRI

Excerpt

Progressive multifocal leukoencephalopathy (PML) is a rare and often fatal demyelinating disease caused by JC virus, a ubiquitous polyomavirus that seroepidemiological studies reveal is present in more than 50 % of the adult population (Berger 2014). The rarity of PML indicates that multiple barriers almost certainly exist to its development. Virtually, all predisposing illnesses are associated with an impairment of cell mediated immunity. From the time of its description in 1958 to the onset of the AIDS pandemic, underlying lymphoproliferative disorders, typically B cell diseases, were the most common predisposing disorders for PML (Brooks and Walker 1984). Currently, HIV is the most common predisposing disorder. Prior to the availability of antiretroviral therapies, as many as one in 20 HIV-infected individuals died with PML (Berger et al. 1987) and even in the era of effective antiretroviral therapy, 1.0 % of AIDS deaths are due to PML (Christensen et al. 2010). The gold standard for diagnosis is brain biopsy in which the characteristic histopathological triad of demyelination, enlarged bizarre astrocytes, and enlarged oligodendroglial nuclei can be found, coupled with the demonstration of the presence of JC virus by immunocytochemistry or electron microscopy. However, the diagnosis is more often established on clinical criteria which include an appropriate clinical picture, typical brain MRI findings, and detection of JC virus (JCV) DNA in the CSF by polymerase chain reaction (Berger et al. 2013). …