Progressive multifocal leukoencephalopathy. A cause of visual loss
R. E. Appen, H. Roth, G. M. ZuRhein and J. N. Varakis
A patient had been treated for chronic lymphocytic leukemia for five years
before developing visual blurring as the manifestation of occipital lobe
lesions of progressive multifocal leukoencephalopathy (PML). The disease is
caused by an infection of the CNS oligodendrocytes by a papovavirus, whose
replication is facilitated by an impairment of the host's cell-mediated
immunologic system. The multiplying virus destroys the oligodendrocytes and
causes extensive demyelination of the white matter of the brain. Antiviral
agents, such as cytarabine, may be beneficial in treating patients with
PML.