ANATOMOPATHOLOGY OF ENCEPHALOMYELITIS CAU SED BY CYTOMEGALOVIRUS AND VARICELLA-ZOSTER VIRUS

Cytomegalovirus (CMV) infection of the nervous system is frequent in a cquired immunodeficiency syndrome (AIDS) and can be responsible for en cephalitis, encephalomyelitis, meningoradiculitis or polyradiculo-neur opathy. Encephalitis is characterized at microscopy by its periventric ular and cerebellar location, and by the presence of cytomegalic cells , containing intranuclear and/or intracytoplasmic inclusions, microgli al nodules and necrotic foci, The virus can infect almost all types of cells. Coexistence of CMV and HIV has been observed in giant cells of macrophagic origin. It has been suggested that the two viruses could act in synergy. The nervous system is seldom infected by the varicella -zoster virus (VZV) in AIDS. The infection can be responsible for mult ifocal leukoencephalitis, ventriculitis, vascular lesions associated o r not with cerebral infarction, or with meningomyeloradiculitis. In al most all cell types Cowdry's type A intranuclear inclusions have been found. The virus can be demonstrated by immunohistochemistry or in sit u hybridization. VZV antigens have been reported in the walls of vesse ls damaged by a non inflammatory obliterating vasculopathy or by a gra nulomatous angiitis. Coexistence of VZV and HIV has been observed in g iant cells of macrophagic origin, and synergy between those two viruse s has been suspected.