THE VASCULOPATHY OF VARICELLA-ZOSTER VIRUS ENCEPHALITIS

Varicella-zoster virus (VZV) encephalitis has become more prevalent in the era of acquired immunodeficiency syndrome and other immunosuppres sive diseases and poses diagnostic and therapeutic challenges for clin icians, radiologists, and pathologists. Six cases studied at our insti tutions shed light on the patterns and pathogenesis of the disease. VZ V encephalitis is predominantly a vasculopathy, involving small and la rge vessels, that generates seizures, mental changes, and focal defici ts. Brain imaging reveals large and small ischemic or hemorrhagic infa rcts, often both, of cortex and subcortical gray and white matter. Dee p-seated white matter lesions often predominate and ate ischemic and/o r demyelinative, depending on the size of blood vessels involved and t he amount of additional demyelination caused by infection of oligodend rocytes. The demyelinative lesions are smaller and less coalescent tha n those seen in progressive multifocal leukoencephalopathy.