MRI in varicella-zoster virus leukoencephalitis in the immunocompromised host.

Immunocompromised patients are at increased risk for CNS and disseminated varicella zoster virus (VZV) infection. In this report we present the MR findings in a leukemic patient with active, biopsy-proven VZV leukoencephalitis. The characteristic MR features of this infection were clustered subcortical plaque-like lesions demonstrating rapid demyelination. Active lesions enhanced with intravenous contrast medium administration. Edema and hemorrhage were not prominent early findings but developed as the infection evolved. These findings were strikingly similar to those reported in prior autopsy studies of immunocompromised patients with VZV leukoencephalitis.