Diagnosis of viral encephalitis by brain biopsy.

Prompt and accurate diagnosis of viral encephalitis has acquired increased significance because of the encouraging results obtained in therapeutic trials with antiviral agents such as adenine arabinoside. Currently, brain biopsy remains the only reliable method to confirm the diagnosis of viral encephalitis. This communication, based on the analysis of eighteen confirmed cases of viral encephalitis, illustrates structural abnormalities common to these conditions and suggests biopsy handling procedures that appear most helpful in arriving at a prompt diagnosis. In addition to the traditionally well-known inflammatory changes, such as satellitosis, gliosis, and neuronophagia, a variety of intranuclear inclusion bodies are illustrated, and the judicious application of immunocytochemistry and electronmicroscopy is emphasized.