Computed tomography in Herpes simplex encephalitis.

Eight patients with Herpes simplex encephalitis had computed cranial tomography (CT). In every case, areas of decreased attenuation were found in the temporal lobe(s); these areas extended to the insular cortex and often to the frontal or parietal lobes. This change developed between the third and the eleventh day of illness. It was present, sometimes only in retrospect, in patients who were alert as well as patients who were comatose. Compared to the isotopic brain scan, electroencephalogram, and cerebral angiogram, CT demonstrates changes that are indicative of H simplex early enough in the course of the illness to be therapeutically useful.