ELECTROENCEPHALOGRAM AND EVOKED-POTENTIALS IN THE PRIMATE MODEL OF VIRAL ENCEPHALITIS

Squirrel monkeys with induced canine distemper virus (CDV) encephaliti s showed characteristic clinical signs such as seizures or myoclonus, with EEGs showing periodic synchronized discharge (PSD). Histopatholog ically, there was gliosis and neuronal degeneration diffusely distribu ted in both the gray and white matters in the subacute phase, the lesi ons resembling those found in childhood acute viral encephalitis and s ubacute sclerosing panencephalitis (SSPE). The auditory brain-stem res ponse (ABR) changes were remarkable in the subacute phase, and the rec overy of latency was correlated with survival. The visual evoked poten tial (VEP) abnormalities disappeared in the acute phase and appeared a gain with delayed latency in the subacute stage. One monkey which did not show clinical signs but had the pathological changes showed the VE P abnormality. These data suggest that the evoked potentials are helpf ul in judging the prognosis, and that this model is useful for the ana lysis of the pathogenesis of viral encephalitis.