[Disseminated herpetic encephalitis: report of an autopsy case with immunohistochemical study].

An autopsied case of disseminated herpetic encephalitis in a previously healthy one-year-and-three-month-old child is reported. He had fever, repeated convulsive crises and alterations of consciousness which progressed into a coma, leading to death in eight days. The neuropathological picture was characterized by necrosis and inflammation in multiple foci disseminated in the cerebral hemispheres, brainstem and cerebellum. The Avidin-Biotin-Peroxidase Complex technique showed, in neurons of the thalamus, intra-cytoplasmatic immunoreactivity, and, very rarely, intranuclear for the Herpes simplex virus type 1 antigens. This case differs from the other herpetic encephalitis ones described in the literature in two aspects: (1) by the dissemination of the lesions, in contrast with the forms topographically limited to the limbic system and, less commonly, to the brainstem; (2) by the presence of necrosis, inflammation and focal hemorrhage, which are alterations that practically do not exist in cases of disseminated encephalitis typically described in immuno-depressed individuals.