[Venezuelan equine encephalitis. Review].

The Venezuelan equine encephalomyelitis (VEE) is one the most serious viral infections of the nervous system. It has a wide geographic distribution and may give rise to sequela like mental retardation, amnesia, abortion, epilepsy and hidroanencephaly in infected humans and animals. The pathology of this infection is focused mainly in two tissues: lymphohematopoietic and nervous. The VEE virus has a special cytopathic activity on the nervous cells (glia and neurons) while the lesions produced in the myelin are probably a consequence of the immunological response of the host to the infection. The alterations produced by the VEE virus in different neuronal types can originate changes in the brain concentrations of several neurotransmitters and their receptors. Some biochemical modifications that have also been reported could be due to the cytopathic effect of the virus.