RESUMO
The CSF-encephalic barrier of brain ventricles was examined at the submicroscopic level at different times of experimental aseptic leptomeningitis. In the acute period of the pathology, (3 to 7 days) the integrity of the bar was found to be disturbed because of acute inflammatory phenomena. In the subacute period (15 to 30 days), CSF hypertension was demonstrable. In the chronic period (90 days), the development of dystrophic and degenerative processes in the structures of the ependyma and vascular plexus were related to the disorders in CSF- and hemodynamics of the brain. Occlusion of the CSF tract was found to be associated with the impairment of the integrity of the blood- and CSF-encephalic barriers, marked edema end disintegration of the nerve tissue.