RESUMO
Craniocerebral trauma, cerebrovascular accidents and most cerebral degenerative processes associated with prophylaxis of postnecrotic confusional states and conditions after cerebral anoxia were critical states observed and in need for cerebral activator. The Encephabol [Pyritinol dihydrochloride monohydrate] was the drug of choice for improving these critical states, as it improved, in particular, disturbed cerebral metabolism promoting the uptake of glucose in the brain [by altering the permeability of the neurone membrane] and activating glucose metabolism. It also increased microcirculation in regions with dificient blood flow. The present work revealed that encephabol retarded the growth of the medulla oblongata of 9 - 14 days treated chick embryo, this retardation of growth was associated with changes of the shape of the fourth ventricle. The retardation of the growth was evidenced by increase in the size of the ependymal and mantle layers, with marked recduction of cell density and poor development of some cranial nuclei while the other nuclei were not differentiated or divided. Some neuroblastic cells became necrotic and the supporting cells were hardly seen. But in 14 days treated embryo, at the middle and caudal level; The medulla increased in size and the fourth ventricle was dilated. Some nuclei became large in size while other nuclei were hardly seen