Histopathological changes in acute ischemic stroke.

We study here the histopathological changes in twenty-two cases of acute ischemic stroke. The average age of the patients was 62-year-old, and the interval from the onset of the disease to the death varied from 6 hours to 15 years. The brain lesions after acute stroke were observed in all regions. Their evolution allowed us to classify them in fourth stages. Phase one changes (1-2 days after onset) (n=2 patients) included red hypoxic and "ghost" neurons and other acute neuronal injury and spongiosis. The second phase (n=14 patients) was subdivided into: (a) a phase of acute inflammation (3-37 days after onset) (n=5 patients), where we observed especially features of acute inflammation together with coagulative necrosis, and (b) phase of chronic inflammation (10 days-53 years after the onset) (n=9 patients), in which prevail mononuclear and macrophage infiltrate, astrogliosis, spongiosis and neo-vascularization. In the third phase (26 days-23 years after the onset), we included six cases characterized by the absence of an inflammatory reaction, presence of cavitation, astrogliosis and macrophages. Our study describes the heterogeneity of brain injury after acute ischemic stroke with the participation of all brain components, and the chronology in which these lesions develop and evolve.