Focal cerebral Isquemia that if follows to the reduction or the interruption of the sanguineous flow for a located area of the brain because of the illness of the great vase (as well as the trombtica or emblica arterial occlusion, frequent in the scene of aterosclerose) or to the illness of the small vases (as well as the vasculite or the secondary occlusion to the arteriosclerticas injuries sights in the hipertenso) (KUMAR; ABBAS; FAUSTO, 2005, P. 1426). The cause enters most common and patognese of the ischemic BIRD is aterosclerose, embolism of cardiac origin that can be trombos walls, cardiopathy to valvar, arrhythmias and embolism paradoxical. Goldman and Cuisiello (2005) agree that, it can be standed out that the riot most common to lead to a BIRD is the formation of ateromas what consequentemente of the beginning to one aterosclerose. These aterosclerticas plates can cause BIRD in three ways: trombo in the place of the aterosclertica injury can occur to the mural formation of one, thus having the blockage of the artery for cogulo, ulcerao and rupture of a plate what it takes the formation of cogulo and for following distal embolizao and hemorrhages in a plate will take the blockage of the artery. Me frequent it occurs trombo from plaquetas and fibrina in the rough surface of the plate of ateroma.
This trombo will be able to be broken up and to float distalmente in the sanguineous chain, until if it lodges in lesser distal branch where the light of the vase is lesser, this process is called embolizao of artery for artery. For Goldman and Auciello (2005) the emblicas occlusions can be symptomatic, therefore the vases distais terminals not they possess collateral irrigation, this increases the probability of the sintomatologia. All is known that the amount of private territory of blood is lesser, saw the symptoms is less serious of what it occurs with the occlusion of the main trunk of a vase.