Hemorrhagic
Etiology
Hemorrhage (hemorrhagic disorder of blood flow) can be caused by various arterial hypertension, vascular aneurysms, congenital angiomas, etc.
Pathogenesis
As a result of the increase in arterial pressure, the plasma and proteins in it are released, which leads to plasma saturation of the walls of the vessels, causing their destruction. A peculiar hyaline-like specific substance is deposited on the vascular walls (a protein that resembles cartilage in its structure), which leads to the development of hyalinosis. The vessels resemble glass tubes, lose their elasticity and the ability to retain blood pressure. In addition, the permeability of the vascular wall is increased and the blood can freely pass through it, impregnating nerve fibers (diapedesis bleeding). The result of such a transformation can be the formation of microaneurysms and rupture of the vessel with hemorrhage and the ingress of blood into the white brain substance. Thus, hemorrhage occurs as a result of:
Plasmatic impregnation of the walls of vessels of the white brain substance or visual tubercles;
Diapedesis bleeding;
The formation of microaneurysms.
Hemorrhage in the acute period is characterized by the development of hematomas with wedging and deformation of the brainstem into the tentorial opening. At the same time, the brain swells and extensive swelling develops. There are secondary hemorrhages, smaller.
Clinical manifestations
Usually occurs during the day, during physical activity. Suddenly, the head starts to ache, there are sickening desires. Consciousness – confused, a person breathes often and with a whistle, there is a tachycardia accompanied by hemiplegia (unilateral limb paralysis) or hemiparesis (weakening of motor functions). The main reflexes are lost. The view becomes fixed (paresis), anisocoria (pupils of different sizes) or strabismus of divergent type occurs.
The cerebral vessels have a unique, perfect structure that perfectly regulates blood flow, ensuring the stability of blood circulation. They are arranged in such a way that when the blood flow to the coronary vessels increases approximately 10-fold during physical activity, the amount of circulating blood in the brain, with increasing mental activity, remains at the same level. That is, there is a redistribution of blood flow. Part of the blood from the brain regions with less stress is redirected to areas with enhanced brain activity.
However, this perfect process of blood circulation is disturbed if the amount of blood entering the brain does not satisfy its need for it. It should be noted that its redistribution across the brain regions is necessary not only for its normal functionality. It occurs also in the occurrence of various pathologies, for example, stenosis of the lumen of the vessel (constriction) or obturation (closure). As a result of impaired self-regulation, the rate of movement of blood in certain parts of the brain and their ischemia slow down.