Types of strokes.
Stroke – acute advanced state of destruction of brain neurons as a result of impaired circulation. Therefore, in medical literature, stroke is more properly called acute violation of cerebral circulation.
On the development of all strokes can be divided into two broad categories. This ischemic and hemorrhagic.
Ischemic strokes develop as a result of cessation of admission to the part of the brain of blood. Among them are vasospastic and thromboembolic. In the first case the blood is not supplied due to spasm of the vessel, and the second of its blockage (embolism). Most often it is the clot.
Hemorrhagic stroke occurs rupture of blood vessels and outpouring of blood into surrounding tissue. At the place of rupture strokes are intracerebral (when the hemorrhage in the internal structure of the brain) subarachnoid (in the lining of the brain).
As options are considered ischemic stroke transient ischemic attack.
There is restoration of blood supply after a few minutes after the attack.
Mechanisms of development of strokes.
Slowing of blood flow with subsequent stop leads to rapid disruption of neurons. First of all, stop the exchange of electrolytes on the membrane. This leads to ostanavlivajutsja nerve impulse – that is, disable the most important functions of nervous cells. Further the lack of blood supply breaks internal metabolism: lack of oxygen and nutrients stops the synthesis at the ribosomes and not the possibility of removal of metabolic products leads to “poisoning” of the cell.
Within 2-4 minutes, without blood supply occurs irretrievable loss of all of a neuron. At the tissue level is called necrosis – the death of groups of cells.
The volume of necrosis depends on the site of the blood supply.
It is necessary to mention that in the focus of necrosis are dying not only neurons, but also axons of those nerve cells that are outside of the affected area. Thus, cells do not die, but lose their ability to hold momentum.
The mechanism of neuronal cell death in ischemic resembles that for those cells that are after the rupture of the vessel. But more important is mechanical damage to brain tissue flowing from the blood vessel.
In the case of hemorrhage from the vessels of the meninges, the blood has more space to spread. Hematoma is large even from a small vessel. In intracerebral hemorrhage in the tissue, quickly develops a hematoma, the size of which depend on the pressure of blood, and therefore the size of the vessel. The exception is the breakthrough of blood into the ventricles of the brain. Then the bleeding may continue until, until it fills the cavity.
The main symptoms of stroke are distinct neurological disorders. All depends on its location and type. That is, from the vessels and extent of brain lesions. The time in which increases the severity of symptoms being directly related to the type of stroke and the diameter of the vessel.
Neurological symptoms is the development of paralysis (impaired motor activity sensitivity) and paresis (violation of sensitivity) of the extremities, oral cavity and larynx (the man begins to paperheads, can’t swallow).
Ischemic stroke most commonly occurs over the age of 55-60 years in the second half of the day. Especially characteristic of persons suffering from cerebrovascular diseases (arterial hypertension, atherosclerosis), diabetes and myocardial infarction.
The beginning often is gradual.
Hemorrhagic stroke often develops before the age of 60. The clinic is characterized by acute onset, until he lost consciousness.
Causes of stroke.
Because the stroke in most cases is a consequence of cerebrovascular disease, and the reasons for its development are similar. It’s Smoking, inadequate treatment (or lack thereof) of hypertension, atherosclerosis, obesity, chronic lung disease and heart.
The treatment of stroke.
Further treatment of a stroke depends on the immediate causes. It includes various therapeutic measures. Of intensive therapy a vasodilator and neurotrophic drugs prior to surgery.