Мидың қан тамырларының жетіспеуінен туындаған салдарлар

Stroke resulting from lack of blood flow

Cerebral infarction, also known as an ischemic stroke, is the pathologic process that results in an area of necrotic tissue in the brain (cerebral infarct). In mid to high income countries, a stroke is the main reason for disability among people and the 2nd cause of death. It is caused by disrupted blood supply (ischemia) and restricted oxygen supply (hypoxia). This is most commonly due to a thrombotic occlusion, or an embolic occlusion of major vessels which leads to a cerebral infarct In response to ischemia, the brain degenerates by the process of liquefactive necrosis. for cerebral infarcts, some of which are described below. The Oxford Community Stroke Project classification (OCSP, also known as the Bamford or Oxford classification) relies primarily on the initial symptoms. Based on the extent of the symptoms, the stroke episode is classified as total anterior circulation infarct (TACI), partial anterior circulation infarct (PACI), lacunar infarct (LACI) or posterior circulation infarct (POCI). These four entities predict the extent of the stroke, the area of the brain affected, the underlying cause, and the prognosis. The TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification is based on clinical symptoms as well as results of further investigations; on this basis, a stroke is classified as being due to (1) thrombosis or embolism due to atherosclerosis of a large artery, (2) embolism of cardiac origin, (3) occlusion of a small blood vessel, (4) other determined cause, (5) undetermined cause (two possible causes, no cause identified, or incomplete investigation).

There are many tests that can be done to prescreen a patient who maybe showing stroke like symptoms. No one test is better than the other and they all have room for improvement. One of these tests that is used by prehospital personal is the Cincinatti Pre Hospital Stroke scale (CPSS). This test looks for facial droop, arm drift, and a change in the person's speech pattern. Another test that can be used and is a modification to the CPSS is the Face Arm Speech Test (FAST). This checks for facial weakness, arm weakness, and speech disturbances. The ROSIER (Recognition of Stroke in The ER), is a test used by an ER physician. Each variable is rated from a 2 to a +5. Loss of consciousness ( 1), convulsive fit ( 1), facial weakness (+1), arm weakness (+1), leg weakness (+1), abnormal speech patterns (+1), and visual defect (+1). In recent years, a study has been done to show how AI can aid in diagnosis of cerebral infarct and improve patient outcomes in areas that may not have stroke trained physicians.

Ischemic strokes usually present as a problem with nerve, spinal cord, or brain function. Depending on where the stroke is located in the brain, symptoms may start within minutes, or they make take hours to present themselves. Most strokes occur without warning. Some common symptoms include one sided weakness, facial paralysis or numbness, vision problems, trouble speaking, problems with walking and keeping balanced. A person can show one or more of these symptoms during a stroke. If person has a decrease in consciousness, they may be suffering from a stroke in more than one part of the brain or in the brain stem. Symptoms of cerebral infarction can help determined which parts of the brain are affected. If the infarct is located in the primary motor cortex, contralateral hemiparesis is said to occur. With brainstem localization, brainstem syndromes are typical: Wallenberg's syndrome, Weber's syndrome, Millard–Gubler syndrome, Benedikt syndrome or others.

Major risk factors for cerebral infarction are generally the same as for atherosclerosis. These include high blood pressure, diabetes mellitus, tobacco smoking, obesity, and dyslipidemia. There are also risks that a person can't control. These include a person's age, family history of strokes, being African American, and being born a male. A person's risk of a stroke doubles each decade after the age of 55. The American Heart Association/American Stroke Association (AHA/ASA) recommends controlling these risk factors in order to prevent stroke. The AHA/ASA guidelines also provide information on how to prevent stroke if someone has more specific concerns, such as sickle cell disease or pregnancy. It is also possible to calculate the risk of stroke in the next decade based on information gathered through the Framingham Heart Study.

Computed tomography (CT) and MRI scanning will show damaged area in the brain. A CT scan will rule out a hemorrhagic stroke, is cheaper for the patient, and can be found in almost all hospitals unlike an MRI machine. Once the Doctor rules out a hemorrhagic stroke, rTPA can be given. The biggest problem with an MRI is it can't be done on a patient with certain metallic implants or if the patient is claustrophobic. A head and neck CT angiogram can be performed within 6 hours of onset of symptoms to see where the occlusion may be located which can help in determining the cause of the stroke. In people who die from a stroke an autopsy can reveal additional diseases or conditions beyond the stroke itself, as well as uncover uncommon causes of a stroke.

In the last decade, similar to myocardial infarction treatment, thrombolytic drugs were introduced in the therapy of cerebral infarction. The use of intravenous rtPA therapy can be advocated in patients who arrive to stroke unit and can be fully evaluated within 3 hours of the onset. The quicker rTPA is started, the better the outcome for the patient. In increasing numbers of primary stroke centers, pharmacologic thrombolysis with the drug tissue plasminogen activator (tPA), is used to dissolve the clot and unblock the artery. Giving rTPA lessens the chance of disability after 3 months by 30%. though no differences have been found between newer and older versions of the devices. The devices have only been tested on patients treated with mechanical clot embolectomy within eight hours of the onset of symptoms. Angioplasty and stenting have begun to be looked at as possible viable options in treatment of acute cerebral ischaemia. In a systematic review of six uncontrolled, single center trials, involving a total of 300 patients, of intra cranial stenting in symptomatic intracranial arterial stenosis, the rate of technical success (reduction to stenosis of <50%) ranged from 90 to 98%, and the rate of major peri procedural complications ranged from 4 10%. The rates of restenosis and/or stroke following the treatment were also favorable. This data suggests that a large, randomized controlled trial is needed to more completely evaluate the possible therapeutic advantage of this treatment. If studies show carotid stenosis, and the patient has residual function in the affected side, carotid endarterectomy (surgical removal of the stenosis) may decrease the risk of recurrence if performed rapidly after cerebral infarction. Carotid endarterectomy is also indicated to decrease the risk of cerebral infarction for symptomatic carotid stenosis (>70 to 80% reduction in diameter). In tissue losses that are not immediately fatal, the best course of action is to make every effort to restore impairments through physical therapy, cognitive therapy, occupational therapy, speech therapy and exercise. Permissive hypertension allowing for higher than normal blood pressures in the acute phase of cerebral infarction can be used to encourage perfusion to the penumbra.