Ischemic stroke

Introduction to ischemic stroke Cerebral infarction is also called ischemic stroke, which is called stroke or stroke in Chinese medicine. The disease is caused by various causes of blood supply disorders in the local brain tissue region, leading to necrosis of hypoxic lesions in the brain tissue, which in turn produces clinically corresponding neurological deficits. Cerebral infarction is divided into major types such as cerebral thrombosis, cerebral embolism and lacunar infarction according to the pathogenesis. Cerebral thrombosis is the most common type of cerebral infarction, accounting for about 60% of all cerebral infarctions. Therefore, the so-called 'cerebral infarction' actually refers to cerebral thrombosis. basic knowledge The proportion of illness: 0.0035% Susceptible people: no specific population Mode of infection: non-infectious Complications: aspiration pneumonia acne urinary tract infection lower extremity deep vein thrombosis pulmonary embolism

Ischemic stroke

Since the etiology of cerebral thrombosis is mainly atherosclerosis, the cause of atherosclerosis is the most common cause of cerebral infarction. The recent global trial of INTERSTROKE shows that 90% of the risk of cerebral infarction can be attributed to 10 simple risk factors, which in turn are hypertension, smoking, excessive waist-to-hip ratio, improper diet, lack of physical activity. , diabetes, excessive drinking, excessive stress and depression, basic heart disease and hyperlipidemia. It should be pointed out that most of the above risk factors are controllable. The specific cause of the disease and its mechanism of action are as follows:

Vascular wall lesions ( 60% ):

The most common is atherosclerosis, which is often associated with risk factors such as hypertension, diabetes, and hyperlipidemia. It can lead to cerebral artery stenosis or occlusive disease, but the arterial involvement of large and medium-sized tube diameter (500m) is more common. The intracranial artery disease of Chinese people is more common than that of extracranial artery disease. Followed by inflammation of the cerebral artery wall, such as tuberculosis, syphilis, connective tissue disease. In addition, congenital vascular malformations, vascular wall dysplasia, etc. can also cause cerebral infarction. Because atherosclerosis occurs in the bifurcations and bends of large blood vessels, the most common sites of cerebral thrombosis are the beginning and siphon of the carotid artery, the beginning of the middle cerebral artery, the vertebral artery and the basilar artery. The next paragraph and so on. When plaques on the intima of these sites rupture, forms of blood in platelets and cellulose form adhesion, aggregation, and deposition to form a thrombus, and thrombus detachment forms an embolus that blocks the distal artery and causes cerebral infarction. Cerebral arterial plaque can also cause significant stenosis or occlusion of the lumen itself, causing blood pressure drop, slowing of blood flow velocity and increased blood viscosity in the perfusion area, resulting in a decrease in blood supply to the local brain region or promotion of local thrombosis. symptom.

Blood composition changes (30%):

Thrombosis can be caused by polycythemia vera, hyperviscosity, hyperfibrinogenemia, thrombocytopenia, oral contraceptives, and the like. In a few cases, there may be high levels of antiphospholipid antibodies, protein C, protein S or hypercoagulable state associated with antithrombotic III deficiency. These factors can also cause embolic events in the cerebral arteries or in situ cerebral arterial thrombosis.

Other (5%):

Drug-induced, traumatic cerebral artery dissection and a very small number of unknown causes.

Ischemic stroke prevention

Active prevention against possible causes. Strengthen the prevention and treatment of atherosclerosis, hyperlipidemia, hypertension, diabetes and other diseases.

1. For patients with hypertension, blood pressure should be controlled at a reasonable level. Because the blood pressure is too high, it is easy to cause microvascular aneurysm and atherosclerotic small artery rupture and hemorrhage in the brain; and low blood pressure, incomplete blood supply to the brain, and microcirculation stasis, it is easy to form cerebral infarction. Therefore, it should prevent various factors that cause sudden decrease in blood pressure, slow cerebral blood flow, increased blood viscosity, and increased blood coagulation.

2. Active treatment of transient ischemic attacks.

3. Pay attention to mental health, many episodes of cerebral infarction are related to emotional excitement.

4. Pay attention to changing bad habits, and moderate physical activity is good for health. Avoid bad habits such as smoking, alcoholism, binge drinking, and overeating. It should be based on low-fat, low-calorie, low-salt diets, and have high-quality protein, vitamins, cellulose and trace elements. Foods that are not conducive to health, mildew, salted fish, and cold foods do not meet the requirements of food hygiene and should be fasted.

5. When the temperature changes suddenly and the pressure and temperature change significantly, most of the elderly, especially the frail and sick, are sick and sick, especially in the cold and summer, the elderly have poor adaptability, reduced immunity, morbidity and death. The rates are higher than usual, so be careful.

6. Pay attention to the signs of cerebrovascular disease in time, such as sudden on one side of the face or upper and lower limbs suddenly feel numb, weak and weak, mouth sputum, drooling; suddenly feel dizzy, shaking uncertain; short-term confusion or lethargy.

Ischemic stroke complications Complications, aspiration pneumonia, urinary tract infection, deep venous thrombosis, lower extremity thrombosis, pulmonary embolism

Various complications are prone to occur in the acute and recovery stages of cerebral infarction. Aspiration pneumonia, hemorrhoids, urinary tract infections, deep venous thrombosis of the lower extremities, pulmonary embolism, and malnutrition caused by dysphagia can significantly increase the risk of poor prognosis. Therefore, effective prevention and close care of these complications is also a key link in the standardized treatment of cerebral infarction.

Symptoms of ischemic stroke Common symptoms Outstretched tongue eccentric eccentric vascular malformation contralateral limb hemiplegia vertigo angle slanted, unable to talk nystagmus

According to cerebral artery stenosis and occlusion, the severity of neurological dysfunction and the duration of symptoms are divided into three types:

1. Transient ischemic attack: internal carotid artery ischemia is characterized by sudden limb movement and sensory disturbance, aphasia, short-term blindness in one eye, and less conscious disturbance. Vertebral artery ischemia is characterized by dizziness, tinnitus, hearing impairment, diplopia, gait instability, and difficulty swallowing. The symptoms last for a short period of time and can be repeated, even several times a day or dozens of times. Can be relieved by itself, without leaving sequelae. There was no obvious infarct in the brain.

2. Reversible ischemic neurological dysfunction (RIND) is basically the same as TIA, but the neurological dysfunction lasts for more than 24 hours, and some patients can reach several days or tens of days, and finally gradually recover completely. The brain can have small infarcts, most of which are reversible lesions.

3. Complete stroke (CS) symptoms are more severe than TIA and RIND, and are constantly worsening, often with disturbances of consciousness. Significant infarcts appear in the brain. Neurological dysfunction can not be recovered for a long time, and complete stroke can be divided into three types: light, medium and heavy.

Ischemic stroke examination

It mainly includes brain structure imaging assessment, cerebrovascular imaging assessment, brain perfusion and functional examination.

(1) Brain structure imaging examination

Head CT

Head CT is the most convenient and commonly used brain structure imaging test. At the very early stage (within 6 hours of onset), CT can produce some minor early ischemic changes: such as high density of the middle cerebral artery, cortical margins (especially the insular leaves), and gray matter boundaries in the nucleus nucleus are unclear. The brain drain disappears. However, CT is not sensitive to ultra-early ischemic lesions and small infarcts in the cortex or subcortex, especially in the posterior fossa brainstem and cerebellar infarction. In most cases, CT can show a uniform lamellae of low-density infarcts after 24 hours of onset. However, due to the disappearance of lesion edema within 2-3 weeks of onset, the lesion has a 'fuzzy effect' equivalent to the surrounding normal tissue density. Lesion.

2. Skull MRI

Standard MRI sequences (T1, T2, and Flair phase) clearly show ischemic infarction, brainstem and cerebellar infarction, venous sinus thrombosis, etc., but are not sensitive to cerebral infarction within a few hours of onset. Diffusion-weighted imaging (DWI) can show the size and location of ischemic tissue early (within 2 hours of onset) and even small infarcts of the subcortex, brainstem and cerebellum. Combined with the apparent diffusion coefficient (ADC), the sensitivity of DWI to early infarction is 88% to 100%, and the specificity is 95% to 100%.

(2) Cerebrovascular imaging

1. Cervical vascular ultrasound and transcranial Doppler (TCD)

At present, the most commonly used non-invasive means for detecting intracranial and extracranial stenosis or occlusion, atherosclerotic plaque, can also be used for the detection of microemboli in surgery. At present, the sensitivity of carotid ultrasound to extracranial carotid stenosis can reach more than 80%, the specificity can exceed 90%, and the sensitivity of TCD to intracranial artery stenosis can reach more than 70%, and the specificity can exceed 90%. However, due to the subjective influence of vascular ultrasound technology operators, and their accuracy is still not as good as MRA/CTA and DSA invasive examination methods, the current recommendation is that cerebral vascular ultrasound (neck vascular ultrasound and TCD) It can be used as the preferred screening method for cerebrovascular disease, but it is not appropriate to use the results as the only method to determine the extent of cerebrovascular disease before vascular intervention.

2. Magnetic resonance angiography (MRA) and computer imaging angiography (CTA)

MRA and CTA are vascular imaging techniques that are less invasive to humans. The main cause of invasiveness in the human body is the use of contrast agents. CTA still has a certain dose of radiation. Both sensitivity and specificity for cerebrovascular disease are higher than those of cerebral vascular ultrasound, which can be used as a reliable test for cerebrovascular assessment.

3. Digital subtraction angiography (DSA)

DSA of cerebral arteries is the most accurate diagnostic tool for evaluating intracranial and extracranial vascular lesions, and it is also the gold standard for the degree of cerebrovascular disease. Therefore, it is often the most reliable basis for reflecting cerebrovascular disease before intravascular intervention. DSA is an invasive procedure and usually has a disability and mortality rate of no more than 1%.

(C) cerebral perfusion examination and evaluation of brain function

1. The purpose of cerebral perfusion examination is to evaluate the distribution of cerebral arterial blood flow in different brain regions. The rapid completion of perfusion imaging in the early stage of the disease can distinguish the core infarct area and the ischemic penumbra area, thus helping to choose reperfusion. Appropriate cases of treatment, in addition to the role of evaluation of neuroprotective agents, preoperative intervention evaluation. At present, the most commonly used methods for cerebral perfusion examination are multimodal MRI/PWI, multimodal CT/CTP, SPECT and PET.

2. Assessment of brain function: mainly includes functional magnetic resonance, EEG and other methods for examining special brain functions such as cognitive function and emotional state.

Diagnosis and diagnosis of ischemic stroke

Diagnostic diagnosis

The diagnosis points of this disease are: 1 middle-aged and elderly patients; many history of risk factors related to cerebrovascular disease; 2 TIA before onset; 3 more frequent onset of rest, often appearing after waking up; 4 rapid appearance Symptoms of focal neurological deficits persist for more than 24 hours, symptoms can be gradually aggravated within a few hours or days; 5 most patients have clear consciousness, but the signs of neurological system such as hemiplegia and aphasia are obvious; 6 head CT is normal early, 24-48 A low-density foci appears after disappearing.

Differential diagnosis

1. Cerebral hemorrhage: The onset is more urgent. Symptoms and signs of focal localization of the nervous system appear within minutes or hours. Symptoms such as headache and vomiting, such as increased intracranial pressure and varying degrees of disturbance of consciousness, are associated with increased blood pressure. However, large areas of cerebral infarction and cerebral hemorrhage, mild cerebral hemorrhage and general cerebral thrombosis symptoms. Feasible head CT for identification.

2. Cerebral embolism: rapid onset, peak symptoms within a few seconds or minutes, often with a history of heart disease, especially atrial fibrillation, bacterial endocarditis, myocardial infarction or other sources of embolism should consider cerebral embolism.

3. Intracranial space: Some subdural hematomas, intracranial tumors, brain abscesses, etc. are also onset faster, and there are symptoms and signs of hemiplegia, which need to be identified with this disease. Possible head CT or MRI identification.

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