Cerebrovascular disease is a common disease that seriously affects the health of our people, of which 75%-90% are ischemic cerebrovascular disease, therefore, the prevention and treatment of cerebrovascular disease, especially ischemic cerebrovascular disease, is the top priority of our medical work. Epidemiological investigation found that 75% of patients with transient ischemic attack (TIA) and 60% of patients with cerebral infarction have different degrees of intracranial and extracranial cerebral perfusion atherosclerotic plaques and stenosis, and there are about 400,000-500,000 new strokes per year in our country, which is 10 times as many as that of the United States, and the number of new strokes is related to the stenosis of intracranial arteries. Stenosis of the intracranial and extracranial segments of the internal carotid artery is one of the main causes of cerebral infarction, and studies have shown that the incidence of cerebral ischemia in patients with stenosis of the intracranial segments of the internal carotid artery is 27.3%, with the incidence of stroke being 15.2%, and transient cerebral ischemia being 12.1%. Most patients with atherosclerotic stenosis are asymptomatic, and the incidence of stroke in the first year in patients with a stenosis greater than 75% is 2-5%. If the plaque is ulcerated, the incidence of stroke reaches 7.5% per year. For patients who become symptomatic, the incidence of stroke is much higher. The North American Symptomatic Carotid Endarterectomy Collaborative Study showed that 70-99% of patients with symptomatic stenosis had a 26% incidence of stroke within 2 years. The main cause of arterial stenosis is atherosclerosis. Rarely, arterial entrapment, arteritis, myofibrillar dysplasia, radiation injury, etc. are seen. Stenosis is most common at the beginning of the artery. The degree of internal carotid artery stenosis is one of the markers for distinguishing the risk of stroke and affecting the prognosis. The more significant the degree of internal carotid artery stenosis is, the higher the risk of stroke and the mortality rate of stroke. Neurosurgery Department of Wuhan Tongji Hospital Yu Jiazhou The process of atherosclerotic plaque formation: 1. Various risk factors, such as hyperlipidemia, hypertension and hyperglycemia, lead to endothelial damage, and inflammatory cells and excess LDL cholesterol accumulate in the damaged vascular endothelium. 2. 2. Monocytes and LDL cholesterol infiltrate the endothelium. 3. Monocytes transform into macrophages, which take up peroxidatively modified LDL cholesterol and eventually transform into foam cells. 4, Foam cells form the basis of the lipid pattern of the arterial wall, and the plaque gradually increases in size as more lipids, macrophages, and smooth muscle cells are added. 5, atherosclerotic plaques contain a lipid core whose surface is covered by a fibrous cap, and plaques with thin fibrous caps are prone to rupture leading to cardiovascular events. Natural history of asymptomatic intracranial and extracranial atherosclerotic stenosis Atherosclerosis is a chronic cumulative systemic progressive disease. Various pathological changes such as lipid patterns, fibrous plaques, atheromatous ulcers, and mixed plaques, as well as localized thrombosis, calcification, and intraplaque hemorrhage, can be seen in the vessel wall. When these pathological changes are present in the cerebral perfusion arteries, then they can lead to ipsilateral hypoperfusion of the brain tissue, which can produce transient cerebral ischemia, or cerebral infarction triggered by the dislodgement of small emboli produced by vulnerable plaques. Asymptomatic carotid artery stenosis occurs when the above pathologic changes are present but clinical symptoms have not yet occurred. Asymptomatic intracranial and extracranial arterial stenosis may cause hemodynamic changes only when the stenosis reaches a certain level. Mild stenosis can keep cerebral blood flow basically constant through vascular autoregulation mechanisms such as distal vasodilatation and lowering of vascular resistance, but as stenosis continues to worsen and peripheral perfusion pressure continues to fall, cerebral infarction occurs as a result of eventual loss of compensation. Epidemiologic data show that in China, about 5% of the elderly over 65 years old have asymptomatic carotid artery stenosis, and up to 10% over 75 years old. The incidence of asymptomatic carotid stenosis >50% is 2-8%, and the incidence of asymptomatic carotid stenosis >80% is 1-2%. The risk of ipsilateral stroke in asymptomatic carotid stenosis is approximately 1-3%. In a long-term study, the 10- and 15-year risk of ipsilateral stroke in patients with asymptomatic carotid stenosis 0%-49% was 8.7%. However, the risk of ipsilateral stroke in patients with asymptomatic carotid stenosis of 50%-99% was 16.6%. Patients with >50% asymptomatic carotid stenosis have a significantly increased risk of myocardial infarction and non-stroke vascular death, and there is evidence that 2%-40% of strokes in patients with asymptomatic carotid stenosis are not caused by the stenosis itself, but rather by cardiac embolism and lacunar infarction. Symptomatic intracranial atherosclerotic stenosis The incidence of stroke is significantly higher in patients with intracranial atherosclerosis. One study showed an annual stroke rate of 7.8% in patients with middle cerebral artery stenosis. Mechanisms of ischemic stroke due to intracranial atherosclerotic stenosis may include: 1) hypoperfusion due to stenosis; 2) thrombosis at the site of stenosis due to plaque rupture; 3) distal thrombus due to dislodgement of emboli at the site of plaque; and 4) occlusion of arteries that are small at the site of plaque. Atherosclerotic stenosis of intracranial and extracranial arteries occurs at the bifurcation of the carotid artery, the vertebral artery from the subclavian artery, the beginning of the carotid artery and the unnamed artery, the internal carotid artery siphon and the anterior cerebral artery, the basilar artery directly sends out a branch site, and so on. Auxiliary tests for intracranial and extracranial arterial stenosis: 1, TCD 2, CTA 3, MRA 4, DSA 5, carotid ultrasound 6, CTP/SPECT Management of intracranial and extracranial arterial stenosis Intervention of intracranial and extracranial arterial stenosis is firstly the control of the risk factors, the management and treatment of hypertension, diabetes mellitus, dyslipidemia, and poor lifestyle habits. Commonly used drugs such as angiotensin-converting enzyme inhibitors, statin lipid-lowering drugs, and antithrombotic drugs. Among them, aspirin is a commonly used drug, but its efficacy is not very satisfactory. The stenosis of intracranial and extracranial arteries is one of the most important risk factors for ischemic stroke, and the 2010 Chinese Guidelines for Primary Prevention of Stroke put forward a recommendation for intracranial and extracranial arterial stenosis, which points out that: Surgery or endovascular intervention is not recommended for asymptomatic carotid stenosis patients, and antiplatelet agents such as aspirin and statins are the first choice for treatment. For patients with severe carotid stenosis (>70%), carotid endarterectomy or endovascular intervention can be considered where available. Risk factors for atherosclerosis and stenosis and their prevention and treatment: Hypertension, diabetes mellitus, abnormal lipid metabolism, smoking, family history of stroke, history of heart disease, etc. are common risk factors for intracranial and extracranial arterial stenosis, and the coexistence of several risk factors can significantly increase the risk of arterial stenosis. Hypertension: Hypertension is an independent risk factor for atherosclerosis and stroke. After controlling other risk factors, every 10 mmHg increase in systolic blood pressure increases the relative risk of stroke by 49%, and every 5 mmHg increase in diastolic blood pressure increases the relative risk of stroke by 46%. A healthy lifestyle is important in the prevention of hypertension and is an essential component of the prevention and treatment of hypertension, especially for people with blood pressure levels in the high normal range. Lifestyle change therapy should be preferred for patients with early or mild hypertension, and those who are still ineffective at 3 months should be treated with antihypertensive drugs at home. Once patients start to apply anti-hypertensive drug treatment, most of them need to follow up on time and adjust the medication or dosage in time until the target blood pressure level is reached. BP lowering goals: patients with normal hypertension should have their BP lowered to <140/90 mmHg; patients with diabetes mellitus or nephropathy should preferably have their BP lowered to <130/80 mmHg. Elderly people (≥65 years of age) can have their systolic BP lowered to <150 mmHg on a case-by-case basis, or further lowered if they are able to tolerate it. Normal high blood pressure (120-139/80-89mmHg) should be given antihypertensive drugs if accompanied by congestive heart failure, myocardial infarction, diabetes mellitus or chronic renal failure. Smoking Smoking is a risk factor for atherosclerosis and ischemic stroke. Long-term passive smoking increases the risk of ischemic stroke, as does active smoking. The most effective preventive measures are not smoking and avoiding passive smoking, and quitting smoking can also reduce the risk of stroke. Diabetes is an independent risk factor for atherosclerosis and ischemic stroke. People with risk factors for cerebrovascular disease should have regular blood glucose testing, and if necessary, measure glycosylated hemoglobin and glycosylated plasma albumin or do glucose tolerance test; patients with diabetes mellitus should improve their life style, firstly, control their diet and strengthen physical exercise; those who are unsatisfied with the control of blood glucose in 2-3 months should be treated with oral hypoglycemic drugs or insulin. 4.Dyslipidemia There is an obvious correlation between dyslipidemia and the occurrence of atherosclerosis and ischemic stroke. men over 40 years old and postmenopausal women should undergo annual blood lipid checkups, and for high-risk groups such as atherosclerosis and other high-risk groups, it is recommended that those who have the conditions should have their blood lipids tested on a regular basis (6 months). Patients with dyslipidemia have target values for lipids based on their risk stratification. The first step is to make therapeutic lifestyle changes, including reducing the intake of saturated fatty acids (fats from animals such as cows, goats, pigs, etc., and a few plants such as coconut oil, cocoa butter, palm oil, olive oil, etc.) and cholesterol (poultry eggs, animal livers, etc.), choosing foods that enhance the effect of LDL cholesterol lowering (corn, soybeans, soybeans, etc.), quitting smoking, losing weight, increasing regular physical activity, and so on. Regular physical activity, and regular blood lipid testing. If lifestyle changes are not effective, medication should be used. Diet and Nutrition The daily diet should be varied: use balanced recipes that include fruits, vegetables, and low-fat dairy products, and are low in total and saturated fat. It is recommended to reduce sodium intake and increase potassium intake: recommended salt intake ≤6g/d, potassium intake ≥4.7g/d. Daily total fat intake should be <30% of total calories and saturated fat <10%; daily intake of fresh vegetables 400-500g, fruits 100g, meats 50-100g, fishes and shrimps 50g, eggs 3-4 per week, dairy 250g per day, edible oils 20-25g per day, less sugar and sweets. 6, hyperhomocysteinemia hyperhomocysteinemia and atherosclerosis there is a link. The general population can meet the recommended daily intake of folic acid (400ug/d), vitamin B6 (1.7mg/d), and vitamin B12 (2.4ug/d) by consuming vegetables, fruits, legumes, meats, fish, and processed and fortified cereals, which may help reduce the risk of atherosclerosis. For patients with intracranial and extracranial arterial stenosis, they should visit the hospital in time to take medication and receive treatment according to the doctor's instruction in order to prevent the occurrence and development of major diseases such as ischemic stroke. Dr. Chen Zhigang, Chief Physician of the Department of Cerebral Diseases of our hospital, has been engaged in the clinical work of cerebral diseases of traditional Chinese medicine for nearly 30 years, and has his unique advantages and characteristics in the treatment of cerebrovascular diseases with traditional Chinese medicine. It is especially effective in improving patients' symptoms and cerebral blood flow of cerebral perfusion.