Case: 75-year-old Mr. Liu frequent dizziness in the past 2 years, and the symptoms gradually aggravated, rest is not good, the dizziness is more serious when the amount of activity, and there is a phenomenon of memory loss, Mr. Liu likes to play chess, in the past 2 years, often appear to be distracted, attention can not be focused on the situation, he thought that it was the reason for the age of the big, and did not take it seriously. Mr. Liu lives on the 5th floor of his home, and on the day of his hospitalization, he walked up the stairs to the door of his house and suddenly went black, followed by loss of consciousness and fell to the ground, and gradually came to his senses after about 2 minutes. After hospitalization, considering the patient’s transient ischemic attack, the patient was urgently given a complete hospitalization examination, and the MRA examination of the head and neck showed that the left internal carotid artery had severe stenosis (stenosis rate of more than 90%), and the right internal carotid artery had moderate-to-severe stenosis (stenosis rate of more than 70%), and considering that the patient’s frequent dizzy spells were related to the stenosis of internal carotid artery, the patient was given a stenting of the left internal carotid artery, and the patient was relieved of dizziness and said goodbye to many years of life. After the operation, the patient’s dizziness symptoms were relieved and she said goodbye to her dizziness for many years. Question 1: Why does carotid artery stenosis cause dizziness? The carotid artery is the main blood vessel that carries blood from the heart to the brain and head. Carotid stenosis is a narrowing of the lumen of the carotid arteries caused by atherosclerotic plaques in the carotid arteries, mostly in the bifurcation of the common carotid artery and the beginning of the internal carotid artery. Some stenotic lesions may progress to complete occlusion. Carotid artery stenosis and ischemic stroke are closely related. Due to insufficient blood supply to the brain caused by carotid artery stenosis, early symptoms mainly include drowsiness, memory loss, inability to concentrate at work, and in severe cases, transient ischemic symptoms such as dizziness, transient loss of consciousness, and immobilization of half of the body, which can be recovered within 24 hours. About 70% of the patients can be relieved within a few minutes and no symptoms remain after recovery. However, regardless of whether the symptoms are mild or severe, you should go to the hospital in time. Question 2: How does carotid artery stenosis occur? Carotid artery stenosis is the narrowing of the lumen of the carotid artery. Carotid artery stenosis, atherosclerotic plaque is the “main culprit”. Studies have found that about 90% of carotid artery stenosis is caused by atherosclerosis. People with age, as well as smoking, hypertension, dyslipidemia, reduced physical activity, emotional stress and a series of factors such as the impact of vascular aging, calcium and lipid deposition in the inner wall of the blood vessels, the formation of “scale”-like sclerotic plaques, so that the arterial wall texture hard, lose elasticity. Part of the plaque gradually protrudes into the lumen of the blood vessel causing narrowing of the lumen. The main causes of carotid artery stenosis are atherosclerosis caused by hypertension, diabetes mellitus, dyslipidemia, etc., followed by inflammation of large arteries and dysplasia of blood vessel walls. Question 3: How can carotid artery stenosis be diagnosed? ①Carotid Doppler ultrasound: Carotid ultrasound has been widely used in clinical medicine for the early diagnosis of ischemic cerebrovascular disease (carotid stenosis) caused by carotid artery lesions, which can detect carotid stenosis in time in order to choose an effective time for treatment. This method is non-invasive and convenient, and is widely used for the initial screening of carotid artery stenosis. ② Magnetic resonance carotid angiography (MRA): this method is non-invasive, intuitive, reliable, painless, and can make a clear diagnosis. However, sometimes there are false positives or “exaggerated” stenosis. Carotid CT angiography (arterial CTA): basically non-invasive. For most of the carotid artery stenosis, carotid CTA is sufficient to meet the needs of examination and diagnosis, especially the introduction of 64-row CT or even 256-row CT, which greatly improves the clarity of CT angiography and diagnosis rate. However, the results of CTA may sometimes exaggerate the stenosis. ④ Carotid angiography (DSA): it is the most accurate indicator for diagnosing carotid artery stenosis and is considered as the gold standard. However, the disadvantages are invasive examination, high price, and cannot be applied to those with serious cardiopulmonary disease or poor general condition.