[Exclusive Interview with Min Weijie] With 3.4 million new strokes occurring in my country each year, how dangerous is stroke?

Introduction: Stroke is a very common disease in my country, with about 3.4 million stroke cases and 2.4 million deaths each year. It is estimated that the number of stroke patients in my country will reach 31 million in 2030. The disease burden caused by stroke is very heavy, so correctly understanding stroke and actively preventing this disease are critical to reducing the burden it brings.

Today, "In-depth Science" is honored to invite Min Weijie, the attending physician of the cerebrovascular department of Shanghai First People's Hospital. Dr. Min is a member of the Chinese Anti-Cancer Association and has been engaged in various surgeries such as cerebrovascular diseases, neuro-tumors, trauma, and neuro-critical care management. Dr. Min is also very enthusiastic about popular science, and he will answer questions about stroke for us next.

What is stroke and its pathogenesis?

Ye Shuisong : Can you tell us what stroke is? What is its main mechanism of disease?

**Min Weijie: **Stroke, also known as cerebral infarction, refers to a sudden accident in the cerebral blood vessels that supply blood to our brain, causing the brain to be unable to function normally.

Sudden blockage is called ischemic stroke , also known as cerebral infarction. Bleeding caused by sudden rupture of blood vessels is called hemorrhagic stroke, also known as cerebral hemorrhage or cerebral hemorrhage. The pathogenesis is that there is a problem with the blood vessels supplying blood to the brain, such as stenosis of the blood vessels, including immune diseases such as amyloidosis, embolus detachment, and sudden blockage eventually causes ischemic stroke.

Hemorrhagic stroke is bleeding and rupture of cerebral blood vessels. For example, blood vessels become more fragile due to long-term high pressure, and immune diseases such as diabetes and congenital diabetes make the blood vessels very poor and fragile. Higher blood pressure or other unexpected situations can easily lead to bleeding and rupture of cerebral blood vessels, resulting in hemorrhagic stroke.

Ye Shuisong : What are the characteristics before and after a stroke? Can you briefly describe them?

**Min Weijie: **In fact, there are some early signs of stroke, called mini-stroke. For example, one eye suddenly turns black and loses sight; language barriers, transient dizziness; the body cannot keep balance; or the pain and tingling sensation on one side of the body suddenly disappears or weakens; there are even problems with movement, such as being unable to walk or stand; sudden severe headaches, nausea, and vomiting when lifting things; transient difficulty swallowing, inability to drink water; crooked mouth and squinting eyes, etc. These are all signs of transient bleeding, indicating that there may be problems with our blood vessels, but they have not yet reached a very serious level. This is actually a warning from the body.

When the stroke actually occurs, these warnings may become real and may cause permanent damage, such as paralysis, speech disorders, mental disorders, cognitive impairment, vision problems or prolonged dizziness, which are the residual effects of the damage caused by the stroke.

Stroke Classification and Risk

Ye Shuisong : What are the categories of stroke? Do different types of stroke have different risks?

**Min Weijie: **Yes. Stroke includes hemorrhagic and ischemic, which are two major types.

There are four types of ischemic stroke:

1. Reversible ischemic neurological function loss. For example, paralysis or speech loss or vision problems for a period of time. This symptom may last for more than 24 hours, but will gradually recover within the next three weeks.

2. Progressive stroke. In this case, the cerebrovascular symptoms are obvious, gradually develop and worsen, and may reach a peak within a few hours or a day or two. There are clear lesions and cerebral infarction foci, and its effects will be residual and may even progress to a very serious degree.

3. Complete stroke: Cerebrovascular symptoms occur rapidly, and may reach a peak in a few minutes or even an hour. This is often a very serious cerebral infarction, which can cause permanent paralysis or even life-threatening conditions.

4. Mini-stroke, which lasts for a very short time and may recover in a few minutes or hours. Medically, it is called transient or ischemic ischemic attack, called TIA or mini-stroke.

So, hemorrhagic stroke actually includes:

1. Bleeding in the brain substance. For example, cerebral hemorrhage caused by hypertension or amyloidosis may occur in the basal ganglia, thalamus, brain stem, cerebral lobes, cerebellum, etc.

2. Spontaneous intraventricular hemorrhage. In fact, it is mostly secondary to cerebral hemorrhage, such as aneurysm or arterial malformation, or high-pressure bleeding in the brain parenchyma, which ruptures into the ventricle due to rupture of the adjacent ventricle.

3. Subarachnoid hemorrhage. This often occurs suddenly when one is tired or emotionally excited, and manifests as a sudden severe headache, which may be accompanied by vomiting, nausea, epilepsy, and even neurological dysfunction. This often has very serious consequences, progresses very quickly, and may cause death.

Patients with this type of cerebral hemorrhage, especially those with subarachnoid hemorrhage, do not have obvious symptoms because a small number of people have spot-type symptoms, and headaches or other symptoms may not be obvious, which can easily lead to misdiagnosis and delay treatment.

The incidence and prevalence trend of stroke in China

Ye Shuisong : The incidence and mortality of stroke in China are very high. What is the current incidence and prevalence trend of stroke in our country?

**Min Weijie: **Currently in my country, there are about 185-219 stroke cases per 100,000 people each year. As people age, this rate will be higher.

Among them, about 72% of stroke patients first suffered from the disease at the age of 65 or above. The overall incidence rate is about 400 to 600 people per 100,000 people. Based on the total population of our country, it may be 6 million to 8 million.

Our country is now facing an aging society, and this data will continue to accumulate. After a stroke, about 60% to 80% of people may suffer from varying degrees of disability, and about 1/4 to 3/4 of them may relapse within two to five years. In other words, a stroke does not happen only once in a lifetime.

Globally, there are two major high-incidence stroke belts: one is the China-Mongolia-Russia area, and the other is in Africa.

For Asians, the risk of stroke increases by 240% for every 10 mm/Hg increase in systolic blood pressure, while for Europeans the risk increase is only 22%.

Singaporeans once conducted a study and found that in fact Asians are more likely to suffer stroke than any other race in the world.

Ye Shuisong : Can you analyze why the incidence of stroke in China is so high?

**Min Weijie: **This is caused by several reasons.

From the perspective of race, Chinese people have some genetic defects. For example, compared with Europeans and Americans, Chinese people's diet and other ability to digest lipids are weaker.

In addition, we can analyze based on the "123" principle. First, the first principle includes the disease principle. The incidence of hypertension and diabetes in our Asian population is high. The incidence in Europe and the United States is about 40%, while the Asian population, especially the Chinese population, is about 60% to 70%.

Another influencing factor is our country's eating habits, especially northerners prefer salty taste and greasy food, which will lead to increased lipid metabolism and high blood pressure. Many of us also have the habit of smoking and drinking, and the overall amount of exercise is actually relatively low, which all have an impact.

Of course, it also includes the influence of some environmental factors. Studies have confirmed that air pollution has a direct impact on stroke.

Association of stroke with age, sex and region

Ye Shuisong : Compared with European and American countries, the age of stroke patients in China is 10 years earlier than in the West. At what age does stroke most often occur? Are there any differences in the incidence rate between different genders? Are there any regional differences?

**Min Weijie: **Stroke often occurs in the middle-aged and elderly people aged 50 to 75. About 72% of people first develop the disease after the age of 65. The age group after 65 is more prone to stroke, and the incidence rate in men is higher than that in women.

There are regional differences in stroke in my country. The stroke prevalence in the north is about twice that in the south, especially in the three northeastern provinces, Inner Mongolia, Hebei, Xinjiang, and northern Tibet. The reason lies in the difference in diet. For example, people in the north like to eat greasy and salty Northeastern cuisine, Shandong cuisine, fried food, etc., which increases fat and high blood pressure, leading to an increase in the proportion of stroke. In the south, people mainly eat light food, especially Guangdong people who love to make soup, with very little oil and salt, and a higher proportion of vegetables, which may be better.

In addition, the temperature difference between the north and the south is also an influencing factor. Thermal expansion and contraction are inevitable. When blood vessels are extremely affected by cold and heat, especially in the winter when the north is colder and sometimes the northeast region may even reach minus 20 to 30 degrees Celsius, the contraction of blood vessels may increase the incidence of stroke.

In addition, northerners tend to drink heavily, and alcohol can increase sympathetic nerve excitement, leading to heart disease, high blood pressure and other diseases, and also increase the risk of stroke.

How to reduce your risk of stroke

Ye Shuisong : What should we do to reduce the risk when we just have a stroke?

**Min Weijie: **We need to quickly identify the symptoms we have. As mentioned earlier, stroke may sometimes show signs of a minor stroke or a precursor to a stroke. In this case, we need to seek medical attention in a timely manner.

There is a mnemonic: “Stroke 120”.

On World Stroke Day in 2016, Professor Renyu Liu of the University of Pennsylvania published a slogan to the world in The Lancet Neurology, which takes into account China's national conditions.

The "1" in "120" is to see if our face is symmetrical, whether there is air leakage from the corners of the mouth, crooked mouth, drooling, or whether there is a problem with the eyes. "2" is to see if there is a bilateral problem, such as numbness in both arms or legs. "0" is a homophone for listening, which means to listen to whether the patient speaks clearly. If you find any problem, call 120 in time.

There is another motto called the "BE FAST" principle. "B" refers to the sudden difficulty in balance, such as dizziness or walking crookedly and having difficulty maintaining one's balance. "E" stands for Eyes, which refers to our problems such as not being able to see things clearly. "F" refers to Face, which means our face is crooked. "A" stands for Arms, which refers to our inability to lift our arms, such as suddenly being unable to pick up chopsticks. "S" refers to Speech, which refers to speech problems. "T" stands for Time. You must call 120 in time and rush to the hospital. You cannot waste time. You cannot afford to delay.

How to treat stroke clinically

Ye Shuisong : How do we treat stroke clinically? What methods and drugs are currently available to intervene in stroke?

**Min Weijie: **Currently, clinical treatments for stroke include both traditional Chinese medicine and Western medicine, and sometimes even a combination of Chinese and Western medicine.

First of all, we need to clarify what kind of stroke the patient has, is it ischemic stroke or hemorrhagic stroke? The causes of their occurrence are different, and the treatment methods are also completely different.

Treatments for ischemic stroke include dehydration and decompression, blood dilution, and antiplatelet drugs. If there is enough time, thrombolysis can be used in a timely manner, and even thrombectomy can be performed in the case of large blood vessel occlusion. In recent years, thrombectomy has made great progress and can save many people's functions and even their lives.

The treatment of hemorrhagic stroke mainly includes dehydration to reduce intracranial pressure, hemostasis and hematoma removal to avoid further brain damage. If it is hypertensive cerebral hemorrhage, we may need to clear the hematoma, such as aneurysm, aneurysm clipping surgery or interventional surgery.

After this acute phase, the patient may also receive rehabilitation treatment, functional disorder treatment, hyperbaric oxygen therapy, traditional Chinese medicine acupuncture treatment, massage and physical therapy, etc. These are all treatment methods.

What should stroke patients pay attention to after recovery?

Ye Shuisong : What issues do stroke patients need to pay attention to after recovery?

**Min Weijie: **There are several aspects.

First, a stroke doesn't happen only once. One-quarter to three-quarters of people may have a second or third stroke. Therefore, regular checkups, including medication adjustments, are important. You should monitor yourself and pay attention to your underlying diseases, such as high blood pressure, high blood sugar, and high blood lipids. Although these indicators may not necessarily lead to an immediate stroke, the final result will lead to changes in the basic conditions of blood vessels and irreversible damage. Therefore, it is most important to control these underlying diseases.

Second, after the acute phase, many people still have functional disabilities. At this time, we can actively participate in functional exercises. Auxiliary treatments such as hyperbaric oxygen can also help our patients recover as much as possible.

Finally, our patients need to examine their lifestyles based on their own situations, such as smoking, alcoholism, daily routines, and living environment, to avoid impatience.

This article is a work supported by Science Popularization China Starry Sky Project

Interviewer: Ye Shuisong

Interviewee: Min Weijie

Reviewer: Mo Dapeng, Chief Physician of Interventional Neurology, Beijing Tiantan Hospital, PhD Supervisor

Produced by: China Association for Science and Technology Department of Science Popularization

Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.