Stroke

A stroke is a medical condition that happens when the blood flow to part of the brain is blocked. This can cause parts of the brain to stop working properly.

There are two main types of stroke: ischemic, which is caused by a lack of blood flow, and hemorrhagic, which is caused by bleeding in the brain.

Common signs and symptoms of a stroke include facial drooping, inability to walk, move or feel on one side of the body, problems understanding or speaking, dizziness, or loss of vision to one side. These symptoms usually appear quickly after a stroke occurs. If they last less than 24 hours, it is called a transient ischemic attack, or mini-stroke. In some cases, a severe headache may also be a sign of a hemorrhagic stroke.

The biggest risk factor for having a stroke is having high blood pressure. Other risks include high blood cholesterol, tobacco smoking, obesity, diabetes mellitus, and having had a previous mini-stroke. Strokes can often be prevented by managing these risk factors and, in some cases, through special medical treatments. When a stroke happens, quick action is important, as early treatment can help save brain function and improve recovery.

Classification

Strokes come in two main types: ischemic and hemorrhagic. An ischemic stroke happens when the blood flow to part of the brain gets blocked, often by a clot. A hemorrhagic stroke happens when a blood vessel in the brain bursts and causes bleeding.

Most strokes, about 87%, are ischemic. The rest are hemorrhagic. Ischemic strokes can be caused by clots that form in the brain or travel there from elsewhere. Hemorrhagic strokes occur when weak spots in the brain's blood vessels break open, leading to bleeding.

Signs and symptoms

A quick way to remember the warning signs of a stroke is FAST: facial droop, arm weakness, speech difficulty, and time to call emergency services. These signs can help doctors treat the stroke faster. If you notice any of these signs, it’s important to get help right away.

Other symptoms can include trouble with balance, vision, or walking. Sometimes people may have trouble speaking or understanding others, or they might notice weakness or numbness on one side of their body. Severe headaches can also be a sign that something is wrong. If you or someone else shows these signs, seek medical help immediately.

Causes

Strokes happen when blood flow to part of the brain stops or when bleeding occurs in the brain. There are two main types: ischemic strokes, where blood flow is blocked, and hemorrhagic strokes, where bleeding occurs.

Ischemic strokes can be caused by blood clots in arteries. These clots can form in large arteries or small blood vessels in the brain. Other causes include heart problems, where clots can travel to the brain. Sometimes, strokes happen without clear symptoms but still damage the brain.

Hemorrhagic strokes happen when small blood vessels in the brain burst, often due to high blood pressure. Other causes can include injuries, bleeding disorders, or certain drugs. Strokes can also be triggered by conditions like cancer.

Pathophysiology

An ischemic stroke happens when blood flow to part of the brain stops. This can be caused by narrow blood vessels, blood clots, or tiny pieces of clots called emboli that block the flow. When blood flow stops, brain cells can’t get the oxygen and energy they need, which can hurt them.

A hemorrhagic stroke occurs when bleeding in the brain causes damage. This bleeding can be due to high blood pressure, a burst aneurysm, or other reasons. The pressure from the blood can squeeze brain tissue and harm cells.

Diagnosis

Stroke is diagnosed using different ways to check the brain and see what is happening. Doctors might do a physical exam and ask about symptoms. They also use special scans like CT scans or MRI scans to look closely at the brain. These scans help see if there is a blockage or bleeding in the brain.

Doctors might do other tests to find out what caused the stroke, like checking the heart or blood vessels. Sometimes, strokes can happen without clear symptoms, called silent strokes. These can still harm the brain over time. It is important for doctors to diagnose strokes correctly to give the right treatment.

Main article: NIHSS

Main articles: MRI scans, Doppler ultrasound, arteriography

Prevention

Preventing stroke is very important for keeping people healthy. One way to help prevent stroke is by taking care of your health, like eating well, exercising, and not smoking. Doctors also recommend medicines for some people, especially if they have had a stroke before or have a high risk of having one. For example, aspirin can help prevent another stroke in some cases.

Some of the biggest risks for stroke are high blood pressure and irregular heartbeats. Keeping these under control can greatly lower the chance of having a stroke. Other risks include high cholesterol, diabetes, and not being active. Women who have had certain pregnancy problems may also have a higher risk of stroke later in life.

Management

Stroke is an emergency that needs quick medical help. The treatment depends on the type of stroke and how soon help is given.

For ischemic strokes, doctors may use medicine to break up blood clots or remove them with special tools. This works best when done quickly. For hemorrhagic strokes, doctors focus on supporting the patient and controlling blood pressure. Special stroke units in hospitals help patients recover better with careful monitoring and care.

Rehabilitation

Stroke rehabilitation helps people who have had a stroke get their skills back and adjust to any changes. The aim is to help them return to normal life as much as possible. This should start as soon as possible and can need many helpers, like doctors, nurses, physiotherapists, occupational therapists, and speech-language pathologists.

Getting better usually happens mostly in the first few months, but some people keep getting better for years. Doing exercises every day and having a healthy way of living can help the brain get better. While getting completely better is rare, many people get better with the right help and care.

Prognosis

Many people who have a stroke may face challenges that affect their work and daily lives. These challenges can be physical, emotional, or mental, and they depend on where and how much of the brain is affected.

Physical effects of stroke can include weakness, numbness, trouble with speech or vision, and difficulty with everyday tasks. Some people may also have trouble controlling their bladder or experience pain.

Emotional and mental effects can include feelings of anxiety, changes in mood, and trouble expressing emotions. Many stroke survivors also experience depression, which can make it harder to stay motivated and recover. Therapy and support from family can help with these emotional challenges. Stroke can also affect thinking skills, memory, and the ability to notice things on one side of the body.

Epidemiology

Stroke is one of the most common causes of death around the world. It often happens to people over 65 years old. People from South Asia have a higher chance of having a stroke.

In the United States, stroke can also cause disability. The chance of having a stroke gets higher as people get older, especially after age 45. Men have a slightly higher chance than women, but because women often live longer, they can face higher risks later in life. If someone has had a stroke before, they are more likely to have another one.

History

People have known about sudden weakness and loss of movement for a very long time. The Greek doctor Hippocrates (460 to 370 BC) was the first to describe what we now call a stroke. He called it apoplexy.

Over many years, doctors have studied this condition to learn more about what causes it.

In 1658, a doctor named Johann Jacob Wepfer said that some strokes happen when there is bleeding in the brain. He also looked at the blood vessels in the brain and thought that blockages in these vessels could cause other types of stroke. Today, we use names like cerebrovascular accident or brain attack to show how important it is to treat a stroke quickly.

Research

Scientists are studying ways to help people get better after a stroke. Since 2017, they have looked at procedures like angioplasty and stents. They want to see if these work better than medicines such as statins, antithrombotics, or antihypertensive drugs.

Studies with animals show that giving a small amount of amphetamine a few days after a stroke might help. This research found changes in brain proteins that could help with recovery.