Ischemic stroke occurs when a blood clot blocks brain blood flow. It’s the most common kind of stroke and about 80% of all strokes occur this way.
Clot-busting medicines (thrombolytic drugs) are available within three to four and a half hours after symptoms start. They dissolve existing clots to help prevent or reduce damage from a stroke.
The arteries that supply blood to the brain may become narrow or blocked. This reduces or stops blood flow to the brain (ischemia) and causes brain cells to die. Blood clots or fatty buildups called plaque often cause ischemic strokes. These clots may form in the arteries of the brain or other blood vessels in the body. They can also break loose from the heart or other places in the body and travel through the bloodstream to block an artery in the brain (ischemic embolism).
Sometimes blood clots form in a carotid artery that supplies oxygen-rich blood to the brain. These clots block blood flow and cut off the brain’s oxygen supply, which damages brain cells. Blood clots can also form in the narrow passageways that branch out from arteries into smaller blood vessels in the brain. These clots, called carotid dissections, can be a major cause of ischemic stroke.
A blood clot that forms inside the skull (intracerebral hemorrhage) can also cause ischemic strokes. Hemorrhage can be caused by a ruptured aneurysm or by a problem with one of the blood vessels that pass through the brain (carotid stenosis). Blood clots formed in the neck (atrial fibrillation) or the brain (carotid artery thrombosis) also can lead to ischemic stroke.
Certain diseases and conditions make you more likely to have a stroke, including atrial fibrillation, high blood pressure, diabetes, high cholesterol and smoking. A family history of stroke can also raise your risk for having a stroke.
If you have a stroke, you will be treated in the hospital to prevent complications and improve your recovery. You will need to be monitored closely for a day or so. After that, your healthcare professional will focus on helping you regain movement and feeling in the parts of your body affected by the damage to your brain. Different parts of the brain control different abilities, such as muscle movement, balance and speech — so the area of the brain affected by your stroke will determine what kinds of symptoms you have.
Treatment for ischemic stroke includes medicines and procedures to remove or break up the clots that cause your stroke. The sooner this treatment starts, the less brain damage you’ll have. The most important medicine is one that dissolves blood clots (thrombolytic medication). It needs to be started within 4 1/2 hours after your stroke begins. Other drugs to prevent clots from forming in your arteries (anticoagulants) and procedures such as a mechanical clot removal with a catheter (thrombectomy) can help reduce your chances of having another stroke.
If you have a clot-caused stroke, the first signs often show up in your face and neck (drooping). You may also have trouble understanding speech or slur your words. A stroke is a medical emergency, and the sooner you get help, the more likely it is that your brain will repair itself. Doctors will want to know exactly when your symptoms started and what they were.
The goal of treatment is to quickly restore blood flow in the brain so that your body can get the oxygen it needs. This is especially important for ischemic strokes caused by a blood clot, because the longer you wait to get treated, the more damage your brain might suffer. The most effective treatments for a clot-caused stroke start within three to four and a half hours of when your symptoms began.
A clot-busting medication can dissolve existing clots and prevent new ones from forming. These drugs are only an option if you can be treated within this time frame because they can cause dangerous complications — such as bleeding — if used after that time. Another possible treatment is a procedure called mechanical thrombectomy. This involves inserting a catheter into the affected artery and retrieving or breaking up the clot. This can be done up to six hours after your symptoms started and sometimes later.
It’s also important to determine what type of stroke you had, because a different treatment approach is needed for hemorrhagic strokes. If you have a hemorrhagic stroke, surgery is needed to repair the leaking blood vessel.
For people with ischemic stroke, treatment is focused on speed and recovery. The quicker the person has medical care when they have a stroke, the less damage there is to their brain and the more likely they are to recover. Treatments may include medicine to break up blood clots, medicines to make the blood less likely to clot and procedures that physically remove a clot or widen a blocked artery.
Most ischemic strokes occur when an artery that supplies blood to the brain is blocked by a clot or fatty deposit (atherosclerosis). These clots cut off oxygen and nutrients to brain cells, leading to the symptoms of a stroke. The longer that part of the brain is deprived of oxygen, the greater the damage and the more severe the symptoms are likely to be. That’s why it’s so important for anyone who has symptoms of a stroke to call 911 and get to the hospital right away.
The first thing that is done is to try to remove the clot that is blocking an artery. This is called thrombolytic therapy and it usually involves an injection of the drug tPA (tissue plasminogen activator) or its generic equivalent, alteplase or tenecteplase. This medication restores blood flow by dissolving the clot, and it has to be given within 4.5 hours from when symptoms started.
Other treatments that are done right away include lowering high blood pressure and giving medicines to prevent more clots from forming. Some people may also have surgery to treat an aneurysm if that’s the cause of their stroke.
Other important treatment is to start rehabilitation or physical therapy right away. This can help you relearn skills that you lost due to the stroke. It can also help you deal with problems like depression or anxiety that sometimes happen after a stroke and can hold you back from making the best progress in your recovery.
The first step in preventing a stroke is recognizing the warning signs. Often, one side of the face will droop when someone is having a stroke, and they may also have trouble raising their arms or speak in slurred speech. If you have a loved one who is experiencing these symptoms, call 911 immediately. You have a short window of time to give them blood-clot-busting drugs (thrombolytics), which can minimize the damage and improve their chances of recovering fully.
The next step is restoring circulation in the brain, usually with medication. Sometimes, it’s possible to do this by inserting a small tube-like device called a catheter into a large blood vessel on the body and threading it up to the clot in the brain. Once the clot is located, the healthcare provider can use the tip of the catheter to break up or suck up the clot. This procedure is referred to as mechanical thrombectomy.
Another treatment involves cooling the brain — a process known as mild hypothermia. This works by lowering the temperature in the brain, which protects cells from the harmful effects of stroke-related toxins and inflammatory molecules.
A health care provider can also lower your risk by managing any health conditions you have, such as heart disease, high cholesterol, diabetes or high blood pressure. They can recommend lifestyle changes and medicines to help.
If you’ve already had an ischemic stroke, you have a higher risk of having another one. You can reduce your risk by following healthy habits, such as exercising regularly, eating a balanced diet and not smoking. You should also take your medicine as prescribed. It’s especially important to see your doctor if you have a history of TIAs or mini-strokes, which are sometimes warning signs for a future stroke.
A stroke is a life-changing event, but with early medical treatment and good lifestyle choices, it’s often possible to recover and regain many of your abilities. You should also seek mental health care, as depression and anxiety are common after a stroke. Your doctor can prescribe medications and recommend therapy or counseling to help.
Ischemic Stroke occurs when an artery that supplies blood to the brain gets blocked by a blood clot. It is the most common type of stroke.
The sooner someone having a stroke is treated with a drug that breaks up clots, the less damage is done. The best way to spot a stroke is to look for signs such as:
Ischemic strokes account for the majority of all strokes and happen when blood flow to the brain is cut off. They can be caused by a blood clot, or they can be due to atherosclerosis (a disease that narrows the arteries over time). The blockage may occur in any of the arteries that supply the brain.
It’s important to notice any difficulty with speaking or swallowing. If you or someone you know is experiencing these symptoms, call 911 and get to the hospital right away. The faster you receive treatment, the less damage will be done and the more likely you are to recover fully.
The doctor will ask questions about the person’s history, then do a physical exam and order imaging tests to check the severity of the stroke and how well the brain is functioning. They will also want to know if you have any symptoms like a drooping face (see the FAST rules below).
Doctors can usually identify which part of the brain is affected by looking at the symptoms and asking the person to do simple tasks, such as answering questions or following directions. They can also test the person’s balance and movement, vision, arm and leg strength, and speech.
Some people who have ischemic strokes also experience other difficulties after the event, such as memory problems or trouble thinking clearly or making judgments. It’s also common to have emotional problems, such as depression, after a stroke.
If a person’s symptoms don’t improve in 3 days, it’s probably because they have a lot of fluid build-up in their brain (edema). This swelling can cause the skull to expand and push the brain against the skull’s rigid structures. This can cause more damage to the brain and make the symptoms worse.
Some people who have hemorrhagic strokes may need surgery to remove the blood clot and relieve pressure on their brain. They may also need a procedure called mechanical thrombectomy, in which a surgeon uses a tool to break up or dislodge the clot. They may also need a procedure to repair damaged blood vessels if an aneurysm, arteriovenous malformation or other condition caused the hemorrhagic stroke.
A stroke can cause problems with walking because of a weakness or loss of feeling on one side of the body. It can also cause difficulties in moving around or standing up because of a change in the way you lift and position your foot while walking (foot drop). This problem is caused by the fact that a blood clot or piece of fatty plaque blocks a blood vessel supplying blood to part of the brain. This is called an ischemic stroke and it accounts for about 87% of all strokes. It can also be caused when layers of the walls of an artery that carries blood to the brain separate from each other (called dissection).
Ischemic stroke symptoms often develop quickly, so it’s important to notice and act fast if you think someone is having a stroke. It’s important to know that getting medical care within hours after the first symptoms start increases a person’s chances of recovering fully.
Look for the FAST signs of a stroke:
F = Face: Ask them to smile and see whether one side of their mouth or eyelid droops or feels numb. A = Arms: Ask them to raise both arms. Does one drift downward? S = Speech: Is their speech slurred or difficult to understand? T = Time: Did the symptoms start suddenly? If so, it’s likely that they are having a stroke.
Sometimes, a clot or narrowing of an artery can cause a temporary condition known as a transient ischemic attack (TIA). These are similar to a stroke but they don’t involve any brain damage. They may disappear in a few minutes and are sometimes called “ministrokes.” People who have TIA should watch out for the early warning signs of a full stroke, as they can be a sign that a person is at high risk of having a permanent one.
Difficulty in swallowing can lead to malnutrition and dehydration, because the affected person isn’t able to take in food and drink. It can also be dangerous because it can affect breathing. If the problem is severe, a patient can inhale food, saliva or vomit into their lungs, and this is called aspiration.
A clot in an artery blocks oxygen-rich blood from reaching part of the brain, causing cells there to malfunction or die. The symptoms depend on which area of the brain is affected and what functions are controlled by those cells. For example, strokes can cause weakness or numbness on one side of the face, trouble walking or problems with vision. They can also lead to memory and concentration problems. If you notice any of these symptoms in another person or yourself, call 911 (or your local emergency services number) and get to the hospital as quickly as possible. Remember, most ischemic strokes occur rapidly, over minutes to hours, so the sooner treatment begins, the better the chance for a good recovery.
The outlook varies greatly, depending on how severe the stroke is and how long it goes untreated. People who receive prompt medical care often recover, but it’s important to understand that many patients have significant disabilities and may need ongoing rehabilitation to regain their former abilities.
To diagnose a stroke, doctors ask questions about the person’s past health and habits and perform tests such as blood work and an electrocardiogram. The person also may be given a CT scan to determine whether the stroke is ischemic or hemorrhagic. MRI and other noninvasive imaging techniques are becoming more common as well.
If the stroke is ischemic, doctors try to determine when it started. This is important because some medications and procedures used to break up clots must be started within 4.5 hours of when the stroke began to be effective.
Other stroke-related symptoms can include headache, nausea or vomiting, difficulty with balance or coordination and a sudden change in mental state, such as confusion or depression. Depression and anxiety can affect a person’s ability to concentrate and perform cognitive tasks, and should be reported to your doctor or therapist.
You can reduce your risk of having a stroke by keeping your blood pressure, cholesterol and body weight in a healthy range. You should avoid smoking, drink alcohol in moderation and take any medicines your doctor prescribes.
A clot or plaque blockages a blood vessel that supplies oxygen to part of the brain. This causes damage and reduces the brain’s ability to function. This type of stroke is called an ischemic stroke. The symptoms can range from a sudden weakness or tingling on one side of the body to trouble walking or understanding what others say (dysphasia). They can also include problems with vision, such as double vision or difficulty recognising people or objects (heteronymous hemianopsia) and problems with speech, including slurred speech or not being able to understand other people’s words (aphasia).
A stroke can also cause emotional changes, such as depression and irritability. It can also make people impulsive and unable to control their behavior, especially when they are anxious or stressed. This may lead to a lack of care for the health needs of family members and friends, as well as social withdrawal.
If someone has an ischemic stroke, doctors must act quickly to restore blood flow to the brain. This is done with “clot-busting” drugs that dissolve a clot and prevent it from causing more damage. They can be given in a vein (IV) or orally (intravenous). They are also used to treat a heart condition called atrial fibrillation, which raises the risk of clots that can travel to the brain.
It is important to know when a person’s symptoms start, so they can get immediate medical attention. The sooner they receive treatment, the more likely it is that the effects of the stroke will be limited and possibly reversible.
A doctor can diagnose an ischemic stroke by asking about the person’s past health and symptoms, doing a physical exam and giving them a neurological exam. Other tests include an electrocardiogram, which looks for signs of heart damage, and lab blood tests to check blood sugar levels, how the liver and kidneys work and whether there are signs of an infection or high blood pressure. A computed tomography (CT) scan may be done to see if there is a clot or other problem that is causing the symptoms.
A clot or piece of a clot blocks blood flow to part of the brain, starving that area of the brain of oxygen. The symptoms depend on the area of the brain affected. They may include weakness or numbness on one side of the body, trouble raising or lowering the arms, and slurred speech.
For the most common type of stroke (ischemic), thrombolytic drugs help break up dangerous blood clots and restore normal blood flow. These medicines are given through an IV in a vein or by using a long catheter that delivers the medicine directly to the clot site. The sooner these clot-dissolving medications start working, the more likely you are to have a good outcome.
Your healthcare provider decides whether to give you a clot-dissolving drug and when based on many factors, including your symptoms and medical history. Most hospitals and ambulances have these medicines on hand so they can give you them as soon as possible. They usually begin within three hours after your first signs of a stroke.
Thrombolytic drugs may be used to treat clots in the arteries that supply the heart and brain — the main cause of most heart attacks and strokes. They are also sometimes given to patients who have a life-threatening blood clot in their legs (deep vein thrombosis) or an artery in the lungs (acute pulmonary embolism).
There are two types of clot-dissolving drugs: alteplase and reteplase. Alteplase is the preferred thrombolytic drug for treating acute ischemic stroke because it has been shown to improve outcomes in several large trials. Several smaller trials have reported similar results.
One possible side effect of clot-dissolving treatments is intracranial hemorrhage. This is a serious complication of the treatment that can be fatal. This happens in up to 25% of patients who receive thrombolytic drugs for ischemic stroke. It can also happen if the clot breaks up and is carried to another part of the body. It is more common in people who have a large clot, and it occurs more often in older adults.
Another possible risk is that the clot that breaks up may be too small to allow normal blood flow. Then the clot might not dissolve properly and could get stuck in the blood vessel or in the lungs, causing a life-threatening pulmonary embolism. This is more common with clots that are hard, large and inflexible.
For patients who experience a stroke caused by a large blood clot, a mechanical extraction device called thrombectomy may be used. A thrombectomy is performed by inserting a thin plastic tube (catheter) into the blood vessel in your groin that supplies blood to the head and brain, usually after first administering clot-busting drugs such as alteplase. The procedure is performed under local or general anaesthesia.
The thrombectomy procedure is typically led by an interventional neuroradiologist, a specialist in blood vessels in the brain and spine. The technique involves using different catheter-based devices, including stent retrievers and direct aspiration methods, under imaging guidance. These devices are typically made of a type of nickel-titanium alloy called nitinol because it is flexible and can be used to break up and remove the clot from the blood vessel.
Thrombectomy has been shown to improve mRS scores and reduce disability at 90 days compared to medical therapy alone. It is particularly effective when a patient has experienced a large blood clot in the large blood vessels that supply up to and into the brain. It is also an important treatment option for those with a blood clot that is resistant to clot-busting medications.
However, there are a number of things that can affect the success of a thrombectomy, such as how much time has passed since the symptoms of a stroke first started. Consequently, it is crucial that patients are assessed as soon as possible after experiencing a stroke-like event. This is best done at a level 1 or level 2 stroke centre, with routine 24/7 access to CT scanning, high dependency care and rehabilitation services, and dedicated teams of catheter laboratory staff and specialised surgeons for thrombectomy.
In most cases, if a clot is removed within six hours of stroke-like symptoms beginning, there is a good chance of a better recovery. This is because the longer the clot blocks the blood flow to the brain, the more damage is expected and the longer it takes to recover. This is why it’s important to act quickly and dial 911 if you have symptoms such as sudden numbness or weakness.
Thrombolysis with recombinant tissue plasminogen activator (rtPA, alteplase) significantly reduces long-term disability after an ischaemic stroke. If given within 4.5 hours after stroke onset, 7% more patients achieve independence 3 months later with thrombolysis compared to placebo, and the benefit is greater the earlier thrombolysis is started. This is the only treatment proven to improve functional outcome after an ischaemic stroke. However, rtPA increases the risk of symptomatic intracranial hemorrhage. It also increases the likelihood of a fatal cardiac event in some patients, and death occurs in 8.4% of those treated with rtPA as compared to 7.7% who received placebo.
The rtPA molecule works by converting plasminogen to plasmin, which dissolves the fibrin that causes blood clots and restores blood flow to brain cells. It is administered intravenously, either as a bolus or over 60 minutes. It is not recommended for patients with a bleed in the head, neck or eye, bleeding disorders, a history of deep venous thrombosis or haemophilia. rtPA can trigger a life-threatening allergic reaction in some people. This is due to the rapid conversion of plasminogen to plasmin, causing mast cell degranulation and subsequent anaphylactic-type reactions. It is also contraindicated in people who are taking aspirin or heparins, or have an International Normalized Ratio (INR) higher than 1.7, or activated partial thromboplastin time (aPTT) above 40 seconds.
A number of randomized trials have shown that IV alteplase reduces the extent and duration of ischemic stroke. Two of the studies – ECASS 1 and the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) – measured lesion size using short-term follow-up imaging, and found that allocation to the alteplase group was associated with less progression in the extent of the ischemic lesion compared to placebo (IST-3).
Other trials have analyzed long-term outcomes and have shown that thrombolysis significantly reduces disability. The Thrombolysis for Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) study, which used the same rtPA formulation as ECASS 1, analyzed both the unadjusted and adjusted analyses of the primary end point, showing that rtPA reduced the risk of a significant disability at 3 months by 7%, and this benefit was even more pronounced when the patients were grouped by whether they had a good or poor prognosis at baseline.
Ischemic strokes happen when part of your brain loses its blood supply, cutting off oxygen and nutrients to cells in the affected area. This can be caused by a blood clot that forms in your brain (thrombosis), a fragment of a clot from somewhere else in your body that breaks free and travels to the brain (embolism) or a blockage in a small vessel in the brain (lacunar stroke).
A new study suggests that surgery can improve the recovery of large areas of dead tissue following an ischemic stroke by helping your body reconnect broken connections around the area of damaged brain. The surgical procedure is called endovascular thrombectomy.
During the operation, your doctor inserts a tube-like device called a catheter into a blood vessel in your arm or leg. Then, using imaging guidance, the healthcare provider guides the catheter to the location of your clot. Once the catheter reaches the clot, it may break apart and suck it up or use a device to remove the clot, such as a stent retriever or a clot removal pump. Mild hypothermia — lowering your body temperature — is sometimes used with this treatment because the brain cells die more quickly at higher temperatures.
After your clot is removed or treated, other treatments can help you prevent another stroke. These can include taking daily medications that reduce your risk of clots, such as antiplatelet drugs or blood thinners. Medications that control high blood pressure and cholesterol can also lower your chances of having another stroke. These medicines include statins (e.g., atorvastatin and lovapride) and other drugs that lower LDL-C levels, such as ezetimibe and PCSK9 inhibitors (e.g., alirocumab and evolocumab).
If you had a hemorrhagic stroke, your doctor may need to clip an artery that has burst (hemorrhage). He or she might also use a device to drain the extra fluid from your skull or neck. You might need a feeding tube to get liquids into your stomach, which can be helpful if you’re not able to drink enough by yourself. The tube is usually placed through your nose into your throat, but if you can’t swallow, the tube may go into your stomach.
