The most common type of stroke is an ischemic stroke, caused by a blood clot blocking an artery supplying blood to the brain. Ischemic strokes are the most common type of stroke, accounting for about 85% of all strokes. They reduce the oxygen and nutrients needed for brain cells to function, resulting in permanent brain damage or death.
The main cause of ischemic stroke is atherosclerosis, which is the buildup of fatty deposits (plaques) on the inner walls of the arteries. As a result of these plaques, blood flow can be reduced, or they can break off and form clots that travel to the brain. Other causes include:
Cardiac embolism: A blood clot that forms in the heart and travels to the brain, usually due to an irregular heartbeat (atrial fibrillation), a heart valve problem, or a heart infection.
Arterial dissection: A tear in the lining of an artery that allows blood to leak into the wall of the vessel, creating a flap that blocks the blood flow or forms a clot.
Small vessel disease: A condition that affects the small arteries in the brain, causing them to become thickened, narrowed, or damaged. This is also known as lacunar stroke or microangiopathy.
Hypercoagulable states: A condition that increases the tendency of the blood to clot, due to genetic factors, medications, or diseases such as cancer or lupus.
The symptoms of ischemic stroke depend on the location and size of the affected brain area, and can vary from person to person. The most common symptoms include:
Sudden weakness or numbness of the face, arm, or leg, especially on one side of the body.
Sudden confusion, trouble speaking, or understanding speech.
Sudden trouble seeing in one or both eyes.
Sudden trouble walking, dizziness, loss of balance, or coordination.
Sudden severe headache with no known cause.
In case you notice any of these symptoms, call 911 or your local emergency number immediately, as timely treatment can make a difference in the outcome of a stroke.
A doctor will perform a physical exam, ask about the patient's medical history, and order some tests to confirm the diagnosis and determine the cause and extent of an ischemic stroke. These tests may include:
Blood tests: To check for blood sugar, cholesterol, clotting factors, and other indicators of stroke risk or infection.
Imaging tests: To visualize the brain and the blood vessels, and to identify the location and size of the stroke, the type of stroke (ischemic or hemorrhagic), and the presence of any bleeding or swelling. The most common imaging tests are computed tomography (CT) scan and magnetic resonance imaging (MRI) scan.
Electrocardiogram (ECG): To measure the electrical activity of the heart and to detect any abnormal rhythms or signs of heart damage.
Echocardiogram: To use sound waves to create a picture of the heart and to assess its structure and function.
Carotid ultrasound: To use sound waves to examine the carotid arteries in the neck and to detect any narrowing or blockage.
Cerebral angiogram: To inject a dye into the blood vessels and to take X-rays to show the blood flow and any abnormalities in the brain or neck arteries.
An ischemic stroke is treated by restoring blood flow to the brain, preventing further damage, and reducing the risk of complications and recurrences. Depending on the type, cause, and severity of the stroke, as well as the time since its onset, there are several treatment options. The most common options include:
Medications: To dissolve the clot, prevent new clots, reduce the blood pressure, lower the cholesterol, and control the blood sugar. The most common medications are:
If there are no contraindications, alteplase (tPA) can be given intravenously within 4.5 hours of the onset of symptoms.
Aspirin is the most commonly used antiplatelet drug, which can be given as soon as symptoms arise, unless there is a bleeding risk or allergy.
Patients suffering from strokes caused by cardiac embolisms or arterial dissections, or those suffering from atrial fibrillation or other heart conditions are usually prescribed anticoagulants. Warfarin, heparin, and newer oral anticoagulants (NOACs) are the most commonly used anticoagulants.
Patients with high blood pressure or other cardiovascular risk factors may benefit from antihypertensives because they lower the blood pressure and reduce the stress on the heart and arteries. Angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), beta blockers, calcium channel blockers, and diuretics are the most commonly used antihypertensives.
Usually used for patients with high cholesterol or other cardiovascular risk factors, statins lower cholesterol levels and prevent plaque formation in the arteries. Among the most commonly used statins are atorvastatin, rosuvastatin, simvastatin, and pravastatin.
Procedures: To remove the clot, widen the artery, or repair the vessel. The most common procedures are:
If the clot is located in a large artery and can be accessed by the catheter, a mechanical thrombectomy can be performed within 24 hours of the onset of symptoms.
In patients with severe narrowing (stenosis) of the carotid artery and a high risk of stroke recurrence, carotid endarterectomy is performed to remove the plaque from the carotid artery and restore blood flow.
A procedure where a metal mesh (stent) is inserted into the carotid artery and expanded to keep the artery open. It is performed for patients with moderate to severe stenosis and a high risk of complications from surgery.
Aneurysm clipping: An operation in which a metal clip is placed at the base of an aneurysm (a bulge in the artery wall) to prevent it from rupturing. In addition to ischemic strokes caused by aneurysms, hemorrhagic strokes caused by ruptured aneurysms can also be treated with it.
A coil of platinum wire inserted into the aneurysm blocks blood flow into it. It can be performed for patients with an ischemic stroke caused by an aneurysm or a hemorrhagic stroke caused by a ruptured aneurysm.
The prevention of ischemic stroke involves reducing the risk factors and adopting a healthy lifestyle. The main prevention strategies are:
The purpose of medications is to prevent or treat conditions that increase the risk of stroke, such as high blood pressure, high cholesterol, diabetes, atrial fibrillation, and others. Preventive medications include antiplatelets, anticoagulants, antihypertensives, and statins, which are also used for treating the disease.
Lifestyle changes: To improve the overall health and well-being, and to lower the risk of stroke and other diseases. The lifestyle changes include:
Quitting smoking and avoiding exposure to secondhand smoke.
Limiting alcohol intake to no more than one drink per day for women and two drinks per day for men.
Eating a balanced diet that is low in salt, saturated fat, trans fat, cholesterol, and added sugars, and high in fruits, vegetables, whole grains, lean protein, and healthy fats.
Exercising regularly for at least 150 minutes per week of moderate-intensity aerobic activity, or 75 minutes per week of vigorous-intensity aerobic activity, or a combination of both, along with muscle-strengthening exercises at least twice per week.
Maintaining a healthy weight and a body mass index (BMI) between 18.5 and 24.9 kg/m2.
Managing stress and coping with emotional problems in a positive way.
Getting enough sleep and treating any sleep disorders, such as obstructive sleep apnea.
Following up with the doctor regularly and taking the prescribed medications as directed.
In the event of an ischemic stroke, medical attention and prompt treatment are necessary immediately. This condition can, however, be prevented or reduced by identifying and modifying the risk factors, and adopting a healthy lifestyle. You will be able to protect your brain and your health, and enjoy a higher quality of life as a result.
