By Medicover Hospitals
What is a Stroke?
A stroke damages the brain due to the interruption of the blood supply. A stroke is a medical emergency. Symptoms of a stroke include difficulty walking, speaking, and understanding, and paralysis or numbness of the face, arm, or leg. Early treatment with medications such as tissue plasminogen activator (tPA (clot buster)) can minimize brain damage. Other treatments focus on reducing complications and preventing further strokes.
A stroke, also known as cerebrovascular accident or stroke, occurs when part of the brain loses its blood supply and the part of the body controlled by blood-starved brain cells stops functioning. This loss of blood supply can be ischemic due to lack of blood flow or hemorrhagic due to bleeding into brain tissue. A stroke is a medical emergency because a stroke may cause death or permanent disability. There are options for treating ischemic strokes, but treatment should be started within the first few hours of the onset of signs of a stroke.
A transient ischemic attack (TIA or mini-stroke) describes a short duration ischemic stroke where the symptoms disappear spontaneously. This situation also necessitates an emergency assessment in an attempt to minimize the risk of a future stroke. By definition, a stroke would be classified as TIA if all symptoms disappeared within 24 hours.
Types of Stroke
Strokes fall into three major categories: transient ischemic attack (TIA), ischemic stroke, and hemorrhagic stroke. These categories are further broken down into other types of strokes, including:
- embolic stroke
- thrombotic stroke
- intracerebral stroke
- subarachnoid stroke
The type of stroke you have affects your treatment and recovery process.
Ischemic stroke
During an ischemic stroke, the arteries supplying blood to the brain narrow or become blocked. These blockages are caused by blood clots or blood flow that's severely reduced. They can also be caused by pieces of plaque due to atherosclerosis breaking off and blocking a blood vessel.
The two most common types of ischemic strokes are thrombotic and embolic. A thrombotic stroke happens when a blood clot forms in one of the arteries supplying blood to the brain. The clot passes through the bloodstream and becomes lodged, which blocks blood flow. An embolic stroke is when a blood clot or other debris forms in another part of the body and then travels to the brain.
Transient ischemic attack (TIA)
A transient ischemic attack, often called a TIA or ministroke, occurs when blood flow to the brain is blocked temporarily. Symptoms, which are similar to those of a full stroke, are typically temporary and disappear after a few minutes or hours.
A TIA is usually caused by a blood clot. It serves as a warning of a future stroke, so don't ignore a TIA.
According to the CDC, more than one-third of people who experience a TIA and don't get treatment to have a major stroke within a year, up to 10 to 15 percent of people who experience a TIA have a major stroke within three months. Here's how to understand TIAs and how to prevent a more serious stroke in the future.
Hemorrhagic stroke
A hemorrhagic stroke happens when an artery in the brain breaks open or leaks blood. The blood from that artery creates excess pressure in the skull and swells the brain, damaging brain cells, and tissues.
The two types of hemorrhagic strokes are intracerebral and subarachnoid. An intracerebral hemorrhagic stroke, the most common type of hemorrhagic stroke, happens when the tissues surrounding the brain fill with blood after an artery burst. Subarachnoid hemorrhagic stroke is less common. It causes bleeding in the area between the brain and the tissues that cover it.
According to the American Heart Association, about 13 percent of strokes are hemorrhagic. Learn more about the causes of hemorrhagic stroke, as well as treatment and prevention.
Causes
Thrombotic stroke
The blockage of an artery in the brain by a clot is the most common cause of a stroke. The part of the brain that is supplied by the clotted blood vessel is then deprived of blood and oxygen. As a result of the deprived blood and oxygen, the cells of that part of the brain die, and the part of the body that it controls stops working. Typically, a cholesterol plaque in one of the brain's small blood vessels ruptures and starts the clotting process.
Risk factors for narrowed blood vessels in the brain are the same as those that cause narrowing blood vessels in the heart and heart attack. These risk factors include:
Embolic stroke
Another type of stroke may occur when a blood clot or a piece of atherosclerotic plaque breaks lose, travels through the bloodstream, and lodges in an artery in the brain. When blood flow stops, brain cells do not receive the oxygen and glucose they require to function and a stroke occurs. This type of stroke is referred to as an embolic stroke. For example, a blood clot might originally form in the heart chamber because of an irregular heart rhythm, like atrial fibrillation. Usually, these clots remain attached to the inner lining of the heart, but occasionally they can break off, travel through the bloodstream, block a brain artery, and cause a stroke. An embolism, either plaque or clot, may also originate in a large artery and then travel downstream to clog a small artery within the brain.
Cerebral hemorrhage
A cerebral hemorrhage occurs when a blood vessel in the brain ruptures and bleeds into the surrounding brain tissue. A cerebral hemorrhage causes stroke symptoms by depriving blood and oxygen to parts of the brain in a variety of ways. Blood flow is lost to some cells. Additionally, blood is very irritating and can cause swelling of brain tissue. Edema and the accumulation of blood from a cerebral hemorrhage increases pressure within the skull and causes further damage by squeezing the brain against the bony skull. This further decreases blood flow to brain tissue and its cells.
Subarachnoid hemorrhage
In a subarachnoid hemorrhage, blood accumulates in the space beneath the arachnoid membrane that lines the brain. The blood originates from an abnormal blood vessel that leaks or ruptures. Often this is from an aneurysm. Subarachnoid hemorrhages usually cause a sudden severe headache, nausea, vomiting, light intolerance, and stiff neck. If not recognized and treated, major neurological consequences, such as coma, and brain death may occur.
Vasculitis
Another rare cause of stroke is vasculitis, a condition in which the blood vessels become inflamed causing decreased blood flow to parts of the brain.
Migraine headache
There appears to be a very slightly increased occurrence of stroke in people with migraine headaches. The mechanism for migraine or vascular headaches includes narrowing of the brain blood vessels. Some migraine headache episodes can even mimic stroke with loss of function of one side of the body or vision or speech problems. Usually, the symptoms resolve as the headache resolves.
Diagnosis
Your doctor will ask you or a family member about your symptoms and what you were doing when they arose. They'll take your medical history to find out your stroke risk factors. They'll also:
- ask what medications you take
- check your blood pressure
- listen to your heart
You'll also have a physical exam, during which the doctor will evaluate you for:
- balance
- coordination
- weakness
- numbness in your arms, face, or legs
- signs of confusion
- vision issues
Your doctor will then do certain tests. A variety of tests are used to aid in the diagnosis of a stroke. These tests can help doctors determine:
- if you had a stroke
- what may have caused it
- what part of the brain is impacted
- whether you have bleeding in the brain
Tests to diagnose strokes
You may go through various tests to further help your doctor determine if you've had a stroke or to rule out another condition. These tests include:
Blood tests
Your doctor might draw blood for several blood tests. Blood tests can determine:
- your blood sugar levels
- if you have an infection
- your platelet levels
- how fast your blood clots
MRI and CT scan
You may undergo either or both a magnetic resonance imaging (MRI) scan and a computerized tomography (CT) scan.
The MRI will help see if any brain tissue or brain cells have been damaged. A CT scan will provide a detailed and clear picture of your brain that shows any bleeding or damage in the brain. It may also show other brain conditions that could be causing your symptoms.
Electrocardiogram (ECG or EKG)
Your doctor may order an electrocardiogram (EKG), too. This simple test records the electrical activity in the heart, measuring its rhythm and recording how fast it beats. It can determine if you have any heart conditions that may have led to strokes, such as a prior heart attack or atrial fibrillation.
Cerebral angiogram
Another test your doctor may order to determine if you've had a stroke is a cerebral angiogram. This offers a detailed look at the arteries in your neck and brain. The test can show blockages or clots that may have caused symptoms.
Carotid ultrasound
A carotid ultrasound, also called a carotid duplex scan, can show fatty deposits (plaque) in your carotid arteries, which supply the blood to your face, neck, and brain. It can also show whether your carotid arteries have been narrowed or blocked.
Echocardiogram
An echocardiogram can find sources of clots in your heart. These clots may have traveled to your brain and caused a stroke.
Treatment
- Because ischemic and hemorrhagic strokes have different causes and effects on the body, both require different treatments.
- Rapid diagnosis is important for reducing brain damage and enabling the doctor to treat the stroke using a suitable method for the type.
- The sections below cover the treatment options for ischemic stroke and hemorrhagic stroke, as well as some general rehabilitation tips for both types.
Ischemic stroke
- Ischemic stroke occurs due to blocked or narrowed arteries. Treatment tends to focus on restoring an adequate flow of blood to the brain.
- Treatment starts with taking drugs that break down clots and prevent others from forming. A doctor may administer blood thinners such as aspirin or an injection of tissue plasminogen activator (TPA).
- TPA is very effective at dissolving clots. However, the injection needs to take place within 4.5 hours of the stroke symptoms starting.
- Emergency procedures include administering TPA directly into an artery in the brain or using a catheter to physically remove the clot. Research is ongoing as to the benefits of these procedures.
- There are other procedures that surgeons can perform to reduce the risk of strokes or TIAs. A carotid endarterectomy, for example, involves opening the carotid artery and removing plaque that could break and travel to the brain.
- Another option is angioplasty. This involves a surgeon inflating a small balloon inside a narrowed artery using a catheter. Afterward, they will insert a mesh tube, or a stent, into the opening. This prevents the artery from narrowing again.
Hemorrhagic stroke
- Blood leaking into the brain can cause a hemorrhagic stroke. Treatment focuses on controlling the bleeding and reducing the pressure on the brain.
- Treatment often begins with taking drugs that reduce pressure in the brain and control overall blood pressure, as well as preventing seizures and any sudden constrictions of blood vessels.
- If a person is taking blood-thinning anticoagulants or antiplatelet medication, such as warfarin or clopidogrel, they can receive medications to counter the effects of the blood thinners.
- Surgeons can repair some of the problems with blood vessels that have led to or could lead to hemorrhagic strokes.
- When an aneurysm - or a bulge in a blood vessel that may burst - causes a hemorrhagic stroke, a surgeon can place small clamps at the base of the aneurysm or fill it with detachable coils to stop the blood flow and shrink the aneurysm.
- If the hemorrhage occurs due to an AVM, a surgeon can remove it. AVMs are connections between arteries and veins that can be at risk of bleeding.
Rehabilitation
- A stroke is a potentially life-changing event that can have lasting physical and emotional effects.
- Successful recovery from a stroke will often involve specific therapies and support systems, including:
- Speech therapy: This helps with problems producing or understanding speech. Practice, relaxation, and changing communication styles can all make communicating easier.
- Physical therapy: This can help a person relearn movement and coordination. It is important to stay active, even though this may be difficult at first.
- Occupational therapy: This can help a person improve their ability to carry out daily activities, such as bathing, cooking, dressing, eating, reading, and writing.
- Support groups: Joining a support group can help a person cope with common mental health issues that can occur after a stroke, such as depression. Many find it useful to share common experiences and exchange information.
- Support from friends and family: Close friends and relatives should try to offer practical support and comfort after a stroke. Letting friends and family know what they can do to help is very important.
- Rehabilitation is an important and ongoing part of stroke treatment. With the right assistance and the support of loved ones, regaining a normal quality of life is usually possible, depending on the severity of the stroke.
When to see a Doctor?
SSeek immediate medical attention if you notice any signs or symptoms of a stroke, even if they seem to come and go or they disappear completely. Think "FAST" and do the following:
- Face: Ask the person to smile. Does one side of the face droop?
- Arms: Ask the person to raise both arms. Does one arm drift downward? Or is one arm unable to rise?
- Speech: Ask the person to repeat a simple phrase. Is his or her speech slurred or strange?
- Time: If you observe any of these signs, call for emergency medical help immediately.
Call the local emergency number right away. Don't wait to see if symptoms stop. Every minute counts. The longer a stroke goes untreated, the greater the potential for brain damage and disability.
If you're with someone you suspect is having a stroke, watch the person carefully while waiting for emergency assistance.
Prevention
These are some preventions for reducing rectal bleeding:
- Eating high-fiber foods
- Exercising regularly to prevent constipation
- Keeping the rectal area clean
- Staying well hydrated
