There are two main types of strokes: hemorrhagic and ischemic.
Hemorrhagic stroke accounts for about 13 percent of stroke cases.
It results from a weakened vessel that ruptures and bleeds into the surrounding brain. The blood accumulates and compresses the surrounding brain tissue. The two types of hemorrhagic strokes are intracerebral (within the brain) hemorrhage or subarachnoid hemorrhage.
Hemorrhagic stroke occurs when a weakened blood vessel ruptures. Two types of weakened blood vessels usually cause hemorrhagic stroke: aneurysms and arteriovenous malformations (AVMs).
- An aneurysm is a ballooning of a weakened region of a blood vessel. If left untreated, the aneurysm continues to weaken until it ruptures and bleeds into the brain.
- An arteriovenous malformation (AVM) is a cluster of abnormally formed blood vessels. Any one of these vessels can rupture, also causing bleeding into the brain.
Symptoms of a hemorrhagic stroke
A hemorrhagic stroke that occurs inside your brain is also called an intracerebral hemorrhage. Symptoms of an ICH can vary from person to person, but are almost always present immediately after the stroke occurs.
Symptoms may include:
- total or limited loss of consciousness
- sudden and severe headache
- weakness or numb feeling in the face, leg, or arm on one side of the body
- loss of balance
- problems with speech or swallowing
- confusion or disorientation
A stroke is a medical emergency. Call emergency medical services or have someone drive you to the hospital if you think you’re having a stroke.
Causes of a hemorrhagic stroke
There are two possible causes of a ruptured blood vessel in the brain. The most common cause is an aneurysm. An aneurysm occurs when a section of a blood vessel becomes enlarged from chronic and dangerously high blood pressure or when a blood vessel wall is weak, which is usually congenital. This ballooning leads to thinning of the vessel wall, and ultimately to a rupture.
A rarer cause of an ICH is an arteriovenous malformation (AVM). This occurs when arteries and veins are connected abnormally without capillaries between them. AVMs are congenital. This means they are present at birth, but they are not hereditary. It is unknown exactly why they occur in some people.
Emergency treatment for a hemorrhagic stroke
Immediate emergency care is crucial for a hemorrhagic stroke. This treatment focuses on controlling the bleeding in your brain and reducing the pressure caused by the bleeding.
Drugs can be used to reduce blood pressure or to slow down the bleeding. If you experience a hemorrhagic stroke while on blood thinners, you are at particular risk for excessive bleeding. Drugs to counteract the effect of the blood thinners are usually given right away during emergency treatment.
Once a hemorrhagic stroke is brought under control with emergency care, further treatment measures can be taken. If the rupture is small and produces only a small amount of bleeding and pressure, supportive care may be the only other form of care you need. This may include:
- IV fluids
- management of other medical problems
- speech, physical, or occupational therapy
For more serious strokes, surgery may be needed to repair the ruptured blood vessel and stop the bleeding. If the stroke is caused by an AVM, surgery may be used to remove it. This is not always possible, however, and depends on the location of the AVM. Surgery may also be required to relieve the pressure caused by the bleeding and brain swelling.
Ischemic (“is-skeem-ic”) stroke occurs when an artery to the brain is blocked. The brain depends on its arteries to bring fresh blood from the heart and lungs. The blood carries oxygen and nutrients to the brain, and takes away carbon dioxide and cellular waste. If an artery is blocked, the brain cells (neurons) cannot make enough energy and will eventually stop working. If the artery remains blocked for more than a few minutes, the brain cells may die. This is why immediate medical treatment is critical.
Ischemic Stroke Symptoms
- Sudden numbness or weakness of the face, arm or leg, especially involving one side of the body
- Sudden confusion, trouble speaking or understanding
- Loss of vision in one or both eyes
- Trouble walking, dizziness, loss of balance or coordination
- Sudden, severe headache with no known cause
What causes it?
Ischemic stroke can be caused by several different kinds of diseases. The most common problem is narrowing of the arteries in the neck or head. This is most often caused by atherosclerosis, or gradual cholesterol deposition. If the arteries become too narrow, blood cells may collect and form blood clots. These blood clots can block the artery where they are formed (thrombosis), or can dislodge and become trapped in arteries closer to the brain (embolism). Another cause of stroke is blood clots in the heart, which can occur as a result of irregular heartbeat (for example, atrial fibrillation), heart attack, or abnormalities of the heart valves. While these are the most common causes of ischemic stroke, there are many other possible causes. Examples include use of street drugs, traumatic injury to the blood vessels of the neck, or disorders of blood clotting.
Emergency treatment for ischemic stroke
Ischemic strokes are the most common kind of stroke and occur when a blood clot blocks blood flow to your brain. Treatment for this type of stroke must start within 4.5 hours of the event and aims to break up the blood clot that’s blocking or disrupting blood flow in the brain.
Doctors often use aspirin in the treatment of strokes. Aspirin thins your blood and can help get blood to the affected area. Be sure to tell your doctor if you’re already taking aspirin for heart disease or other conditions.
Your doctor may also administer drugs to break up clots. A common intravenous drug, tissue plasminogen activator is given during an active stroke if the person is a good candidate. This medication can dissolve the clot that’s causing the stroke in order to stop it. After a stroke, your doctor may prescribe oral drugs, such as clopidogrel or warfarin. These are used to thin your blood in order to reduce the risk of stroke in the future. Statins have also been shown to reduce the incidence of future stroke.
If drugs don’t adequately break up the blood clot and if the stroke is acute, or localized to one area, your doctor may use a catheter to access the clot and remove it manually. The catheter is threaded through your blood vessels toward the area where the clot is lodged. Your doctor can remove the clot either by a corkscrew-like device attached to the catheter or by using clot-busting agents administered through the catheter directly into the clot.
A large stroke can lead to serious swelling in the brain. In some cases, surgical intervention may be necessary if drugs don’t adequately relieve the swelling. Decompressive craniotomy aims to relieve and prevent the buildup of pressure inside of your skull before it becomes dangerous. For the procedure, your surgeon will open up a flap of bone in your skull in the area of the swelling. Once the pressure is relieved, typically the flap will be returned.