The cerebrum is the largest part of the brain. It is made of a left and a right hemisphere. In most people, the left hemisphere is in charge of the functions on the right-side of the body. It is also involved in abilities such as the ability to speak, or use language.
A left-side stroke happens when the blood supply to the left side of the brain is interrupted. Without oxygen and nutrients from blood, the brain tissue quickly dies.
There are two main types of stroke ischemic and hemorrhagic. An ischemic stroke is the most common type of stroke.
An ischemic stroke is caused by a blockage of the blood flow, which may be due to:
- A clot from another part of the body like the heart or neck. The clot breaks off and flows through the blood until it becomes trapped in a blood vessel supplying the brain.
- A clot that forms in an artery that supplies blood to the brain.
- A tear in an artery supplying blood to the brain. Called an arterial dissection.
A hemorrhagic stroke is caused by a burst blood vessel. Blood spills out of the broken blood vessel and pools in the brain. This interrupts the flow of blood and causes a build up of pressure on the brain.
Certain factors increase your risk of stroke but can not be changed, such as:
- Race—People of African American, Hispanic, or Asian/Pacific Islander descent are at increased risk.
- Age: Older than 55 years of age
- Family history of stroke
Other factors that may increase your risk can be changed such as:
Certain medical condition that can increase your risk of stroke. Management or prevention of these conditions can significantly decrease your risk. Medical conditions include:
- High blood pressure
- High cholesterol levels—specifically high-LDL bad cholesterol
- Low bone mineral density, especially in women
- Obesity and metabolic syndrome
- High blood homocysteine level
- Diabetes mellitus or impaired glucose tolerance
- Atrial fibrillation
- Blood disorders such as sickle cell disease and polycythemia
- Vascular dementia
- Disease of heart valves, such as mitral stenosis
- Prior stroke or cardiovascular disease, such as heart attack
- Peripheral artery disease
- Transient ischemic attack (TIA) —a warning stroke with stroke-like symptoms that go away shortly after they appear
- Conditions that increase your risk of blood clots such as:
- Certain autoimmune diseases
- Migraine with aura
- Having a blood vessel abnormality
Risk factors specific to women include:
- Previous pre-eclampsia
- Use of birth control pills, especially if you are over 35 years old and smoke
- Long-term use of hormone replacement therapy
- Pregnancy—due to increased risk of blood clots
Symptoms occur suddenly. Exact symptoms will depend on the part of the brain affected. Rapid treatment is important to decrease the amount of brain damage. Brain tissue without blood flow dies quickly.
Call for emergency medical help right away if you notice any of the following:
- Sudden weakness or numbness of face, arm, or leg, especially on the right side of the body
- Sudden confusion
- Sudden trouble speaking or understanding
- Sudden trouble seeing in one or both eyes
- Sudden dizziness, trouble walking, loss of balance, or coordination
- Sudden severe headache with no known cause
If you or someone you know has any of these symptoms, call for emergency medical services right away. Brain tissue without blood flow dies quickly. Early care can decrease damage.
Longer-lasting effects of the stroke may include problems with:
- Left-sided weakness and/or sensory problems
- Speaking and swallowing
- Vision (eg, inability for the brain to take in information from the left visual field)
- Perception and spatial relations
- Attention span, comprehension, problem solving, judgment
- Interactions with other people
- Activities of daily living (eg, going to the bathroom)
- Mental health (eg, depression , frustration, impulsivity)
The doctor will do a physical exam and look for muscle weakness, visual and speech problems, and movement difficulty. If possible, you will be asked about your symptoms and medical history. Your doctor may use a CT scan or MRI scan of the brain to confirm a stroke or rule out other conditions.
Your doctor may also order tests that create detailed images of blood vessels. These test will help see which blood vessels may be creating the problem:
- Magnetic resonance angiography (MRA) —maps blood flow
- CT angiogram (CTA)—creates detailed images of the blood vessels and their blood flow
- Doppler ultrasound —evaluates flow of blood in the head and neck
Blood tests can also help determine if there is a bleeding problem.
Immediate treatment is needed to:
- Dissolve or remove a clot causing an ischemic stroke
- Stop the bleeding during a hemorrhagic stroke
Oxygen therapy may be needed.
For an ischemic stroke, medication may be given to:
- Dissolve clots and prevent new ones from forming
- Thin blood
- Control blood pressure
- Treat an irregular heart rate
- Treat high cholesterol
For a hemorrhagic stroke, the doctor may give medication to:
- Work against any blood-thinning drugs you may regularly take
- Prevent seizures
- Reduce how your brain reacts to bleeding
- Control blood pressure
For an ischemic stroke, procedures may be done to:
- Reroute blood supply around a blocked artery.
- Remove the clot or deliver clot-dissolving medicine.
- Remove fatty deposits from a arteries in the neck .
- Widen carotid artery and add a mesh tube to keep it open.
For a hemorrhagic stroke, the doctor may:
- Place a clip or tiny coil in the aneurysm to stop it from bleeding.
- Remove a piece of the skull to relieve pressure on the brain.
A rehabilitation program focuses on:
- Physical therapy—to regain as much movement as possible
- Occupational therapy—to assist in everyday tasks and self-care
- Speech therapy—to improve swallowing and speech challenges
- Psychological therapy—to help adjust to life after the stroke
Many of the risk factors for stroke can be changed. Lifestyle changes that can help reduce your chance of getting a stroke include:
- Exercise regularly.
- Eat more fruits, vegetables , and whole grains . Limit dietary salt and fat .
- Stop smoking .
- Increase your consumption of fish.
- Drink alcohol only in moderation (1-2 drinks per day).
- Maintain a healthy weight.
- Check blood pressure frequently . Follow your doctor's recommendations for keeping it in a safe range.
- Take aspirin if your doctor says it is safe.
- Keep chronic medical conditions under control. This includes high cholesterol and diabetes.
- Talk to your doctor about the use of a statins. These types of drugs may help prevent certain kinds of strokes in some people.
- Seek medical care if you have symptoms of a stroke, even if symptoms stop.
- Stop the use of recreational drugs such as cocaine.
- Reviewer: Rimas Lukas, MD
- Review Date: 12/2013 -
- Update Date: 06/02/2014 -