Stroke is a brain injury caused by an interruption in blood flow. Brain tissue that does not get oxygen and nutrients from blood can die within minutes. The damage to the brain can cause a sudden loss in neurologic functions. The types of functions that are affected will depend on the part of the brain that is damaged.
Two blood flow problems that cause a stroke. Strokes may be hemorrhagic or ischemic.
A hemorrhagic stroke is caused by a ruptured blood vessel. It may be:
- Intracerebral hemorrhage—bleeding in the brain
- Subarachnoid hemorrhage —bleeding in the tissue around the brain
- An ischemic stroke is caused by a blocked blood vessel.
A hemorrhagic stroke can occur because of abnormal blood vessels in the brain. These vessels are weaker than normal vessels and break open under pressure. The blood leaks out of the broken blood vessel and into the brain. This can lead to brain damage because blood flow is interrupted and the pooled blood can cause pressure on the brain.
Blood vessels may be weakened by:
- Abnormality in blood vessel structure
- Arterio-venous (AV) malformation —an abnormal knot of blood vessels
- Aneurysm —a weakened spot in a blood vessel wall
- Other illness or medical conditions like hypertension
Blood vessels damage can also be caused by trauma like a blow to the head or a car accident.
Factors that may increase your risk of stroke include:
- Sex: Men are more likely to have a stroke than women
- Age: Risk of stroke increases with age particularly after 55 years of age.
- Family history of stroke
Factors that can weaken your blood vessels and increase your risk of hemorrhagic stroke include:
Blood disorders or medications that reduce blood clotting can also increase your risk of a hemorrhagic stroke.
Rapid treatment is important to decrease the amount of brain damage. Brain tissue without blood flow dies quickly. Call for medical help right away if you notice any of the following symptoms.
Symptoms will depend on the part of the brain affected. Call for immediate medical help if you have any of the following:
- Sudden weakness or numbness of face, arm, or leg, especially on one 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
- Loss of consciousness
Other symptoms that may go along with the above symptoms include:
- Neck stiffness
- Nausea or vomiting
- Sensitivity to light
The doctor will look for muscle weakness, visual and speech problems, and movement difficulty. If possible, you will be asked about your symptoms and medical history. A CT scan may be done to confirm the diagnosis.
Detailed images of blood vessels will help identify the cause of the bleeding. Images may be taken with one or more of the following tests:
- Magnetic resonance angiography (MRA)—maps flow of blood
- CT angiogram (CTA)—creates detailed images of the blood vessels and their blood flow
- Conventional angiogram —a catheter is passed into the blood vessels in the brain to create detailed images of the blood vessels
- Doppler ultrasound —to check blood flow in the head and neck
Blood tests can also help identify clotting problems in the blood. Your doctor may also examine the fluid that surrounds your brain and spine.
Immediate treatment is needed to stop the bleeding and relieve pressure on the brain.
If you were taking medications that reduce your blood’s ability to clot you will be given medication to help your blood clot again. This may also include vitamin K.
You may also be given medication to help:
- Decrease pressure in your brain
- Prevent seizures
- Lower blood pressure
Surgery may be done to help stop the bleeding. Some surgeries can be done by passing catheters from blood vessels in the groin to the affected vessels in the brain.
Options will depend on the cause and location of the bleeding:
- For a burst aneurysm—A clip may be placed just before the damaged vessel to stop bleeding.
- For a leaking or intact aneurysm—A special coil may be placed in the aneurysm. The coil will help a clot form in the aneurysm to prevent bleeding. A clip, as used in burst aneurysms, may be placed instead of a coil.
- For an abnormal tangle of blood vessels—Surgery may be done to repair the blood vessels. This may include removing the tangles or rerouting the blood around this tangle.
A stroke can cause swelling in the brain. A surgery, such as craniotomy, may be needed to relieve the pressure in the brain to prevent further damage.
If brain tissue was damaged, rehabilitation can be an important part of recovery. Rehabilitation may include:
- 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 improve mood and decrease depression
Management and monitoring of medical conditions like aneurysms and high blood pressure can prevent complications like stroke.
Other habits that may reduce your risk of stroke include:
- Getting regular exercise
- Eating more fruits, vegetables, and whole grains
- Limiting dietary salt and fat
- Quitting smoking
- Drinking alcohol only in moderation (1-2 drinks per day)
- Maintaining a healthy weight
- Check blood pressure frequently. Follow your doctor's recommendations for keeping it in a safe range
- Stop the use of recreational drugs (such as cocaine)
- Reviewer: Rimas Lukas, MD
- Review Date: 05/2014 -
- Update Date: 05/30/2014 -