Definition

The brainstem is located directly above the spinal cord. It helps control involuntary functions like heartbeat, breathing, and blood pressure. Normal brainstem function is vital to survival. Nerves that are used for eye movement, hearing, talking, chewing, swallowing, and muscle movement are also controlled by the brainstem.

A brainstem stroke happens when the blood supply to the brainstem is interrupted. This type of stroke can result in death, since the damaged brainstem can no longer control the body’s vital functions.

There are two main types of stroke: ischemic and hemorrhagic. An ischemic stroke is the most common type of stroke.

Causes

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. This is 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.

Risk Factors

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:

• Drug abuse from cocaine, amphetamines, or heroin use
• Smoking
• Physical inactivity

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
• Atherosclerosis
• 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:
  • Cancer
  • 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
• Menopause
• Pregnancy—due to increased risk of blood clots

Symptoms

The symptoms of a brainstem stroke can be severe and may include:

• Problems with vital functions, such as breathing
• Difficulty with chewing, swallowing, and speaking
• Weakness or paralysis in the arms, legs, and/or face
• Problems with balance or sensation
• Hearing loss
• Vision problems
• Vertigo —a feeling of spinning or whirling when you are not moving
• Locked-in syndrome, which occurs when only the eyes are able to move
• Coma

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.

Diagnosis

Since this is an emergency, the doctor will make a diagnosis as quickly as possible. An exam of your nervous system will be done.

Your bodily fluids may be tested. This can be done with blood tests.

Images may be taken of your bodily structures. This can be done with:

• CT scan
• Angiogram —to assess the heart and its blood supply
• CT angiogram
• MRI scan
• Magnetic resonance angiography (MRA)
• Doppler ultrasound

Your heart function will be examined. This can be done with tests such as electrocardiogram and echocardiogram.

Your kidney and liver function will also be tested.

Treatment

Immediate treatment is needed to:

• Dissolve or remove a clot for ischemic stroke
• Stop bleeding for hemorrhagic stroke

If needed, steps may be taken to help support your heart and lungs. A tube may be placed into the windpipe to provide oxygen.

Prevention

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.
• If you smoke, talk to your doctor about ways to quit.
• Increase your consumption of fish.
• Drink alcohol only in moderation. This means 1-2 drinks per day.
• Maintain a healthy weight.
• Check your 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 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.
• If you use drugs, talk to your doctor about rehabilitation programs.

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Stroke Survivors Association of Ottawa http://www.strokesurvivors.ca

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