Definition

The brainstem is located directly above the spinal cord. It helps controls 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, and swallowing 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.

Brainstem

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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. 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

Factors that may increase your risk of stroke include:

• Sex: Men are more likely to have strokes than women but women are more likely to die of strokes than men
• African American, Hispanic or Asian/Pacific Islander descent
• Age: Risk of stroke increases with age particularly after 55 years of age.
• Family history of stroke

Medical conditions that can increase your risk of stroke include:

• High blood pressure (the number one risk factor for ischemic stroke)
• High blood homocysteine level
• Atherosclerosis
• High cholesterol levels —specifically high-LDL "bad" cholesterol
• Diabetes mellitus or impaired glucose tolerance
• Atrial fibrillation
• Blood disorders such as sickle cell disease and polycythemia
• 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
  • Pregnancy
  • Certain autoimmune diseases
• Having a blood vessel abnormality

Lifestyle factors that can increase your risk of stroke include:

• Drug abuse (heroin, cocaine, amphetamines)
• Smoking
• Use of birth control pills , especially if you are over 35 years old and smoke
• Long-term use of hormone replacement therapy
• Physical inactivity
• Alcohol abuse

Symptoms

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

• Problems with vital functions (eg, breathing)
• Difficulty with chewing, swallowing, and speaking
• Weakness or paralysis in the arms, legs, and/or face
• Problems with sensation
• Hearing loss
• Vision problems
• Vertigo (feeling of spinning or whirling when you are not moving)
• “Locked-in syndrome” (only the eyes are able to move)
• Coma

If you or someone you know has any of these symptoms, call for medical help right away. Brain tissue without blood flow dies quickly.

Diagnosis

Since this is an emergency, the doctor will make a diagnosis as quickly as possible. Tests may include:

• Exam of nervous system
• Computed tomography (CT) scan —a type of x-ray that uses a computer to make pictures of the brain
• CT angiogram—a type of CT scan that evaluates the blood vessels in the brain and/or neck
• Magnetic resonance imaging (MRI) —a test that uses magnetic waves to make pictures of the brain
• Magnetic resonance angiography (MRA) —a type of MRI scan that evaluates the blood vessels in the brain and/or neck
• Angiogram —a test that uses a catheter (tube) and x-ray machine to assess the heart and its blood supply
• Heart function tests (eg, electrocardiogram, echocardiogram)
• Doppler ultrasound —a test that uses sound waves to examine blood vessels
• Blood tests
• Tests to check the level of oxygen in the blood
• Kidney and liver function tests

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.
• 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.