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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, 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.
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.
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
- 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
- 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
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
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.
Since this is an emergency, the doctor will make a diagnosis as quickly as possible. An exam of your nervous system will be done.
Images may be taken of your bodily structures. This can be done with:
- CT scan
- CT angiogram
- MRI scan
- Magnetic resonance angiography (MRA)
- Doppler ultrasound
- Angiogram —to assess the heart and its blood supply
Your bodily fluids may be tested. This can be done with:
- Blood tests
- Tests to check the level of oxygen in the blood
Your kidney and liver function will also be tested.
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.
For an ischemic stroke, medication may be given to:
- Dissolve clots and prevent new one