A brain stem stroke is a life threatening condition. That’s because your brain stem controls several vital functions, like breathing and your heartbeat. Still, recovery is possible with prompt diagnosis and treatment.

A stroke occurs when there’s a disruption to the blood supply to part of your brain. The effects and severity of a stroke depend on which part of the brain suffers damage and to what degree.

Sitting just above the spinal cord, the brain stem controls your breathing, heartbeat, and blood pressure. It is also involved in controlling your speech, swallowing, hearing, and eye movements. Impulses sent by other parts of the brain travel through the brain stem on their way to various body parts.

A stroke that affects the brain stem threatens vital bodily functions, making it a life threatening condition.

Parts of the brain stem

Your brain stem consists of three parts with various functions:

  • midbrain, which is involved in vision, hearing, and movement
  • pons, which is key in sensation, sleep-wake cycles, and breathing
  • medulla oblongata, which controls vital functions like heartbeat, breathing, and blood pressure

The effects of a brain stem stroke may differ depending on which part of the brain stem is affected. The pons is the most common site.

Most brain stem strokes are ischemic. That means they’re due to a blockage that disrupts blood flow to the brain stem. Possible causes of that blockage include:

  • atherosclerosis, the buildup of fats and cholesterol that narrows artery walls
  • a blood clot that either forms in an artery that supplies blood to the brain or has formed elsewhere and traveled to the brain
  • arterial dissection, a tear in an artery
  • lipohylanosis, the buildup of deposits in arterial walls
  • a tumor
  • trauma

The other type of stroke is called a hemorrhagic stroke. This is when a weak blood vessel bursts, causing blood to pool and pressure to build in the brain.

Brain stem stroke is the deadliest type of stroke. That’s because the brain stem controls many basic life functions.

It’s difficult to specify a survival rate for brain stem stroke, as the outcome can depend on the cause of the stroke, where in the brain stem it occurred, and how much of the brain stem was affected.

In a 2019 study of hemorrhagic strokes, 69% of people with brain stem strokes had died within 12 months of the stroke. Only 20% to 30% of people who have hemorrhagic brain stem strokes are expected to survive beyond 30 days.

But ischemic brain stem strokes are more common and tend to have a better outlook. Survival rates could be as high as 90.1% with prompt, high-technology treatment.

Stroke symptoms depend on which area of the brain is affected.

A stroke in the brain stem can interfere with vital functions such as breathing and heartbeat. It can affect other functions we perform without thinking, such as eye movements and swallowing. It can also impair your speech, hearing, and balance.

Possible symptoms of brain stem stroke include:

Brain stem stroke syndromes

Different areas of the brainstem receive blood supply from specific arterial branches, so a stroke there can cause various combinations of symptoms. Scientists have identified several syndromes to classify these symptoms. Identifying the syndrome can provide more detailed information on how the stroke has affected the brain.

The most common of these is Wallenberg syndrome. A rare but notable syndrome is locked-in syndrome.

Doctors can often identify syndromes based on which symptoms appear on the side of the stroke and which appear on the other side.

Some symptoms of a brain stem stroke may persist long-term. For example, a brain stem stroke can cause you to lose your sense of smell and taste.

Other rare and serious complications include:

Anybody can have a stroke, but your risk increases with age. However, the average age of brain stroke hemorrhage seems to be younger than other types of stroke — 47 years.

A family history of stroke or mini-stroke (aka transient ischemic attack) increases your risk.

People who are Black, Alaska Native, American Indian, or Hispanic are also at higher risk. Females have a higher lifetime risk of stroke, but males are significantly more likely to have a brain stroke hemorrhage.

Hypertension (high blood pressure) is one of the most significant risk factors for both ischemic and hemorrhagic brain stem strokes. Other factors that increase your risk of a brain stem stroke include:

Are brain stem strokes rare?

Experts estimate that brain stem strokes account for 10% to 15% of the 795,000 strokes each year in the United States. They’re usually ischemic, accounting for about 11% of all ischemic strokes.

But brain stem hemorrhagic strokes are fairly uncommon, occurring in 2 to 4 per every 100,000 people each year. Research suggests that 5.0% to 13.4% of hemorrhagic strokes are brain stem strokes.

A brain stem stroke is a life threatening medical emergency. If a doctor suspects a stroke, they’ll likely order imaging tests, such as:

These can help them identify the cause and location of the stroke and assess blood flow in the brain.

Other tests may include:

In the event of ischemic stroke, the first line of treatment is to dissolve or remove the blood clot. If doctors can diagnose the stroke quickly enough, they may be able to provide clot-busting medication. Within 24 hours of the start of symptoms, they can also perform surgery to remove the clot.

Doctors can sometimes use angioplasty and stenting to widen an artery and keep it open.

For a hemorrhagic stroke, doctors need to stop the bleeding. This involves clipping or coiling the aneurysm. It may also require medication to reduce clotting.

In the meantime, your medical team may need to take additional measures to keep your heart and lungs functioning.

Your outlook after any type of stroke often depends on the extent of the damage and how quickly you received treatment.

A brain stem stroke can result in serious long-term problems. Medication and ongoing therapy may be necessary, including:

Some survivors of brain stem stroke continue to have severe disabilities. In these cases, psychological counseling can help them adjust.

In a 2018 study of people who had ischemic brain stem strokes, 70% were free of disability after 1 year.

Once you’ve had a brainstem stroke, your risk of another stroke is 10% to 15%. Despite the risks that you can’t avoid, there are things you can do to decrease your chances of another stroke. Some general guidelines to follow include:

If you have a condition that’s a risk factor, like hypertension or diabetes, follow your doctor’s recommendations for managing it.

A brain stem stroke can be fatal without prompt diagnosis and treatment. Symptoms include difficulty breathing, hearing and vision problems, and muscle weakness.

Prompt diagnosis and treatment are essential to limiting brain stem damage. Emergency treatment may include medications and surgery. Recovery can take months and often involves various types of rehabilitative therapies.