Wallenberg Syndrome

What Is Wallenberg Syndrome? Symptoms, Causes, Diagnosis, Treatment, and Prevention

By Medically Reviewed by 
Reviewed:
Medically Reviewed
Wallenberg syndrome, also known as lateral medullary syndrome or Wallenberg’s syndrome, is a condition that affects the nervous system. It’s often caused by a stroke in the brain stem — the base of the brain that connects with the spinal cord. When this happens, you may experience temporary or long-term neurological problems.

Wallenberg syndrome is the most common posterior ischemic stroke syndrome.

Ischemic stroke, the most prevalent form of stroke, occurs when a vessel supplying blood to the brain is blocked.

Ischemic strokes can affect any part of the nervous system, including the brain stem. Brain stem ischemic strokes occur when blood vessels to parts of the brain stem become occluded or blocked off.

Wallenberg syndrome refers to the set of clinical symptoms that result from ischemic injury (for example, a stroke) to a specific area of the brain stem (lateral medulla).

Signs and Symptoms of Wallenberg Syndrome

The symptoms of Wallenberg syndrome vary depending on the cause and location of the brain damage. The most common symptoms include:

  • Trouble swallowing (dysphagia)
  • Feeling hoarse
  • Dizziness
  • Nausea and vomiting
  • Rapid involuntary eye movements (nystagmus)
  • Difficulty with balance and gait (walking)
  • Problems with body temperature sensation
  • Lack of pain and temperature sensation on one side of the face and the other side of the body
  • Vertigo
  • Hiccups
  • Horner syndrome (decreased pupil size, upper eyelid droop, and little or no sweating on one side of the face)

Causes and Risk Factors of Wallenberg Syndrome

Wallenberg syndrome is usually caused by a brain stem stroke that occurs in the vertebral or posterior inferior cerebellar arteries of the brain stem. Less often, it can be caused by a stroke that occurs in the medullary arteries.

Other causes include:

  • Cerebral embolism (blood clot that travels to the brain)
  • Vertebral artery dissection (which may be due to neck manipulation or injury)
  • Marfan syndrome
  • Ehlers-Danlos syndrome
  • Fibromuscular dysplasia (abnormal cell development in the artery wall)

Risk Factors

Risk factors for Wallenberg syndrome include:

  • Hypertension (high blood pressure)
  • Smoking
  • Diabetes

How Is Wallenberg Syndrome Diagnosed?

Your doctor will likely conduct a physical exam, and may order tests including:

  • A magnetic resonance imaging scan (MRI) with diffusion-weighted imaging (DWI) to confirm the location of the stroke
  • A computed tomography (CT) scan or magnetic resonance angiogram (X-ray of blood vessels) to identify the location of the blocked blood vessel and to rule out uncommon causes of stroke
  • An electrocardiogram (ECG) to rule out any underlying atrial fibrillation (irregular heartbeat) or acute coronary syndrome (blocked blood supply to the heart)
  • An echocardiogram to evaluate for a cardiac cause of embolic strokes
  • Blood tests

Prognosis of Wallenberg Syndrome

The severity of the damage caused by Wallenberg syndrome depends on how much brain damage occurred during the stroke.

In general, however, people with Wallenberg syndrome have better outcomes than people who’ve had other stroke syndromes. Most recover well; the most common lingering problems tend to be with balance and walking.

Duration of Wallenberg Syndrome

Sometimes, symptoms subside after a few weeks or months after a stroke causes Wallenberg syndrome. Other times, complications can linger for years afterward.

Treatment and Medication Options for Wallenberg Syndrome

Treatment for Wallenberg syndrome usually involves managing the symptoms caused by the stroke.

Medication Options

Acute management of an ischemic stroke often involves intravenous (IV) tissue plasminogen activator (tPA), which must be given within three hours of stroke onset. If you suspect a stroke, it’s imperative that you seek emergency medical attention immediately.

In some cases, doctors prescribe the anti-epileptic drug gabapentin (Neurontin).


Your doctor may also consider anti-emetics to treat persistent nausea and vomiting.

If you’ve already had an ischemic stroke, your doctor may recommend certain medications to help reduce your risk of having another one.

These include:

Speech and Swallowing Therapies

The majority of patients with Wallenberg Syndrome have swallowing impairment, which places them at risk for aspiration pneumonia. A speech language pathologist typically will do a swallowing evaluation, which may include a modified barium swallow test. A feeding tube may be required in some cases if your ability to swallow becomes very impaired.

Speech or swallowing therapy can also be helpful.

Prevention of Wallenberg Syndrome

The following healthy lifestyle tips can help prevent a stroke:


  • Control high blood pressure with healthy lifestyle changes and medications.
  • Reduce the amount of cholesterol and saturated and trans fats in your diet, which may reduce buildup in your arteries.
  • If you use tobacco, quit. Smoking increases the risk of stroke for smokers as well as nonsmokers exposed to secondhand smoke.
  • Manage diabetes with diet, exercise, and weight loss or medication if necessary.
  • Maintain a healthy weight to prevent stroke risk factors such as high blood pressure, cardiovascular disease, and diabetes.
  • Eat five or more daily servings of fruits or vegetables to reduce your risk of stroke. The Mediterranean diet, which is rich in olive oil, fruit, nuts, vegetables, and whole grains, may be beneficial.
  • Exercise regularly to lower your blood pressure, increase your levels of good cholesterol, improve the health of your blood vessels and heart, lose or maintain your weight, control diabetes, and reduce stress.
  • If you drink alcohol, do so in moderation. Heavy consumption of alcohol raises your risk of high blood pressure and ischemic strokes. On the other hand, small to moderate amounts of alcohol, such as one drink a day, may help prevent ischemic stroke.
  • Seek treatment if you suspect you may have obstructive sleep apnea (OSA), a sleep disorder that causes you to stop breathing for short periods while you sleep.
  • Avoid illegal drugs, such as cocaine and methamphetamine, which are risk factors for stroke.
  • If you’ve already had an ischemic stroke, take prescribed medications to prevent another one.

Complications of Wallenberg Syndrome

Stroke syndromes can cause permanent disability and affect normal daily functioning.

The most common complications of posterior circulation strokes include:
  • Aspiration pneumonia
  • Deep vein thrombosis
  • Pulmonary (lung) embolism
  • Heart attack
  • Lung infections (due to mechanical ventilation and the use of a nasogastric tube)
  • Corneal damage

Research and Statistics: Who Has Wallenberg Syndrome?

Approximately 800,000 people have an acute stroke each year in the United States, and 83 percent of these are ischemic strokes. Twenty percent of ischemic strokes occur in the posterior circulation, leading to an estimated 60,000 new cases of Wallenberg syndrome each year. Many people who have Wallenberg syndrome are men in their sixties.

BIPOC and Wallenberg Syndrome

Statistics for Wallenberg syndrome and Black, Indigenous, and People of Color (BIPOC) are limited, but research shows that the risk of stroke varies with race.

Black Americans and Stroke

Black Americans have nearly twice the risk of having a first stroke as white Americans; they also have the highest rate of stroke death.

They’re also more likely than white Americans to have transient ischemic attacks (TIA, a stroke that only lasts for a few minutes) and to be hospitalized for stroke, according to research from 2022.

Black American stroke survivors also tend to have more disabilities than white American stroke survivors.

Hispanic Americans and Stroke

Mexican Americans are more likely to have transient ischemic attacks than white Americans, per a review from 2011.

Related Conditions and Causes of Wallenberg Syndrome

Wallenberg syndrome is often caused by an ischemic stroke. Ischemic strokes account for about 83 percent of all strokes.

Several other disorders or conditions reportedly have been associated with Wallenberg syndrome.

These include:
  • Trauma to the vertebral artery in the neck
  • Inflammation of the wall of the vertebral artery
  • Hematoma (swelling of clotted blood)
  • Aneurysm (enlargement) of the vertebral artery
  • Head injury
  • Multiple sclerosis
  • Brain stem tuberculoma (a rare form of TB)

Resources We Love

American Stroke Association (ASA)

The ASA is a division of the American Heart Association (AHA) that works to prevent, treat, and reduce the incidence of stroke around the world. Learn more about the warning signs of stroke on their website.

National Institute of Neurological Disorders and Stroke (NINDS)

NINDS is a division of the National Institutes of Health (NIH) that researches the brain and nervous system, and conducts work related to Wallenberg syndrome.

Editorial Sources and Fact-Checking

Show Less