Wallenberg Syndrome: Symptoms, Causes, and Treatments

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Wallenberg syndrome is also known as a lateral medullary syndrome or PICA (posterior inferior cerebellar artery) Syndrome. It is a condition of the central nervous system after a stroke. If you think that you or someone you know is having a stroke, call 911 immediately. You can develop Wallenberg syndrome after a stroke in the brain stem. The loss of blood flow damages the brain stem, resulting in certain symptoms that begin suddenly. If you have Wallenberg syndrome, you may experience difficulty swallowing, hoarse voice, dizziness, and problems with balance, among other symptoms. Older adults with vascular risk factors like smoking, hypertension, and diabetes, are the most likely to develop Wallenberg syndrome. Among those patients, males in their 60’s are more likely to be affected. 

Signs and Symptoms of Wallenberg Syndrome

People with Wallenberg syndrome have symptoms in the central nervous system, which includes the brain and spine. These symptoms are caused by a stroke or blockage of blood flow so that the symptoms will come about suddenly over the course of a few hours.

The most common symptoms of Wallenberg syndrome include:

  • Difficulty swallowing
  • Hoarseness of voice
  • Dizziness
  • Vertigo or feeling like the room is spinning around you
  • Nausea and vomiting
  • Balance problems
  • Problems with coordination, especially with your walking 

While those are the most common symptoms, there are other neurological deficits associated with Wallenberg syndrome like having:

  • A loss of temperature sensation or pain on only one side of the 
  • Pain or numbness on one side of the face
  • Difficulty speaking or changes in taste sensation
  • Double vision or eyelid droop

It’s important to note that there are many different ways that Wallenberg syndrome can present. If you have new neurologic symptoms like any of these, you should call 911 immediately.

Causes and Risk Factors

The cause of Wallenberg syndrome is usually a stroke in the brainstem, meaning there isn’t enough blood flow to the brain tissue. These strokes are typically caused by a thrombosis, which forms because of atherosclerotic plaques in the brain’s blood vessels. Therefore, people with atherosclerosis, or hardening of the arteries, are at the highest risk. 

People with hypertension or high blood pressure are at a greater risk of Wallenberg syndrome. Hypertension over a period of time can cause the hardening or thickening of the arteries. This can lead to a blockage in the arteries.

Smoking and diabetes are also risk factors. These are important risk factors because making lifestyle changes can decrease your risk.

Some less common factors include: 

  • Marfan Syndrome: an inherited condition that affects connective tissue, the heart, eyes, blood vessels, and skeleton. 
  • Ehlers-Danlos Syndrome:  affects the connective tissue causing your skin, joints, and blood vessel walls to become overly flexible.
  • Fibromuscular dysplasia: which causes narrowing of the arteries
  • Vertebral artery dissection: a tear in the vertebral artery located in the neck. The vertebral artery supplies blood to the brain. 


Your doctor will perform a history and physical exam to determine if you have Wallenberg syndrome or PICA stroke. From there, your doctor will order tests such as brain imaging. These tests may include:

  • MRI with diffusion-weighted imaging: This type of MRI helps to determine whether there was a stroke based on the presence of damaged or dead tissue.  
  • CT angiogram or MR angiogram: These types of imaging help to locate the blood vessel that had a blockage.
  • Other tests: your doctors may order include EKG and blood tests.

Treatment for Wallenberg Syndrome

Like any other kind of stroke, treatment for Wallenberg syndrome depends on the stroke’s location and size. Quick diagnosis leading to quick treatment is best. 

Options to treat your stroke and return blood flow to the brainstem include:

  • Intravenous thrombolysis: This is a typical treatment for strokes that tries to break up the blockage in the blood vessel. It uses an intravenous line to deliver medicine to the location of the arterial blockage. This is most effective within three to four hours of the start of the stroke.
  • Mechanical thrombectomy: This is a surgical procedure to help clear blockages in the artery and remove any plaque contributing to the blockage. This is most effective within six hours of the start of the stroke.

Other treatments that can start while you’re in the hospital include:

  • Blood pressure management: Since hypertension is one of the causes of strokes, managing your blood pressure can help avoid strokes and other health issues.
  • Speech therapy: works to strengthen the muscles of the face to help restore speech to its previous levels and ensure that you can swallow liquids and foods safely without choking. 

Preventing Wallenberg Syndrome

If you want to prevent Wallenberg syndrome, following these recommendations can help: 

  • Control Hypertension: Hypertension or high blood pressure leads to blockages of the arteries. Keep your blood pressure in a safe range to keep your blood flowing smoothly. 
  • Eat Healthily: In particular, eat plenty of fruits and vegetables and avoid foods high in unhealthy fats and contribute to high cholesterol levels.
  • Stop Smoking: Smoking contributes to stroke risk. Stop using any other kinds of tobacco products as well. 
  • Manage Diabetes: It’s important to keep your blood sugar in a healthy range as those with diabetes are prone to health issues. 
  • Maintain a Healthy Weight: Too much weight is a contributing factor to strokes as well as other health issues. 
  • Exercise: The benefits of regular exercise include lower blood pressure, high levels of good cholesterol, lower weight, and stress reduction.
  • Limit Alcohol Intake: Excessive amounts of alcohol consumption increase your risk for health problems. 
  • Treat Obstructive Sleep Apnea: If you have sleep apnea, you snore or stop breathing for short amounts of time during sleep. Sleep apnea is associated with a host of health problems but is treatable with a breathing machine.

Next Steps

If you or someone you know has the signs or symptoms of Wallenberg syndrome, call 911 immediately.

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