Wallenberg's Syndrome

Wallenberg's syndrome is a neurological condition that happens when a stroke occurs in a certain area of the brain called the brain stem. Experts also use the term "posterior inferior cerebellar artery" or "lateral medullary" when referring to Wallenberg syndrome. The name refers to the arteries that supply to that specific brain stem area.

Last Updated: February 24, 2024

Most of the time, atherosclerotic (a buildup of plaques in and on the arterial walls) occlusion of the vertebral artery causes Wallenberg syndrome. This is followed by occlusion of the posterior inferior cerebellar artery and, less often, the medullary arteries. 

Hypertension is the most common risk factor, and smoking and diabetes are the next most common. 

Vertebral artery dissection is another important cause. It can happen when moving the neck or hitting the head or if a person has Marfan syndrome, Ehlers-Danlos syndrome, or fibromuscular dysplasia. 

In younger people, Wallenberg syndrome is most often caused by a tear in the vertebral artery.

The most common type of posterior ischemic stroke is Wallenberg syndrome. Men in their 60s are more likely to have this condition than women. Atherosclerosis and clots in large arteries cause about 75% of the cases. In comparison, cardioembolic events account for 17% of all occurrences, while spinal dissection accounts for the remaining 8%.

Some of the symptoms include: 

  • Difficulty in swallowing 
  • Hoarseness
  • Dizziness 
  • Nausea and vomiting 
  • Rapid, uncontrollable movements of the eyes (called nystagmus)
  • Difficulty walking and keeping balance. 

Some people will only lose the ability to feel pain and temperature on one side of their face. Some will have a pattern of symptoms on the opposite sides of their body, like paralysis or numbness on the right side of their face and weak or numb limbs on the left side. 

There may also be uncontrollable hiccups, and some people lose their sense of taste on one side of the tongue. 

Some patients with Wallenberg syndrome have trouble walking upright because the world appears to be skewed in their vision.

Most of the time, history taking and physical examination are enough to make a diagnosis.

The best way to find out if the infarct is in the inferior cerebellar area or the lateral medulla is to do an MRI with diffusion-weighted imaging (DWI).

A CT or MR angiogram can help find where a blood vessel is blocked and rule out rare causes like vertebral artery dissection.

An ECG can help rule out atrial fibrillation or sudden acute coronary syndrome as a cause. Doctors also check the serum electrolytes of the patient.


Doctors administer intravenous (IV) thrombolysis with IV tissue plasminogen activator (TPA) within three to four and a half hours of the onset of an ischemic stroke.

Then doctors perform endovascular revascularization for large vessel intracranial occlusion after IV thrombolysis.

Doctors also employ the following critical management:

  • Use of normal saline IV fluids; 
  • BP management;
  • Assessing swallowing function and preventing aspiration;
  • Deep vein thrombosis prophylaxis such as low-dose or low-molecular-weight heparin (LWMH);
  • Blood sugar control;
  • Aspirin as antithrombotics.

The following prevention strategies are found to be effective:

  • Smoking cessation
  • Management of diabetes
  • Maintaining a healthy blood pressure
  • Maintaining a balanced diet and regular exercise.


Lui F, Tadi P, Anilkumar AC. Wallenberg Syndrome. [Updated 2022 Oct 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470174/


National Institute of Neurological Disorders and Stroke (2022). Wallenberg's Syndrome. Retrieved December 22, 2022, from https://www.ninds.nih.gov/health-information/disorders/wallenbergs-syndrome-

Last Updated: February 24, 2024