What Is Wallenberg Syndrome?

Medically Reviewed by Jabeen Begum, MD on October 13, 2022
4 min read

Wallenberg syndrome is a set of neurological symptoms that result from damage to part of the brainstem. This damage is typically caused by a stroke or by damage to arteries that provide blood flow to this area of the nervous system. Treatment of Wallenberg syndrome often involves immediate interventions to resume blood flow to the area, followed by long-term implementation of rehabilitative therapies. 

The brain is divided into many different areas that perform many different functions. The brainstem is an area that is located at the base of the brain on the side closest to the back of the neck. It connects the brain to the spinal cord. 

The brainstem performs numerous critical functions, such as regulating breathing and heart rate, performing reflexes like sneezing and swallowing, and maintaining balance and posture. Damage to the brainstem can disrupt these functions, leading to disorders like Wallenberg syndrome.

Wallenberg syndrome is a neurological condition that is also referred to as lateral medullary syndrome or posterior inferior cerebellar artery syndrome. An estimated 60,000 new cases occur each year in the United States.

The most common cause of Wallenberg syndrome is damage to a part of the brainstem called the medulla. This damage is usually the result of reduced blood flow to the area. 

The brain has a vast network of arteries that deliver blood and oxygen to all parts of the brain. Without this oxygen, brain tissue quickly begins to die. This often results in a stroke.

About 80% of cases of Wallenberg syndrome are caused by blockage of the vertebral artery, which supplies blood to the brainstem. Blood clots, fatty plaque deposits, or other particles can all cause blockage, resulting in an ischemic stroke that can lead to brain damage and Wallenberg syndrome.

Wallenberg syndrome may also be caused by a tear in or damage to the vertebral artery. Vertebral artery tears are the most common cause of Wallenberg syndrome in patients younger than 45 years old. Damage to the vertebral artery may be caused by:

  • Neck injury
  • Fibromuscular dysplasia
  • Connective tissue disorders like Ehlers-Danlos syndrome

Risk factors for Wallenberg syndrome. Wallenberg syndrome is seen most often in patients who are over 60 years old. Other common risk factors include:

  • High blood pressure (hypertension)
  • Smoking
  • Diabetes

Wallenberg syndrome may include different combinations of symptoms depending on where the vertebral artery is torn or blocked and how extensively the brain tissue is damaged. 

Common symptoms of Wallenberg syndrome include:

  • Difficulty swallowing
  • Dizziness or vertigo
  • Nausea and vomiting
  • Difficulty balancing or coordinating movement 
  • Involuntary eye movements (also called nystagmus)
  • Uncontrollable hiccups
  • Loss of taste
  • Loss of pain or temperature sensation on one side of the body

Due to the anatomy of the brainstem and its widespread connections, patients may experience some symptoms on one side of the body and other symptoms on the other side of the body. For example, some patients may experience a loss of pain sensation on the right side of their body while also having difficulty maintaining balance when using the left side of their body.

Diagnosis of Wallenberg syndrome typically requires a clinical examination and a patient history. This can be combined with others tests and diagnostic imaging to confirm the location and severity of brain damage. 

Several types of diagnostic tests may be used to confirm brainstem damage and diagnose Wallenberg syndrome. These tests include:

  • An MRI with diffusion-weighted imaging, which tracks the movement of water in the brain and can help confirm a stroke.
  • An angiogram, which measures blood flow through arteries.
  • An electrocardiogram, which ensures that symptoms were not caused by an underlying heart issue.

Treatment for Wallenberg syndrome varies depending on the severity of the damage. Immediate treatment may include intravenous administration of drugs that break up blood clots or direct surgical intervention to remove clots and repair a damaged artery.

Depending on the patient’s symptoms, long-term treatment may include rehabilitative therapy. Starting speech therapy, occupational therapy, and physical therapy early in the recovery process can improve outcomes for patients. 

Patients experiencing chronic pain as a symptom of Wallenberg syndrome may benefit from taking gabapentin, an anti-epileptic drug.

There is no cure for Wallenberg syndrome, and patient prognosis varies depending on the amount of damage sustained by the brain tissue. Patients with extensive damage may have significant long-term disabilities, while patients with less damage may see improvements in symptoms within a few weeks or months. 

Immediate intervention may help reduce the chances of extensive brain damage and long-term complications. If you are experiencing symptoms of a stroke, seek emergency medical care immediately.

Artery damage and stroke may be unavoidable in some circumstances. However, there are ways to manage your risk of Wallenberg syndrome. You might consider:

  • Maintaining a healthy diet and exercising regularly
  • Asking your doctor for help quitting smoking
  • Managing diabetes or high blood pressure with help from your physician

Seek medical care early. Transient ischemic attacks (TIAs) are small strokes that block blood flow to the brain for a short period of time. Since blood flow is only blocked briefly, TIAs are typically less severe than full ischemic strokes.

It is critical to seek immediate medical care in the event of a TIA. These transient attacks often precede a major stroke. Seeking treatment during and after a TIA can help lower your risk of a major stroke like those that cause Wallenberg syndrome.

Wallenberg syndrome arises due to a blockage of or damage to arteries providing blood to the brainstem, often caused by a stroke. Work with your doctor to manage your risks of stroke, and seek immediate medical attention if you experience symptoms of a stroke or Wallenberg syndrome. Early detection and intervention can improve your chances of long-term recovery.