Wallenberg syndrome is a condition that affects the nervous system. It typically results from a stroke in the brain stem and can impair a person’s coordination, balance, eye movement, and ability to swallow.

Doctors also refer to Wallenberg syndrome as lateral medullary syndrome, posterior inferior cerebellar artery (PICA) syndrome, or vertebral artery syndrome. The name Wallenberg syndrome derives from Dr. Adolf Wallenberg, a German neurologist. The condition occurs due to an infarction, or stroke, in part of the brain stem.

A person with Wallenberg syndrome may require immediate medical attention and rapid evaluation to improve their outcome and prognosis. They may also require additional long-term treatments, including swallowing and speech therapy.

In this article, we will discuss Wallenberg syndrome, including its symptoms, diagnosis, and treatment options.

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Wallenberg syndrome describes a rare neurological condition that affects the nervous system. It is the most common posterior circulation ischemic stroke syndrome. This refers to when a stroke affects the back part of the brain. It occurs when a blockage develops in the arteries that supply this portion of the brain. Due to a reduction in blood supply, there may be damage to the brain tissue, resulting in symptoms.

Wallenberg syndrome occurs due to an ischemic stroke occurring in one of the arteries that supply blood to the back portion of the brain. When oxygenated blood does not reach part of the brain due to a blockage, that part of the brain may become damaged or die.

Specifically, a blockage occurs in the vertebrobasilar system, most commonly in the posterior inferior cerebellar artery, or the vertebral artery. This results in insufficient blood reaching the posterior, or back, portion of the brain.

This area of the brain includes the different parts of the brain stem, most notably the medulla oblongata. The brainstem is a lower extension of the brain and is responsible for many important functions, such as eye movement, balance, and swallowing. An insufficient blood supply can damage the lateral part of the medulla oblongata, resulting in the symptoms of Wallenberg syndrome.

The involvement of these arteries and parts of the brain is where many of the other names for the condition originate.

Evidence notes that hypertension is the most common risk factor for Wallenberg syndrome. Other potential risk factors may include:

Additionally, a vertebral artery dissection, or a flap-like tear of the inner lining of the vertebral artery, can result in a stroke that may lead to Wallenberg syndrome. Risk factors for this can include:

  • neck injuries
  • Marfan syndrome, a genetic condition that affects connective tissues
  • Ehler-Danlos syndrome, a group of genetic disorders that affect the body’s connective tissues
  • fibromuscular dysplasia, a condition that affects the artery walls

The brain stem delivers messages to the spinal cord, making a person’s motor and sensory functions possible. As such, damage to this area can affect the nervous system. Symptoms of Wallenberg syndrome include:

  • dysphagia, or difficulty swallowing
  • vertigo with involuntary eye movement
  • dizziness
  • difficulty in maintaining balance
  • difficulty walking
  • nausea and vomiting
  • hiccups
  • problems with body temperature sensation
  • a decrease in sweating

Sometimes people with Wallenberg syndrome may experience paralysis or numbness on one side of their body. This can occur anywhere, such as in their limbs or a small area of their face or body. The condition may also cause a slow heart rate and high or low blood pressure.

A doctor will ask questions about symptoms and carefully review a person’s medical history before making a diagnosis.

A person with suspected Wallenberg syndrome may need to undergo an MRI or CT scan. These types of imaging tests can confirm if there is a blockage in an artery supplying the lateral medulla and may help the doctor make the final diagnosis. A doctor may also carry out a physical examination to assess a person’s motor and sensory problems that can affect their face and cranial nerves on the same side of the stroke.

Similar to managing other conditions that arise due to ischemic stroke, doctors usually aim to reduce the size of the infarction and help prevent further medical complications.

Treatment options for Wallenberg syndrome are typically symptomatic. This means that a person receives therapy to help ease the symptoms they are experiencing. As such, options may include:

  • a feeding tube if swallowing is difficult
  • swallowing therapy
  • speech therapy
  • pain medications, which may include the anti-epileptic drug gabapentin

In some severe cases, a doctor may perform surgery to remove the clot that is causing a blockage. However, doctors rarely opt for this type of treatment due to difficulties in reaching that area of the brain during surgery.

The prognosis of Wallenberg syndrome usually depends on the size and location of the damage to the brain stem. In some cases, a person may notice a reduction in symptoms within weeks or months. Others may experience neurological symptoms that persist for years.

The long-term outlook for people with Wallenberg syndrome is reasonably positive and typically has a better outcome than most other stroke syndromes. Many individuals can return to most activities of daily living.

Wallenberg syndrome describes a condition where a stroke reduces blood flow to the brain stem. As this causes damage to this part of the brain, it can affect its function. This may result in symptoms such as balance problems, involuntary eye movement, and difficulty swallowing.

Treatment involves managing symptoms of the condition. The prognosis of the condition can vary, but it generally has a better outcome than other stroke syndromes.