Understanding Wallenberg Syndrome


A type of stroke called Wallenberg syndromeis a stroke that involves the lower part of the brainstem. This is caused by blockage of a small blood vessel in the brain and it causes a characteristic collection of unique signs and symptoms. If your doctor has told you that you have Wallenberg syndrome or lateral medullary syndrome, this is what you should expect.

Lateral Medullary Syndrome/ Wallenberg Syndrome

This is a stroke that manifests with an unusual set of symptoms that are confusing even for most doctors.

The reason these unusual symptoms appear together is that Wallenberg Syndrome is a tiny stroke that affects a vital part of the brainstem that controls many different bodily functions. The lateral medulla, which is the part of the brain affected by this type of stroke, connects the brain to the lower part of the body.


Usually one side of the face is numb. Typically there is also a loss of sensation to temperature or pain on one side of the face.

The eyelid may be droopy on the same side as the numbness and there may be a change in the pupil size as well. Often, there is a jerking movement of the eyes as they move from side to side. This is called nystagmus

Some patients may have weakness of the face and mouth as well.

Arms and Legs

There is usually numbness and decreased sensation of the arm, leg or both on the opposite side of the body as the numbness of the face. Sometimes, there is mild to moderate weakness of the arm or leg.

Most people who have a lateral medullary stroke have coordination problems of the numb arm or leg.

Other Symptoms

People who have a stroke of the lateral medulla may experience dizziness, a hoarse a voice and trouble swallowing. Interestingly, this type of stroke can cause persistent hiccups lasting for days.

In fact, this can be the tip off of lateral medullary syndrome as people go from doctor to doctor because of the persistent hiccups.


Usually the symptoms are subtle. Typically, a doctor has to do a careful neurological examination to identify all of the signs and put them together to diagnose lateral medullary syndrome.


Diagnosis of lateral medullary syndrome is normally made by neurological examination and then confirmed by a brain MRI. The brain MRI confirms the location of the abnormality and also determines whether the stroke is a hemorrhagic stroke, and ischemic stroke or even if it is not a stroke at all, but instead a brain tumor or an infection.

Normally a brain CT scan does not detect a stroke in the brainstem, so a brain CT would not detect the abnormality that is present in lateral medullary syndrome.


The treatment for a lateral medullary stroke includes blood pressure control and possibly blood thinners. Usually, management of lateral medullary stroke depends on the diagnostic evaluation, which includes a search for hypertension, heart disease, high cholesterol, diabetes or a blood clotting disorder. Once the cause of the stroke is determined, medical treatment is initiated to manage the stroke risk factor to prevent another stroke.

What to Expect

After s lateral medullary stroke, the symptoms may worsen over the first 48-72 hours, especially if you are not under medical care. After that, stroke survivors who have experienced lateral medullary syndrome usually go on to improve over time, although the symptoms rarely completely disappear.

A brainstem stroke can cause unconsciousness or loss of vital functions, so a large lateral medullary stroke is dangerous.

Wallenberg’s syndrome or lateral medullary syndrome is a stroke that can be difficult for most doctors to diagnose. If you have been told that you have Wallenberg syndrome or lateral medullary syndrome, find out more about stroke treatment, prevention and prognosis.

If you or someone you know has had persistent hiccups for days, you need to seek medical care because it may be the sign of a stroke or another neurological disorder.


Martin Samuels and David Feske, Office Practice of Neurology,  2nd Edition, Churchill Livingston, 2003

Continue Reading