What is Lateral Medullary Syndrome (Wallenburg Syndrome)?
Lateral medullary syndrome (LMS), also known as Wallenberg syndrome or posterior inferior cerebellar artery syndrome, is a condition caused by a blood vessel problem in a part of the brain called the medulla oblongata. This syndrome was named after Adolf Wallenberg, a famous Jewish nerve doctor who first reported the condition and worked out of Germany. The condition commonly involves the posterior inferior cerebellar artery (PICA) or the vertebral artery.
This syndrome has a variety of unique nerve-related symptoms because it affects specific areas of the brain and spinal cord. This includes the lower part of the cerebellum, a region inside the brain that helps us to balance; the dorsolateral medulla, crucial for basic functions like breathing, and heart rate; the descending spinal tract, which carries information from the brain to different parts of the body; the trigeminal nerve, which provides sensation to the face; the vagus and glossopharyngeal nerves, which control functions like swallowing; sympathetic nerve fibers, which control the body’s reaction to stress; the spinothalamic tract, which carries pain and temperature sensations; and the vestibular nuclei, which helps us maintain our balance.
What Causes Lateral Medullary Syndrome (Wallenburg Syndrome)?
Lateral medullary syndrome is a condition caused by different factors that include:
1. Atherosclerotic disease: a disease that can cause blood clots or, less commonly, insufficient blood supply leading to tissue death due to lack of oxygen.
2. High blood pressure
3. Dissection of vertebral arteries: If a young patient comes in with a migraine and shows signs of lateral medullary syndrome, this condition and aneurysm, a bulging or ballooning in a blood vessel, need to be looked into.
4. Cardiogenic embolism: This is a condition where clots travel from the heart to the brain. It can happen due to irregular heartbeat conditions like atrial fibrillation, artificial heart valves, clots in the heart chambers, heart muscle disease causing enlargement, heart attack, and an infection in the heart. It can also occur due to substance misuse like cocaine, neck adjustments, tumors, radiation damage, and blood clots.
5. Small vessel disease: a condition that involves the small arteries.
Another rare cause is an underdeveloped vertebral artery, often contributing to a stroke in young patients if they have other risk factors.
Vertebrobasilar dolichoectasia: This is a condition where patients can experience a lack of blood supply to the rear of the brain. Risk factors for this include being male, high blood pressure, smoking, and previous heart attack. This condition ties into aortic dilations, ectatic coronary arteries, Marfan syndrome, late-onset Pompe disease, and polycystic kidney disease.
Other rarer causes of inadequate blood flow with a tendency for the back part of the brain circulation are subclavian steal syndrome, a rare disorder, Fabry disease, a genetic disorder, mitochondrial encephalopathy, a brain disorder due to the result of alterations in the mitochondria, lactic acidosis, a high level of lactic acid, migraines, and they can also cause lateral medullary syndrome.
Risk Factors and Frequency for Lateral Medullary Syndrome (Wallenburg Syndrome)
Posterior circulation strokes, which make up about 20% of all strokes caused by blockage in the blood vessels, are more common in people who drink alcohol. Specifically, they’re often seen in people with vertebral artery disease. In fact, a study showed that 67% of these strokes are associated with this condition, compared to just 10% with posterior inferior cerebellar artery disease.
Interestingly, cases of posterior inferior cerebellar artery disease are mostly linked to clotting caused by heart issues, as compared to other causes. It’s also worth noting that a large majority of those with lateral medullary syndrome, which is related to these types of strokes, struggle with swallowing to some extent. The range varies, but anywhere between 51% and 94% of patients encounter this problem.
Signs and Symptoms of Lateral Medullary Syndrome (Wallenburg Syndrome)
Lateral medullary infarction, also known as lateral medullary syndrome, is a specific type of stroke. Its symptoms may vary widely, but commonly include dizziness, unsteady gait, nausea, vomiting, difficulty swallowing (dysphagia), and hiccups. Some patients also experience speech difficulties, facial pain, changes in vision, and headaches.
- Different sensation of pain and heat on the opposite side of the body (trunk and limbs)
- Different sensation of pain and heat on the same side of the face
- The same-sided (ipsilateral) Horner syndrome
- Unsteady movement in limbs on the affected side (ipsilateral limb ataxia)
- Difficulty swallowing (dysphagia)
- Uncontrolled, fast eye movements (nystagmus) – often more noticeable when looking downward
- Hiccups – can easily be missed
- Heightened pain sensitivity on the affected side (ipsilateral hyperalgesia)
In more detail, research shows that for about 75% of patients, symptoms of lateral medullary syndrome appear suddenly. For the other 25%, symptoms emerge more gradually. Sensory symptoms such as changes in pain and temperature sensation are the most common. Some patients may also experience facial weakness, speech difficulties, and abnormal eye movements including double vision and problems controlling the direction of gaze. For those with a gradual onset of symptoms, headaches, dizziness, unsteady gait, or vertigo usually appear first, with changes in sensation, difficulty swallowing, voice changes, and hiccups occurring later.
People with lateral medullary syndrome often have abnormal eye movements, such as uncontrolled, rapid eye movement (nystagmus) and a tendency for their eyes to move towards the side of their brain where the stroke occurred. Among these, a specific type of eye movement (ipsipulsion) is more common in people with this condition.
Testing for Lateral Medullary Syndrome (Wallenburg Syndrome)
The process of figuring out if you have Lateral Medullary Syndrome (LMS) involves a thorough check of your health history, physical exam, and specific tests. We’ll look at factors that put people at higher risk of having a stroke, such as high blood pressure, diabetes, smoking, and heart disease. If you’ve recently had neck pain, experienced trauma, or had a headache, this could suggest Lateral Medullary Syndrome, especially if you’re a younger patient.
We’ll do a thorough check-up of your nerve function (neurological examination). LMS is generally diagnosed based on your health history and certain physical symptoms. We may also do blood tests that look at blood sugar levels and balance of minerals in the blood (serum electrolytes).
An electrocardiogram (EKG) might be used to check if the heart’s rhythm is regular or irregular – irregular heartbeats, or atrial fibrillation, can sometimes lead to strokes. We might also use ultrasound technology to produce images of your heart (echocardiography) and main blood vessels in the neck (carotid Doppler).
We’ll perform some assessments of your swallowing, making use of videofluoroscopy (using X-rays to see how your mouth and throat move when you swallow), and fiber-endoscopic examination (a thin, flexible tube with a camera is inserted into throat to view the swallowing process).
We are likely to complete some imaging tests. Usually, we’ll first do a Computed Tomography (CT) scan of the brain. CT scans involve taking a series of X-rays that can be combined to produce detailed images of the brain. However, these images might not show early signs of damage to brain tissue. CT scans are also not good at providing clear images of the structures at the back of the brain.
Instead, Magnetic Resonance Imaging (MRI) often provides a better view as it uses radio waves and powerful magnets to create high-quality images of the body. An MRI can help by giving us a clearer view of any damage that has occurred in the medulla, a part of brain. A special type of MRI scan, known as Diffusion-Weighted Imaging (DWI), can often detect areas of brain damage earlier.
Finally, we may perform neurovascular studies. These involve using advanced scanning methods like Computed Tomography Angiography (CTA) and Magnetic Resonance Angiography (MRA) which can help pinpoint where the brain damage is.
Treatment Options for Lateral Medullary Syndrome (Wallenburg Syndrome)
Patients who are suffering from severe health conditions often require monitoring in the ICU (intensive care unit). This is important since they could experience respiratory failure, which is a life-threatening condition where the lungs can’t provide the body with enough oxygen.
Aside from monitoring the patient’s lung function, doctors must also watch for signs of increased pressure inside the patient’s head, known as intracranial pressure. This could include symptoms like confusion, tiredness, headaches, and vomiting. To manage increased intracranial pressure, doctors may raise the head of the patient’s bed, control blood pressure to ensure good blood flow to the brain, manage the patient’s breathing, and give medication to decrease swelling (osmotherapy) and sedatives to help the patient relax. In severe cases, a surgery may be necessary.
Thrombolytic therapy, a treatment that uses drugs or devices to break up dangerous blood clots, could be a treatment option. This would involve an IV drip that includes a clot-dissolving drug, recombinant tissue-plasminogen activator (IV-rt-PA), or a specialized procedure to manually remove the clot.
To prevent future strokes, patients might also take medications like antiplatelet drugs to prevent blood clots, drugs to lower blood pressure (antihypertensives), and medications to lower cholesterol (statins). Healthy lifestyle changes and managing other health conditions can also reduce the risk of future strokes.
If patients have difficulty swallowing or eating, they might need a tube inserted through their nose and down to their stomach (nasogastric tube). Other options to help manage swallowing problems (dysphagia) include dietary changes, modifying how the patient sits or lies when eating, and doing exercises to strengthen the muscles used for swallowing. Medication may be used in cases of severe or long-lasting dysphagia, and sometimes a surgery may be required to insert a feeding tube directly into the stomach.
Patients might also need to take low-molecular-weight heparin, a blood thinner, to prevent blood clots in the deep veins (deep vein thrombosis).
A speech therapist can help patients who have difficulty speaking, and a medication called gabapentin might be used to treat a condition known as hiccups that are persistent and difficult to get rid of.
If a patient’s heart cannot pump enough blood to the rest of the body, they might need a pacemaker, which is a small device placed in the chest to help control the heartbeat.
In some cases, patients could develop an eye condition known as keratitis due to nerve damage caused by the disease. This condition can cause a loss of sensation in the eye, leading to damage to the eye surface (epithelial erosions). Treatment could include the use of artificial tears, eye creams, a serum made from the patient’s own blood (autologous serum), and in rare cases, eye surgery.
Gabapentin might also be used to treat chronic disabling facial pain caused by the condition.
Regular check-ups to monitor the patient’s speech and physical movements are also often part of the long-term management of such complex conditions.
What else can Lateral Medullary Syndrome (Wallenburg Syndrome) be?
When diagnosing a headache, doctors should also consider and rule out the following conditions that may present with similar symptoms:
- Migraine or cluster headache
- Internal brain bleeding (Intracranial hemorrhage)
- Cancer (Malignancy)
- Mental health related conditions (Psychiatric conversion disorders)
- Temporary brain blood vessel narrowing (Reversible cerebral vasoconstriction syndrome)
- Inflammation of large and medium-sized blood vessels (like Giant Cell Arteritis)
- Damage to one of the main arteries in the neck (Vertebral artery dissection)
What to expect with Lateral Medullary Syndrome (Wallenburg Syndrome)
Lateral medullary syndrome generally has a good outcome. Thanks to advancements in respiratory care, patients typically recover and can often return to their normal activities. This includes those who experience dysphagia, a condition making it difficult to swallow, associated with LMS, which also has a good prognosis.
Possible Complications When Diagnosed with Lateral Medullary Syndrome (Wallenburg Syndrome)
Some less common effects that can happen due to lateral medullary syndrome may include:
- SIADH or Syndrome of inappropriate antidiuretic hormone secretion (this usually occurs less often in patients with lateral medullary syndrome compared to other stroke patients)
- Neurotrophic keratopathy, a condition that can result in corneal damage and potential infection
- Severe difficulty swallowing, also known as dysphagia
- Trigeminal neuralgia, a condition causing facial pain
- Rarely, complications related to the heart (since the Nucleus tractus solitarii which is involved in heart regulation can be affected)
- Obstruction of the flow of cerebrospinal fluid, resulting in a condition known as hydrocephalus
- Respiratory complications, including issues like aspiration pneumonia, respiratory failure, and Ondine’s curse or hypoventilation syndrome. In rare cases, respiratory failure due to issues with the autonomic nervous system can occur. This can potentially lead to apnea, a condition characterized by temporary pauses in breathing, or even death in severe cases
Preventing Lateral Medullary Syndrome (Wallenburg Syndrome)
Patients suffering from lateral medullary syndrome, a condition affecting the side of the brainstem, are recommended to participate in physical and occupational therapy. These therapies help patients gradually regain their physical strength. It’s important for patients to understand strategies for preventing a second stroke. If a patient is experiencing dysphagia (difficulty swallowing), they should take part in rehabilitation exercises designed to aid swallowing.
In severe cases of dysphagia, a gastrostomy tube might be needed. This is a tube that goes directly into the stomach through the abdomen, helping patients to get the nutrients they need when it’s too hard to swallow. Regular check-ins for speech evaluations are also crucial in this process, as they can help monitor progress and adjust treatment if necessary.
