What is Medial Medullary Syndrome (Dejerine Syndrome)?
The medulla oblongata, often simply called the medulla, is a part of the brainstem. The brainstem is located at the base of the brain and connects the brain to the spinal cord. The medulla extends from another part of the brainstem called the pons to the top of the spinal cord, about at the height of the first neck bone. Structures located in the middle part of the medulla control different body functions and are nourished by an artery that branches off from the vertebral artery, the main artery supplying the brain.
One important condition related to the medulla is called medial medullary syndrome, also known as Dejerine syndrome. It’s caused by a blockage that prevents blood from reaching this area of the brain. This condition was first explained in 1915 by a doctor named Joseph Jules Dejerine. Understanding the medulla’s role in the body can help us understand the effects of this syndrome.
What Causes Medial Medullary Syndrome (Dejerine Syndrome)?
Medial medullary syndrome usually happens due to a blockage in specific arteries that provide blood flow to the spine and brain. This blockage is often caused by fatty deposits in these arteries. Some common factors that raise the risk of this condition are high levels of fats in the blood, high blood pressure, diabetes, and smoking.
There are other, less common risk factors too. If people have problems with their heart rhythm, specifically a condition called atrial fibrillation, or if they have a hole in the heart wall, known as atrial septal defect or patent foramen ovale, these can also increase the risk. Migraines and a rare type of inflammation of the blood vessels called Takayasu arteritis can too. Sometimes, an injury that causes a tear in one of the arteries leading to the brain, which is known as a vertebral artery dissection, can lead to medial medullary syndrome, especially in younger patients.
Risk Factors and Frequency for Medial Medullary Syndrome (Dejerine Syndrome)
Stroke, a condition that often results in disability, is the second leading cause of death worldwide. In the United States alone, around 800,000 people experience a stroke each year. The majority of these cases, about 83%, are due to ischemic strokes, which happen when the blood supply to the brain is reduced.
One of the causes of ischemic strokes is the blockage of the vertebrobasilar artery. This blockage, which affects what is known as the posterior circulation of the brain, is responsible for 20 to 25% of ischemic strokes. Different neurological problems can arise from a blockage in this artery, one of which is a rare condition called the medial medullary syndrome. This syndrome is the cause of approximately 1% of all brain infarctions, which are areas of the brain that have died due to lack of blood supply.
Signs and Symptoms of Medial Medullary Syndrome (Dejerine Syndrome)
Medial medullary syndrome is a condition that can lead to various symptoms and signs. Some patients may experience paralysis of the opposite side of the upper and lower body parts because of the involvement of a nerve pathway in the brain known as the lateral corticospinal tract. A decreased sense of body position, vibration, and fine touch sensation can also occur if another nerve pathway, the medial lemniscus, is involved. While some people report unusual sensations or lack of sensation in the opposite side of the trunk and lower body parts, many do not show any clear signs of position, touch, or vibration sense loss.
- Paralysis of the opposite side of the upper and lower body
- Decreased sense of body position
- Reduced vibration and fine touch sensation
- Unusual or lack of sensation in the opposite trunk and lower body parts
- Some people may experience a slight loss of position and vibration sense, particularly in the foot on the opposite side.
- The tongue may deviate to one side due to damage to the hypoglossal nerve on the same side.
It’s also interesting to note that difficulty swallowing, a condition known as dysphagia, is frequently seen in patients with a similar condition called lateral medullary syndrome. However, dysphagia is even more common in cases of bilateral medial medullary infarct. In fact, in a review of 28 cases of this type, 11 were found to have dysphagia or paralysis of the palate.
Testing for Medial Medullary Syndrome (Dejerine Syndrome)
To assess possible health issues, your doctor may ask questions about your medical history, conducts a physical examination, and orders relevant diagnostic tests which may include:
Checking for risk factors of stroke: This involves looking for conditions that could increase your chance of having a stroke. These include high cholesterol or dyslipidemia, high blood pressure or hypertension, diabetes, smoking, irregular heartbeats or atrial fibrillation, a hole in the heart’s wall or atrial septal defect, migraines, and a type of inflammatory disease that attacks the arteries called Takayasu arteritis.
Neurological examination: A thorough neurological examination can help your doctor determine the state of your nervous system. This procedure is especially important because the condition, known as medial medullary syndrome, is often diagnosed through a clinical examination.
Imaging: Your doctor might order a computerized tomography (CT) scan or a magnetic resonance imaging (MRI) to better visualize the location and size of a stroke. An MRI can provide a more effective view of the damage to the nervous system than a CT scan, which might not clearly show certain areas of the brain due to the surrounding bone structure. In certain types of MRI films known as diffusion-weighted (DWI) and T2-weighted scans, the area affected by medial medullary syndrome will appear unusually bright or ‘hyperintense’.
Observing the vascular obstruction: To pinpoint the blocked artery or vein, your doctor may order a detailed vessel test known as a magnetic resonance (MR) angiogram or a CT angiogram.
Checking the heart rhythm: An electrocardiogram or ECG can be done to rule out a type of irregular heartbeat known as atrial fibrillation which might have contributed to the stroke.
Other important tests: A series of baseline tests may be used to check your overall health. These could include measuring sugar levels in your blood (serum glucose), the balance of minerals in your blood (serum electrolytes), and the levels of different types of fats in your blood after a period of fasting (fasting lipid panel).
Treatment Options for Medial Medullary Syndrome (Dejerine Syndrome)
Medial medullary syndrome is a type of stroke that requires prompt action for successful treatment. Getting to a specialized stroke center as quickly as possible can greatly improve a patient’s chances of survival and recovery.
Before reaching the hospital, there are vital steps to ensure the patient’s stability. Maintaining the patient’s breathing and circulation, monitoring their heart, measuring their blood sugar levels, and ensuring they consume no food or drink are essential measures.
Once in the hospital, doctors aim to dissolve or remove the blood clot that caused the stroke as soon as possible. This is usually done within 3 to 4.5 hours from the onset of stroke symptoms. Medications can be administered intravenously to dissolve the clot. Sometimes, doctors perform an endovascular intervention in which they thread a thin tube through the blood vessels to reach and remove the clot, especially in cases where the clot is in a large vessel.
Throughout the treatment process, doctors monitor the patient’s blood pressure and try to reduce it gradually if it’s too high. They also aim to keep the blood sugar level within normal limits and treat any other existing medical conditions. It’s essential to evaluate the patient’s swallowing ability before they start eating, drinking, or taking oral medications. If there’s a risk of pneumonia, doctors will prescribe antibiotics. Patients who are bedridden may receive anticoagulants to prevent blood clots from developing in their legs.
Doctors try to avoid using urinary catheters unless necessary, as these are associated with an increased risk of urinary tract infections. Additionally, patients should start physical and occupational therapy as soon as possible to aid their recovery process.
When it’s time to discharge the patient, they may be prescribed oral anticoagulants if the blood clot originated from their heart. If the clot was from another source, they might be given antiplatelet medications to prevent the formation of new clots. They could also be prescribed statins to manage their cholesterol levels if necessary.
What else can Medial Medullary Syndrome (Dejerine Syndrome) be?
The following are medical conditions which might be a bit complex to understand:
- Amyotrophic lateral sclerosis (ALS), in its advanced stages
- Brown-Sequard syndrome, a partial damage of the spinal cord
- Hemimedullary infraction, a type of stroke affecting one half of the medulla in the brain
- Injury to the hypoglossal nerve, a nerve that is located in the neck and head
- Intracranial tumor, a brain tumor or growth inside the skull
- Posterior cord syndrome, a condition which affects the back part of the spinal cord
What to expect with Medial Medullary Syndrome (Dejerine Syndrome)
The brain is made of permanent tissue, meaning any damage it sustains is not fully recoverable. However, thanks to advancements in medical science, if conditions like medial medullary syndrome (a stroke syndrome affecting a particular part of the brain, the medulla) are diagnosed and treated early, along with the use of rehabilitation services, there is a fair chance of improvement.
If a patient has severe hemiparesis (muscle weakness on one side of the body) or experiences loss of sense on one side of the body (hemi-sensory loss), these symptoms might persist for their entire life. There was a review of 26 earlier reported cases where patients had damage on both sides of the brain leading to lingual paresis (weakness of the tongue muscles), total body paralysis (quadriplegia) and breathing issues. These cases had a worse prognosis, meaning there were lower chances of recovery.
Possible Complications When Diagnosed with Medial Medullary Syndrome (Dejerine Syndrome)
Common complications of medial medullary syndrome include deep vein thrombosis and pulmonary embolism. People with this syndrome may have a severe inability to swallow, especially if it affects both sides of the medulla in the brain. This difficulty in swallowing can lead to aspiration pneumonia, wherein food or drink is breathed into the lungs, which can get quite serious if not treated immediately and could turn deadly. A pulmonary embolism, which can cause sudden difficulty in breathing, may also be fatal. Patients suffering from paralysis on one half of the body (hemiplegia) can develop bedsores. Unfortunately, these bedsores can worsen into infections and could potentially lead to a full-body infection, called septicemia. This could also be fatal.
Possible Complications:
- Deep vein thrombosis
- Pulmonary embolism
- Severe difficulty in swallowing
- Aspiration pneumonia
- Fatality if not immediately treated
- Development of bedsores in patients with hemiplegia
- Infection of bedsores
- Septicemia
- Death due to complications
Recovery from Medial Medullary Syndrome (Dejerine Syndrome)
For patients who have had a stroke, starting rehabilitation early can be beneficial. However, research has indicated that beginning rehabilitation within the first 24 hours after a stroke isn’t more helpful compared to the usual care given in a stroke unit. Therefore, it’s best to avoid starting rehab within the first 24 hours after a stroke.
Preventing Medial Medullary Syndrome (Dejerine Syndrome)
Once the patient’s condition has become stable, it’s important to start secondary preventive measures to avoid long-term complications. These measures usually involve educating the patient and their family about certain practices that can help prevent future health issues. In this particular case, we want to help lower the risk of having another stroke.
The following are risk factors for a stroke, and actions that the patient can take to lessen these risks:
- Quit smoking: Smoking is harmful to your health and heightens your risk of stroke. Striving to quit can greatly reduce your risk.
- Control diabetes: Properly managing your diabetes can help lower your risk of getting a stroke.
- Control blood pressure: High blood pressure can contribute to a stroke, so it’s important to take measures to keep it under control.
- Adopt a low-fat diet: Consuming a lot of high-fat products can lead to health problems that increase your risk of having a stroke. Switching to a low-fat diet can aid in this.
- Lose weight: If you are overweight, losing weight may greatly lower your stroke risk.
By making these changes, the likelihood of having a secondary stroke can be significantly reduced.
