A rare disease that needs to be seen: acute disseminated encephalomyelitis!

Author: Dong Huiqing, Chief Physician, Xuanwu Hospital, Capital Medical University

Reviewer: Xu Jun, Chief Physician, Beijing Tiantan Hospital, Capital Medical University

There is a rare disease that only occurs in about 1 in 1 million people, but it causes great harm to patients. This disease is acute disseminated encephalomyelitis!

1. What is acute disseminated encephalomyelitis?

Acute disseminated encephalomyelitis is actually a demyelinating disease caused by immune disorder after acute infection. What does demyelinating disease mean?

We all know that the brain and nerves need to conduct. When conducting, the brain has nerve fibers, which are like the skin of wires. If the skin of the wires is detached, it means that the myelin sheath of the nerve fibers is diseased, which we call demyelinating disease. Acute disseminated encephalomyelitis is a demyelinating disease.

The age of onset of acute disseminated encephalomyelitis is generally younger, with more cases occurring in children and adolescents aged 5-18 years old.

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2. What are the causes of acute disseminated encephalomyelitis?

From the patient's prodromal symptoms, the causes of acute disseminated encephalomyelitis can be divided into several categories:

For example, vaccinations, such as measles vaccine, diphtheria, pertussis, hepatitis B vaccine, influenza vaccine, etc. Of course, the preventive effect of vaccines is indispensable. Although some of them may have side effects, the incidence rate is very low, just like you may bite your tongue when eating. We must not give up eating because of choking.

Another is infection. For example, many rashes are caused by viral infection, while bacterial and fungal infections are less common. After viral infection, there is a process of viremia, fever, and the condition worsens after the fever subsides, with mental abnormalities, headaches, vomiting, body numbness, or poor memory. We call this fever-induced illness. This situation may also be caused by infection causing acute disseminated encephalomyelitis.

There is also a small number of patients who are idiopathic, with no immunization or viral infection, and suddenly develop abnormalities. This type is called idiopathic immune-mediated acute disseminated encephalomyelitis.

3. What are the types of acute disseminated encephalomyelitis?

In terms of anatomy, location of damage, and severity, there are roughly several types:

If there is damage to the brain and spinal cord at the same time, it is the classic acute disseminated encephalomyelitis, which we call acute cerebrospinal type. If it is limited to the brain, it is called brain type. There is also a situation where demyelination is in the spinal cord but not in the brain, which we call spinal cord type. These are the three most common types.

There is another more dangerous type, which is that not only is there inflammation, but the blood vessels are invaded and there is also bleeding and necrosis. We call it acute hemorrhagic necrosis. This type is even rarer.

So it is roughly divided into three types: acute cerebrospinal type, brain type, and spinal type. However, if the damage to the brain and spinal cord is relatively serious at the same time, there will be meningeal damage, combined with cerebral edema causing some meningeal damage, but simple meningeal type is rare.

4. What are the symptoms of brain and spinal cord damage in patients with acute disseminated encephalomyelitis?

The brain is responsible for higher-level functions, and problems with higher-level functions may occur, such as mental and behavioral abnormalities, memory loss, and abnormal cognitive functions, and the onset of the disease is often very acute.

The brain also controls the body and movement, which can cause hemiplegia and paraplegia. It also controls all of our sensory functions, which can cause a variety of sensory symptoms, such as the feeling of crawling insects on the face or body, or a burning sensation.

If the spinal cord is affected, autonomic nervous system symptoms may occur, such as abnormal sweating, abnormal heart rate, changes in blood pressure, urinary incontinence, fecal incontinence, etc.

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5. How to treat acute disseminated encephalomyelitis? Can it be cured?

Timely treatment of acute disseminated encephalomyelitis is very important, and there are many treatment methods. Because it is caused by immune abnormalities, immune-regulating drugs should be used in the acute phase. For example, the most commonly used one is glucocorticoids, such as methylprednisolone shock therapy. In addition, large doses of immunoglobulin can also be used for treatment.

If the treatment is not effective, some monoclonal antibodies can also be used, such as the most classic rituximab.

In addition, symptomatic treatment is also required. For example, patients with epilepsy should use anti-epileptic drugs, patients with cerebral edema should use dehydration drugs, and patients with large amounts of bleeding may need to consider surgical treatment, etc.

In general, more than 80% of patients have a good prognosis, but if the condition is very serious, some patients may have various complications, such as intellectual abnormalities, mental disorders, hemiplegia, etc.