Acute disseminated encephalomyelitis (ADEM) is a disease of the central nervous system (CNS). It is also known as perivenous encephalomyelitis or Hurst encephalitis and predominantly affects children.
What is acute disseminated encephalomyelitis?
Acute disseminated encephalomyelitis (ADEM) is a disease of the central nervous system (CNS). ADEM belongs to the group of acquired demyelinating diseases of the CNS. A more well-known disease in this group is multiple sclerosis (MS). Acute disseminated encephalomyelitis is a rather rare disease. It manifests itself by an acute inflammation in the area of the central nervous system and often occurs one to four weeks after an infection. In many cases, the symptoms regress completely. However, damage can also remain. Only in rare cases does the disease end fatally.
Causes
Acute disseminated encephalomyelitis is an autoimmune disease. In many cases, the disease occurs after an infection. Triggering infections include harmless upper respiratory tract infections, rubella, chickenpox, Epstein-Barr virus (glandular fever), or hepatitis viruses. Vaccinations can also result in ADEM. In addition, it has been reported that ADEM can also be triggered by treatment with certain medications or follow trauma. Cases without any triggering cause (idiopathic ADEM) are also known. A genetic background of the disease is discussed. Typical for the disease is an occurrence in winter and early spring. It is assumed that the inflammation in the central nervous system is caused by a cross-reaction between brain proteins and pathogen components. This means that during the infection that precedes ADEM, the body creates antibodies against the pathogens of that infection. These antibodies attach themselves to the pathogens and work with other components of the immune system to render the pathogen harmless. In a cross-reaction, the antibodies that are actually directed against the pathogen then react with the body’s own cells. In ADEM, the antibodies attach themselves to the nerve cells and to the myelin layer that surrounds the nerve cells. The myelin layer plays an important role in the nervous system in conducting excitation. The binding of antibodies to these cells causes an inflammatory reaction. So-called focal, i.e. focal-shaped, demyelination foci occur. These are sites on the nerve cords where the myelin layer is damaged. These damages can occur in the brain and in the spinal cord. They are often accompanied by swelling.
Symptoms, complaints, and signs
Acute disseminated encephalomyelitis is characterized by a variety of symptoms, not all of which may always occur. The symptomatology depends on the particular localization of the injury. Overall, the symptoms are comparable to those of multiple sclerosis. However, while multiple sclerosis shows a relapsing course, the course of acute disseminated encephalomyelitis is limited to a single phase. In most cases, complete recovery occurs after the course of the disease. In a few cases, however, only a defect healing takes place, in which individual symptoms remain after the disease has ended. In the course of acute disseminated encephalomyelitis, such symptoms as slowing of movements, impaired consciousness or even depression may occur. Furthermore, hemiplegia, gait disturbances, speech disorders, confusion or lethargy may occur. Acute disseminated encephalomyelitis is also characterized by bilateral inflammation of the optic nerve leading to visual disturbances. Onset is often nonspecific with fever, general ill feeling, headache, nausea, and vomiting. The disease progresses rapidly. Thus, severe neurologic deficits symptoms may develop within hours of the uncharacteristic onset. Partial or complete paralysis may occur. If the respiratory muscles are affected by the paralyses, artificial ventilation is required. Patients often present with meningismus. Meningismus is the painful stiffness of the neck caused by irritation of the meninges. In addition to paralysis, gait or visual disturbances may occur. Double vision is characteristic.Epileptic seizures may also occur. Some patients lose consciousness. Comatose states are also conceivable. Overall, the prognosis is rather favorable. In the majority of patients, symptoms regress completely; only rarely do defects persist. In rare cases, a particularly fulminant form of the disease may occur, also known as Hurst encephalitis. In this form of encephalitis, hemorrhage into the brain tissue occurs due to the death of blood vessels. As a result, the affected brain tissue often dies completely. Therefore, Hurst encephalitis is often fatal.
Diagnosis and course
Various diagnostic procedures are used when acute disseminated encephalomyelitis is suspected. Because computed tomography (CT) can only visualize larger lesions of the myelin layer, cerebral or spinal magnetic resonance imaging (MRI) is the method of choice. MRI is used to detect demyelination and to exclude other diseases, such as multiple sclerosis. MRI is also used to monitor the course of the disease. To confirm the diagnosis, the cerebrospinal fluid (CSF) of the patient is also examined. Here, changes typical of the disease are found, such as an increased protein content or an increase in white blood cells, especially lymphocytes.
Complications
In the presence of acute disseminated encephalomyelitis, the most common complications include coma and syncope (loss of consciousness or fainting), headache, peripheral neuropathies (nerve damage to peripheral nerve tracts, for example, paralysis in the arms and legs), and ataxia (gross incoordination of muscle movements). In addition to coma, delirium (confusion) and involuntary spasms over the entire body (kouristukset) are among the most visible neurological signs of disseminated encephalomyelitis. In addition, other problems include optic neuritis, myelitis (inflammation of the spinal cord), and manifested neuromyelitis optica. Myelitis can lead to paralysis of the extremities, but also to complete incontinence (both urinary incontinence and fecal incontinence) if the disease progresses poorly. Neuromyelitis optica can lead to loss of vision (up to complete blindness), headaches, impaired consciousness, and seizures or spasms (convulsions). Inflammation of the optic nerve can in turn lead to significant loss of vision. Coma with complete loss of consciousness is, apart from the lethal outcome of the disease, the most serious complication of acute disseminated encephalomyelitis. To avoid the aforementioned complications or to mitigate the symptoms, early and comprehensive diagnosis is the method of choice.
When should you see a doctor?
Since the symptoms of this disease spread relatively quickly, a quick and immediate diagnosis and treatment is definitely necessary to prevent further complications. A doctor should therefore be consulted whenever there are lesions on the skin. These lesions are in most cases also accompanied by fever and nausea. Furthermore, it is not uncommon for those affected to also suffer from headaches or vomiting. Likewise, this disease can lead to various disorders of sensitivity and also paralysis. If disturbances of this kind occur or the affected person suffers from complaints of motor function, a doctor must be consulted directly. Visual disturbances or hearing difficulties can also be symptoms of this disease. In the worst case, the affected person suffers an epileptic seizure or even loses consciousness. In this case, the hospital can also be visited directly or an emergency doctor can also be called if it is an acute emergency. General disorders of consciousness must also be examined by a doctor. Ideally, the examination should take place in a hospital to avoid further epileptic seizures, which could possibly lead to the death of the affected person.
Treatment and therapy
Few studies exist for the treatment of acute disseminated encephalomyelitis, so treatment recommendations are based on experience. Patients usually receive intensive medical care. In most cases, high-dose steroid therapy is given, that is, various corticosteroids are used.In addition, immunoglobulins are administered. If steroid therapy is not successful, plasmapheresis is performed. Plasmapheresis involves the exchange of blood plasma. Blood plasma is the liquid part of the blood. This consists mainly of water, but other substances such as the antibodies responsible for acute disseminated encephalomyelitis are also dissolved in the blood plasma. Using a plasmapheresis device, the patient’s blood plasma is centrifuged and filtered. This is to remove the disease-causing antibodies circulating in the blood from the body. In individual cases, various immunosuppressants and cytostatics are also used to treat acute disseminated encephalomyelitis.
Outlook and prognosis
Disseminated encephalomyelitis primarily affects children. In most cases, however, a late diagnosis occurs because the initial symptoms are not disease-specific and thus do not indicate this disease. The symptoms are severe fever and headache. Furthermore, the children also suffer from vomiting and severe nausea. As the disease progresses, paralysis occurs in various parts of the body. The quality of life is considerably limited and reduced by these paralyses. In addition to the paralysis of the body, vision may also be impaired and movement may be restricted. It is not uncommon for those affected to suffer from epileptic seizures, which are also associated with pain. In severe cases, there may be disturbances of consciousness and further loss of consciousness. The epileptic seizures should be treated immediately. Often the parents and relatives of the patients also suffer from psychological stress or depression and need treatment accordingly. The treatment of the disease itself is carried out with the help of medication and blood plasma. This can greatly limit the symptoms if early treatment is given.
Prevention
Because the exact causes of acute disseminated encephalomyelitis are not yet completely understood, prevention of the disease is not possible. However, rapid diagnosis and prompt therapy can favorably influence its course. If a child develops a fever again shortly after an infection and possibly complains of visual disturbances, a doctor should be consulted immediately. The same applies to the occurrence of brief “dropouts” or paralysis after an infection or vaccination.
What you can do yourself
Because the disease primarily affects children, self-help measures in everyday life are primarily to be implemented by adults and guardians. Medical care is necessary for relief of symptoms to develop. Self-treatment of the child is not recommended, as this is expected to increase the irregularities. To strengthen the physical as well as mental forces, various guidelines can be followed. It is important to strengthen the patient’s immune system. The premises should be supplied with sufficient oxygen. If possible, outdoor stays are recommended. The diet should be healthy and conscious. Vitamins and nutrients are necessary to support the body’s defense system. Sleep conditions should be optimized so that the patient can recover sufficiently during night sleep or necessary rest periods. Optimally, rest and wake phases should be adapted to the natural course and regulation should only be initiated if necessary. To strengthen the psyche, positive elements should be embodied. Encouraging words and the promotion of fun and play are elementary components of self-help. Relatives should educate the patient about his or her condition in an understandable manner while pointing out ways to improve. Well-being should be promoted by designing the environment in accordance with the available possibilities.
