Autoimmune encephalitis is diagnosed in patients of any age, most often in children and adolescents. The disease is characterized by damage predominantly to the gray matter of the brain. The pathology may accompany the tumor process or develop without the primary appearance of the tumor. It manifests itself as a change in the level of consciousness, impairment of cognitive functions and motor activity.
Development mechanism
There is still no exact information about the development of this disease. In most cases, such dysfunctions of the immune system occur under the influence of:
- Autoimmune antibodies.
- Viral infections.
- Cytotoxic T-lymphocytes.
The pathological process is associated with the spontaneous formation or the formation of autoaggressive antibodies that began as a result of infection, which have a special structure consisting mainly of protein. Under their influence, healthy cells of the body are damaged or completely destroyed.
Cytostatic T lymphocytes are responsible for the immune response. They constitute the body’s antiviral defense and are responsible for eliminating damaged cells. That's why they are also called T-killers.
Under the influence of viral infections, the stability of the immune system is often disrupted. In this case, the production of autoimmune antibodies occurs and the targets of T-lymphocytes are disrupted, which, according to experts, affect autoimmune encephalitis.
An irreversible consequence of the disease is the drying out of one hemisphere. Atrophic processes in tissues develop as a result of a decrease in the number of neurons. This is a natural phenomenon that cleanses the nervous system of old cells. It is called apoptosis. This is an uncontrollable process, but in the absence of health problems it does not cause neurodeficiency.
In encephalitis, astrocytes are susceptible to apoptosis. These cells are important components of white and gray matter. They nourish, protect and support the functioning of nerve cells. When their number decreases, pathological changes begin in the brain.
Complications
The consequences of autoimmune encephalitis always occur. But in the absence of therapy they appear earlier. These include:
- short or long-term loss of consciousness;
- vegetative state of the body (a person is unconscious, connected to artificial ventilation);
- decreased intelligence;
- severe neurological disorders (lack of sensation in the legs, hand tremors, nystagmus);
- death.
If one of the symptoms of a neurological disorder appears, you should immediately consult a doctor. Timely therapy will improve the patient’s quality of life and prevent lethal effects at an early age. Self-medication is not acceptable; the patient must strictly adhere to the therapy prescribed by the attending physician. It must be carried out throughout life; stopping taking the drugs is fraught with complications and death. The prognosis for autoimmune encephalitis is not good. Patients in advanced stages are unable to walk, fall into a vegetative state, and then die.
Autoimmune encephalitis is a disease in which autoantibodies damage the white and gray matter of the brain and cause degenerative processes. This is a dangerous pathology that in a short time leads to serious disorders of brain function that are difficult to treat.
Why does it occur
Autoimmune encephalitis has different causes. It is impossible to determine exactly what causes the pathological process. There are a number of factors that increase the likelihood of violations. The risk of encephalitis increases:
- if a person has previously suffered an inflammatory disease of the brain and its membranes;
- in the presence of systemic lupus erythematosus, polyarteritis nodosa, and other pathologies of the immune system;
- when serious brain damage has been sustained;
- with gene mutations;
- for prion diseases;
- if tumor processes develop in the brain and spinal cord.
Classification
There are several types of pathological process, including:
- Rasmussen's encephalitis. This is the most dangerous type of disease. There are currently no methods that would help eliminate violations. In the pathological process, one or both hemispheres are affected. Most patients are teenagers aged 14 years and older, due to the instability of the immune system. This encephalitis differs from other types of persistent attacks of epilepsy that are not controlled by medications. In this case, one hemisphere atrophies and shrinks. Brain shrinkage is irreversible.
- Schilder's encephalitis. It is also called diffuse sclerosis. The pathological process extends to the white matter, cerebellum and pons. During the examination, foci of inflammation in the white matter, degeneration of the axial cylinders and cells of the cerebral cortex are detected. The disease occurs in children from 5 to 15 years old. The reasons for it have not been established. Symptoms occur early in development and progress rapidly. The pathological process can occur over several years. Diagnosis is difficult because the disease is similar to multiple sclerosis or a tumor. There are no treatment methods. They try to alleviate the patient's condition with the help of corticosteroids. It is impossible to reverse the disorders, as well as to stop the development of the pathology.
- Autoimmune limbic encephalitis is a rare neurological syndrome in which memory and cognitive functions are impaired, mental disorders and epileptic seizures develop. The disease is also accompanied by dyskinesia, vegetative and endocrine problems. The pathology is characterized by a paraneoplastic nature, but recently idiopathic disorders have also been observed.
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If the diagnosis is made in time, then even with encephalitis, most of the body’s functions can be preserved.
Differential diagnosis
Differential diagnosis is carried out on the basis of diagnostic methods. It is necessary to exclude infection, mycoses, injuries, tumors, viruses that cause the same signs of neuralgia as autoimmune encephalitis. Hereditary disorders of brain structures, autoimmune diseases of other organs, inflammation of blood vessels (vasculitis) of the brain, and sclerosing conditions of the brain have similar symptoms.
The main distinguishing feature of autoimmune encephalitis is the presence of inflammation in the blood, cerebrospinal fluid, leukocytosis (increased white blood cells), and the absence of a bacterial focus. No other data on laboratory signs are revealed. CT and MRI scans show foci of brain inflammation in the early stages, and atrophy of one hemisphere in the later stages. With age, characteristic symptoms of a neurological disorder are added.
Stages of the disease
Rasmussen's encephalitis goes through several stages. Each one exhibits certain symptoms and requires special therapeutic actions.
The pathological process is divided into the following stages:
- Premonitory. Its development is noted in children aged seven. The disease occurs within eight months. Epilepsy attacks are rare, muscle tissue has not yet been weakened. In half of the cases there is an acute course and a gradual transition to the next stage.
- Spicy. In this situation, there is a history of muscle weakness, muscle paralysis, and seizures of epilepsy. The patient suffers from dementia. He remains in this state for seven months, after which the disease enters the final stage.
- Residual. It manifests itself as a residual course of the disease after therapeutic measures. The frequency and duration of epileptic seizures decreases slightly.
The third stage depends on how timely and effective the treatment is. Mental retardation and paralysis persist for the rest of their lives in most patients.
An assessment of a person’s condition and the stage of development of the disease is carried out based on the number and severity of epilepsy attacks. With exacerbation, the amount of brain damage increases. Wherein:
- There is a violation of muscle motor functions.
- The attacks become more frequent several times.
- Medicines do not help control seizures.
The clinical picture will be common for patients of any age. But children experience a faster progression of the disease than adults. Symptoms progress over two years. In this case, an increase in epileptic seizures is observed.
Privileged body
The brain is an organ that is remarkable in many ways [1]. The infinite complexity of the device, its functionality and the connection between our lives and its state attract the attention of researchers to the brain. The relationship between the brain and the immune system of our body is also special: the brain is an immune-privileged organ. Immune reactions that easily develop in other tissues (liver cells, muscles, fatty tissue) rarely occur in the brain. Along with the brain, the thyroid gland, testicles and some eye tissues, in particular the cornea, found themselves in such a special relationship with the immune system.
It has long been believed that the basis of the immune privilege of the brain is the presence of the blood-brain barrier (BBB). The BBB is a complex of cellular and extracellular structures that separate the blood flowing in the capillaries from the neurons of the brain parenchyma. The cells of the vascular walls, the basement membrane on which they lie, and astrocytes participate in the formation of the BBB. The immune privilege of parts of the central nervous system was in good agreement with the extent of the BBB within it. The brain parenchyma is reliably protected by the BBB, and inflammatory processes (encephalitis) rarely occur in it. The choroid plexus, which produces cerebrospinal fluid, and the membranes of the brain do not have such cover, and their inflammation (choroiditis, meningitis) is much more common (Fig. 1).
Figure 1. Structure of the central nervous system. The parts that are well protected by the BBB include the gray and white matter. Other components do not have this protection.
The brain has difficulty delivering activated immune cells to the cervical lymph nodes. Dendritic cells are responsible for working with antigens in the brain. In other organs, they recognize the antigen and then provide information about it to T and B lymphocytes in the lymph nodes. During inflammation in the brain, this process does not occur: dendritic cells do not migrate to the lymph nodes and do not present antigen. The immune response becomes localized and is regulated by dendritic cells in the brain parenchyma. If in other organs the cellular elements of immunity, after the presentation of the antigen, rush to the site of bacterial penetration [6], then with the development of inflammation in the brain parenchyma this does not happen. The brain has to rely on itself. A similar locality of the immune response is observed in the parenchyma, but not in the choroid plexuses and meninges.
How it manifests itself
Autoimmune encephalitis has pronounced symptoms. With the development of the pathological process:
- The infection worsens, the muscles move involuntarily.
- The sensitivity of the limbs decreases and gradually paralyzes them.
- The patient experiences dementia, memory impairment, and confusion of speech.
An electroencephalogram reveals a decrease in the activity of one hemisphere. Recent studies have found that tongue convulsions occur with encephalitis. During the development of the disease, subacute symptoms appear in the form of:
- mental and vision disorders;
- decreased interest in the outside world;
- emotional disorders;
- aphasic and apraxic disorders;
- damage to the facial nerves, which leads to muscle paralysis and deafness;
- muscle weakness and seizures.
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Symptoms
Symptoms of encephalitis include:
- headache;
- vomit;
- nausea;
- aches and pain in the joints;
- high body temperature (above 38 degrees Celsius);
- confusion;
- drowsiness;
- disorientation;
- convulsions;
- changes in personality behavior.
Not in all cases, but still, photophobia, loss of vision, neck stiffness, involuntary movements of the head, limbs, body, and insemination of body parts may also be noted. Sometimes you can experience anxiety, delusions, paranoia, and hallucinations.
Initially, the patient may seem like just a person who has the flu. But a change in his mental background already indicates that it is worth sounding the alarm and urgently calling an ambulance.
Treatment Options
Rasmussen's encephalitis is a serious pathology that requires timely diagnosis and treatment. For any form of autoimmune encephalitis, an electroencephalogram, magnetic resonance imaging and tests are prescribed. The acute stage does not require such an approach, since a diagnosis can be made based on pronounced symptoms. After identifying the problem, immunostimulating drugs are used. They help slow down the development of dementia and severe speech impairment.
Advanced stages are not treated, and it becomes difficult for the body to tolerate antiepileptic medications. Degraded areas of the brain can be surgically removed.
At the beginning of the development of pathology, a combination of drugs against epilepsy with proper nutrition can alleviate the condition. The patient should focus on fatty acids and reduce the intake of proteins and carbohydrates. There are many essential substances in unrefined vegetable oils.
Transcranial magnetic stimulation is considered a new treatment method. With its help, epilepsy is eliminated. They also resort to plasmapheresis and blood filtration. To alleviate the condition, people turn to hormonal and immunomodulating drugs.
Diagnostics
Diagnosis of the autoimmune type of encephalitis should be comprehensive, and for this you need to use EEG, MRI and pass all the necessary tests. At the acute stage, it is quite easy to determine the pathology by all the accompanying symptoms, but identifying it at the prodromal stage is extremely difficult. After all, the disease may not have any special signs at first. Delay in this situation can cost the patient his health, since it is at the initial stage that immunostimulating medications work well.
