Encephalitis
Encephalitis is an inflammation of the substance of the brain. This term usually refers to infectious and allergic brain lesions, as well as lesions caused by toxic reactions. According to the timing of occurrence, they talk about primary and secondary encephalitis.
The content of the article:
Classification of encephalitis
Treatment of encephalitis
Prevention of encephalitis
Encephalitis
Primary encephalitis includes:
Tick;
Japanese mosquito-type encephalitis;
Economy type.
Secondary encephalitis includes:
korevoy;
postvaccinal;
flu – like;
bacterial;
parasitic.
Regardless of what type of encephalitis is detected in a person, he will be shown complex therapy, which includes such types of treatment:
etiotropic (antibacterial, antiviral or antiallergic);
infusion;
dehydration;
anti-inflammatory;
vascular;
neuroprotective;
symptomatic.
According to the pace of its development, they say about:
acute;
super – sharp;
subacute;
relapsing;
chronic encephalitis.
At the site of the lesion , they are distinguished:
cortical;
subcortical;
stem (including damage to the cerebellum and near the underlying structures).
Another classification distinguishes the following types:
stem;
cerebellar;
mesencephalic;
diencephalic.
According to the prevalence of the disease , they say about:
leukoencephalitis (affecting the white matter);
polyencephalitis (in this case, the gray matter of the brain is affected);
panencephalitis.
Regarding morphological signs, there are: necrotic and hemorrhagic encephalitis. If we talk about the severity of the course of the disease, then encephalitis can be: moderate, severe and extremely severe. Among the complications that can occur after a person has had encephalitis, there are: cerebral edema, coma, cystic, epileptic syndrome, brain dislocation.
This disease can end either with a complete recovery or partial (with the spread of a vegetative state in the patient). After the disease, focal symptoms may appear.
Classification of encephalitis
Primary encephalitis
Tick-borne encephalitis
As a rule, the causative agent of this type of disease is the neurotropic tick-borne encephalitis virus. The carriers of the virus are considered to be ixodic ticks that enter the human body through a tick bite or alimentary, which means by eating raw infected milk. In the future, the penetration of the virus into the plane of the nervous system will be hematogenic.
Usually, the duration of the incubation period of patients with encephalitis is up to 30 days if the virus was penetrated through a tick bite. In some cases, the incubation period will reach 60 days. If the infection was alimentary, then the interval of such a period will be 4-7 days.
A microscopy of the brain may reveal hyperemia and various gliotic or mesodermal reactions, as well as infiltrates arising from mononuclear or polynuclear cells.
As a rule, inflammatory changes are localized on the nuclei of the medulla oblongata, as well as in the anterior parts of the so-called horn of the cervical segments located in the spinal cord and on the bridge of the brain. In addition, the cerebral cortex can be invaded by the inflammatory process.
The traditional symptoms of tick-borne encephalitis will be: acute onset, which manifests itself in the form of an increase in body temperature to 40 degrees; aching joints; pain in the lower extremities and lower back.
In the very first days of the disease, the patient is characterized by such typical symptoms of encephalitis as nausea, vomiting and headache. There is also confusion of consciousness, which in some cases reaches the development of mental disorders that express themselves in the form of delirium, sound hallucinations and severe depressive disorder.
To date , there are several forms of tick-borne encephalitis:
polio;
encephalitic;
meningeal;
feverish;
polyradiculoneuritic;
two-wave viral.
The difference between all these forms is how pronounced certain neurological symptoms are. In the diagnosis of tick-borne encephalitis, anamnesis is of great importance. As you know, a very small percentage of ticks (up to 5%) are considered carriers of the pathogen virus, so you should not take every disease for encephalitis if it occurred after a tick bite.
The determination of encephalitis is carried out on the basis of the obtained neutralization reactions, complement binding reactions or hemagglutination inhibition. In the diagnosis, great importance is given to the type of virus found in the blood or liquor. Usually, in laboratory tests, ESR is determined in the blood, as well as leukocytosis, whereas in the liquor itself, lymphocytic pleocytosis is “searched” with a protein increase present with an index of up to 1 g / l.
First of all, the signs of tick-borne encephalitis differentiate with typhus, acute polio and serous meningitis.
Japanese mosquito encephalitis
This type of disease is caused by a neurotropic virus. Usually, its vector is considered to be those types of mosquitoes that have a transovarial type of transmission of the virus. At the same time, the incubation period lasts up to 14 days. It should be said that Japanese mosquito encephalitis develops very sharply. It begins with a sudden increase in body temperature (which in some patients is up to 40 degrees). Other symptoms include vomiting and severe headaches.
Symptoms such as tachycardia, herpetic rashes, facial hyperemia and dry tongue are also characteristic of the symptomatic picture of this type of disease. To date , there are several forms of Japanese mosquito encephalitis:
convulsive;
hemiparetic;
bulbar;
hyperkinetic;
lethargic.
The difference between these forms consists in the presence of one or another predominant syndrome. Regardless of the form of Japanese mosquito encephalitis, the course of this disease is particularly acute. In the first 5 days, the symptoms increase, the body temperature rises and remains high for 12-14 days. Body temperature can usually decrease lytically. If we talk about the fatal outcome, then it is inherent in 70% of patients in the first week of the development of the disease. Of course, a fatal outcome is possible at a later stage of the disease. This is facilitated by a complication that has joined, which is most often pulmonary edema.
Considerable importance in the diagnosis of this disease is given to its seasonality and the collected epidemiological data. Verification of the diagnosis is carried out on the basis of complement and neutralization reactions, as well as the determination of antibodies, which is possible already in the second week of the disease.
Epidemic lethargic encephalitis Economo
To date, epidemic lethargic encephalitis Economo practically does not occur, and its causative agent has not yet been definitively identified. In their clinic , the disease is divided into two stages:
acute stage (characterized by inflammatory character);
chronic stage (it is characterized by a progressive course of a degenerative nature).
The classic variant of the symptomatic severity of the lethargic form of encephalitis, which has developed to an acute stage, begins with a high body temperature, which often reaches 39 degrees, vomiting, general weakness and severe headaches. The patient has been feverish for two weeks. At the same time, neurological symptoms such as constant drowsiness (or, conversely, insomnia), abnormalities in the work of the oculomotor nerves occur, which sometimes leads to ptosis.
Among the extrapyramidal symptoms that are characteristic of the chronic stage of this disease, hyperkinesis (athetosis, choreoathetosis or eye cramps), amymia, muscle rigidity, akinesis (which is akinetic-rigid syndrome) are often distinguished.
In special cases, at the acute stage, epidemic encephalitis can occur with such pronounced psychogenic disorders as auditory or visual hallucinations, which manifests itself in the inability to correctly distinguish the color of surrounding objects.
The acute stage of this pathology is often characterized by lymphocytic pleocytosis, a slight increase in the level of glucose, lymphocytes and eosinophils in the blood. The acute stage of the disease can last for 4 days, and in some cases up to several months, after which either the patient recovers, or the disease turns into a chronic form with the possible preservation of partial symptoms in the form of depression, ptosis, insomnia or convergence.
The main symptomatic manifestation of the chronic stage of encephalitis Economo is Parkinsonism syndrome, in parallel with which there are all kinds of endocrine disorders (menstruation disorders, infantilism, obesity, cachexia or diabetes insipidus).
It is very difficult to diagnose epidemic encephalitis at the acute stage. Diagnosis, as a rule, is based on forms of sleep disturbance, which is accompanied by a psychosensory disorder and manifestations of impaired functionality of the oculomotor nerves. Considerable attention should also be paid to increasing body temperature.
If we talk about the diagnosis of the chronic stage of this disease, it is based on the study of Parkinsonism syndrome, as well as on the verification of endocrine disorders (central genesis) and possible changes in the psyche and behavior of the patient.
Secondary encephalitis
Influenza encephalitis
Influenza encephalitis is caused by influenza viruses B, A1, A2 and A3. The disease occurs as a complication after the flu. Among the main pathogenetic mechanisms of this disease, dyscirculatory phenomena occurring in the brain are in the first place. In addition to them, neurotoxicosis affects the disease. As you know, it is almost impossible to avoid damage to the nervous system with the flu. Usually, such lesions of the nervous system manifest themselves in the form of muscle and headaches, drowsiness and adynamia. If influenza encephalitis continues to develop, then the patient abruptly begins to feel bad, vomiting and dizziness occur.
If we talk about the cerebrospinal fluid, then a slight increase in protein levels may be detected in it, as well as a slight pleocytosis, which is revealed in the case of a lumbar puncture, when the cerebrospinal fluid begins to flow due to increased pressure.
In many cases, at the acute stage of influenza-type encephalitis, a severe lesion may develop, which manifests itself as a hemorrhagic type of influenza encephalitis, which begins with a sharp rise in body temperature, as well as chills and impaired consciousness, which in rare cases even leads to coma. Blood traces are often observed in the liquor. The course of this form of the disease is particularly severe, so very often a fatal outcome can occur. If the disease has a positive outcome, then some neurological disorders will still be preserved in the patient even after recovery.
Measles encephalitis
Measles encephalitis refers to infectious and allergic types of encephalitis. It develops quite quickly and in an acute form, which manifests itself on day 5 in the form of a rash or measles, even when the body temperature, it would seem, has already returned to normal, it suddenly jumps to 40 degrees.
Very often, with measles encephalitis, severe disorders of consciousness may occur, such as:
sound or visual hallucinations;
generalized seizures;
psychomotor type arousal;
movement coordination disorders;
characteristic paresis of the extremities;
hyperkinesis;
malfunctions in the functioning of the pelvic organs.
During the study of the cerebrospinal fluid, an increased protein content can be determined, as well as possible pleocytosis. Doctors note a very severe course of this disease, the mortality rate of outcomes is about 20-25%.
Postvaccinal encephalitis
If we talk about such a special type of encephalitis as post-vaccination, then as a rule, they occur after the introduction of DPT or ADS vaccines, or in the case of anti-rabies vaccinations, as well as after the introduction of measles vaccine. The disease itself develops very acutely with an inherent body temperature of up to 40 degrees, characteristic headaches, vomiting, changes in consciousness and adequate perception of reality, as well as with the appearance of generalized seizures.
When the extrapyramidal system is affected, hyperkinesis and possible movement coordination disorder begin to manifest. In the case of a study of the cerebrospinal fluid, which often results from an increase in blood pressure, doctors can determine the presence of lymphocytic cytosis, as well as an increase in protein and glucose levels in the blood.
The main characteristic of the course of encephalitis in the case of its development after anti-rabies vaccination will be an acute type of phenomenon such as encephalomyelopolyradiculoneuritis, which often has a progressive character and can even lead to death due to bulbar disorder.
Treatment of encephalitis
In the treatment of any type of encephalitis in neurology, several types of therapies are used, which may include several directions at once:
Dehydration and methods to combat swelling of the brain (usually a 20% solution of mannitol is used for this, which is administered intravenously at 1.5 g per kilogram of the body, furosemide, which is also administered intravenously; as an option, acetazolamide 40 mg per dose can be used).
Desensitization (using diphenhydramine, chloropyramine or clemastine).
Hormone therapy that can have an anti-inflammatory, dehydrating or desensitizing effect on the patient’s body. In addition, hormone therapy helps protect the adrenal cortex from their depletion (prednisone is usually prescribed at 10 mg per kilogram of the patient’s body, injected into the body with pulse therapy for the next 5 days, and dexamethasone is often prescribed intravenously or intramuscularly at 16 mg per day).
Isotonic dextran solution administered by intravenous dropper. Such therapy significantly improves microcirculation.
Parenteral or enteral type of nutrition, the use of potassium chloride or dextran — all this helps to maintain normal homeostasis and water-salt balance.
The use of angioprotectors (for example, a combination of ethamivan, hexobendine, vinpocetine or pentoxifylline).
The use of antihypoxants, including ethylmethylhydroxypyridine succinate.
Treatment of cardiovascular abnormalities may be prescribed. Usually such treatment involves the use of glycosides, glucocorticoids, camphor and vasopressors. To normalize the patient’s breathing in case of encephalitis, it will be possible with the help of hyperbaric oxygenation or oxygen therapy, as well as by intubation or ventilation.
In the treatment of encephalitis, specialists may be faced with the need to restore proper metabolism inside the brain. For this purpose, the use of special vitamins, piracetam or polypeptides is prescribed. Salicylates and ibuprofen are often prescribed among anti-inflammatory drugs.
If we talk about such a common type of therapy as etiotropic, then it implies the use, first of all, of antiviral drugs, for example, nucleases that can delay the reproduction of the virus. So, for example, interferon alpha-2 is often prescribed or combined with ribavirin (only in the most extreme cases). If doctors are dealing with DNA-viral encephalitis, then the most effective treatment will be the use of tilorone, while drugs from the group of corticosteroids (for example, metipred) are prescribed at the rate of 10 mg per kilogram of the body daily for three to four days.
Symptomatic therapy is one of the most common in the treatment of encephalitis. It involves performing manipulations in several directions:
antipyretic treatment;
anticonvulsant therapy;
treatment of delirious syndrome.
In order to stop an epileptic seizure, diazepam can be used (usually it is prescribed 10 mg in the form of an intravenous dextrose solution) or a one percent solution of sodium thiopental (also intravenously). In addition, doctors may prescribe phenobarbital or primidone.
Among antipyretics, lytic mixtures, solutions of sodium metamizole, ibuprofen or droperidol are usually prescribed. If we talk about individual therapy of delirious syndrome, then the use of magnesium sulfate or lithium mixtures comes first.
To restore the normal functioning of the nervous system and rehabilitate consciousness, all kinds of biostimulants, antidepressants or tranquilizers are prescribed.
As for restorative therapy, it involves the use of several drugs at once that fight Parkinsonism, Kozhevnik’s epilepsy, muscle paresis, neuroendocrine disorders. For example, parkinsonism is treated with the help of cholinolytics or levodopa, whereas the stereotactic type of surgery is indicated in the case of increased rigidity and poor efficacy in drug treatment. As for the use of metabolic drugs, tranquilizers or neuroleptics, they are indicated in the treatment of hyperkinesis.
The use of anticonvulsants and neuroleptics helps in the treatment of Kozhevnik’s epilepsy, while for the treatment of severe paresis, energy correctors and medications are used that can stimulate metabolic processes inside the brain. If we talk about ways to treat neuroendocrine disorders, then the use of metabolic drugs, neuroleptics and desensitizing medications is shown here.
Doctors strongly recommend performing physical therapy, therapeutic massage or physiotherapy.
Prevention of encephalitis
Among the main preventive measures against encephalitis (whether tick-borne or mosquito-borne), vaccination of people who live in the infected area is still considered. The standard type of vaccination involves three vaccinations, which allows you to strengthen the immune system for three years. Secondary prevention involves a timely diagnosis, as well as correctly prescribed therapy for any infectious disease.
