Causes and methods of treatment of herpetic encephalitis

Herpes viruses are common infectious agents that cause characteristic rashes in the skin, eyes (HSV type 1) and external genitalia (HSV type 2). An infectious agent can cause various diseases of the central nervous system. Herpetic encephalitis, which occurs against the background of a viral infection, is especially severe. The share of the disease in the general structure of encephalitis of viral etiology is 20%. Prevalence – 2-3 cases per 1 million population annually.

The concept of pathology

This acute infectious disease occurs in the brain. Herpetic encephalitis is usually caused by the herpes simplex virus type 1 (about 95% of cases). It is considered a complication of herpes virus infection, leading to damage to the temporal and frontal regions of the brain.

Peaks of the disease occur in young people from 5 to 25 years old, as well as people over 50 years old. The main flow of patients with this pathology is observed in the spring season. It can develop immediately after infection (mainly found in children) or during an exacerbation of infection within the body (mainly in adults), complemented by diseases such as chickenpox, herpes zoster, infectious mononucleosis or herpetic lesions of the genitals or nasolabial triangle.

Of all types of acute encephalitis, this type accounts for more than 10% of cases, which makes it possible to classify this disease as quite common.

Mostly children pick it up. This is due to the fact that their blood-brain barrier is not sufficiently developed, through which the virus enters the brain.

Characteristics of the disease

According to statistics, the herpes virus is detected in 90% of the population. In approximately 20% of cases, a viral infection causes serious disruptions in the body's functioning. Once entering the body (hematogenous, neuronal route), HSV (herpes simplex viruses) remain in it forever. An infectious agent can be in different states, which determines the degree of its impact on health. The following forms of pathology are distinguished:

• Latent (hidden).
• Persistent (chronic).
• Progressive (with increasing symptoms).
• Recurrent (with alternating periods of progression and remission).

Under favorable conditions, reactivation of a latent infection occurs. The acute form of the pathology can lead to loss of ability to work, disability, and death. HSV is characterized by pantropism - the ability to infect different organs and systems. Infectious agents cause pathological autoimmune reactions, induce the formation and growth of malignant neoplasms, and cause perinatal pathologies.

Penetrating into the central nervous system, viruses provoke the development of temporal lobe epilepsy of the median type. Encephalitis caused by viral agents is a common (about 76% of cases) forms of encephalopathies of various (bacterial, fungal, anaplasmic) etiologies. Herpetic encephalitis in children usually occurs acutely and provokes the appearance of persistent neurological deficits, often of a focal type. The disease often causes retardation in the mental and physical development of the child.

Herpetic encephalitis in adults is more often detected in patients of two age groups: under 30 years of age and over 50 years of age. In most cases (about 95% of cases), the infectious agent is type 1 HSV, which affects the mucous membrane and skin of the face in the mouth area. HSV type 2 affects the mucous membrane of the genital organs. It is more often detected in newborns, who are transmitted from an infected mother during fetal development.

In the body of 70-90% of infected people, antibodies to the viral agent are detected, which in normal conditions helps to suppress the activity of HSV by one’s own immune system. From the point of view of pathomorphology, the disease is an acute necrotizing process, which is characterized by the appearance of multiple foci of hemorrhage, lymphocytic and plasmacytic infiltration in the brain tissue.

In the acute stage of the disease, eosinophilic elements (granulocyte leukocytes) are found in the nuclei of nerve cells (neurons, neuroglia). Typical localization of the pathological focus is the medial (middle) part of the temporal lobes and the orbital (lower) part of the frontal lobes. In the residual (after the acute stage) stage of the course, cystic-glial tissue is formed at the site of foci of necrosis.

Causes of occurrence in adults

The causes of herpetic encephalitis are that the herpes simplex virus enters the human body through the oral mucosa, and then moves through nerve cells through the axons of olfactory neurons. But getting into the body does not mean brain damage. Because in unfavorable conditions, the virus goes into a dormant state and is activated only when immunity decreases.

The risk of developing this disease increases if:

• diseases associated with immunodeficiency;
• stressful situations for a long time;
• respiratory infections;
• oncology;
• stroke;
• brain injury.

It mainly occurs as a result of complications of herpes simplex, which manifests itself as rashes in the nasal and oral mucosa. Much less often, viral herpetic encephalitis develops against the background of genital encephalitis.

Today there are two hypotheses for the existence of this disease:

• the resumption of activity of virus particles in the nerve ganglia contributes to its spread along the nerves;
• it lies dormant in nerve cells, from where it reactivates.

Causes

The main reason for the development of herpes encephalitis in brain tissue is infection with a viral agent. Scientists have not yet reached a consensus on the conditions for the initiation of the disease. It is unclear whether the pathology occurs due to primary infection or reactivation of the viral agent.

Typical clinical cases (about 25%) are initiated by reinfection, when the patient simultaneously had several strains of HSV found in the studied material from different parts of the head (nasopharynx, brain).

It is assumed that the virus penetrates the tissues of the central nervous system through the trigeminal nerve ganglia or olfactory bulbs, which determines the localization of the pathological focus - the anterior parts of the brain. The spread of the infectious agent through the nerve structures is carried out through the fibers that innervate the vessels located in the meninges.

Signs in children

Newborns can be born with this pathology due to intrauterine infection from the mother. A child is born with increased intracranial pressure.

The main signs of the disease in this case are as follows:

• bulging fontanelle on the skull;
• tearfulness;
• vomit;
• constant screams, worsening upon awakening in the morning;
• lack of appetite;
• increased excitability;
• motor restlessness.

In addition to the brain, other organs and systems of the body may be affected in a newborn:

• spleen;
• kidneys;
• lungs;
• liver.

Herpetic encephalitis can appear after suffering from gingivitis, stomatitis and other diseases of a similar nature, that is, when the virus enters the brain through the trigeminal nerve.

Symptoms of meningitis and meningoencephalitis

Viral infections, including herpes, are not characterized by predominant involvement of only the meninges; most often the underlying disease, relapse, is accompanied by acute herpes meningoencephalitis.

Damage to the substance and membranes of the brain occurs with general cerebral, focal symptoms and clinical inflammation of the membranes.

Clinic of herpetic meningitis and meningoencephalitis:

• body temperature indicators reach febrile values;
• convulsions;
• unbearable headache;
• repeated vomiting that does not bring relief;
• photophobia, excessive auditory and tactile sensitivity;
• subcutaneous hemorrhages;
• pain when pressing on the eye area;
• stiffness of the neck muscles - inability to touch the chin to the chest;
• focal symptoms (see above).

Important!

Signs of herpes meningitis can begin extremely quickly - in less than one day from the onset of infection. Possible death from shock of infectious origin.

Clinical picture

Symptoms of herpetic encephalitis:

• rashes appear in the mouth, nasal mucosa, and skin;
• the temperature increases, which decreases with difficulty when using antipyretics;
• headaches appear;
• convulsions occur throughout the body, which are difficult to stop with medications;
• thought processes are disrupted, the patient’s behavior changes;
• there is a disturbance in the sense of reality, which can contribute to coma or hearing loss;
• neurological disorders are noted.

Some symptoms of herpetic encephalitis in adults do not appear in all cases and are individual in nature. These include:

• the appearance of double vision or sideways glance;
• nervous excitement;
• tachycardia;
• increased blood pressure;
• movement disorder;
• speech distortion;
• paralysis of the limbs on one side;
• memory losses;
• hyperhidrosis;
• the appearance of hallucinations indicating a malfunction in the central nervous system requiring immediate treatment.

Sluggish course of the disease

The disease becomes chronic due to chronic inflammation of the central nervous system, accompanied by periodic increases in temperature to 37–38 degrees and asthenic syndrome. This condition can last for months, and after about six months, sluggish encephalitis begins with focal brain disorders.

The main symptoms that may occur at the onset of this disease are:

• short-term convulsions;
• resulting paralysis of the muscles of one part of the body;
• muscular dystonia;
• asymmetry of reflexes.

Impaired consciousness in this form, as a rule, does not occur.

Despite the fact that herpetic encephalitis in this form is not violent, as in an acute case, the risk of death is higher. This happens for two reasons. Firstly, the diagnosis can be made quite late, often at the stage of signs of dementia. Secondly, this form is characterized by resistance of the herpes simplex virus to acyclovir, which leads to unproductive treatment.

After an illness, a person in most cases is left with neurological and mental consequences. Their main symptoms:

• paralysis;
• severe fatigue, weakness;
• headaches, dizziness;
• weakened memory and attention;
• impaired coordination of movements;
• dementia;
• visual, hearing and speech impairments;
• enuresis, encopresis;
• drowsiness;
• irritability, aggressiveness.

Although there are cases where the consequences of encephalitis are absent or mild. People could return to normal life. This is facilitated by the acute form of the disease (not chronic), adequate treatment (quickly started with high doses), the immune status of the body, its ability to recover, and the patient’s age.

As a result of his herpes encephalitis, Clive Wareing developed symptoms of memory loss. His sensory functions, speech and speech understanding are intact. Intelligence remained at the same level. But there was a gap between the transition of information from instant memory and back, and he was only able to remember anything for 30 seconds. Wareing lives in the present tense all the time, not knowing what happened a minute ago or a long time ago.

Certain conclusions can be drawn. Encephalitis of this type is a serious infectious disease that is accompanied by various neurological and psychiatric symptoms of varying severity. The success of treatment depends on the time of contacting a doctor and the type of different course of the disease. After an infection, the likelihood of clinical consequences occurring is high.

Sluggish pathology

In relation to the disease in question, its sluggish form is distinguished. In this case, the central nervous system is exposed to chronic inflammation, which contributes to the development of asthenic syndrome and an increase in body temperature. Six months later, encephalitis develops, characterized by focal brain damage. Patients experience the following symptoms:

• muscular dystonia;
• reflex asymmetry;
• unilateral paralysis;
• short convulsions.

As a rule, this form of the disease ends in the death of the patient due to late diagnosis and resistance of viruses to Acyclovir.

Symptoms

There is a triad of first signs of the disease that are characteristic only of encephalitis caused by herpetic infection. They are observed in all patients without exception.

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Classic symptoms include:

1. Rapid increase in body temperature to 39°C.
2. The appearance of convulsions, disturbance of movements (can be observed both in the whole body and in its individual parts).
3. Disturbance of consciousness (ranges from confusion and oblivion to coma).

The classic symptom is the appearance of seizures.

The general clinical picture of herpetic brain disease in its acute form is similar to other types of encephalitis. Observed:

• disturbances in the functioning of the organs of vision, accompanied by double vision, strabismus;
• the occurrence of stiff neck muscles, drowsiness, vomiting and headaches;
• behavior changes;
• the appearance of hallucinations (olfactory and gustatory);
• increased sensitivity to light;
• memory and speech disorder;
• paralysis;
• instability while walking;
• increased sweating.

With herpetic brain disease, drowsiness is observed.

The appearance and severity of symptoms depend on the location of the herpetic lesion, its area, as well as the degree of tissue changes.

The sluggish form of the disease is characterized by:

• short-term convulsions;
• muscle dystonia;
• reflex asymmetry;
• one-sided paralysis.

Symptoms of low-grade encephalitis caused by herpes infection may be vague. This makes diagnosis difficult, increases the risk of complications, and increases the likelihood of death.

Symptoms of sluggish encephalitis may be vague - this increases the likelihood of death.

Prevention

Basically, infection with herpetic encephalitis is carried out by airborne droplets, so the set of preventive measures generally coincides with those for a cold, and also includes general recommendations for the prevention of sexually transmitted infections:

• increasing immunity;
• protected sex using condoms;
• avoiding contact with sick people and carriers of the virus;
• taking multivitamins.

It is necessary to understand that this pathology is dangerous and can lead to irreversible brain dynamics and human death.

The main symptoms of the pathology

As a rule, herpes encephalitis of the brain begins acutely - literally in a few hours or one day, the infection completely affects all structures of the central nervous system. The pathology is especially difficult in children.

Against the background of a sharp rise in body temperature - up to 40 degrees and above, the patient experiences a characteristic triad of encephalitis:

• cramps - can affect the entire body or a separate muscle group;
• consciousness - impaired from short-term episodes of disorientation in space to severe coma;
• fever - chills, increasing weakness, drenching sweat.

In addition to the above clinical manifestations, other symptoms may be observed with herpetic encephalitis:

• appetite is significantly reduced - up to its complete loss;
• headache – intense, increasing, unresponsive to analgesics;
• violation of the functional activity of the oculomotor nerve - strabismus, double vision of objects before the eyes;
• hallucinations – short-term or long-lasting, vivid;
• sweating - after the temperature decreases, patients literally “bathe” in their own sweat;
• memory - individual episodes of life during the acute period of encephalitis are completely erased;
• speech – impaired, slurred;
• failure in the vestibular apparatus - a person with herpetic lesions of the brain loses the ability to control voluntary movements of the limbs;
• paresis/paralysis in one half of the body - herpes agents led to inflammation of the temporal lobe of the cerebral cortex;
• sleep disturbance.

In its typical course, herpetic encephalitis does not cause diagnostic difficulties for specialists. However, in some cases, laboratory and instrumental diagnostics help put everything in its place.

Diagnostics

It is carried out by performing CT and MRI of the brain. The type of pathogen is determined by analyzing cerebrospinal fluid and blood using PCR. But the amount of antibodies in them increases only 10 days after infection, so this method is used only to confirm the diagnosis and the appropriateness of the therapy.

A brain biopsy is also prescribed. In addition, examinations of the cerebrospinal fluid and, as a retrospective form of diagnosis, serological reactions can be carried out.

It is most important to undergo an MRI or CT scan as soon as possible, as this allows you to identify the exact cause of the pathology. Here the stage of the disease is determined, after which doctors can make any predictions.

Upon completion of the examination, various diagnoses can be made:

• cerebral vasculitis;
• viral encephalitis;
• encephalopathy of toxic type;
• encephalomyelitis of acute disseminated type.

Diagnosis of herpetic encephalitis↑

During the infectious period, diagnosis is often difficult due to the similarity of the picture with influenza and other acute diseases of a viral nature. This leads to a fatal loss of time - the patient does not receive specific therapy against the herpes virus.

If GE is suspected, it is necessary to conduct virological tests as soon as possible and, if possible, detect antibodies to HSV-1. Alas, this does not guarantee ideal accuracy of diagnosis; there are cases when a blood test and tissue samples taken from the mucous membranes of the nasopharynx did not detect the presence of antibodies to HSV-1, and a serological study of brain tissue after the death of the patient demonstrated the presence of inclusions characteristic of GE.

After the addition of neurological symptoms, signs of encephalitis are confirmed using electroencephalography, computed tomography, MRI and cerebrospinal fluid examination.

Treatment

The patient is placed in the intensive care unit or intensive care unit to prevent the development of dysgraphia and breathing disorders. Treatment of herpetic encephalitis is carried out with drugs such as:

• "Zovirax";
• "Virolex";
• "Acyclovir".

They can be used orally or, in severe cases, administered by injection.

The first two days after the patient is admitted to the hospital, he is given high doses of these drugs (10-15 mg/kg body 3 times a day). Thanks to this, it is possible to reduce mortality from this disease and prevent serious consequences. Therapy usually continues for 7-14 days. In the hospital, the body is detoxified, restoring the water-salt balance.

Some doctors prescribe interferons, but studies conducted in Europe do not show the effectiveness of these drugs. When cerebral edema begins, take corticosteroids for no more than 7 days. When the patient is in a coma, ventilation of the lungs and tracheal intubation are performed.

In addition, diuretics may be prescribed to relieve cerebral edema. If the body is dehydrated, the patient is prescribed droppers with a solution of ascorbic acid.

In severe cases of the disease, nootropics may be prescribed.

Treatment of herpetic encephalitis

If the development of encephalitis caused by a herpetic infection is confirmed, the person is hospitalized in the intensive care unit. Therapy is not carried out at home. This is due to the high likelihood of developing respiratory problems. Many patients require emergency ventilation.

The only treatment for the disease is drug therapy. To select the right drugs, the herpetic type of inflammation of the brain is differentiated from other diseases that have a similar clinical picture, and the degree of tissue damage is established.

Therapy is not carried out at home. This is due to the high likelihood of developing respiratory problems.

Diagnostics

Several examination methods help to recognize pathology and determine its severity. These include:

1. Magnetic resonance imaging. It is a key method for identifying affected areas of the brain, assessing the localization of herpetic lesions and monitoring the dynamics of the development of pathology. Allows differential diagnosis with other types of encephalitis, as well as ganglioglioma (neoplasm), sclerosis, hypoxic disorders, and epilepsy.
2. Electroencephalography. Helps to record the presence of characteristic periodic or semi-rhythmic bioelectrical activity in the brain. The presence of discharges indicates the development of encephalitis, which is of a herpetic nature.
3. Cerebrospinal fluid examination. Makes it possible to detect the DNA of the herpes virus and the presence of antibodies (10-12 days after the onset of the disease). The study is used to confirm the appropriateness of the prescribed treatment.
4. Biopsy of brain tissue. The analysis is performed if there is no result from treatment or it is impossible to make a diagnosis in another way.

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Drugs

When treating herpetic brain lesions, medications are used. They are divided into 3 groups:

1. Etiotropic (help eliminate the cause of the pathology). Acyclovir (Virolex, Zovirax) is used. It is administered intravenously. Immunostimulants are auxiliary medications. They enhance the immune response of cells, helping the body cope with herpes infection.
2. Pathogenetic (affects affected brain tissue). To relieve inflammation, glucocorticoids (Cortisone, Dexamethasone) are used. Decongestants (Glycerol, Mannitol) help reduce swelling. To improve blood microcirculation, angioprotectors and metabolic medications (Cavinton, Piracetam) are used.
3. Symptomatic (help eliminate external manifestations of pathology). Medicines used: antiparkinsonian (Parcopan), antipyretic (Paracetamol), anticonvulsant (Sibazon), improving the transmission of nerve impulses (Proserin).

Prevention

To prevent relapses, rehabilitation therapy is carried out. It helps restore normal brain function. To do this, the doctor prescribes:

• physiotherapeutic procedures;
• taking vitamins;
• massage;
• physical therapy.

To prevent relapses, rehabilitation therapy is carried out, one of them is physical therapy.

For prevention and quick recovery, experts recommend including in the diet a sufficient amount of macro- and microelements for the body.

Complications

The consequences of herpetic encephalitis are almost always very severe and are of a mental and neurological nature:

• decreased attention;
• memory impairment;
• paralysis;
• the appearance of apathy;
• increased fatigue;
• impaired coordination of movements;
• blurred vision;
• hearing loss;
• the appearance of dizziness and headaches;
• drowsiness;
• dementia leading to impairment of cognitive functions (the appearance of dementia with the loss of acquired knowledge and the inability to acquire new ones);
• deterioration of speech coherence;
• decreased intelligence;
• loss or sharp decrease in tactile sensations;
• the appearance of irritability and aggressiveness;
• urinary incontinence.

With a mild course of the disease, increased immunity, the therapy used, depending on the age of the patient, a person can return to a full life, since these consequences may not be expressed at all or be mild in nature.

Young children may develop intracranial hypertension syndrome. This is due to the fact that the circulation of intracerebral fluid is impaired.

The disease itself is not as dangerous as its consequences.

Possible complications and consequences

Complications of the disease are associated with irreversible damage to nerve tissue. Deviations in the mental and emotional sphere are more often observed. It is possible to develop conditions such as akinetic mutism (loss of the ability to speak and move while maintaining the physical ability to perform these actions) and apallic syndrome (loss of cognitive functions of the brain while maintaining vegetative ones). In some cases, the patient loses the ability to work and becomes disabled.

Forecast

The main problem of this pathology is that during the incubation period it is quite difficult to identify. Once the signs become pronounced, the infection has affected the brain deeply enough, the process is difficult to stop.

The prognosis of herpetic encephalitis can be positive if it is detected early and treated promptly. If the disease starts, it is quite disappointing: adverse consequences may occur, including the death of the patient. The most dire prognosis is when patients with herpetic encephalitis of the brain fall into a coma. According to statistics, only 10% of patients recover from it, the rest die.

Sometimes pathology develops very quickly. This contributes to severe swelling of the brain, which leads to respiratory arrest. The patient in this case rarely survives. If this happens, the signs of this disease will remain with him for a long time. It is very rare that a person’s health is completely restored.

Development of the disease

Herpetic encephalitis often occurs against the background of an inflammatory process caused by another infectious disease. In addition to external herpes, this can be any respiratory disease, stomatitis (including herpes) and the like. The disease begins acutely: the brain swells and becomes inflamed, cells die, and necrosis forms. Lesions can be diffuse (typical of young children) or focal and affect the cerebral cortex, white matter, occipital, parietal, frontal, and temporal lobes.

The acute onset of the disease has similar symptoms that can be observed in other types of encephalitis:

• fever with high temperature (up to 39-41 degrees);
• Jacksonian spasms - twitching in the right or left side of the body, turning into a general spasm;
• drowsiness, lethargy, lethargy or severe agitation to the point of loss of consciousness, aggressiveness;
• severe headaches;
• nausea and vomiting;
• hallucinations, delusions and confusion;
• speech disorders;
• paralysis of various groups of nerves and muscles;
• incoordination of movements;
• numbness of body parts, tingling.

In complicated cases, as well as when treatment is not started in a timely manner, serious consequences appear: meningitis with possible simultaneous damage to the spinal cord (meningoencephalomyelitis develops).

Herpetic encephalitis in children in the initial phase can be very difficult: depression of consciousness quickly occurs until it is completely lost and coma. Brain disorders lead to the development of convulsive syndrome, which is difficult to stop. A child, having regained consciousness, often loses oral and written speech skills and some motor reflexes. Memory suffers greatly.

Aphasia is a common symptom of brain disorders, including herpetic encephalitis. A person can fully understand speech but say nothing. If hearing is preserved, a person may cease to understand what is said around him, as well as to pronounce words correctly. The patient may not remember the names of objects (with intact memory of the properties of this thing). For example, instead of the word “glass,” one might say “this is what people drink water from to quench their thirst.”

Diagnostics

For differential diagnosis, computer and magnetic resonance imaging of the brain and electroencephalography are used. Very effective for accurately determining the source of infection is the analysis of blood and cerebrospinal fluid using PCR (polymerase chain reaction). But the problem is that the antibody content in these fluids increases only 10 days after the onset of the disease. This method is used to confirm the preliminary diagnosis of “herpetic encephalitis” and the chosen method of treating the patient. A biopsy of necrotic brain tissue can also be used to determine the virus.

Treatment in the acute stage

The patient is isolated and sent to the intensive care unit or intensive care unit. The main drug that suppresses the effect of the virus and relieves the main symptoms is acyclovir. It is known to the population mainly as an external remedy, but is also used injectively and orally. In the first days, high doses are prescribed to administer the substance. It is known that such a measure reduces mortality from 70% to 5% and prevents severe consequences and disability in survivors.

Some doctors consider it necessary to prescribe interferons (viferon, cycloferon and the like) during treatment, but Western studies do not confirm their effectiveness in the fight against the herpes simplex virus.

Acyclovir was discovered by scientist Howard Schaeffer in 1974. In the eighties, based on the studied properties of this drug, its action, and application, Gertrude Elion wrote a paper and in 1988 was awarded the Nobel Prize “for the discovery of important principles of drug therapy.”

Treatment tactics

If a person is suspected of having herpetic encephalitis, he should be immediately sent to the hospital, since the risk of a rapid deterioration in consciousness, even to the point of coma, is extremely high already in the first day from the moment of infection of the brain tissue.

Before establishing the herpes nature of the pathogen, the patient is given symptomatic measures:

• drugs to reduce fever;
• medications to reduce intracranial pressure and relieve swelling of brain tissue;
• means for boosting immunity - immunomodulators.

However, herpetic encephalitis requires complex treatment, which is based on antiviral drugs - Acyclovir, Virolex, Zovirax. In the first 1-2 days they are administered parenterally - injections or droppers, then in tablet form - for another 10-14 days. The optimal doses of medications are selected by the doctor individually , taking into account the patient’s age, weight, and severity of the disease.

At the same time, they continue to take corticosteroids, immunomodulators, antipyretics, anticonvulsants, and neuroprotectors. The key to success in the fight against encephalitis is the use of modern, multicomponent treatment regimens. This allows you to reduce the likelihood of deaths to 20–25%.