Clinical characteristics of paralytic forms of acute polio. Signs of polio in children and adults Polio clinic diagnosis treatment

It is an acute infectious viral disease that affects the nervous system. The main impact of polio occurs on the gray matter of the spinal cord. In addition, the polio virus causes inflammatory damage to the intestinal mucosa and nasopharynx, similar to an intestinal infection or acute respiratory infection. This infectious disease is caused by polio virus of three antigenic types: I, II and III types.

Outbreaks of polio epidemics are usually associated with type I virus. The source of infection with polio can be a patient, regardless of the form of the disease, as well as an asymptomatic carrier of the virus. The polio virus is transmitted through contaminated hands, food, water, and household items. It is also possible to become infected with polio by swimming in a polluted body of water.

Causes

Viruses remain viable in water, milk, and feces for a long time—up to 4 months. Polio most often affects young children (usually under six years of age), but adults can also get it. Transmission of the polio virus usually occurs through the fecal-oral route due to the high concentration of the pathogen in the feces of an infected person. In addition, an airborne mechanism of infection cannot be ruled out. The polio virus enters the human body through the intestinal mucosa or nasopharynx.

In the case of fecal-oral infection, the virus is localized in the lymphoid follicles of the intestinal wall; in the case of airborne infection, the virus is localized in the tonsil area.

Manifestations and symptoms

The first signs of polio are most often a sore throat, cough and runny nose, accompanied by nausea, vomiting and loose stools. In addition, a sharp increase in body temperature is very often observed. The person feels unwell and tired. In addition to the general toxic signs of the disease, muscle paralysis is a characteristic symptom of polio. Paralysis of the diaphragm can lead to serious respiratory problems, which can cause death in a person from polio.

Clinical picture of polio

The incubation period of polio ranges from 5 to 12 days, less often – from 2 to 35 days. Poliomyelitis is known in two forms: non-paralytic and paralytic.

Non-paralytic form of polio

The non-paralytic form (otherwise visceral, or abortive) is characterized by catarrhal manifestations (sore throat, runny nose, cough), short-term fever, as well as symptoms of dyspepsia (loose stools, vomiting, nausea). All symptoms of the disease usually disappear after a few days. Another variant of non-paralytic poliomyelitis is also possible in the form of serous meningitis, characterized by a mild course. Poliomyelitis in the non-paralytic form is most dangerous for others, since the patient may not be aware of the cause of his illness, but the pathogen is eliminated into the environment with the same intensity as in the case of paralytic poliomyelitis.

Paralytic form of polio

Paralytic poliomyelitis is divided into four stages:

preparalytic;
paralytic;
restorative;
stage of residual effects.

Preparalytic stage of polio

The duration of the preparalytic stage of polio is from 3 to 5 days. The onset of the disease is acute. The temperature rises sharply. In the first days of the disease (about three days), headache, pharyngitis, runny nose, and general malaise are noted. This is followed by a period of apyrexia, lasting from two to four days. In some cases, apyrexia may be absent. Following the period of apyrexia, the next feverish wave occurs.

Rigidity of the muscles of the lower back and neck appears. In addition, soreness occurs in the muscles, which will later be paralyzed. The patient's condition rapidly deteriorates, the headache intensifies, hyperesthesia appears, and consciousness is confused. There may be a decrease in tendon reflexes, muscle strength, twitching of individual muscles, convulsive shudders, autonomic disorders (goose bumps, red spots, etc.)

Paralytic stage of polio

The paralytic stage of polio manifests itself in the form of flaccid paralysis with decreased tone of the affected muscles, partial limitation or complete impossibility of active movements, and absence of tendon reflexes. The development of paralysis is accompanied by muscle pain without loss of sensitivity.

Paralytic polio comes in several forms:

spinal (paralysis of the neck, torso, diaphragm, limbs);
bulbar (disorders of cardiac activity, speech, breathing, swallowing);
encephalitic (focal brain damage);
pontine (damage to the nucleus of the facial nerve, paresis of facial muscles);
mixed - characterized by a multiplicity of lesions.

The consequence of paralysis of the diaphragm and respiratory muscles, as well as damage to the medulla oblongata, is severe breathing disorders that pose a serious danger to the lives of patients. The mortality rate for polio is 14%. In surviving patients, the paralytic stage lasts up to fifteen days.

Recovery stage and stage of residual effects

The recovery period for polio lasts up to three years, but can take several months. Recovery of muscle functions is rapid at first, then slows down. At the stage of residual effects of poliomyelitis, persistent flaccid paralysis, contractures and deformations of the trunk and limbs, and muscle atrophy are observed. It is known that a quarter of patients with paralytic polio become disabled.

Diagnostics

The diagnosis of poliomyelitis is established based on the clinical picture, epidemiological prerequisites (contact with patients with poliomyelitis, summer time) and laboratory data. Diagnosis of non-paralytic forms of polio and its pre-paralytic stage, before the appearance of movement disorders, is very difficult. If polio is suspected, feces and blood should be tested for the presence of the virus.

Laboratory tests for poliomyelitis consist of determining the antibody titer in paired sera. Serum collection interval: three to four weeks. Preferred methods: RSC, as well as neutralization reaction (in the form of a modified color test). The causative agent of polio is isolated on tissue cultures from the feces of patients and from nasopharyngeal swabs.

Treatment

There are no specific treatments for polio. Patients with suspected polio are hospitalized. During the preparalytic and paralytic period of the disease, patients require strict bed rest. To reduce deformations, paralyzed muscles are protected with splints. A damp, hot cloth is applied to the affected muscles.

In case of paralysis of the pharyngeal muscles, timely suction of secretions from the pharynx is necessary. Paralysis of the muscles involved in the respiratory process requires artificial ventilation. For the symptomatic treatment of polio, analgesics and sedatives are used. Upon completion of the acute stage of polio, physical therapy is used; exercises are very effective under water.

It is recommended to conduct classes in special orthopedic clinics. Complications of polio can include interstitial myocarditis, pulmonary atelectasis, and pneumonia. In the bulbar form, acute dilatation of the stomach and severe gastrointestinal disorders accompanied by ulcers, bleeding, ileus, and perforation are possible.

Prevention

To protect yourself from polio, you should not swim in polluted waters. Milk must be consumed only in boiled or pasteurized form, kill flies and reliably protect food products from them. Vaccination, which provides lifelong immunity, is of great importance in the prevention of polio. The effectiveness of the oral polio vaccine is 50% when administered once.

Three-time administration of this vaccine allows you to get a 95% effect. The effectiveness of OPV in hot countries may be reduced due to the vaccine's sensitivity to heat. As a rule, it is recommended to use OPV - a live oral vaccine (otherwise known as Sabin's vaccine) for immunization because of the better immunity it provides. The vaccine is considered quite safe, but rare cases (one in several million) of paralytic polio have been observed, most often associated with the first or, much less often, the second OPV vaccination.

In most cases, this occurred during the first dose of the vaccine in people with immunocompromise. In this regard, they are currently switching to IPV - the inactivated polyvalent Salk vaccine. This vaccine provides much less protection for the body, but avoids the paralytic stage of the disease. There are no data on serious complications after the use of IPV; slight swelling and pain at the injection site are possible. Both polio vaccines include all three existing types of the virus, which provides protection against all possible variations of the disease.

It is customary to distinguish four stages of the paralytic form of poliomyelitis: preparalytic, paralytic, restorative and residual. The last two merge into each other without clear boundaries. In a pronounced form, these stages are present only in spinal forms, and what is described below applies specifically to these forms.

The incubation period in most patients is asymptomatic. Sometimes there are mild signs of a general infectious disease. These symptoms are similar to those described for abortive poliomyelitis and are expressed within 2-3 days. Then comes an apparent recovery; after 1-3 days of a favorable condition, the temperature rises again and sharply, the general condition becomes serious. But more often the disease develops acutely, without warning signs, right from the development of the preparalytic stage. Preparalytic stage. The disease begins with a sudden increase in temperature to high (39-40°). Much less often, the temperature rises gradually over 1-2 days. The temperature curve is constant throughout the febrile period, often it is double-humped; in these cases, the second increase corresponds to the invasion of the virus into the central nervous system and is always accompanied by a significant worsening of the patient’s general condition. The temperature drops critically or gradually. There is an increase in heart rate that does not correspond to the temperature, which, as a rule, persists for quite a long time even after the temperature has normalized. Bradycardia occurs in rare cases. Normalization of the pulse occurs gradually. General infectious symptoms of the reparalytic stage of polio are similar to those described above for the abortive form of the disease. According to the clinic of the Poliomyelitis Institute (E.N. Bartoshevich and I.S. Sokolova), serous rhinitis, tracheitis and bronchitis were observed in 25-30% of patients, tonsillitis - in 15%, and gastrointestinal disorders - in 55-60% sick. There have been significant fluctuations in these symptoms during various epidemic outbreaks of polio. General infectious symptoms include enlarged spleen, liver, and swollen lymph nodes. Various scarlet fever- or measles-like rashes are observed quite rarely. It should be taken into account that the rash can be a consequence of excessive sweating. Blood and urine are normal in most patients. Changes in the internal organs, as well as various associated biochemical disorders, are observed in severe paralytic cases. The development of cerebral symptoms occurs immediately with an increase in temperature or on the 2-3rd day, and with a two-phase temperature - usually on the first day of the second increase. General cerebral disorders also include epileptoid seizures with tonic or clonic convulsions. Convulsive seizures occur more often the younger the child. Children become lethargic, apathetic, lack of initiative, and drowsy. An excited state is less common. Confusion is often noted. Against this background, meningeal symptoms, headaches, and single and double vomiting often develop in the afternoon. The severity of meningeal symptoms varies, but, as a rule, they are not as significant as with purulent and tuberculous meningitis. There are also some relationships between individual meningeal symptoms that are characteristic of poliomyelitis. Rigidity of the neck muscles is not pronounced, and in many patients it is absent. Most patients experience severe hyperesthesia and pain with changes in position and movements, even passive ones. Patients try to lie still and protest against any change in their position in bed, which is called the “spinal symptom” and distinguishes polio from meningitis. Pain syndrome is one of the constant and characteristic signs of polio. Spontaneous pain, which is especially pronounced in the legs, increases sharply with changes in position; this is the most important reason for the immobility of patients before the development of paresis and paralysis, which should be taken into account when analyzing the clinical symptoms of the early period of poliomyelitis. Along with pain, muscle spasms are noted, which are a reflex contraction of muscles in response to stretching. The symmetry of pain and muscle spasms is very characteristic of polio. Pain due to pressure along the nerve trunks and nerve roots, observed in polio, is also expressed symmetrically. Older children often complain of paresthesia: crawling, numbness, and less often a burning sensation. Unlike motor disorders, which in polio are characterized by their asymmetry and mosaic, sensory disorders are usually symmetrical. In the preparalytic phase, irritative motor disturbances are common: trembling in the legs or arms, fascicular, much less often fibrillar twitching in the muscles, motor restlessness of an unspecified type in various muscles. These phenomena of motor irritation quickly pass. Sometimes it is possible to notice that they were more pronounced in those muscles in which paresis occurred in the subsequent course. The low motor mobility of patients, mentioned above, also applies to the facial muscles - it is hypomimic (without paresis of the facial nerves or before it), with doll-like, porcelain eyes, slight cyanosis of the lips and cheeks with a pale oral triangle. Often, especially in severe forms of the disease, the patient’s sedentary, pale face is covered with large drops of sweat. Increased general or local sweating is a common symptom of polio. There is no parallelism between the increase in temperature and the degree of sweating. Early symptoms of damage to nervous tissue include nystagmus, which usually does not last long. Changes in the excitability of the vestibular apparatus are equivalent in non-paralytic and paralytic poliomyelitis. The preparalytic stage of the disease lasts 3-6 days, sometimes shortening to 1-2 days and rarely lengthening to 10-14 days (the development of paralysis means the transition to the paralytic stage).

Poliomyelitis (infantile paralysis) is caused by a virus and is a highly contagious viral infection. In its most serious form, polio can cause rapid and irreversible paralysis; until the late 1950s, it was one of the most dangerous infectious diseases and often occurred in epidemics. Post-polio syndrome or post-polio progressive muscular atrophy can occur 30 years or more after the initial infection, gradually leading to muscle weakness, wasting, and pain. Polio can be prevented by building immunity and is now virtually extinct in developed countries; however, the risk of disease still exists. Polio is still common in many countries around the world, and there is no way to cure it; therefore, until the polio virus is eradicated, vaccination remains the main method of protection.

In summer and early autumn, when polio epidemics most often occur, parents first of all remember it when their child gets sick. The disease, like many other infections, begins with general malaise, fever and headache. Vomiting, constipation, or mild diarrhea may occur. But even if your child has all these symptoms, plus leg pain, you should not rush to conclusions. There's still a good chance it's the flu or a sore throat. Of course, you call a doctor anyway. If he is away for a long time, you can reassure yourself this way: if the child can lower his head between his knees or tilt his head forward so that his chin touches his chest, he probably does not have polio. (But even if it fails these tests, it is still not proof of disease.)
Despite significant progress in eradicating polio in our country, the problem of diseases accompanied by acute flaccid paralysis (AFP) has not lost its relevance. Pediatricians often encounter various infectious diseases of the brain, spinal cord, and peripheral nerves. The study of the structure of neuroinfections indicates that lesions of the peripheral nervous system occur in 9.6% of patients, infectious diseases of the spinal cord - in 17.7%. Among the latter, acute infectious myelopathies predominate, while acute paralytic vaccine-associated poliomyelitis, acute myelopathy, and enceare much less common. In this regard, in modern conditions it is necessary to pay special attention to the differential diagnosis of AFP, monitoring the epidemic situation, which will avoid overdiagnosis, improve treatment results, and reduce the frequency of unfounded registration of post-vaccination complications.

Acute paralytic poliomyelitis is a group of viral diseases united according to the topical principle, characterized by flaccid paresis, paralysis caused by damage to motor cells in the anterior horns of the spinal cord and the nuclei of the motor cranial nerves of the brain stem.

Etiology. The etiological structure of infectious diseases of the nervous system is diverse. Among the etiological factors are “wild” polioviruses type 1, 2, 3, vaccine polioviruses, enteroviruses (ECHO, Coxsackie), herpesviruses (HSV, HHV type 3, EBV), influenza virus, mumps virus, diphtheria bacillus, borrelia, UPF (staphylococci, gram-negative bacteria).

Of particular interest is spinal paralysis caused by the “wild” polio virus, which belongs to the picornavirus family, a genus of enteroviruses. The pathogen is small in size (18-30 nm) and contains RNA. Virus synthesis and maturation occur inside the cell.

Polioviruses are not sensitive to antibiotics and chemotherapy. When frozen, their activity persists for several years, in a household refrigerator - for several weeks, at room temperature - for several days. At the same time, polio viruses are quickly inactivated when treated with formaldehyde, free residual chlorine, and do not tolerate drying, heating, or ultraviolet irradiation.

The polio virus has three serotypes - 1, 2, 3. Its cultivation in laboratory conditions is carried out by infecting various tissue cultures and laboratory animals.

Causes

Poliomyelitis is caused by a viral infection with one of three forms of the polio virus.

The virus can be transmitted through contaminated food and water or through contaminated saliva during a cough or sneeze.

The source of infection is a sick person or carrier. The greatest epidemiological significance is the presence of the virus in the nasopharynx and intestines, from where it is released into the external environment. In this case, the release of the virus in feces can last from several weeks to several months. The nasopharyngeal mucus contains the polio pathogen for 1-2 weeks.

The main routes of transmission are nutritional and airborne.

Under conditions of mass specific prevention, sporadic cases were recorded throughout the year. Mostly children under seven years of age were ill, of whom the proportion of young patients reached 94%. The infectiousness index is 0.2-1%. Mortality among unvaccinated people reached 2.7%.

In 1988, the World Health Organization raised the question of the complete eradication of polio caused by the “wild” virus. In this regard, 4 main strategies have been adopted to combat this infection:

1) achieving and maintaining a high level of population coverage with preventive vaccinations;

2) carrying out additional vaccinations on national immunization days (NDIs);

3) creation and operation of an effective epidemiological surveillance system for all cases of acute flaccid paralysis (AFP) in children under 15 years of age with mandatory virological examination;

4) carrying out additional “cleaning up” immunization in disadvantaged areas.

At the time of the adoption of the Global Polio Eradication Program, the number of patients in the world was 350,000. However, by 2003, thanks to ongoing activities, their number dropped to 784. Three regions of the world are already free from polio: American (since 1994), Western Pacific (since 2000) and European (since 2002). However, polio caused by wild poliovirus continues to be reported in the Eastern Mediterranean, African and South-East Asia regions. India, Pakistan, Afghanistan, and Nigeria are considered endemic for polio.

Since December 2009, an outbreak of polio caused by type 1 poliovirus has been registered in Tajikistan. It is assumed that the virus came to Tajikistan from neighboring countries - Afghanistan, Pakistan. Taking into account the intensity of migration flows from the Republic of Tajikistan to the Russian Federation, including labor migration and active trade relations, the “wild” polio virus was imported into the territory of our country, and cases of polio in adults and children were registered.

Russia began implementing the Global Polio Eradication Program on its territory in 1996. Thanks to maintaining a high level of vaccination coverage among children in their first year of life (more than 90%) and improving epidemiological surveillance, the incidence of this infection in Russia has decreased from 153 cases in 1995. up to 1 - in 1997. By decision of the European Regional Certification Commission in 2002, the Russian Federation received the status of a polio-free territory.

Before the transition to the use of inactivated polio vaccine, diseases caused by vaccine polioviruses were recorded in Russia (1 - 11 cases per year), which usually occurred after the first dose of live OPV was administered.

Diagnostics

Medical history and physical examination.

Blood tests.

Lumbar puncture (spinal tap).

Laboratory diagnostics. Only based on the results of virological and serological studies can a final diagnosis of polio be made.

The following are subject to virological testing for polio in the laboratories of regional centers for epidemiological surveillance of polio/AFP:

- sick children under 15 years of age with symptoms of acute flaccid paralysis;

- contact children and adults from foci of poliomyelitis and AFP in the case of late (later than the 14th day from the moment of detection of paralysis) examination of the patient, as well as if there are people around the patient who arrived from areas unfavorable for poliomyelitis, refugees and internally displaced persons (one-time) ;

- children under the age of 5 years who arrived during the last 1.5 months from the Chechen Republic, the Republic of Ingushetia and sought medical care in medical institutions, regardless of the profile (one time).

Patients with clinical signs of poliomyelitis or acute flaccid paralysis are subject to mandatory 2-fold virological examination. The first fecal sample is taken within 24 hours of diagnosis, the second sample is taken 24-48 hours later. The optimal volume of feces is 8-10 g. The sample is placed in a sterile special plastic container. If the delivery of collected samples to the regional polio/AFP surveillance center will be carried out within 72 hours from the date of collection, then the samples are placed in a refrigerator at a temperature of 0 to 8 ° C and transported to the laboratory at a temperature of 4 to 8 ° C (reverse cold). chain). In cases where the material is planned to be delivered to the virology laboratory at a later date, the samples are frozen at a temperature of -20 °C and transported frozen.

The frequency of virus isolation in the first two weeks is 80%, in the 5th-6th week - 25%. No permanent carriage was detected. Unlike the Coxsackie and ECHO viruses, the polio virus is isolated extremely rarely from the cerebrospinal fluid.

In case of death, material is collected from the cervical and lumbar extensions of the spinal cord, the cerebellum and the contents of the colon. With paralysis lasting 4-5 days, it is difficult to isolate the virus from the spinal cord.

The following are subject to serological examination:

— patients with suspected polio;

For serological testing, two samples of the patient’s blood (5 ml each) are taken. The first sample should be taken on the day of the initial diagnosis, the second - after 2-3 weeks. Blood is stored and transported at a temperature of 0 to +8 °C.

RSC detects complement-fixing antibodies to the N- and H-antigens of poliovirus. In the early stages, only antibodies to the H-antigen are detected, after 1-2 weeks - to the H- and N-antigens, in those who have recovered - only N-antigens.

During the first infection with poliovirus, strictly type-specific complement-fixing antibodies are formed. Upon subsequent infection with other types of polioviruses, antibodies are formed predominantly to heat-stable group antigens, which are present in all types of polioviruses.

PH detects virus-neutralizing antibodies in the early stages of the disease; it is possible to detect them during the hospitalization of the patient. Virus-neutralizing antibodies can be detected in urine.

RP in agar gel reveals precipitins. Type-specific precipitating antibodies can be detected during the recovery period and circulate for a long time. To confirm the increase in antibody titers, paired sera are examined with an interval of 3-4 weeks; a dilution of the serum that is 3-4 times or more higher than the previous one is taken as a diagnostic increase. The most effective method is ELISA, which allows one to quickly determine a class-specific immune response. It is mandatory to carry out PCR to detect RNA viruses in individual feces and cerebrospinal fluid.

Symptoms

Fever.

Headache and sore throat.

Stiff neck and back.

Nausea and vomiting.

Muscle pain, weakness, or spasms.

Difficulty swallowing.

Constipation and urinary retention.

Bloated belly.

Irritability.

Extreme symptoms; muscle paralysis; difficulty breathing.

Pathogenesis. The entry point for infection in polio is the mucous membrane of the gastrointestinal tract and upper respiratory tract. The virus multiplies in the lymphatic formations of the back wall of the pharynx and intestines.

Overcoming the lymphatic barrier, the virus penetrates the blood and is carried by its current throughout the body. Fixation and reproduction of the polio pathogen occurs in many organs and tissues - lymph nodes, spleen, liver, lungs, heart muscle and, especially, in brown fat, which is a kind of virus depot.

Penetration of the virus into the nervous system is possible through the endothelium of small vessels or along peripheral nerves. Distribution within the nervous system occurs along cell dendrites and possibly through intercellular spaces. When the virus interacts with cells of the nervous system, the most profound changes develop in motor neurons. The synthesis of polioviruses occurs in the cytoplasm of the cell and is accompanied by suppression of the synthesis of DNA, RNA and proteins of the host cell. The latter dies. Within 1-2 days, the titer of the virus in the central nervous system increases, and then begins to fall and soon the virus disappears.

Depending on the state of the macroorganism, the properties and dose of the pathogen, the pathological process can stop at any stage of viral aggression. In this case, various clinical forms of poliomyelitis are formed. In most infected children, due to the active reaction of the immune system, the virus is eliminated from the body and recovery occurs. Thus, with the inapparant form, there is a nutritional phase of development without viremia and invasion into the central nervous system, with the abortive form, there are nutritional and hematogenous phases. Clinical variants accompanied by damage to the nervous system are characterized by a sequential development of all phases with damage to motor neurons at different levels.

Pathomorphology. Morphologically, acute poliomyelitis is most characterized by damage to large motor cells located in the anterior horns of the spinal cord and the nuclei of the motor cranial nerves in the brain stem. In addition, the pathological process may involve the motor area of the cerebral cortex, the nuclei of the hypothalamus, and the reticular formation. In parallel with damage to the spinal cord and brain, the soft meninges are involved in the pathological process, in which acute inflammation develops. At the same time, the number of lymphocytes and protein content in the cerebrospinal fluid increase.

Macroscopically, the spinal cord appears swollen, the border between the gray and white matter is blurred, and in severe cases, the cross section shows retraction of the gray matter.

Microscopically, in addition to swollen or completely disintegrated cells, unchanged neurons are found. This “mosaic” pattern of damage to nerve cells is clinically manifested by an asymmetric, random distribution of paresis and paralysis. In place of dead neurons, neuronophagic nodules are formed, followed by the proliferation of glial tissue.

Classification

According to modern requirements, the standard definition of polio and acute flaccid paralysis (AFP) is based on the results of clinical and virological diagnostics (Appendix 4 to Order M3 of the Russian Federation No. 24 dated January 25, 1999) and is presented as follows:

- acute flaccid spinal paralysis, in which the “wild” polio virus is isolated, is classified as acute paralytic poliomyelitis (according to ICD 10 revision A.80.1, A.80.2);

- acute flaccid spinal paralysis that occurred no earlier than the 4th and no later than the 30th day after taking the live polio vaccine, in which the vaccine-derived poliovirus was isolated, is classified as acute paralytic polio associated with the vaccine in the recipient (according to ICD 10 revision A .80.0);

- acute flaccid spinal paralysis that occurs no later than the 60th day after contact with a vaccinated person in which vaccine-derived poliovirus is isolated is classified as acute paralytic poliomyelitis associated with a vaccine in a contact (according to ICD 10 revision A.80.0). Isolation of vaccine-derived poliovirus in the absence of clinical manifestations has no diagnostic value;

- acute flaccid spinal paralysis, in which the examination was not carried out completely (the virus was not isolated) or was not carried out at all, but residual flaccid paralysis is observed by the 60th day from the moment of their onset, is classified as acute paralytic poliomyelitis, unspecified (according to ICD 10 revision A .80.3);

- acute flaccid spinal paralysis, in which a full adequate examination was carried out, but the virus was not isolated and no diagnostic increase in antibodies was obtained, is classified as acute paralytic poliomyelitis of another, non-poliomyelitis etiology (according to ICD 10 revision A.80.3).

Isolation of a “wild” strain of the virus from a patient with catarrhal, diarrheal or meningeal syndromes without the occurrence of flaccid paresis or paralysis is classified as acute non-paralytic poliomyelitis (A.80.4.)

Acute flaccid spinal paralysis with the release of other neurotropic viruses (ECHO, Coxsackie viruses, herpes viruses) refers to diseases of a different, non-poliomyelitis etiology.

All these diseases, based on the topical principle (damage to the anterior horns of the spinal cord), appear under the general name “Acute poliomyelitis”.

Classification of polio

Forms of polio	Phases of virus development
Without CNS damage
1. Inapparant	Alimentary phase of virus development without viremia and invasion into the central nervous system
2. Abortive form	Alimentary and hematogenous (viremia) phases
Forms of poliomyelitis with damage to the central nervous system
!. Nonparalytic or meningeal form	Sequential development of all phases with invasion into the central nervous system, but subclinical damage to motor neurons
2. Paralytic forms: a) spinal (up to 95%) (with cervical, thoracic, lumbar localization of the process; limited or widespread); b) pontine (up to 2%); c) bulbar (up to 4%); d) pontospinal; e) bulbospinal; e) pontobulbospinal	Sequential development of all phases with damage to motor neurons at different levels

Based on the severity of the process, mild, moderate and severe forms of polio are distinguished. The course of the disease is always acute, and can be smooth or non-smooth in nature, depending on the presence of complications (osteoporosis, fractures, urolithiasis, contracture, pneumonia, bedsores, asphyxia, etc.).

Clinic. The incubation period for polio is 5-35 days.

The spinal form of polio in children occurs with greater frequency than other paralytic forms. In this case, more often the pathological process develops at the level of the lumbar thickening of the spinal cord.

During the course of the disease, there are several periods, each of which has its own characteristics.

The preparalytic period is characterized by an acute onset of the disease, a deterioration in general condition, an increase in body temperature to febrile levels, headache, vomiting, lethargy, adynamia, and meningeal signs. General infectious, cerebral and meningeal syndromes can be combined with catarrhal or dyspeptic symptoms. In addition, there are positive symptoms of tension, complaints of pain in the back, neck, limbs, pain on palpation of nerve trunks, fasciculations and horizontal nystagmus. The duration of the preparalytic period is from 1 to 6 days.

The paralytic period is marked by the appearance of flaccid paralysis or paresis of the muscles of the limbs and torso. The main diagnostic signs of this stage are:

- sluggish nature of paralysis and its sudden appearance;

- rapid increase in movement disorders over a short period of time (1-2 days);

- damage to proximal muscle groups;

- asymmetrical nature of paralysis or paresis;

- absence of disturbances in sensitivity and function of the pelvic organs.

At this time, changes in the cerebrospinal fluid occur in 80-90% of patients with poliomyelitis and indicate the development of serous inflammation in the soft meninges. With the development of the paralytic stage, general infectious symptoms fade away. Depending on the number of spinal cord segments affected, the spinal form can be limited (monoparesis) or widespread. The most severe forms are those accompanied by impaired innervation of the respiratory muscles.

The recovery period is accompanied by the appearance of the first voluntary movements in the affected muscles and begins on the 7-10th day after the onset of paralysis. If 3/4 of the neurons responsible for the innervation of any muscle group die, the lost functions are not restored. Over time, atrophy increases in these muscles, contractures, joint ankylosis, osteoporosis, and limb growth retardation appear. The recovery period is especially active during the first months of the disease, then it slows down somewhat, but continues for 1-2 years.

If after 2 years the lost functions are not restored, then they speak of a period of residual effects (various deformities, contractures, etc.).

The bulbar form of polio is characterized by damage to the nuclei of 9, 10, 12 pairs of cranial nerves and is one of the most dangerous variants of the disease. In this case, there is a disorder of swallowing, phonation, and pathological secretion of mucus in the upper respiratory tract. Of particular danger is the localization of the process in the medulla oblongata, when damage to the respiratory and cardiovascular centers poses a threat to the patient’s life. Harbingers of an unfavorable outcome in this case are the occurrence of pathological breathing, cyanosis, hyperthermia, collapse, and impaired consciousness. Damage to the 3rd, 4th, 6th pairs of cranial nerves in polio is possible, but less common.

The pontine form of polio is the most mild, but the cosmetic defect can remain with the child for life. The clinical characteristic of this form of the disease is damage to the nucleus of the facial nerve. In this case, immobility of the facial muscles on the affected side suddenly occurs and lagophthalmos, Bell's symptoms, “sails”, and pulling of the corner of the mouth to the healthy side when smiling or crying appear. The pontine form of polio most often occurs without fever, general infectious symptoms, or changes in the cerebrospinal fluid.

The meningeal form of poliomyelitis is accompanied by damage to the soft meninges. The disease begins acutely and is accompanied by a deterioration in general condition, an increase in body temperature to febrile levels, headache, vomiting, lethargy, adynamia, and meningeal signs.

Symptoms characteristic of the meningeal form of poliomyelitis are pain in the back, neck, limbs, positive symptoms of tension, pain on palpation of the nerve trunks. In addition, fasciculations and horizontal nystagmus may be observed. The electromyogram reveals subclinical damage to the anterior horns of the spinal cord.

When performing a spinal puncture, cerebrospinal fluid usually flows out under pressure and is transparent. His research reveals:

— cell-protein dissociation;

— lymphocytic pleocytosis (the number of cells increases to several hundred per 1 mm3);

- normal or slightly increased protein content;

- increased sugar content.

The nature of changes in the cerebrospinal fluid depends on the timing of the disease. Thus, the increase in cytosis may be delayed and in the first 4-5 days from the onset of the disease the composition of the cerebrospinal fluid remains normal. In addition, sometimes, in the initial period, a short-term predominance of neutrophils in the cerebrospinal fluid is observed. After 2-3 weeks from the onset of the disease, protein-cell dissociation is detected. The course of the meningeal form of poliomyelitis is favorable and ends with complete recovery.

The inapparent form of polio is characterized by the absence of clinical symptoms with the simultaneous isolation of a “wild” strain of the virus from feces and a diagnostic increase in the titer of antiviral antibodies in the blood serum.

The abortive form or minor disease is characterized by an acute onset, the presence of general infectious symptoms without involvement of the nervous system in the pathological process. Thus, children may experience fever, moderate lethargy, decreased appetite, and headache. Often the listed symptoms are combined with catarrhal or dyspeptic symptoms, which serves as the basis for the erroneous diagnosis of acute respiratory viral or intestinal infections. Typically, the abortive form is diagnosed when a patient is hospitalized from the outbreak and receives positive results of a virological examination. The abortive form proceeds benignly and ends with complete recovery within a few days.

The development of vaccine-associated poliomyelitis is associated with the use of live oral vaccine for mass immunization and the possibility of reversing the neurotropic properties of individual clones of vaccine virus strains. In this regard, in 1964, a special WHO committee determined the criteria by which cases of paralytic poliomyelitis can be classified as vaccine-associated:

- onset of the disease no earlier than the 4th and no later than the 30th day after vaccination. For those who have been in contact with a vaccinated person, this period is extended to the 60th day;

- development of flaccid paralysis and paresis without impaired sensitivity with persistent (after 2 months) residual effects;

— absence of progression of the disease;

- isolation of a polio virus similar in antigenic characteristics to the vaccine virus and at least a 4-fold increase in type-specific antibodies.

Treatment

Rest in bed is necessary until severe symptoms subside.

Painkillers may be used to reduce fever, pain, and muscle spasms.

Your doctor may prescribe betanekol to combat urinary retention and antibiotics to treat an associated bacterial urinary tract infection.

A urinary catheter, a thin tube connected to a bag to collect urine, may be needed if bladder control has been lost due to paralysis.

Artificial respiration may be needed if breathing is difficult; In some cases, surgery to open the throat (tracheotomy) may be necessary.

Physiotherapy is necessary in cases of temporary or permanent paralysis. Mechanical devices such as braces, crutches, wheelchairs and special boots can help you walk.

A combination of occupational and psychological therapy can help patients adjust to the limitations imposed by the disease.

Treatment of polio in the acute period should be etiotropic, pathogenetic and symptomatic.

The development of clinical variants of polio with damage to the nervous system requires mandatory, as early as possible hospitalization of the patient, providing careful care and constant monitoring of basic vital functions. A strict orthopedic regimen must be followed. Affected limbs are given physiological

position with the help of plaster splints and bandages. The diet must meet the child’s age-related needs for basic ingredients and includes the exclusion of spicy, fatty, and fried foods. Particular attention should be paid to feeding children with bulbar or bulbospinal forms, since due to impaired swallowing there is a real threat of developing aspiration pneumonia. Tube feeding of the child allows you to avoid this dangerous complication.

As for drug treatment, an important point is to limit intramuscular injections as much as possible, which contribute to the worsening of neurological disorders.

As etiotropic agents for meningeal and paralytic forms, it is necessary to use antiviral drugs (pleconaril, isoprinosine pranobex), interferons (viferon, roferon A, reaferon-ES-lipint, leukinferon) or inducers of the latter (neovir, cycloferon), immunoglobulins for intravenous administration.

Pathogenetic therapy of the acute period involves the inclusion in complex therapy of:

— glucocorticoid hormones (dexamethasone) in severe forms for health reasons;

- vasoactive neurometabolites (trental, actovegin, instenon);

— nootropic drugs (gliatilin, piracetam, etc.);

— vitamins (A, B1, B6, B12, C) and antioxidants (vitamin E, mexidol, mildronate, etc.);

- diuretics (diacarb, triampur, furosemide) in combination with potassium-containing drugs;

- infusion therapy for the purpose of detoxification (5-10% solutions of glucose with electrolytes, albumin, infucol);

- inhibitors of proteolytic enzymes (Gordox, Ambien, Contrical);

- non-narcotic analgesics (for severe pain);

— physiotherapeutic methods (paraffin or ozokerite applications on the affected limbs, UHF on the affected segments).

The appearance of the first movements in the affected muscle groups marks the beginning of the early recovery period and is an indication for the prescription of anticholinesterase drugs (prozerin, galantamine, ubretide, oxazil). As the pain syndrome is relieved, exercise therapy, massage, UHF are used, then electrophoresis, pulsed current electromyostimulation, and hyperbaric oxygenation.

After discharge from the infectious diseases department, the course of treatment with the medications described above continues for 2 years. The optimal solution should be the treatment of polio convalescents in specialized sanatoriums.

It is not yet known whether the infection can be stopped once it has started. On the other hand, many infected children do not suffer from paralysis. Many who are temporarily paralyzed then make a full recovery. Most of those who do not recover permanently make significant improvement.

If mild paralysis is observed after the acute phase of the disease, the child should be under constant medical supervision. Treatment depends on many factors. At each stage, the decision is made by the doctor, and there are no general rules. If paralysis persists, various operations are possible to restore the mobility of the limbs and protect them from deformation.

Prevention

When there are cases of polio in your area, parents start asking how to keep their child safe. Your local doctor will give you the best advice. There is no point in panicking and depriving children of all contact with others. If there are cases of the disease in your area, it is wise to keep children away from crowds, especially indoor areas such as shops and cinemas, and away from swimming pools that are used by many people. On the other hand, as far as we now know, it is not at all necessary to prohibit a child from meeting close friends. If you take care of him like this all your life, you won’t even allow him to cross the street. Doctors suspect hypothermia and fatigue increase susceptibility to the disease, but both are wise to avoid at all times. Of course, the most common case of hypothermia in the summer is when a child spends too much time in the water. When he begins to lose his color, he should be called out of the water - before his teeth chatter.
. There are a number of vaccines that are recommended to be given at two months of age, then again at four and 18 months, and a booster dose when the child starts school (between four and six years of age).

Immunization of children is the basis of the polio eradication strategy, and the level of vaccination coverage during routine immunization should be at least 95% among children of decreed ages in accordance with the Preventive Vaccination Calendar.

National immunization days are the second important component of the polio eradication strategy. The goal of these campaigns is to stop the circulation of wild poliovirus by immunizing as quickly as possible (within a week) all children in the age group at highest risk of disease (usually children under three years of age).

In Russia, National Polio Immunization Days covering about 4 million children under 3 years of age (99.2-99.5%) were held for 4 years (1996-1999). Immunization was carried out in two rounds, with an interval of one month, with live oral polio vaccine (OPV), with vaccination coverage of at least 95% of the number of children of the specified age groups located in the given territory.

The main preventive drug both in our country and throughout the world is the Seibin live vaccine (LSV), recommended by WHO. In addition, imported vaccines Imovax Polio (Sanofi Pasteur, France), Tetracoc (Sanofi Pasteur, France) are registered in Russia. The Pentaxim vaccine (Sanofi Pasteur, France) is under registration. The listed vaccines are inactivated polio vaccines. Vaccines are stored at 2-8 °C for 6 months. An opened bottle should be used within two working days.

Currently, for immunization of the child population against polio, OPV is used - oral types 1, 2 and 3 (Russia), IPV - Imovax Polio - inactivated enhanced (types 1, 2, 3) and Pentaxim (Sanofi Pasteur, France).

Vaccination begins at the age of 3 months three times with an interval of 6 weeks with IPV, revaccination at 18 and 20 months, and at 14 years with OPV.

The dose of domestically produced live vaccine is 4 drops per dose. It is administered orally an hour before meals. It is not allowed to drink the vaccine, eat or drink within an hour after vaccination. If regurgitation occurs, a second dose should be given.

Contraindications to VPV vaccination are:

- all types of immunodeficiency;

— neurological disorders due to previous VPV vaccinations;

- presence of acute diseases. In the latter case, vaccination is carried out immediately after recovery.

Non-severe illnesses with an increase in body temperature up to 38 °C are not a contraindication for VPV vaccination. If diarrhea is present, vaccination is repeated after stool normalization.

The oral polio vaccine is considered the least reactogenic. However, when using it, the possibility of an adverse post-vaccination event cannot be excluded. The greatest degree of risk is observed during primary vaccination and during contact infection of non-immune children.

It is possible to prevent the occurrence of vaccine-associated polio in children, especially from risk groups (IDF, born to HIV-infected mothers, etc.), by using an inactivated polio vaccine for initial vaccination or by conducting a full course of immunization.

According to epidemiological indications, additional immunization is carried out. It is carried out regardless of previous preventive vaccinations against polio, but not earlier than 1 month after the last immunization. Children under the age of 5 years are subject to a single immunization with OPV (the age composition of children can be changed), who communicated in epidemic foci with patients with polio, diseases accompanied by acute flaccid paralysis, if these diseases are suspected in the family, apartment, house, preschool educational and medical -preventive institution, as well as those who communicated with those arriving from polio-prone areas.

Nonspecific prevention of polio infection involves hospitalization and isolation of the patient, and monitoring contact children under 5 years of age for 20 days. According to epidemiological indications, a one-time virological examination of contacts is carried out. In the epidemic focus of POLI/AFP, after hospitalization of the patient, final disinfection is carried out.

In adults, polio vaccination is recommended only before traveling to areas where polio is common.

Contact your doctor immediately if you or your child experience symptoms of polio or if you may have been infected with the virus and have not yet been vaccinated.

Contact your doctor to get the polio vaccine if you have not been vaccinated and plan to travel to areas where polio is common.

Attention! Call an ambulance if someone has trouble breathing or paralysis of a limb.

There are non-paralytic poliomyelitis, which includes abortive and meningeal forms, and paralytic poliomyelitis.

Abortive the form occurs with general nonspecific symptoms (catarrhal phenomena, gastrointestinal disorders, general weakness, increased body temperature, etc.); These cases are the most dangerous in epidemiological terms.

Meningeal the form manifests itself as serous meningitis.

In the most common paralytic form of polio - spinal - after general infectious symptoms, paralysis of muscle groups innervated by the motor cells of the spinal cord appears; on the legs the following are most often affected: the quadriceps muscle, adductors, flexors and extensors of the foot; on the arms: deltoid, triceps and forearm supinators. Paralysis of the thoraco-abdominal barrier is especially dangerous, leading to severe respiratory failure.

Bulbarnaya the form is caused by damage to various parts of the medulla oblongata, and the pontine form is caused by damage to the nucleus of the facial nerve.

For non-paralytic forms the disease usually ends with complete recovery; in paralytic forms, in some cases, the functions of the affected muscles are not fully restored, the defect persists for a long time, sometimes for life. The most severe cases, especially those affecting the respiratory centers of the medulla oblongata, can be fatal. The diagnosis of polio is made on the basis of clinical, epidemiological and laboratory data .

Pathogenesis The entry point for infection is the mucous membrane of the mouth and nasopharynx. Primary reproduction of the virus occurs in the epithelial cells of the mucous membrane of the mouth, pharynx and intestines, in the lymph nodes of the pharyngeal ring and small intestine (Peyer's patches).

From the lymphatic system the virus enters the blood. The viremia stage lasts from several hours to several days. In some cases, the virus enters neurons in the spinal cord and brain, apparently through the axons of peripheral nerves. This may be due to increased permeability of the blood-brain barrier due to the formation of immune complexes.

Reproduction of the virus in the motor neurons of the anterior horns of the spinal cord, as well as in the neurons of the cerebrum and medulla oblongata, leads to profound, often irreversible changes. Crystal-like accumulations of virions are found in the cytoplasm of affected neurons, which undergo profound degenerative changes.

Symptoms and course. The incubation period lasts on average 5-12 days (variations from 2 to 35 days are possible). There are non-paralytic and paralytic forms of polio.

Non-paralytic form occurs more often in the form of a so-called “minor illness” (abortive or visceral form), which is manifested by short-term fever, catarrhal (cough, runny nose, sore throat) and dyspeptic symptoms (nausea, vomiting, loose stools). All clinical manifestations usually disappear within within a few days. Another variant of the non-paralytic form is mild serous meningitis.

In development paralytic poliomyelitis allocate 4 stages: preparalytic, paralytic, restorative and stage of residual effects. The disease begins acutely with a significant increase in body temperature. During the first 3 days, headache, malaise, runny nose, pharyngitis are observed, and gastrointestinal disorders (vomiting, loose stools or constipation) are possible. Then, after 2-4 days of apyrexia, a secondary feverish wave appears with a sharp deterioration in the general condition. In some patients, the period of apyrexia may be absent. Body temperature rises to 39-40°C, headache intensifies, pain in the back and limbs, severe hyperesthesia, confusion and meningeal phenomena appear. In the cerebrospinal fluid there are from 10 to 200 lymphocytes in 1 μl. There may be a decrease in muscle strength and tendon reflexes, convulsive shudders, twitching of individual muscles, tremors of the limbs, pain in the tension of peripheral nerves, autonomic disorders (hyperhidrosis, red spots on the skin, goose bumps and other phenomena). The preparalytic stage lasts 3-5 days.

The appearance of paralysis usually seems sudden; in most patients it develops within a few hours. Flaccid (peripheral) paralysis with decreased muscle tone, limitation or absence of active movements, with partial or complete reaction of degeneration and absence of tendon reflexes. The muscles of the extremities, especially the proximal parts, are mainly affected. The legs are most often affected. Sometimes paralysis of the muscles of the trunk and neck occurs. With the development of paralysis, spontaneous muscle pain occurs: there may be pelvic disorders. No sensory disturbances are observed. In the paralytic stage, cell-protein dissociation in the cerebrospinal fluid is replaced by

Ecology and distribution. The stability of poliovirus in the external environment is relatively high. It retains its infectious properties in wastewater at 0 °C for a month. Heating at a temperature of 50 °C inactivates the virus within 30 minutes in water, and at 55 °C in milk, sour cream, butter and ice cream. The virus is resistant to detergents, but is highly sensitive to UV rays and drying, as well as to chlorine-containing disinfectants (bleach, chloramine). Children are most susceptible to polio, but adults also get sick. Often the spread of polio becomes epidemic. The source of infection is patients and virus carriers. Isolation of the virus from the pharynx and feces begins during the incubation period. After the first symptoms of the disease appear, the virus continues to be excreted in feces, 1 g of which contains up to 1 million infectious doses. Therefore, the fecal-oral mechanism of transmission of infection through water and food contaminated with feces is of primary importance. Flies play a certain role. In epidemic foci, people can become infected through airborne droplets.

Epidemiology and specific prevention. Polio epidemics occurred in 1940-1950. thousands and tens of thousands of people, of whom 10% died and approximately 40% became disabled. The main measure to prevent polio is immunization. The widespread use of the polio vaccine led to a sharp decrease in the incidence.

The first inactivated vaccine for the prevention of polio was developed by the American scientist J. Salk in 1953. However, parenteral vaccination with this drug created only general humoral immunity, did not form local resistance of the mucous membranes of the gastrointestinal tract (GIT) and did not provide reliable specific protection.

The incubation period is asymptomatic or with mild symptoms of general malaise, increased fatigue, decreased appetite, bad mood and lethargy.

During paralytic poliomyelitis, in addition to the indicated initial phenomena, 4 stages are distinguished:

1) preparalytic;

2) paralytic;

3) restorative;

4) residual, or residual.

Preparalytic stage, as a rule, this stage precedes the development of paralysis.

In vaccinated people, the preparalytic stage may be absent, and mild paresis develops at normal temperature and satisfactory general condition.

The entire preparalytic stage is often also called the meningeal stage.

The disease begins with a sudden rise in temperature, often up to 39-40°.

Sometimes the temperature rises gradually, may have a remitting nature, or remains at high levels throughout the entire febrile period, which lasts from one to several days, on average 3-5, less often 7-10; in some cases, the increase in temperature lasts only a few hours.

The temperature drop can be critical or lytic. A “two-phase” temperature curve is observed quite often. The first rise corresponds to general infectious phenomena, the second – the invasion of the virus into the nervous system and the appearance of neurological symptoms, mainly meningeal.

The first rise lasts 1-3 days and is replaced by a latent period with normal temperature and apparent recovery lasting 1-7 days. The second rise in temperature occurs with a sharp deterioration in general condition.

From the first days, many patients experience an increase in heart rate that is inappropriate for the rise in temperature. Characterized by mild excitability of the pulse, which quickens at the slightest stress. In some patients, the pulse may be slow.

In the first days, the symptoms are general infectious and are expressed by fever, general malaise, which is accompanied by disorders of the gastrointestinal tract or catarrhal symptoms of the upper respiratory tract.

Gastrointestinal disorders are expressed in lack of appetite, nausea, regurgitation in infants, abdominal pain, diarrhea, and somewhat less commonly - constipation.

The stool may have a foul odor, a significant admixture of mucus, sometimes blood and even pus. Unlike dysentery, dysentery-like phenomena in polio are short-term and go away without specific therapy.

Catarrhal phenomena from the upper respiratory tract occur as sore throats, nasopharyngitis with runny nose and cough, and bronchitis. Sometimes conjunctivitis and stomatitis are observed.

In some epidemics, gastrointestinal disorders are more often observed, in others - catarrhal phenomena from the upper respiratory tract. Various types of rashes and herpetic eruptions are observed rarely and are not characteristic of polio.

Against the background of elevated temperature and catarrhal symptoms, neurological symptoms appear. This combination of general infectious and neurological signs is typical for polio.

Headaches, vomiting, general lethargy, apathy, increased drowsiness, bad mood, pain in the back, neck, and limbs are constant symptoms, varying in their severity and combinations.

Less commonly observed are increased irritability, agitation, restlessness, increased fearfulness, sometimes confusion, tonic or clonic convulsions. In infants, seizures occur more frequently.

The stages of the disease described are typical for the most common - spinal - forms; There are significant differences between stem and other forms. Short-term symptoms of motor irritation in the form of shudders, trembling, twitching, and vague anxiety in individual muscle groups are typical symptoms. Sometimes spontaneous twitching is observed in those muscles that are subsequently paralyzed.

Symptoms of irritation of the meninges and roots occur suddenly against a background of elevated temperature, often in the afternoon. The severity of meningeal symptoms varies, but, as a rule, they are not as significant as with tuberculous or purulent meningitis.

Spinal tension often comes to the fore. Opisthotonus is usually absent. There is significant pain during passive movements, especially in the spine, which often becomes completely motionless - a “spinal symptom”. The symptoms of tension are positive, with the Lasegue symptom having the greatest significance.

There is pronounced pain when pressure is applied to the nerve trunks. The pain is spontaneous, but it sharply intensifies with movements and changes in position. Pain and muscle spasms in the preparalytic stage are symmetrical on both sides, in contrast to paralysis, which is usually expressed asymmetrically.

Of the vegetative disorders, the first place is occupied by increased general or local sweating, which is expressed in the last days of the preparalytic stage and intensifies in the paralytic stage. Increased sweating of the head is especially common.

Vasomotor reactions, especially on the skin of the face and neck, are labile, bright hyperemia quickly gives way to pallor. Often limited red spots (Trousseau spots) and pronounced red dermographism appear for a short period of time.

There is an increase in the pilomotor reflex (“goose bumps”). Violation of vestibular functions, revealed by special studies, is a common symptom, but, unlike other diseases, dizziness is a rather rare complaint. At the end of the preparalytic stage, a state of general adynamia appears, which is characterized by the fact that while motor function is preserved, the strength of active movements and muscle resistance during passive ones are diffusely reduced.

The basis of adynamia is hypotension (mainly expressed in the muscles, which are then paralyzed) combined with rigidity of some muscle groups and pain. The preparalytic stage of the disease usually lasts 3-5 days, but can be shorter (1-2 days) or longer.