Multiple sclerosis: the causes of the onset, clinical signs

Multiple sclerosis (MS, multiple sclerosis, disseminated sclerosis, sclerosis disseminata, SD) is chronic disease of the nervous system, in which the neural tissue in places is replaced by a connective formation of plaques. Replacement of the tissue causes a disruption of the functions of the nervous system, which is manifested by various symptoms. Usually the course of multiple sclerosis has a wavy-progressive character. The disease gradually leads to a limitation of vital activity and can shorten the life expectancy of the patient. From this article you can find out how and how multiple sclerosis develops, how it manifests itself and how it affects the duration of life.

Multiple sclerosis is considered as an autoimmune-inflammatory process. In this disease, the myelin sheath of nerve cells under the action of their own antibodies is destroyed. This phenomenon is called demyelination. However, this does not happen to every person, prerequisites are needed to start the process.

Causes

According to modern concepts, multiple sclerosis refers to multifactorial diseases, i.e., has a combination of several causes at the same time.

The most important factors are:

• viral infection;
• hereditary (genetic) predisposition of the immune system;
• geographical features of the place of permanent residence.

Viral infection

It is believed that multiple sclerosis is a consequence of so-called slow infections. Typical features of slow infections are: a long period without any symptoms (latent), selectivity lesions (ie, the same organs and systems), development only in a particular species of animal or human, constantly progressing flow.

A specific specific infection that causes the development of multiple sclerosis has not yet been detected, but the role of many viruses is confirmed various facts: the connection of the onset of the disease or exacerbation with a transferred viral infection, the presence of a high titer of antiviral antibodies in the blood of patients with multiple sclerosis, the causing of multiple sclerosis in an experiment in the laboratory in animals under the influence viruses.

Among the causative agents of infections, which can supposedly serve as a starting point in the development of diffuse sclerosis, it should be noted retroviruses, measles, herpes, rubella, mumps, Epstein-Barra. Most likely, that the causative agent penetrates into the body even in childhood, and then, in the presence of other factors, provokes immune disorders on the surface of nerve cells. The immune system starts producing antibodies against these viruses. However, antibodies attack not the pathogen itself, but the nerve cells, which are perceived by it as a danger. As a result, the nerve tissue is destroyed. To implement such a mechanism, a special hereditary predisposition is needed.

Hereditary predisposition

To date, it has been established that the disease occurs in families where there is a patient with multiple sclerosis, 20-50 times more often than in the general population. This is especially true for relatives of the first, second line of kinship (children, brothers, sisters). Cases of family multiple sclerosis account for up to 10% of the total number.

It was revealed that some genes of the 6th chromosome determine the unique nature of the immune response, characteristic of multiple sclerosis. Other genes responsible for the structure and functions of nonspecific enzymes, immunoglobulins, myelin protein, are also involved in the development of the disease. T. e. in order for the disease to arise, a person must have a combination of several genes. It is believed that even features of the course of multiple sclerosis are encoded by certain hereditary structures.

Geographical features

Statistical studies have revealed that the prevalence of multiple sclerosis is higher in areas with increased humidity and cool climate, in river valleys, with less sunlight (short light in the afternoon).

The content in the soil and natural waters of copper, zinc, cobalt, especially the nutrition of certain regions (increase in protein and animal fat content in developed countries) also affect the prevalence of diffuse sclerosis.

It is noted that in the northern countries, more remote from the equator (this phenomenon is called the gradient of latitude), in people of the European race the risk of the disease is much higher. The prevalence of multiple sclerosis in Germany, Austria, Switzerland, South Australia, in the north of the US is much higher than in other countries of the world.

Such an interesting pattern has been revealed: if a person lived in a locality with a high risk of developing multiple sclerosis in childhood, and before reaching the age of 15, he changed the region of his habitat, having moved to a place where the incidence is several times less, then he has a significant risk of falling ill decreases. If the migration takes place after 15 years, then the change of residence does not affect in any way, and the risk remains high. It is suggested that this is due to the peculiarities of the formation of the immune system before reaching adolescence.

How does multiple sclerosis occur?

At casual coincidence at the person of genetic features of reaction of immune system with factors of an environment (a zone of residing, features of ecology and nutrition, etc.) in response to a viral infection in the body, a whole cascade of immune violations.

Antigens of viruses, penetrating into the nervous system, attach to the surface of nerve cells, in particular to myelin (the protein membrane of nerve fibers). The immune system attacks alien entities, perceiving them as a danger. The attack consists in the formation of antibodies against viral particles, but since the latter bind to myelin, the antibodies are also produced against it. Develops an incorrect immune response (autoimmune) - the body is fighting against their own structures. In the following, myelin is perceived as foreign, and antibodies are produced continuously.

The production of antibodies is accompanied by the release of various formations that stimulate the inflammatory process. The result of such events is demyelination (destruction of myelin) and damage to the structure of the nerve fiber (axonal degeneration). Instead of destroyed structures, connective tissue develops, and so-called plaques are formed, which are scattered throughout the nervous system. Therefore, the disease also received the name of multiple sclerosis (sclerosis in this case means the formation of connective tissue scar in place of normal nervous tissue).

Clinical signs

Multiple sclerosis usually affects young people - from 18 to 45 years. Women suffer more often than men. If the disease occurs after 50 years, the inter-sex ratio is equalized.

Multiple sclerosis is a multifaceted disease. It manifests itself in a variety of symptoms because it is based on the formation of sclerotic plaques throughout the central nervous system.

It should be noted that there are no specific clinical symptoms that are characteristic only of multiple sclerosis. Therefore, the diagnosis of this disease is very complicated.

Typical manifestations of multiple sclerosis include:

• motor disorders;
• coordination disorder (atactic syndrome);
• sensitivity disorders;
• symptoms of damage to the brain stem and cranial nerves;
• vegetative disorders of the pelvic organs;
• malfunctions in the psychoemotional sphere.

Motor disorders manifest themselves in the form of muscle weakness (paresis) in different parts of the body. More often the paresis of the lower extremities develops, more pronounced in the muscles of the lower leg and thigh, in large muscle massifs. Over time, muscle weakness is aggravated, pareses spread to the arms, all four limbs are involved - tetraparesis. Usually, muscle weakness is combined with increased muscle tone. This is called spastic paresis. In the prone position, the tone is less pronounced, when walking becomes more noticeable. With multiple sclerosis, pareses can also be combined with a decrease in muscle tone. Tendon reflexes are increased (flexor-ulnar, extensor-elbow, carp-radial, knee, Achilles), and the zone with which the reflex is called expands. Surface reflexes (from mucous membranes, cutaneous abdominal, plantar), on the contrary, are lost. When examined, the pathological stop signs are revealed: Babinsky's symptom (slow extension the thumb of the foot with the dashed stimulation of the outer edge of the sole), Rossolimo, Zhukovsky, Gordon et al. All these symptoms testify to the defeat of nerve conductors from the cortex of the cerebral hemispheres to the motor neurons of the spinal cord.

Atactic syndrome is a violation of stability. The patient appears unsteady when walking, and later when standing. Shakiness can be so pronounced that it leads to falls. Violated the accuracy of coordination of movements: there is a miss when trying to take something, a missed when performing even the most simple movements (combing, brushing teeth). Particularly difficult are actions that require a rapid change in the opposite movements in the joints of the hands. Do not fasten buttons, do not strip the shoelaces, do not hit the thread in the needle, etc. Perhaps the appearance of jitters in the limbs when performing movements (intentional tremor). Because of a violation of the agreed contraction and relaxation of the muscles of the tongue, larynx and pharynge, speech may be broken: she becomes slow, as if jerky, with the division of words into syllables, with several accents in one word. Another characteristic feature of atactic syndrome is nystagmus. These are rhythmic vibrational movements of one or both eyes, which arise involuntarily, more often with a maximum view to the side or upwards.

Disturbances of sensitivity are different symptoms. The patient complains of crawling crawling in various parts of the body, numbness, burning, itching, tingling. Sometimes pains of paroxysmal character may be disturbing: along the nerve trunks, along the spine, in the head. Patients are described as lumbago, compared with the passage of current from head to foot (a symptom of Lermitt). Possible pain in the muscles due to increased tone. On examination, violations of pain, temperature sensitivity are detected, and no touch is felt in any parts of the body. The loss of joint-muscle feeling is characteristic: when a patient with closed eyes can not determine to which finger The doctor touches and in what direction makes passive movement with this finger (bends, unbends, points aside). As the disease progresses, such disorders appear even in large joints: ankle, wrist.

Because of the atactic syndrome, motor and sensitive disorders in patients, the gait changes. She becomes insecure, as if "feeling" the surface under her feet, with excessive ejection of her legs forward. Sometimes the patient needs to look under his feet, so as not to fall. If such a patient is asked to walk with his eyes closed, then all these manifestations increase dramatically. It is difficult for the patient to turn sharply or stop suddenly.

Symptoms of damage to the brain stem and cranial nerves are often found already in the early stages of multiple sclerosis, and as the disease progresses only progress. They include a feeling of double vision, dizziness, noise in the ears. Ophthalmic, oculomotor, diverting, trigeminal, facial nerves are more often affected, more rarely - the vestibulocchlear nerve. This is manifested by impaired vision, strabismus, weakness of facial muscles, paroxysmal pains in the face, hearing impairment. Symptoms of damage to the brain stem include violent laughter and crying (uncaused and uncontrolled), revealed by the doctor when examined by reflexes Oral automatism (for example, when you touch your lips, sucking movements occur, tapping on the back of the nose causes the lips to stretch tube).

Functions of pelvic organs are disrupted in most patients. More often it occurs at later stages of the disease, but it can also be the first sign. There may be a delay in urination or incontinence. Of course, the maximum severity of these symptoms does not occur immediately. At first, the patient simply has to push harder to carry out the act of urination; or the urge to urinate becomes so pronounced that it requires immediate satisfaction. Otherwise, the patient is unable to retain urine. Already at later stages of the disease, similar situations develop in the act of defecation. In the final of the disease, most patients do not control the physiological functions. From other vegetative disorders in patients with multiple sclerosis, impotence and menstrual cycle disorders are observed.

Psychoemotional disorders begin gradually, asthenic syndrome develops. Memory, attention, memory, and intellectual thinking are gradually decreasing. There is excessive emotionality, tearfulness or, conversely, euphoria. Sometimes patients are not able to objectively assess their symptoms. Some patients develop depression, occasionally schizophrenic-like psychoses are possible. Chronic fatigue syndrome is characteristic.

Multiple sclerosis has some characteristics of the development of symptoms that help to diagnose this disease. Especially good these symptoms are expressed in the initial stages of the disease:

• clinical dissociation or cleavage - a discrepancy between the severity of the symptoms of the lesion of one or more functional systems. For example, with a significant decrease in vision when examining the fundus, pathological changes are not detected at all. Or the patient simultaneously has a combined lesion of different functional systems: for example, high reflexes and paresis in the legs due to injury central motor neuron and low muscle tone due to cerebellar involvement (although with damage to the central motor neuron, the tone usually increases);
• The symptom of a hot bath (a symptom of Uthoff) is the temporary increase in the severity of individual manifestations after taking a bath, after taking hot food, with an increase in body temperature or the environment (heat in summer day). After a short time (usually about 30 minutes) the symptoms return to their original level. This is due to the increased sensitivity of nerve fibers left without the myelin sheath;
• phenomenon of flickering of symptoms: within a short period of time, the severity of symptoms fluctuates. It may even be during the day. For example, in the morning, weakness in the legs was such that it impeded independent movement, and by the evening of strength in the legs again enough. This is associated with the sensitivity of the affected structures to fluctuations in the indices of the internal environment (homeostasis).

There are several types of multiple sclerosis:

• the debut of the disease;
• relapsing-remitting course;
• primary-progressive;
• secondary-progressive.

The type of course plays a role in relation to the prognosis of the disease and the purpose of treatment.

The debut is the first time revealed reliable multiple sclerosis.

The recurrent-remitting type is characterized by a wavy course of the disease with clear periods exacerbations (when the condition worsens, new symptoms appear) and remissions (restoration of impaired functions).

The primary-progressive course is characterized by a steady deterioration of the condition without "light" gaps from the very beginning of the disease.

The secondary-progressive form occurs when the remission-remitting type of the course ends remission periods and the improvement no longer occurs. Within 10 years, this transformation occurs in 50% of patients, in 25 years - in 80%.

Primary and secondary-progressive types of flow are characterized by a worse prognosis for work capacity and life.

The lifetime of patients with multiple sclerosis

The life span of a patient with multiple sclerosis depends on many factors:

• age of onset of the disease;
• timely diagnostics;
• type of flow;
• whether the patient receives preventive therapy (you can learn about this type of treatment from the same article);
• development of complications of multiple sclerosis (bedsores, infections of the urinary tract and lungs, etc.);
• concomitant pathology, that is, the presence of other diseases.

The life of a patient with multiple sclerosis is affected by the timeliness of the diagnosis more than in many other diseases. It is such an insidious disease that its first symptoms can be ignored or ignored by the patient, and he will not seek medical help. So, will not receive such a topical treatment. After all, if therapy is started in the debut of the disease, it significantly improves the quality of life, in many cases stops the progression of the disease, helps to prevent disability and prolong the term life.

At the beginning of the XX century, patients diagnosed with multiple sclerosis lived a maximum of 30 years in the case of a favorable course of the disease. In the 21st century, the life span has significantly extended.

Statistical data indicate that in the early diagnosis of a disease, a relapsing-remitting type course, complete treatment on average, patients live 7 years less than their peers who do not have such diagnosis.

Patients who had the disease diagnosed after 50 years of age, with an average of 70 years of age, are treated with quality care. Patients with the presence of complications in this case live up to 60 years. However, each rule has exceptions, so it is very difficult to accurately predict how the disease behaves and how much a particular patient will live.

Multiple sclerosis is an autoimmune inflammatory disease that affects the human nervous system, the causes of which have not yet been fully studied. Clinical symptoms in MS are very diverse and nonspecific, which makes diagnosis difficult. The life expectancy of such patients is influenced by many factors, including timely access to medical care.

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