Spinal amyotrophy of Werdnig-Hoffmann: causes, symptoms, treatment

Spinal amyotrophy of Werdnig-Hoffmann (acute malignant infantile spinal amyotrophy of Verdnig-Hoffman, type I spinal amyotrophy) Is a hereditary disease of the nervous system, characterized by the development of muscle weakness in virtually all the muscular structures of the body. It leads to a violation of the ability to sit, move and self-service. There are no effective treatments for the disease. Prenatal diagnosis helps to avoid the birth of a sick child in the family. From this article you can learn about how this disease is inherited, what is manifesting and how it is possible to help such patients.

The disease is called the two scientists who first described it. At the end of the XIX century, Verdnig and Hoffmann proved the morphological essence of the disease. They assumed the only similar form of the disease. However, in the twentieth century, Kukelberg and Welander described another clinical form of spinal amyotrophy, which had the same genetic cause as the Verdnig-Hoffmann spinal amyotrophy. To date, the concept of spinal amyotrophy combines several clinically different forms of the disease. But they are all related to the same hereditary defect.

Causes of spinal amyotrophy

The disease is hereditary. The basis is a genetic mutation in the 5th human chromosome. Mutation is subjected to the gene responsible for the production of the protein SMN. Synthesis of this protein provides normal development of motor neurons. In the case of mutation, the motor neurons are destroyed or are underdeveloped, which means that the transfer of momentum from the nerve fiber to the muscle is impossible. The muscle does not work. Consequently, all movements associated with a non-functioning muscle are not performed.

The wrong gene has an autosomal recessive type of inheritance. This means the following: in order for spinal amyotrophy to develop, it is necessary that the two mutant genes coincide from the mother and from the father. That is, the mother and father of the child should be carriers of the pathological gene, but they are not sick because of the simultaneous presence at them healthy dominant (prevailing) gene (genes at each person paired). If the mother and father are carriers of the pathological gene, the risk of producing a sick child is 25%. It is estimated that about every 50th person on the planet is a carrier of a mutant gene.

Symptoms

To date, there are 4 forms of spinal amyotrophy. All of them differ in terms of the onset of the disease, certain symptoms and longevity. Common to all forms is the absence of sensitive and mental disorders. The functions of the pelvic organs never suffer. All symptoms are associated only with the defeat of the motor sphere.

Type I spinal amyotrophy

The debut of the disease before the age of 6 months has an extremely unfavorable prognosis.

Possible violations of sucking and swallowing, difficulty in the movement of the tongue. In the language itself fasciculations can be seen (involuntary muscular contractions, "waves" run around the tongue), and he looks atrophied. The cry of the child is sluggish and weak. If the pharyngeal reflex decreases, there are problems with feeding, as a result of which food gets into the respiratory tract. And this causes aspiration pneumonia, from which the child can die.

The defeat of the diaphragm and intercostal muscles is manifested in violation of the act of breathing. At first, this process is compensated, but gradually the respiratory insufficiency is aggravated.

It is characteristic that facial muscles of the face and muscles responsible for eye movements are not affected.

These children are lagging behind in motor development: they do not hold their heads, do not turn over, they do not reach for the object, they do not sit. If any motor skills and could be realized before the onset of the disease, they will be lost.

In addition to motor disorders, the disease is characterized by deformation of the chest.

If signs of the disease are visible immediately after birth, then such children often die within the first 6 months of life. If signs appear after 3 months, then the life span is somewhat longer - about 2-3 years. Inevitably, the infection is associated with respiratory disorders, from which such babies die.

Spinal amyotrophy can be combined with congenital malformations: oligophrenia, a small skull, heart defects, congenital fractures, hemangiomas, clubfoot, undescended testicles.

Spinal amyotrophy of type II

This form of the disease occurs between the first 6 months and 2 years of life. Until then, the child does not reveal any violations. He starts keeping his head on time, turning over and sitting, and sometimes walking. And then gradually there is a muscle weakness. Usually it all starts with the muscles of the thighs. Slowly walking becomes impossible, tendon reflexes are reduced and lost. Muscular weakness progresses slowly. All limbs are involved. Develops muscle atrophy. The process can also capture respiratory muscles. Also, as with the I-th type of spinal amyotrophy, the facial muscles and muscles of the eye are not affected. There may be trembling of the hands, twitching in the tongue and limbs. The weakness of the neck muscles is manifested by the dangling of the head.

Very characteristic are bone-joint deformations: scoliosis, funnel-shaped chest, dislocation of the hip joint.

This form has a benign course than type I spinal amyotrophy, but in most patients there are respiratory disorders during the adolescent period. A poor chest excursion contributes to the attachment of infections from which the child may die.

Spinal amyotrophy of type III

This form is described by Kukelberg and Welander. It is considered a juvenile spinal amyotrophy. The onset of the disease is between 2 and 15 years.

The first symptom is always unstable walking due to the growing weakness in the legs. Tone in the legs decreases, muscular atrophy develops (the muscles are thinned), but this is not always noticeable due to the well-developed layer of subcutaneous adipose tissue to this age. Children stumble, fall, awkwardly move. Gradually, movements in the legs become impossible, and the patient stops walking.

Gradually, the disease also captures the upper limbs, the hands are affected later. With this form, the weakness of facial muscles develops, but eye movements remain in full. There are no reflexes from those muscle groups that are already involved in the process.

Deformations of the skeleton are also characteristic: the funnel-shaped chest, contractures of the joints.

This form of the disease, when carrying out maintenance therapy, allows patients to live up to 40 years.

Spinal amyotrophy of type IV

This form of the disease is considered "adult", because it manifests itself after 35 years. There is also a weakness in the muscles of the legs, a decrease in reflexes, muscle atrophy, which, in the end, leads to a complete loss of movement in the legs. At the same time, the respiratory muscles are not involved in the process, there is no violation of breathing. Life expectancy with this form of the disease is almost the same as in healthy people. The course is the most benign in comparison with other forms.

Diagnostics

When symptoms similar to spinal amyotrophy appear, electroneuromyography is performed (spontaneous activity is detected in the form of potentials of fasciculations at rest and an increase in the average amplitude of action potentials of motor units).

Finally, the issue of diagnosis is resolved after a genetic study (DNA-diagnosis): find a mutation of the gene in the 5 th chromosome.

In families where there have been cases of such diseases, prenatal (prenatal) DNA diagnosis is performed in the fetus. When the pathology is identified, the issue of abortion is decided.

Principles of treatment of spinal amyotrophy

Unfortunately, this incurable hereditary disease. At the present stage, studies are under way which, perhaps, will help regulate the synthesis of the SMN protein, but no results so far.

To alleviate the condition of patients with spinal amyotrophy help:

• Periodic course administration of drugs that improve the metabolism of nervous tissue and muscles (Cerebrolysin, Cytoflavin, Glutamic acid, ATP, Carnitine chloride, Methionine, Potassium orotate, Tocopherol acetate, etc.);
• vitamins of group B (Milgamma, Neurovitan, Kombilipen);
• anabolic steroids (Retabolil, Nerobol);
• drugs that improve neuromuscular conduction (Prozerin, Neurromidine, Galantamine, Dibasol);
• courses of massage and physiotherapy;
• Physiotherapy (muscle electrical stimulation, carbon-sulphide baths);
• methods of orthopedic correction (with the development of contractures of the joints and deformation of the spine).

Verdnig-Hoffmann's spinal amyotrophy, like other forms of this disease, is a hereditary pathology. The appearance of the disease in a child is explained by the presence of a mutant gene in both the mother and the father. The disease is characterized, mainly, by muscle weakness, which causes immobility and respiratory disorders. The disease, to date, is incurable.