Friedreich's ataxia

Friedreich's ataxia is an autosomal recessive pathology, when a sick child is born to a visually healthy couple, but one of the parents is the owner of the pathogenic gene. The disease is expressed in the damage of nerve cells - predominant damage to the Goll bundles, pyramidal tracts, roots and peripheral nerve fibers, neurons of the cerebellum, brain. At the same time, other organs can be affected: the cellular structures of the heart muscle, pancreas, retina and musculoskeletal system are involved in the process.

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Epidemiology

According to world medical statistics, Friedreich's ataxia is the most common ataxia variant. On average, 2-7 patients out of 100,000 people suffer from this disease, and one person out of 120 is a carrier of the gene disorder.

Both men and women are susceptible to the disease. However, the disease does not affect people of the Asian and Negroid races.

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Causes Friedreich's ataxia

Friedreich's hereditary ataxia develops due to a deficiency or disruption of the structure of the protein frataxin, produced intracellularly in the cytoplasm. The function of the protein is to transfer iron from the energy organelles of the cell - mitochondria. The iron-storing capacity of mitochondria is due to active oxidation processes in them. When the concentration of iron in the mitochondria increases more than tenfold, the amount of total intracellular iron does not exceed the normal limits, and the amount of cytoplasmic iron decreases. In turn, this provokes stimulation of the gene structures that code for enzymes that transfer iron - ferroxidase and permease. As a result, the iron balance inside the cells is even more noticeably disrupted.

An increased amount of iron inside the mitochondria causes an increase in the number of aggressive oxidants – free radicals, which damage vital structures (in this case, cells).

A supporting role in the etiology of the disease may be played by a disorder of antioxidant homeostasis – the protection of human cells from harmful active oxygen species.

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Symptoms Friedreich's ataxia

Friedreich's familial ataxia, as we have already said above, is a hereditary disease. However, the first signs of the disease appear only at the age of 8-23 years. At the same time, the initial clinical picture is clearly associated with ataxia, which affects the person's gait. The patient becomes unsteady while walking, unsteadiness appears, weakness in the legs (the legs seem to get tangled). There are difficulties in coordinating movements. Gradually, the person begins to experience difficulties with pronunciation.

Signs of Friedreich's ataxia tend to get worse when the eyes are closed.

Over time, the symptoms become permanent, and the severity of clinical manifestations increases. The cause is damage to the cerebellum, which is responsible for coordinating limb movements.

Then the patient develops hearing and visual impairments. An important sign appears – a decrease or loss of natural reflexes and the emergence of pathological ones, for example, the Babinsky reflex is observed. Sensitivity in the extremities decreases: the patient loses the ability to feel objects in the palms and support under the feet.

After a while, movement disorders in the form of paralysis or paresis are recorded. Such problems begin with damage to the legs.

Mental abilities are usually not impaired. The disease develops gradually over decades. Sometimes short stable periods can even be observed.

Among the accompanying signs, it is necessary to note the change in the shape of the skeletal bones: this is especially noticeable on the hands and in the area of the feet, as well as on the spinal column. Heart problems appear, diabetes mellitus may develop, and vision damage may occur.

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Diagnostics Friedreich's ataxia

Diagnosis of the disease can present certain difficulties, because in the initial stages many patients seek help from a cardiologist due to heart problems, or from an orthopedist due to pathology of the musculoskeletal system or spine. And only when a neurological picture appears, patients end up in the office of a neurologist.

The main instrumental diagnostic methods for Friedreich's ataxia are MRI and neurophysiological testing.

Brain tomography helps to determine atrophy of some of its areas, in particular, the cerebellum and medulla oblongata.

Tomography of the spinal column reveals structural changes and atrophy – these symptoms are more noticeable in the later stages of the disease.

The conduction function is examined using the following methods:

• transcranial magnetic stimulation;
• electroneurography;
• electromyography.

In case of extraneural signs, auxiliary diagnostics are carried out: the cardiovascular, endocrine and musculoskeletal systems are examined. In addition, consultation with specialists such as a cardiologist, orthopedist, ophthalmologist, endocrinologist may be required. A number of studies are carried out:

• blood glucose level, glucose tolerance test;
• determination of hormone levels in the blood;
• electrocardiography;
• stress tests;
• ultrasound examination of the heart;
• X-ray of the spine.

Particular importance in diagnosing ataxia is given to medical genetic consultation and complex DNA diagnostics. It is carried out on the materials of the patient himself, his closest relatives and parents.

In pregnant women, Friedreich's ataxia in the unborn child can be determined by analyzing the DNA of chorionic villi from the eighth to the twelfth week of gestation, or by analyzing the amniotic fluid from the 16th to the 24th week.

Friedreich's ataxia is differentiated from hereditary tocopherol deficiency, hereditary metabolic disorders, neurosyphilis, neoplasms of the cerebellum, multiple sclerosis, etc.

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Treatment Friedreich's ataxia

Treatment of the disease cannot lead to a cure, but in this way it is possible to prevent the development of some consequences and complications. In order to slow down the growth of symptoms of the disease, mitochondrial group medications, antioxidants and other drugs that reduce the concentration of iron inside the mitochondria are used.

Medicines are usually prescribed in combination, at least 3 drugs at a time. Antioxidants are used, for example, tocopherol and retinol, as well as an artificial analogue of coenzyme Q 10 (idebenone), which inhibits neurodegenerative processes and the growth of myocardial hypertrophy - cardiomyopathy.

In addition, for treatment they use agents that improve metabolic processes in the heart muscle: it is recommended to take riboxin, preductal, cocarboxylase, etc.

In most cases, 5-hydroxypropane is prescribed, the effect of which is noticeable, but this drug has not been fully studied.

Adjuvant treatment is prescribed according to symptoms – for example, antidiabetic drugs and cardiovascular agents are used.

General strengthening therapy (vitamin complexes) and improvement of tissue metabolism (piracetam, cerebrolysin, aminolone) are carried out.

Depending on the indications, surgical intervention may be possible in the form of correction of the shape of the feet and the use of Botox in the muscles affected by spasm.

Physiotherapy and gymnastics can significantly improve the effectiveness of treatment. But for a lasting effect, classes and sessions must be regular, with an emphasis on training balance and muscle strength.

Since Friedreich's ataxia is the result of genetic disorders, which cannot be a reversible condition, folk remedies do not work in the treatment of this disease.

In the diet of patients with ataxia, it is necessary to reduce or eliminate the consumption of carbohydrate foods, since the disease is associated with an excess of energy in the cells. A large amount of carbohydrate products (sweets, sugar, pastries) can lead to a deterioration in the patient's condition.

Prevention

A special role in prevention is given to DNA testing at the initial pre-symptomatic stages, for the timely initiation of preventive treatment.

Direct relatives of the already identified sick person are definitely examined. Initially, the disease can be suspected by clinical signs: the appearance of ataxia, decreased muscle tone, sensitivity disorders, disappearance of tendon reflexes, development of paresis, polyneuropathies, signs of the disease on the ECG, the occurrence of diabetes mellitus, changes in the bone and joint system, atrophic processes (in particular, in the optic nerves), curvature of the spinal column, etc.

Periodic monitoring and observation by a neurologist and endocrinologist are necessary. Great preventive importance is also given to therapeutic gymnastics and physiotherapeutic treatment.

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Forecast

Friedreich's ataxia is an incurable and dynamically progressive disease that gradually worsens the patient's condition and eventually leads to fatal consequences. Usually, the patient dies from cardiac insufficiency or from respiratory spasm, less often from infectious diseases.

Unfortunately, about half of all patients with Friedreich's ataxia are unable to live to the age of 35. At the same time, the prognosis for the disease in women is considered more favorable: as a rule, all women with this diagnosis definitely live at least 20 years from the onset of the disease. For men, this figure is only 60%.

Very rarely do patients survive to old age, provided there are no heart problems or diabetes.