Chorea in children, what is it, symptoms, treatment, prognosis

What is chorea minor?

Chorea (also called rheumatic chorea, chorea or "St. Vitus dance") Is a rare neurological disorder characterized by sudden onset chorea, usually in childhood. Chorea is defined as random, continuous, involuntary movements that can affect the entire body. Involuntary movements often involve the face and tongue. Hand and foot symptoms are often worsened on one side of the body. Additional symptoms of chorea minor may include slurred speech and difficulty maintaining a firm grip on the hands. Anxiety, sadness, inattention, and obsessive obsessive thoughts and behaviors can also occur.

Sydenham's chorea most often affects children over 5 years of age and adolescents. The disorder usually develops within weeks or months after beta-hemolytic streptococcal infection group A and can occur as a single disease or as a serious complication of acute rheumatic fever.

Signs and symptoms

The severity of involuntary movements and the presence of non-chorea minor symptoms can vary greatly from person to person. In most cases, streptococcal infection occurs. Streptococci are a group of bacteria that can cause several different infections, most often "acute pharyngitis"- often with sore throat (acute tonsillitis) or fever. Symptoms of rheumatic chorea can appear anywhere from 1 week to 6 months after a streptococcal infection.

The onset of involuntary movements (chorea) that characterize the disease are most often sudden - appear after hours and reach a peak within a few hours or days. Chorea is rarely seen by pediatricians and emergency doctors and may not be recognized. Initially, doctors may mistakenly attribute restless movements and involuntary facial expressions small chorea in a child who is extremely fussy, hyperactive, clumsy and / or deliberately refuses to try help. Parents (and children) tend to recognize, however, that these movements are obvious changes from the child's normal status.

Abnormal movements in chorea minor range from mild symptoms affecting coordination and performance of tasks such as writing to severe symptoms, impaired walking, speaking, and performing basic tasks such as dressing, eating, or simply holding items. Choreic movements can fluctuate during the day. In most cases, chorea disappears during sleep.

In addition to choreic movements, people with rheumatic chorea may develop muscle weakness, slurred speech (dysarthria), decreased muscle tone (hypotension), tics, obsessions, compulsions, inattention, anxiety, labile mood and decreased speech load. In some extremely rare cases (less than 2%), severe muscle weakness, irritability, or confusion may be deep, and affected children may become bedridden, a condition sometimes called paralytic chorea.

Because Sydenham's chorea is a complication of rheumatic fever, some people develop additional symptoms of arthritis or arthralgia, inflammation of the heart valves, resulting in permanent valve damage, and ongoing fever.

Chorea minor symptoms usually resolve within 3 weeks to 6 months. However, symptoms can last longer than one year. At times, symptoms of rheumatic chorea recur later in adulthood, especially in young women during the first trimester of pregnancy.

Causes and risk factors

Chorea is believed to be autoimmune disease. Most cases develop after a streptococcal infection or more severe rheumatic fever. An autoimmune disorder occurs when the body's immune system mistakenly reacts to healthy tissue. In rheumatic chorea, streptococcal infection prompts the body's immune system to produce antibodies to fight the infection. For unknown reasons, these antibodies persist and subsequently target specific cells in the joints, kidneys, heart and, in the brain, especially on the cells of the basal ganglia (a key part of the brain for the control of motor movements). Researchers believe that this ultimately leads to the characteristic symptoms of chorea minor.

The exact mechanisms underlying chorea lesser are not fully understood. Researchers believe that antigens (substances that can stimulate the immune response systems) on bacterial cells of streptococcus are similar to antigens found in cells of basal ganglia. When the immune system creates antibodies to fight streptococcal infections, these antibodies also have genetically predisposed people mistakenly bind to healthy brain cells and disrupt them function.

Affected populations

According to most studies, rheumatic chorea affects girls more often than boys. The disease usually develops in children aged 5-15 years, more often after a streptococcal infection. One of the hallmarks of chorea minor is that it almost never occurs in children under 5 years of age. The disorder has rarely been reported in adults. Rheumatic chorea affects people of all races and nationalities.

The disorder can arise as a complication of rheumatism. About 25 percent of people with rheumatic fever develop chorea. Rheumatism common in developing countries. Chorea minor is the most common cause of acute chorea in childhood. Rheumatic chorea remains a major public health problem in many developing countries, mainly due to cases of damaged heart valves.

Symptomatic disorders

Symptoms of other disorders may be similar to those of chorea minor. While small chorea should be suspected as the most likely cause of acute chorea in children, there are other conditions that doctors should consider.

Many different disorders and conditions can be associated with acute chorea. In many developed countries, chorea occurs when psychiatric drugs are started, increased, or stopped too abruptly. In particular, abrupt cessation of dopamine receptor blocking drugs (such as haloperidol, risperidone, or aripiprazole) can cause chorea. These drugs, also known as antipsychotics or antipsychotics, are prescribed for conditions such as bipolar disorder, autism with irritability, schizophrenia and Tourette's syndrome. Other medications, such as stimulants used to treat ADHD, or levodopa or anticholinergics, may cause chorea when first taken or if the dose is increased to a high level. Other acute chorea may be autoimmune due to lupus erythematosus or antiphospholipid syndrome, or metabolic, caused by mitochondrial or other genetic metabolic diseases.

There are also many neurological diseases that are chronic or degenerative, which can include chorea as one of the symptoms. As a rule, in such conditions, neurologists recognize that the time interval, other non-chorea symptoms, and neurologic examination are different from chorea minor. Such diseases include hereditary (genetic) disorders such as Huntington's disease, neuroacanthocytosis, ataxia-telangiectasia (Louis Bar syndrome), Wilson's disease.

Diagnostics

To diagnose rheumatic chorea, it is necessary to collect anamnesis, in particular, an epidemiological one, to conduct a general and neurological examination and laboratory and instrumental studies. An important role is played by the presence of systemic manifestations of rheumatism and its laboratory signs. The study of cerebrospinal fluid is usually uninformative. Diffuse slow-wave brain activity appears on the EEG. With neuroimaging, transient focal changes in the striatum can be detected. In addition, MRI or CT scan of the brain is used.

Standard treatments

— Secondary prevention.

A confirmed diagnosis of rheumatic chorea is almost always an indication for long-term antibiotic treatment until adulthood. The goal of this treatment is to prevent permanent damage to the heart valve that can occur if the child experiences recurrent streptococcal infections. The most commonly used drug is penicillin.

Chorea is a suppressive treatment.

Chorea suppressants should be considered. Some mild cases may not require intervention because the disorder usually resolves on its own within a few weeks. When chorea symptoms are disabling, low doses of potent dopamine receptor blocking agents such as haloperidol, dopamine depleting drugs such as tetrabenazine, anticonvulsants such as valproic acid or benzodiazepines. Since in most cases treatment will only be needed for weeks or months and at low doses, side effects such as tardive dyskinesia are extremely unlikely. However, as with any neurological drug, it is advisable to carefully discuss both the potential benefits and risks.

- Treatment of the immune system.

Adjunctive short-term immune therapy has been used to treat people with chorea minor for the first weeks of symptoms, based on the fact that ongoing acute inflammation contributes to the appearance symptoms. There is some scientific validity for the use of oral steroids and intravenous immunoglobulins from small but rigorous clinical trials.

Forecast

In general, the forecast is good. The duration of symptoms, according to various sources, ranges from 3-6 to 12-15 weeks. With an uncomplicated course, complete recovery usually occurs. However, in some cases, the disorder can last up to 2 years or more. Such cases are more common in more severe cases of the disorder, such as generalized chorea, or in patients with heart inflammation.

In some patients, especially in the chronic course of the disease, changes persist in the form of mild hyperkinesis, tics, and cerebrasthenia. The character may change (sensitivity increases, a tendency to irritability, resentment, stubbornness appears), sometimes hysterization of the personality, anxiety-depressive disorders, obsessive compulsive disorder, attention deficit hyperactivity disorder.

Within a period from several months to 3-6 years, rheumatic chorea may recur in 35% of patients. In 5-10% of patients, two or more relapses occur at intervals of 1.5-2.5 years. Most often they occur spontaneously, although they can be associated with new streptococcal infections. Recurrent chorea is the least favorable among atypical forms in terms of outcome and treatment. Sometimes, after a minor chorea, hyperkinesis may intensify or reappear when taken even in small doses of psychostimulants, levodopa, dopamine receptor agonists, phenytoin.

Oral contraceptive-induced chorea has also been associated with the potential for recurrence of childhood chorea. In a number of cases, chorea of ​​pregnant women is a recurrence of Sydenham's chorea: at least 35% of such patients had a history of it, and 4% had previously suffered from acute rheumatic fever. The course of rheumatism in chorea is relatively benign. Death is rare. However, due to the accompanying endocarditis these patients can develop heart disease, which can lead to serious complications and death.