Rheumatic chorea

Rheumatic chorea (Sydenham's chorea, minor chorea or "St. Vitus dance") is an important neurological disorder, manifested by sharp uncontrollable and irregular strokes, muscle weakness and emotional distress. Chorea can develop as a single symptom ("pure" chorea) or in association with other manifestations of rheumatic fever. 

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Epidemiology

Rheumatic chorea is found mainly in children, after 20 years it is rare. As a rule, it develops in girls and almost never in boys in the post-pubertal period. The prevalence of chorea in patients with RL varies from 5 to 36%.

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Symptoms of the rheumatic fever

Sydenham's chorea is characterized by emotional lability, uncoordinated movements and muscle weakness.

1. Emotional lability. The beginning of the process can be difficult to determine, usually a child becomes capricious, irritable, fidgety, does not want to learn. Excessive excitation, sleep and memory disturbance are also possible. Emotional changes in them are manifested by outbreaks of causeless behavior, including crying and excitement. In rare cases, mental abnormalities can be severe and can be expressed in transient psychosis.
2. Violation of coordination of movements and hyperkinesis can manifest as "clumsiness", a tendency to "drop" objects, which later turns into spasmodic, aimless, uncoordinated movements. All muscle groups can be affected, but the eccentric movements of the arms, legs and face are most noticeable. Movement of facial muscles can include grimacing, grin, frown. They note the abruptness of speech and the violation of the letter. Although horeiform movements are usually bilateral, they can be unilateral (hemichorea). Choreiform motions increase with emotional and physical stress, disappear in sleep, decrease during rest and sedation and can be suppressed by will power for a short time (several movements).
3. Muscular hypotension (combined with hyperkinesis).
4. Disorders of the autonomic nervous system.

Rheumatic chorea as one of the criteria for rheumatic fever has a number of characteristics:

• a longer latent period after streptococcal infection, 1-7 months, resulting in polyarthritis and Sydenham's chorea practically not found together;
• titres of streptococcal antibodies, laboratory signs of inflammation, subsided by the time of occurrence of horeiform movements.
• In 1/3 of the cases, recurrences of chorea are noted.

Small chorea should be differentiated from many diseases, as non-rheumatic chorea can develop due to various collagen, endocrine, metabolic, neoplastic, genetic and infectious diseases.

1. Collagen diseases (SLE, nodular periarteritis). The CNS is often involved in the pathological process with SLE, and less than 2% of patients manifest the disease with chorea. Differential diagnosis between SLE and RL is complicated by the presence of fever, arthritis, carditis and skin lesions in both diseases.
2. Family chorea: Huntington disease (autosomal dominant type of inheritance, men aged 30-50 years are more likely to suffer, hyperkinesis appear long before mental disturbance, dementia progresses), benign family chorea (debut in the first decade of life, hyperkinesis is more pronounced in the muscles of the head and torso).
3. Drug intoxication: oral contraceptives, thyroid hormones, narcotic drugs, neuroleptics, lithium preparations, phenytoin (diphenin), digoxin, amitriptyline, metoclopramide.
4. Hepatocerebral degeneration (Wilson-Konovalov's disease): combination of dysarthria, large-scale tremor, gradual decrease of intelligence and cirrhosis of the liver (reduction of serum ceruloplasmin level, increase of copper excretion in urine, Kauser-Fleischner ring).
5. Endocrinological disorders (hypoparathyroidism, thyrotoxicosis) and disorders of mineral metabolism (hyponatremia, hypocalcemia).
6. Lyme disease.
7. Chorea is pregnant: it often occurs during the first pregnancy in I or in the II trimester. In about 1/3 of cases, the chorea of pregnant women is a relapse of childhood rheumatic fever. Hyperkinesis in pregnant women is more pronounced, the changes in the psyche are more pronounced, the flow is usually benign.
8. Simple motor tics in children with Tourette's syndrome (a combination of hyperkinesis and violent vocalization, coprolalia).

Neuropsychiatric disorders in patients with streptococcal infection (PANDAS) are also described in the absence of RL development, which is most relevant in differential diagnosis with rheumatic chorea.

Working criteria PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections)

• The presence of obsessive-compulsive disorders (obsessive thoughts and obsessive movements) and / or tick states.
• Children's age: the debut of the disease falls on the interval from 3 years to the puberty period.
• Paroxysmal course of the disease, which can manifest itself as separate symptoms or episodes of dramatic deterioration. Symptoms usually significantly regress between seizures and in some cases are completely resolved between exacerbations.
• Proven chronological association with BGSA: excretory excretion in the smear from the throat and / or diagnostic increase in antibody titers (anti-streptopysin-O and anti-DNAase)
• Association with neurological changes: hypermotorics, choreiform hyperkinesis.

Treatment of the rheumatic fever

Treatment of chorea is carried out depending on whether it is isolated or combined with other manifestations of rheumatic fever (rheumatic carditis or polyarthritis).

With isolated chorea, anticonvulsants are used as the means of choice [phenobarbital at a dose of 0.015-0.03 g every 6-8 hours before the termination of hyperkinesis with gradual withdrawal within 2-3 weeks. Or carbamazepine (fimplexin) in a dose of 0.4 g / day].

Benzodiazepine drugs may also have a beneficial effect in the treatment of rheumatic fever.

Forecast

The rheumatic chorea with RL varies considerably, its course varies from one week to several years, on average the attack of chorea takes about 15 weeks. After the end of the rheumatic fever attack, hypotension of the muscles and hyperkinesia may completely disappear, although small involuntary movements, imperceptible on examination, can persist for several years.

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