Rheumatic chorea

Rheumatic chorea (Sydenham's chorea, chorea minor, or "St. Vitus's dance") is a major neurological disorder characterized by sudden, uncontrolled, and arrhythmic involuntary movements, muscle weakness, and emotional distress. Chorea may develop as the only symptom ("pure" chorea) or in association with other manifestations of rheumatic fever.

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Epidemiology

Rheumatic chorea occurs 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 LC varies from 5 to 36%.

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Symptoms rheumatic chorea

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

1. Emotional lability. The onset of the process can be difficult to determine, usually the child becomes capricious, irritable, fussy, does not want to study. Expressed agitation, sleep and memory disorders are also possible. Emotional changes in them are manifested by outbursts of causeless behavior, including crying and agitation. In rare cases, mental deviations can be severe and can be expressed as transient psychosis.
2. Impaired coordination of movements and hyperkinesis may manifest as clumsiness, a tendency to drop objects, which later develops into spasmodic, aimless, uncoordinated movements. All muscle groups may be affected, but eccentric movements of the arms, legs, and face are most noticeable. Facial muscle movements may include grimacing, baring teeth, and frowning. Discontinuous speech and impaired writing are noted. Although choreiform movements are usually bilateral, they may also be unilateral (hemichorea). Choreiform movements increase with emotional and physical stress, disappear during sleep, decrease during rest and sedation, and can be suppressed by willpower for a short time (a few movements).
3. Muscle hypotonia (combined with hyperkinesis).
4. Disorders of the autonomic nervous system.

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

• a longer latent period after streptococcal infection, amounting to 1-7 months, as a result of which polyarthritis and Sydenham's chorea almost never occur together;
• streptococcal antibody titers and laboratory signs of inflammation subside by the time choreiform movements appear.
• In 1/3 of cases, relapses of chorea are observed.

Minor chorea should be differentiated from many diseases, since non-rheumatic chorea can develop as a result of various collagen, endocrine, metabolic, neoplastic, genetic and infectious diseases.

1. Collagen diseases (SLE, periarteritis nodosa). The CNS is often involved in the pathological process in SLE, and less than 2% of patients present with chorea. Differential diagnosis between SLE and LC is complicated by the presence of fever, arthritis, carditis, and skin lesions in both diseases.
2. Familial chorea: Huntington's disease (autosomal dominant inheritance, most often affects men aged 30-50 years, hyperkinesis appears long before mental disorders, dementia progresses), benign familial chorea (onset in the first decade of life, hyperkinesis is more pronounced in the muscles of the head and trunk).
3. Drug intoxication: oral contraceptives, thyroid hormones, narcotics, neuroleptics, lithium preparations, phenytoin (diphenin), digoxin, amitriptyline, metoclopramide.
4. Hepatocerebral degeneration (Wilson-Konovalov disease): a combination of dysarthria, large-scale tremor, gradual decline in intelligence and liver cirrhosis (decreased serum ceruloplasmin levels, increased copper excretion in urine, Kauser-Fleischner ring).
5. Endocrinological disorders (hypoparathyroidism, thyrotoxicosis) and mineral metabolism disorders (hyponatremia, hypocalcemia).
6. Lyme disease.
7. Chorea of pregnancy: most often occurs during the first pregnancy in the first or second trimester. In about 1/3 of cases, chorea of pregnancy is a relapse of rheumatic fever suffered in childhood. Hyperkinesis in pregnant women is more pronounced, mental changes are more pronounced, the course is usually benign.
8. Simple motor tics in children with Tourette syndrome (a combination of hyperkinesis and forced vocalization, coprolalia).

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

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

• The presence of obsessive-compulsive disorders (obsessive thoughts and obsessive movements) and/or tic conditions.
• Childhood: the onset of the disease occurs between the age of 3 and puberty.
• An attack-like course of the disease that may manifest itself as isolated symptoms or episodes of dramatic deterioration. Symptoms usually regress significantly between attacks and in some cases resolve completely between exacerbations.
• Proven chronological association with GABHS: isolation of the pathogen in a throat swab and/or diagnostic increase in antibody titers (antistreptopizin-O and anti-DNAase)
• Association with neurological changes: hypermotor activity, choreiform hyperkinesis.

Treatment rheumatic chorea

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

In isolated chorea, the drugs of choice are anticonvulsants [phenobarbital at a dose of 0.015-0.03 g every 6-8 hours until hyperkinesis ceases, with gradual withdrawal over 2-3 weeks, or carbamazepine (fimplepsin) at a dose of 0.4 g/day].

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

Forecast

The course of rheumatic chorea in RL is quite variable, its course varies from one week to several years, on average, an attack of chorea takes about 15 weeks. After the end of the attack of rheumatic fever, muscle hypotonia and hyperkinesis can completely disappear, although small involuntary movements, imperceptible during examination, can persist for several years.

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