Sydenham’s chorea: causes, symptoms and treatment

This neurological disease produces automatic, involuntary movements.

Sydenham's chorea is a rare neurological disease caused by infection with a bacterium called group b-hemolytic streptococcus.It is caused by infection with a bacterium called group A b-hemolytic streptococcus. Its main symptom is an alteration of the movements. This disease was first described by an English physician, Thomas Sydenham, in 1686.

In this article we explain what this disease consists of, relevant data and what are its causes, symptoms and treatments.

Sydenham's chorea: definition and general characteristics.

Sydenham's chorea is a rare neurological disease. Other names it receives are: Chorea Minor, rheumatic chorea or St. Vitus' ball. It is a movement disorder caused by the infection of some bacteria belonging to group A "Streptococcus".

As for its characteristics, it is a degenerative, non-progressive and inflammatory disease of the central nervous system (CNS). degenerative, non-progressive and inflammatory disease of the central nervous system (CNS).The CNS consists of the encephalon (brain) and the spinal cord.

Its onset is usually insidious and of limited duration. In relation to its evolution, this is variable, and it is not easy to specify. Its disappearance is usually gradual. Symptoms may last approximately 3 months, although in some cases they last up to 6 and 12 months.

On the other hand, the movements that appear in Sydenham's chorea have no apparent purpose, they are non-repetitive and involuntary. These movements eventually disappear and fortunately do not leave neurological sequelae.. Depending on the case, the symptoms may be more severe or milder, and may even consist only of transitory psychic alterations, such as emotional instability, restlessness and irritability.

This disorder appears more frequently in girls who have not yet reached puberty. However, Sydenham's chorea can also appear in boys.

A little history...

Sydenham's chorea appeared more than 600 years ago, in the form of an epidemic (around 1418). However, it was not until 1686 that an English physician, Thomas Sydenham, described the disease.

Later, it was Richard Bright, another English physician, who discovered in 1831 that Sydenham's chorea was associated with the disease. Sydenham's chorea was associated with rheumatic fever (RF), and so he described it.and so he described it.

More facts

When does Sydenham's chorea usually appear? It all depends on the age at which the person becomes infected with the bacteria, logically, although this age ranges from six to 15 years. These patients usually have a history of rheumatic or cardiac disease.

Its frequency is higher, as we mentioned earlier, in the female sex. In fact, in adolescence, people affected by Sydenham's chorea are practically all female.

Causes

As we have already mentioned, the cause of Sydenham's chorea is an infection of the bacteria belonging to group A Streptococcus. Streptococcus is a type of bacteria that causes other conditions such as rheumatic fever and strep throat. Specifically, the bacteria that cause Sydenham's chorea are called group A b-hemolytic streptococci.

How do these group A bacteria act? By interacting with a specific area of the brain: the basal ganglia (involved in movement, posture and speech). Thus, through a reaction of this brain structure, Sydenham's chorea originates.

On the other hand, Sydenham's Chorea affects about 10% of people affected by rheumatic fever.. This association is related to autoimmune mechanisms in the body.

Symptoms

In fact, Sydenham's chorea is actually a symptom (or rather a sign) of another condition, caused by the group A bacterium StreptococcusThe condition is acute rheumatic fever (RF).

Two options can occur: either the person has this fever or has had it recently.. Some people with RF only show this sign, Sydenham's chorea, while others show several others.

As for the symptoms that accompany this disease (which usually last 3 months, there are cases of up to 6 and 12) are the following four:

1. Movement disorders

We have said that the main alteration of Sydenham's chorea is a movement disorder. Thus, movements appear with the following characteristics: they have no apparent purpose (i.e., they are "meaningless" movements), they are not repetitive, they are involuntary, rapid, poorly coordinated and abrupt. Their duration is limited and they do not leave neurological sequelae.

These movements disappear during sleep, and affect any muscle group. affect any muscle group (except the ocular muscles of the eyes). In addition, it should be specified that in mild cases of Sydenham's chorea, patients simply present difficulties in dressing and feeding themselves, as well as a clumsy appearance.

2. Psychic disturbances

Another symptom of Sydenham's chorea is psychic disturbances, which are transient in nature. The most frequent are three: emotional instability, restlessness and irritability.

3. Rheumatic fever

As we have seen, rheumatic fever is another symptom of chorea (or one of its signs), which also appears as a also occurs as a consequence of group A streptococcal infection.. It is an inflammatory disease that can lead to heart, skin, brain and joint involvement.

4. Rheumatic carditis

On the other hand, one third of cases of chorea are associated with another symptom: rheumatic carditis. This consists of a condition that causes permanent damage to the Heart valves..

Treatment

Regarding the treatment of Sydenham's chorea, there is currently no drug that is 100% effective in Sydenham's chorea. there is no drug that is 100% effective in all cases of chorea..

On the other hand, when the involvement is severe, it is sometimes necessary to sedate the patient in order to protect him/her from self-injury that may be caused by chorea (e.g. hitting arms and legs).

Although there is no drug that is 100% effective in all cases of chorea, there are drugs that can alleviate the symptoms. Depending on the severity of the symptoms, four options are usually available:

1. Phenobarbital

Phenobarbital is a barbiturate, and is the drug of choice for treating Sydenham's chorea. It is administered orally and its prescription is held for as long as necessary to eliminate the abnormal movements.. Its efficacy is around 80%.

2. Diazepam

Diazepam is a benzodiazepine (anxiolytic), which is usually the second option. That is to say, it is administered in cases where phenobarbital has failed..

3. Haloperidol

The third option for treating Sydenham's chorea is haloperidol, a type of antipsychotic. It is used when the previous drugs have not worked. However, it is very toxic in children..

4. Corticosteroids?

Corticosteroids have also been used in some cases, although it has not been 100% proven that they can improve the symptoms of chorea.

Bibliographic references:

• Avellaneda, A. and Izquierdo, M. (2004). FEDER (Spanish Federation of Rare Diseases). (2004).
• Díaz-Grez, F. Lay-Son, L., Del Barrio-Guerrero, E. and Vidal-González, P. (2004). Sydenham's chorea. Clinical analysis of 55 patients with prolonged follow-up. Rev Neurol, 39 (9): 810-815.
• MedLinePlus. (2019). Sydenham's chorea.