Sydenham's Chorea: Causes, Symptoms, and Treatment

Sydenham's chorea is a rare neurological disease, caused by infection with a bacterium called group A b-hemolytic streptococci. Its main symptom is a movement disorder. 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 its causes, symptoms and treatments are.

• Related article: "The 15 most frequent neurological disorders"

Sydenham's chorea: definition and general characteristics

Sydenham's chorea is a rare neurological disease. Other names it receives are: Minor Corea, Rheumatic Corea or Dance of San Vito. It is a movement disorder, caused by the infection of some bacteria belonging to group A "Streptococcus".

Regarding its characteristics, it is a degenerative, non-progressive, inflammatory disease of the central nervous system (CNS); Remember that the CNS is made up 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. The symptoms can last about 3 months, approximately, 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, are non-repetitive and involuntary. These movements end up disappearing and luckily they do not leave neurological sequelae.. Depending on the case, it may be that the symptoms are more serious or milder, and even that they only consist of in 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 children.

A little history…

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

More data

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

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

Causes

As we have already mentioned, the cause of Sydenham's chorea is an infection from 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 bacterium that causes Sydenham's chorea is called group A b-hemolytic streptococci.

How do this type of group A bacteria act? 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 Korea originates.

On the other hand, Sydenham's Korea affects approximately 10% of people affected by rheumatic fever. This association is related to autoimmune mechanisms of the organism.

Symptoms

In fact, Sydenham's chorea is actually a symptom (more like a sign) of another condition, caused by group A bacteria. streptococcus; this condition is acute rheumatic fever (RF).

Two options can occur: either that the person suffers from this fever, or that they have suffered from it recently. Some people with RF only show this sign, Sydenham's Chorea, while others show a few more.

Regarding the symptoms that accompany this disease (which usually last 3 months, with cases of up to 6 and 12), we find the following four:

1. movement disorders

We have said that the main disorder of Sydenham's chorea is a movement disorder. Thus, movements appear that present the following characteristics: they do not have an apparent purpose (that is, that is, they are “meaningless” movements), they are not repetitive, they are involuntary, fast, 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 (minus the ocular muscles, of the eyes). In addition, it is necessary to specify that in mild cases of Sydenham's chorea, the patients simply present difficulties in dressing and eating, in addition to a clumsy appearance.

• You may be interested in: "The 7 types of movement disorders: characteristics and symptoms"

2. mental disorders

Another symptom of Sydenham's Korea is temporary mental disturbances. The most frequent are three: emotional instability, restlessness and irritability.

3. Rheumatic fever

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

4. rheumatic carditis

On the other hand, a third of the cases in Korea appear associated with another symptom: rheumatic carditis. This consists of a condition that causes permanent damage to the valves of the heart.

Treatment

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

On the other hand, when the involvement is severe, it is sometimes necessary to sedate the patient, in order to protect you from self-harm that can be caused by chorea (for example, hitting arms and legs).

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

1. phenobarbital

Phenobarbital is a barbiturate, and it is the drug of choice to treat Sydenham's chorea. It is administered orally and its prescription is maintained for the time necessary to eliminate abnormal movements. Its efficiency is around 80%.

2. diazepam

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

• You may be interested in: "Diazepam: uses, precautions and side effects of this drug"

3. haloperidol

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

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 Left, M. (2004). FEDER (Spanish Federation for Rare Diseases). (2004).
• Diaz-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.