Sydenham chorea is a rare neurological disease , caused by infection with a bacterium, called group A b-hemolytic streptococcus. Its main symptom is impaired movement. This disease was first described by an English physician, Thomas Sydenham, in 1686.
In this article we explain what this disease is, relevant data and what are its causes, symptoms and treatments.
Sydenham Korea: definition and general characteristics
Sydenham Korea is a rare neurological disease. Other names for it are: Minor Korean, Rheumatic Korean or St. Vitus’ Dance. 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) ; let us remember that the CNS is formed by the brain and the spinal cord.
Its beginning is often insidious and of limited duration. In relation to its evolution, this is variable, and not easy to specify. Its disappearance is usually gradual. The symptoms can last about 3 months, approximately, although in some cases they can last up to 6 and 12 months.
On the other hand, the movements that appear in Sydenham Korea have no apparent purpose, are non-repetitive and involuntary. These movements end up disappearing and fortunately do not leave any neurological sequelae . Depending on the case, it may be that the symptoms are more serious or milder, and even that they only consist of transitory psychic alterations, such as: emotional instability, restlessness and irritability.
This disorder appears most often in girls who have not yet reached puberty. However, Sydenham’s chorea can also occur in boys.
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 Korea was associated with rheumatic fever (FR) , and described it as such.
When does Sydenham’s Korea usually appear? It all depends on the age at which a person is infected with the bacteria, of course, although the age ranges from six to 15. These patients usually have a history of rheumatism or heart disease.
Its frequency is higher, as we were saying, in the female sex. In fact, in adolescence, the people affected by Sydenham’s Korea are practically all women.
As we have already mentioned, the cause of Sydenham’s Korea 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 Corea is called group A b-hemolytic streptococcus.
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 Korea affects about 10% of people with rheumatic fever . This association is related to the body’s autoimmune mechanisms.
In fact, Sydenham Chorea is actually a symptom (rather a sign) of another condition, caused by group A bacteria Streptococcus ; that condition is acute rheumatic fever (ARF).
Two options may occur: either the person has this fever, or has had it recently . Some people with FR only show this sign, Sydenham’s Korea, while others show a few more.
As for 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 disturbance in Sydenham Korea is a movement disorder. Thus, movements appear that have the following characteristics: they have no apparent purpose (that is, they are “senseless” 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 (except the eye muscles). In addition, it should be specified that in mild cases of Sydenham’s Korea, patients simply present difficulties in dressing and feeding, as well as an awkward appearance.
2. Psychic alterations
Another symptom of Sydenham’s Korea is psychic disturbances, which are of a transitory 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 consequence of Group A Streptococcal infection . This is an inflammatory disease that can lead to conditions of the heart, skin, brain, and joints.
4. Rheumatic Carditis
On the other hand, one third of the cases in Korea are associated with another symptom: rheumatic carditis. This consists of a condition that causes permanent damage to the heart valves .
Regarding the treatment of Sydenham’s Korea, currently there is no 100% effective drug in all cases in Korea .
On the other hand, when the condition is severe, sedation is sometimes required to protect the patient from self-injury that may result from Korea (e.g. hitting arms and legs).
Although no drug is 100% effective in all cases in Korea, there are drugs that can alleviate the symptoms. Depending on the severity of the symptoms, there are usually four options:
Phenobarbital is a barbiturate, and it is the drug of choice for treating Sydenham’s Korea. It is administered orally and its prescription is kept as long as necessary to eliminate abnormal movements . Its efficacy is around 80%.
Diazepam is a benzodiazepine (anxiolytic), which is usually the second choice. That is, is administered in cases where phenobarbital has failed .
The third option for treating Sydenham’s Korea is haloperidol, a type of antipsychotic. It’s used when previous drugs haven’t worked. However, in children it is very toxic .
Steroids have also been used in some cases, although it has not been 100% proven that they can improve the symptoms of Korea.
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