Sydenham’s Korea is a rare neurological disease , caused by the infection of a bacterium, called group A-hemolytic streptococci. Its main symptom is a movement disorder. This disease was first described by an English doctor, Thomas Sydenham, in 1686.
In this article we explain what this disease consists of, relevant data and what are its causes, symptoms and treatments.
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Sydenham Korea: definition and general characteristics
Sydenham’s Korea consists of a rare neurological disease. Other names he receives are: Korea Minor, Rheumatic Korea or San Vito 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) ; remember that the CNS is formed by the brain (brain) and the spinal cord.
Its beginning 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 approximately 3 months, although in some cases they reach 6 and 12 months.
On the other hand, the movements that appear in Sydenham Korea have no apparent purpose, they 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 severe or milder, and even that they only consist of transient psychic disturbances, such as emotional instability, restlessness and irritability.
This disorder appears more frequently in girls who have not yet reached puberty. However, Sydenham Korea may 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 doctor, 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.
When does Sydenham Korea usually appear? It all depends on the age at which the person becomes infected with the bacteria, logically, although this age ranges between six and 15 years. These patients usually have a rheumatic or cardiac history.
Its frequency is greater, as we anticipated, 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, said bacterium that causes Sydenham Korea is called b-hemolytic streptococci of group A.
How do these type 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 Korea originates.
On the other hand, Sydenham Korea affects approximately 10% of people affected by rheumatic fever . This association is related to autoimmune mechanisms of the organism.
In fact, Sydenham’s Korea is actually a symptom (rather a sign) of another condition, caused by group A of Streptococcus bacteria ; This condition is acute rheumatic fever (FR).
Two options may occur: either that the person suffers from this fever, or that he has suffered recently . Some people with FR only show this sign, Sydenham’s Korea, while others show some more.
Regarding the symptoms that accompany this disease (which usually last 3 months, there are cases of up to 6 and 12) we find the following four:
1. Movement disorders
We have said that the main alteration of Sydenham’s Korea is a movement disorder. Thus, movements appear that have the following characteristics: they have no apparent purpose (that is, they are “nonsense” movements), they are not repetitive, they are involuntary, fast, poorly coordinated and abrupt. Its duration is limited and they do not leave neurological sequelae.
These movements disappear during sleep, and affect any muscle group (except the eye muscles, the eyes). In addition, it should be specified that in mild cases of Sydenham Korea, patients simply have difficulty dressing and feeding, as well as a clumsy appearance.
- You may be interested: ” The 7 types of movement disorders: characteristics and symptoms“
2. Psychic disorders
Another symptom of Sydenham’s Korea is the psychic alterations, 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 of the symptoms of Korea (or one of its signs), which also appears as a result 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, one third of 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 .
In relation to the treatment of Sydenham Korea, there is currently no 100% effective drug in all cases of Korea .
On the other hand, when the affectation is severe, it is sometimes required to sedate the patient, in order to protect him from the self-injuries that can be caused in the wake of Korea (for example, hitting his arms and legs).
Although there is no 100% effective drug in all cases of Korea, there are drugs that can alleviate the symptoms. Depending on their severity, four options are usually used:
Phenobarbital is a barbiturate, and it is the drug of choice to treat Sydenham’s Korea. It is administered orally and its prescription is maintained for the time necessary to eliminate abnormal movements . Its effectiveness is around 80%.
Diazepam is a benzodiazepine (anxiolytic), which usually consists of the second option. That is, it is administered in cases where the phenobarbital has failed .
- You may be interested: ” Diazepam: uses, precautions and side effects of this drug“
In third option to treat Sydenham’s Korea we have haloperidol, a type of antipsychotic. It is used when the previous drugs have not worked. However, in children it is very toxic .
Corticosteroids have also been used in some cases, although 100% have not been shown to improve the symptoms of Korea.
- 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 Korea. Clinical analysis of 55 patients with prolonged follow-up. Rev Neurol, 39 (9): 810-815.
- (2019). Sydenham Korea.