Korea disease

Actually Korea is a neurological pathology and encompasses different kinds of diseases, some acquired and others hereditary, which are characterized by these movements, the best known being the huntington's korea and Sydenham's chorea.

How is it produced?

Huntington's chorea occurs as a result of an alteration in the short arm of chromosome 4. It is an autosomal dominant disease, that is, it is enough that one of the two inherited copies of the gene is altered for the disease to manifest itself, and it usually appears between the ages of 30 and 50. It affects between 4 and 8 people in 100,000.

Huntingtin protein alteration

It has been observed that in this alteration there is a unnecessary repetition of a DNA base triplet, so that the protein for which they code, huntingtin is altered. Likewise, it has been seen that the greater the number of repetitions, the greater the severity of the disease and the greater the risk of suffering from it. It seems that this protein accumulates in neurons in certain parts of the brain, the basal ganglia, especially at the thalamus and putamen, causing neuronal atrophy.

GluN3A protein alteration

The implication of another protein, GluN3A, a protein that destroys brain synapses during brain formation to repair abnormal neuronal connections, but then disappears, which does not appear to be the case in these patients.

Common causes of Korea

• Primary or hereditary causes: Huntington's chorea, benign familial chorea, familial inverted choreoathetosis, and neuroacantocytosis
• Secondary or acquired causes: Infectious (Sydenham's chorea, borreliosis, herpesvirus), autoimmune (systemic lupus erythematosus, antiphospholipid syndrome), metabolic (,, hypernatremia, hyponatremia, thiamine deficiency, Wilson's disease, phenylketonuria) or poisonings carbon monoxide, ethyl alcohol, or manganese.

Sydenham chorea

It is a disease that affects one in every 200,000 people and is secondary to a late inflammatory reaction, rheumatic fever, after having suffered from pharyngotonsillitis caused by it. Of all patients with S. pyogenes pharyngotonsillitis, only between 1 1% and 3% develop rheumatic fever. It mainly affects people between the ages of 5 and 20 and the process is probably due to an autoimmune reaction triggered by the bacterial infection.

What symptoms does it produce?

Jerky and involuntary movements of the limbs

These movement occurs both in the upper and lower extremities; They are wide and jerky movements. They may begin as more subtle disturbances in finger movements, such as a fine tremor or a handwriting disturbance, but progress to more motley movements and poorer control.

Psychiatric disorders

In the case of Huntington's chorea, motor symptoms are usually preceded by psychiatric disorders, such as emotional lability, depression, irritability, aggressiveness or psychotic disorders, as well as milder memory deficits.

Also, patients with Huntington's chorea eventually develop one because of neuronal degeneration.

Pharyngo-tonsillar infection

In the case of Sydenham's chorea there will be a first infection at the pharyngo-tonsillar level, with odynophagia and fever, and the picture of involuntary contractions, in case of rheumatic fever, may appear up to 6 months later.

Swelling of the extremities

In addition to jerky movements of the extremities, patients with this disease may present with inflammation of various joints, as well as severe cardiac involvement, erythema, and subcutaneous nodules.

How is it diagnosed?

The diagnosis of chorea will be based initially on the examination of the patient, observing the movements of chorea typical of this disease.

• In adult patients Huntington's chorea should be suspected, so it is essential to ask about the family history, as well as imaging tests such as a computerized axial tomography (), a nuclear magnetic resonance () or a positron emission tomography (). It is also advisable to carry out a genetic study and carry out neuropsychiatric tests.
• In young patients Sydenham's chorea will be the first suspicion, so it is important to investigate the existence of a pharyngo-tonsillar infection by S. pyogenes in the past year. Ideally, at the time of infection, an throat swab culture, as well as determining antistreptolysin antibodies in the blood. The existence of said infection and the presence of chorea and some other criteria such as cardiac involvement, polyarthritis, erythema, subcutaneous nodules, fever, leukocytosis or changes in the electrocardiogram will be enough to determine that it is a Sydenham chorea.

Obviously, the possibility of metabolic disorders, autoimmune diseases, other infections or poisonings as possible causes of chorea should also be investigated.

Treatment

Huntington's chorea has no treatment and the Life expectancy After the beginning of the disease it is usually about 15 years. Treatment will be symptomatic, using dopamine antagonist drugs to improve movement disorders, as well as neuroleptics, antidepressants or anxiolytics to treat psychiatric disorders.

In the case of Sydenham Korea the prognosis is much better, the vast majority of patients improve with treatment without sequelae, although in some cases the symptoms may reappear. Treat streptococcal infection with penicillin and chore movements with dopamine antagonists. In case of joint or cardiac involvement, the appropriate treatments will be administered, such as corticosteroids or non-steroidal anti-inflammatory drugs.

The cases of chorea due to metabolic disorders disappear after correcting them.