Prepared by: Dr. John Tharakan
Gleneagles Medini Hospital
1. Is Sydenham chorea common among children in Malaysia? What are the percentage of children who get affected by this disease?
Sydenham chorea, also known asa St. Vitus’s dance, is a complication of rheumatic fever, which itself is a childhood infection caused by certain streptococci. In a retrospective clinical study of admissions to University Malaya Medical Centre from 1967 to 1997, it was reported that there were 313 patients with acute rheumatic fever with 12 percent of this number affected by Sydenham chorea.
With the vast improvement in the health delivery system that we have today, the incidence rate of rheumatic fever has drastically decreased and most children recover completely. Sydenham chorea typically disappears on its own between three to six months after initial appearance, with cases rarely lasting longer than a year. Girls seem more prone to the condition than boys and a majority of patients are in the five to 15-year-old age range.
2. What causes the disease?
Chorea is a symptom and not a specific disease, in the same way a fever can happen for many different reasons. In most forms of chorea, there is an excess of dopamine, the main neurotransmitter in the basal ganglia, leading to abnormal excessive movements. Some of the common causes of chorea that may be found in children are:
- Genetically determined conditions such as Huntington’s disease
- Lupus (systemic lupus erythematosus)
- Overactivity of the thyroid gland (hyperthyroidism)
- A high blood sugar level (hyperglycaemia)
- A tumour or stroke affecting a part of the basal ganglia called the caudate nucleus
3. What are the common symptoms parents should look out for?
Similar to other movement disorders, Sydenham chorea causes patients to experience trouble controlling motor movements due to abnormal signals from the brain. This manifests in the form of fidgeting or restlessness that can occur at rest or while active, and may intensify during distracting activities like counting. These involuntary movements typically affect the whole body but may sometimes affect only one side or even just the face, hands, or arms. Muscle weakness is another warning sign of Sydenham chorea.
4. What are the treatments for Sydenham chorea?
Treatment is often not necessary as the symptoms are mild and will eventually dissipate in time. However, when the movements become severe to such a degree that they interfere with daily activities, patients would be prescribed sedative drugs (like barbiturates or benzodiazepines), anti-epileptic medication (like valproic acid) or dopamine-depleting drugs.