Sydenham's Chorea

Overview

Sydenham's chorea is a neurological disorder that causes rapid, irregular, involuntary movements of the face, hands, arms, and legs. The word chorea comes from the Greek for "dance," reflecting the flowing, jerky movements. It is one of the recognized features of rheumatic fever, an illness that can follow an untreated streptococcal (strep) throat infection.

The condition is thought to result from the immune system reacting to the strep infection and mistakenly affecting part of the brain that controls movement. It mainly affects children and is more common in girls. Sydenham's chorea usually improves on its own over weeks to months, but because it signals rheumatic fever, the heart needs to be checked and protected.

Symptoms

Symptoms often begin gradually, weeks to months after a strep infection, and can be mistaken for clumsiness or fidgeting at first. They include:

• Rapid, irregular, involuntary movements that flow from one body part to another
• Difficulty with fine tasks such as writing, dressing, or holding objects
• Clumsiness and an unsteady, dance-like walk
• Facial grimacing and unusual expressions
• Slurred or jerky speech
• Weakness and reduced muscle tone
• Emotional changes, irritability, or difficulty concentrating

The movements typically stop during sleep and worsen with stress or activity. They may be more noticeable on one side of the body.

Causes

Sydenham's chorea is caused by an immune reaction that follows infection with group A streptococcus bacteria, the same germ that causes strep throat and scarlet fever. After the infection, the immune system produces antibodies that, in some people, cross-react with and disrupt a part of the brain involved in controlling movement.

• Streptococcal infection: The triggering event, often a strep throat that may have been mild or untreated.
• Rheumatic fever: Sydenham's chorea is one of its major manifestations and may appear alone or with joint and heart involvement.
• Immune cross-reaction: Antibodies affecting movement-control areas of the brain.

Risk Factors

• A recent untreated or partially treated strep throat infection
• Childhood, typically between about 5 and 15 years of age
• Being female, as it is more common in girls
• A history of rheumatic fever
• Living in areas where rheumatic fever is more common

Diagnosis

There is no single test for Sydenham's chorea; it is diagnosed from the characteristic movements and evidence of a recent strep infection or rheumatic fever.

• Clinical examination: Recognizing the typical involuntary movements and ruling out other causes.
• Tests for strep: Blood tests that show evidence of a recent streptococcal infection.
• Heart evaluation: An echocardiogram and exam to check for rheumatic heart involvement, since chorea is a feature of rheumatic fever.
• Other tests: Sometimes done to exclude other causes of chorea.

Treatment

Treatment focuses on protecting the heart, easing the movements, and supporting the child while the condition resolves.

• Antibiotics: To clear any remaining strep infection, followed by long-term preventive antibiotics to guard against future rheumatic fever and heart damage.
• Medications for movements: If the chorea is severe or interferes with daily life, certain medicines can reduce the involuntary movements.
• Rest and a calm environment: Since stress and activity can worsen the movements.
• Supportive care: Help with daily tasks and safety, plus monitoring of the heart.

Most children recover over several weeks to months, although symptoms can sometimes return.

Prevention

Prevention centers on preventing rheumatic fever by treating strep infections and, once rheumatic fever has occurred, preventing it from happening again:

• Seek treatment for sore throats that may be strep so they can be tested and treated with antibiotics
• Complete the full course of prescribed antibiotics for a strep infection
• Take long-term preventive antibiotics as advised after rheumatic fever or Sydenham's chorea
• Attend follow-up appointments to monitor the heart

When to See a Doctor

See a clinician if a child develops new involuntary movements, unusual clumsiness, jerky speech, or emotional changes, especially after a recent sore throat or strep infection. Prompt evaluation is important because Sydenham's chorea signals rheumatic fever, and the heart needs to be checked. Seek urgent care if movements are severe enough to risk injury or if there are signs of heart problems such as breathlessness or chest pain.

Related Topics

Frequently Asked Questions

References

1. National Institute of Neurological Disorders and Stroke (NINDS). Sydenham Chorea.
2. MedlinePlus, U.S. National Library of Medicine. Rheumatic fever.
3. American Heart Association. Rheumatic Heart Disease.
4. National Organization for Rare Disorders (NORD). Sydenham's Chorea.