Definition

Sydenham chorea is a movement disorder that occurs after infection with specific bacteria called group A streptococcus.

Alternative Names

St. Vitus dance; Chorea minor; Rheumatic chorea; Rheumatic fever - Sydenham chorea; Strep throat - Sydenham chorea; Streptococcal - Sydenham chorea; Streptococcus - Sydenham chorea

Causes

Sydenham chorea is caused by an infection with bacteria called group A streptococcus. This is the bacteria that causes rheumatic fever (RF) and strep throat. Group A streptococcus bacteria can trigger an immune response that reacts with a part of the brain called the basal ganglia to cause this disorder. The basal ganglia are a set of structures deep in the brain. They help control movement, posture, and speech.

Sydenham chorea is a major sign of acute RF. The person may currently or recently have had the disease. Sydenham chorea may be the only sign of RF in some people.

Sydenham chorea occurs most often in girls before puberty, but may be seen in boys.

Symptoms

Sydenham chorea mainly involves jerky, uncontrollable and purposeless movements of the hands, arms, shoulder, face, legs, and trunk. These movements look like twitches, and disappear during sleep. Other symptoms may include:

• Changes in handwriting
• Loss of fine motor control, especially of the fingers and hands
• Loss of emotional control, with bouts of inappropriate crying or laughing

Symptoms of RF may be present. These may include:

• High fever
• Heart problem
• Joint pain or swelling
• Skin lumps or skin rashes
• Nosebleeds

Exams and Tests

Your health care provider will perform a physical exam. Your provider will ask questions about your symptoms.

If a Group A streptococcus infection is suspected, tests will be done to confirm the infection. These include:

• Throat swab
• Anti-DNAse B blood test
• Antistreptolysin O (ASO) blood test

Further testing may include:

• Blood tests such as ESR, CBC
• MRI or CT scan of the brain

Treatment

Antibiotics are used to kill the Group A streptococcus bacteria. Your provider may also prescribe antibiotics to prevent future RF infections. This is called preventive antibiotics, or antibiotic prophylaxis.

Severe movement or emotional symptoms may need to be treated with medicines.

Outlook (Prognosis)

Sydenham chorea usually clears up in a few months. In rare cases, an unusual form of Sydenham chorea may begin later in life.

Possible Complications

No complications are expected.

When to Contact a Medical Professional

Contact your provider if your child develops uncontrollable or jerky movements, especially if your child has recently had a sore throat.

Prevention

Pay careful attention to your children's complaints of sore throats and get early treatment to prevent acute RF. If there is a family history of RF, be watchful, because your children may be more likely to develop this infection.

References

Jankovic J. Parkinson disease and other movement disorders. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 96.

Okun MS, Ostrem JL. Other movement disorders. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 379.

Shulman ST, Jaggi P. Nonsuppurative poststreptococcal sequelae: rheumatic fever and glomerulonephritis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 198.