Sydenham chorea

Alternative names

St. Vitus dance

Definition

Sydenham chorea is a movement disorder associated with rheumatic fever.

Causes, incidence, and risk factors

Sydenham chorea is one of the major signs of acute rheumatic fever. It is discussed here as a separate entity because it may be the only sign of rheumatic fever in some patients.

The movements seen in Sydenham chorea are involuntary, jerky, and purposeless. They are not rhythmic and occur sporadically in different muscle groups. For example, a sitting child might suddenly have an arm jerk upward followed by a leg extension, then a head nod. The movements occur in such a way that the child is constantly in motion and seems to be twitching everywhere.

Fine motor control becomes difficult, and handwriting may change dramatically.

Sydenham chorea occurs most frequently in prepubescent girls but may be seen in boys.

Symptoms

• History of sore throat preceding, by several weeks, the appearance of Sydenham's chorea
  
• Onset of uncontrollable movements
  
• Movements are jerky and purposeless
  
• Loss of fine motor control
  
• Emotional lability with bouts of inappropriate crying or laughing
  
• Any other signs of rheumatic fever
  

Signs and tests
There may be a history of sore throat for several weeks preceding the appearance of Sydenham's chorea.

Blood tests that may show signs of rheumatic fever include:

• ESR
  
• ASO
  
• CRP (C-reactive protein)
  
• Streptozyme test
  

Other tests related to acute rheumatic fever:

• ECG
  
• Echocardiogram (ultrasound of the heart)
  

Treatment
Antibiotics are given to assure clearing of streptococci, the bacteria that cause rheumatic fever. Continuous preventive antibiotics (antibiotic prophylaxis) may be prescribed.

Supportive care is given as necessary to control symptoms of Sydenham chorea. Sedation may be advised in severe cases.