DefinitionSydenham chorea is a movement disorder that occurs with rheumatic fever.Alternative NamesSt. Vitus danceCauses, incidence, and risk factorsSydenham chorea is one of the major signs of acute rheumatic fever. It is discussed here separately because it may be the only sign of rheumatic fever in some patients.Sydenham chorea occurs most often in girls before puberty, but may be seen in boys.SymptomsChanges in handwritingJerky, uncontrollable, and purposeless movements in different muscle groups (looks like twitching)Loss of fine motor control, especially of the fingers and handsLoss of emotional control, with bouts of inappropriate crying or laughingSymptoms of rheumatic fever (see acute rheumatic fever)Signs and testsThere may be a history of sore throat for several weeks before Syd