St. Vitus dance.

An 11-year-old boy presented to our clinic with abnormal involuntary jerky movements of the limbs for 3 months. Examination revealed fidgetiness with frequent rapid, irregular, and aimless involuntary movements of all 4 limbs, hypotonia, frequent facial grimacing, and dysarthria (Movie I in the online-only Data Supplement). The movements used to disappear with sleep. He was unable to sustain his hands raised above the head with palms facing outward (pronator sign). He was also unable to maintain his tongue protruded (darting tongue sign; Movie I in the online-only Data Supplement). He had a history of fever associated with migratory arthritis 6 months back. He had no other complaints. His electrocardiogram was normal. Antistreptolysin O titer was within normal limits. Echocardiogram demonstrated thickened mitral leaflets with mild mitral regurgitation (Figure). There was no family history of chorea. Other causes of chorea were ruled out. He was diagnosed with Sydenham chorea with rheumatic heart disease and started on secondary antibiotic prophylaxis. His symptoms improved with haloperidol and carbamazepine. Sydenham chorea, also known as St. Vitus dance, is a neuropsychiatric manifestation of rheumatic fever with an incidence varying from 5 to 35%. It may occur alone or concomitantly with other manifestations of rheumatic fever. It usually occurs after a latency of several months and hence the lab evidence of prior streptococcal infection may be absent at the time of presentation, as in this case. Approximately 50% of patients with Sydenham chorea subsequently develop rheumatic heart disease. The motive of this image is to emphasize the importance of secondary antibiotic prophylaxis in all patients with Sydenham chorea irrespective of valve disease to prevent recurrent rheumatic fever and valvular damage.