Sydenham chorea is a post-Streptococcal neuropsychiatric movement disorder. It is named for the 17th Century English physician Thomas Sydenham.
Mechanism: immune mediated extrapyramidal syndrome due to antibodies involving the basal ganglia
Clinical features:
(1) untreated group A Streptococcal infection
(2) chorea of the hands and feet (uncoordinated jerking)
(3) choreic hand ("spooning" of the hand with wrist flexion and extension of the digits)
(4) milkmaid's grip while trying to clench the fist
(5) slurred speech
(6) head jerking
(7) psychiatric and/or behavioral change (obsessive-compulsive disorder, ADHD, depression)
(8) variable language impairment
Laboratory features:
(1) evidence of group A Streptococcal (Streptococcus pyogenes) on culture or by ASO titer
Differential diagnosis:
(1) PANDAS (post-Streptococcal neuropsychiatric disorder with tics)
(2) other causes of chorea
The prognosis tends to be good but some patients may still be symptomatic two years later and relapses can occur.
