Immune-mediated extrapyramidal
movement disorders typically occur in previously healthy children. Immune-mediated
movement disorders may occur as a postinfectious, paraneoplastic, or idiopathic process.
Sydenham chorea (SC) is the classical poststreptococcal movement and
psychiatric disorder, and may be associated with other features of
rheumatic fever. The outcome is typically good, although residual
chorea, psychiatric disturbance, and relapses are possible.
Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) is a syndrome of streptococcal-induced
tics and
obsessive-compulsive disorder. Although a number of investigators have reported an association between
streptococcal infection and neuropsychiatric syndromes, the PANDAS hypothesis is controversial.
Encephalitis lethargica is an encephalitic illness with
parkinsonism,
dyskinesias, and psychiatric disturbance as dominant features. The exact disease mechanism is not understood, although an autoimmune process is suspected.
NMDA-R
encephalitis is a new entity characterized by
encephalitis with dramatic psychiatric disturbance,
dyskinesias, cognitive alteration, and
seizures. Patients have
autoantibodies against the
NMDA-R that appear to be pathogenic: immune
therapies appear warranted to minimize disability.
Movement disorders are also described associated with
systemic lupus erythematosus and
antiphospholipid syndrome. The differential diagnosis and investigation approach of acute-onset
movement disorders are also discussed.