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Chorea is nonrhythmic, jerky, rapid, nonsuppressible involuntary movements, mostly of distal muscles or the face; movements may merge imperceptibly into purposeful or semipurposeful acts that mask the involuntary movements. Athetosis is nonrhythmic, slow, writhing, sinuous movements predominantly in distal muscles, often alternating with postures of the proximal limbs to produce a continuous, flowing stream of movement. Hemiballismus is usually a unilateral, nonrhythmic, rapid, nonsuppressible, violent, flinging movement of the proximal arm.

Chorea and athetosis often occur together (as choreoathetosis). They are manifestations of overactivity in certain pathways of the basal ganglia. Huntington's disease (see Movement and Cerebellar Disorders: Huntington's Disease) is the most common degenerative disease causing chorea. Other causes include thyrotoxicosis, SLE affecting the CNS, and drugs (eg, antipsychotics) Rheumatic fever sometimes leads to Sydenham's chorea (see Rheumatic Fever: CNS). A tumor or infarct of the caudate nucleus can cause acute unilateral chorea (hemichorea). Chorea may occur as an isolated symptom in patients > 60 (as senile chorea); this chorea tends to be symmetric and does not cause dementia.

The cause is treated or corrected if possible. Sydenham's chorea and chorea due to infarcts of the caudate nucleus often lessen over time. Chorea due to thyrotoxicosis usually lessens when thyroid dysfunction is corrected. In Huntington's disease, drugs that suppress dopaminergic activity, such as antipsychotics (eg, risperidone Some Trade Names
RISPERDAL
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), and dopamine Some Trade Names
INTROPIN
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-depleting drugs (eg, reserpine Some Trade Names
SERPASIL
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, tetrabenazine) can be used. However, improvement may be limited.

Chorea gravidarum occurs during pregnancy, often in patients who had rheumatic fever. Chorea usually begins during the 1st trimester and resolves spontaneously by or after delivery. Treatment is sedation with barbiturates; other sedatives may harm the fetus. Rarely, a similar disorder occurs in women taking oral contraceptives.

Hemiballismus is caused by a lesion, usually an infarct, around the contralateral subthalamic nucleus. Although disabling, hemiballismus is usually self-limited, lasting 6 to 8 wk. Treatment with antipsychotics is often effective.

Last full review/revision August 2007 by David Eidelberg, MD; Michael Pourfar, MD

Content last modified August 2007