Chorea, athetosis, and hemiballismus

[Julene]

Chorea is characterized by repetitive, brief, irregular, somewhat rapid involuntary movements that start in one part of the body and move abruptly, unpredictably, and often continuously to another part. Chorea typically involves the face, mouth, trunk, and limbs. Athetosis is a continuous stream of slow, flowing, writhing involuntary movements. It usually affects the hands and feet. Hemiballismus is a type of chorea, usually involving violent, involuntary flinging of one arm and/or one leg. Movements are wider and more intense than chorea.

Chorea and athetosis are usually symptoms of another disorder, although chorea may develop on its own in older people or in pregnant women.
Chorea and athetosis can occur together, usually causing writhing, dancelike movements.
Hemiballismus affects a limb (the arm more often than the leg) on one side of the body, causing it to fling wildly.
For chorea and athetosis, treating the cause may help, as may antipsychotic drugs.

(See also Overview of Movement Disorders.)
Chorea and athetosis, which may occur together as choreoathetosis, are not disorders. Rather, they are symptoms that can result from several very different disorders.

[Kit]

Chorea is a nonrhythmic, jerky, rapid, nonsuppressible involuntary movement, mostly of the distal muscles and face; movements may be incorporated into semipurposeful acts that mask the involuntary movements. Athetosis (slow chorea) is nonrhythmic, slow, writhing, sinuous movements predominantly in distal muscles, often alternating with postures of the proximal limbs. Hemiballismus is unilateral rapid, nonrhythmic, nonsuppressible, wildly flinging movement of the proximal arm and/or leg; rarely, such movement occurs bilaterally (ballismus). Hemiballismus may be considered a severe form of chorea.
(See also Overview of Movement and Cerebellar Disorders.)
Chorea and athetosis are defined by clinical manifestations; many experts believe that when they occur together (as choreoathetosis), athetosis is a dystonia superimposed on chorea. Chorea and athetosis result from impaired inhibition of thalamocortical neurons by the basal ganglia. Excess dopaminergic activity may be the mechanism.
Clinicians should seek and treat the cause of chorea whenever possible.
Huntington disease is the most common degenerative disorder causing chorea. In Huntington disease, drugs that suppress dopaminergic activity, such as antipsychotics (eg, risperidone , olanzapine ), and dopamine -depleting drugs (eg, deutetrabenazine, reserpine [no longer available in US], tetrabenazine) can be used to treat chorea. Antipsychotics may also help by lessening the neuropsychiatric symptoms commonly associated with Huntington disease (eg, impulsivity, anxiety, psychotic behavior). However, improvement may be limited and transient. All of these drugs may be judiciously used to treat choreas without a definable cause.
Other causes of chorea include

Hyperthyroidism
Hypoparathyroidism
Hyperglycemia
Systemic lupus erythematosus (SLE) that affects the central nervous system (CNS)
Drugs (eg, levodopa in patients with Parkinson disease, phenytoin , cocaine, tricyclic antidepressants, oral contraceptives)
Tardive dyskinesia (due to use of typical and atypical antipsychotics or other drugs that block dopamine receptors in the brain), which may manifest as chorea or dystonia independent of the other tardive syndromes such as tics, stereotypic movements, and akathisia (motor restlessness)
Autoimmune disorders
Paraneoplastic syndromes
Stroke
Pregnancy

Sydenham chorea can occur in rheumatic fever and may be the first symptom of it. A tumor or an infarct in the striatum (caudate or putamen) can cause acute unilateral chorea (hemichorea) on the opposite side of the body. Sydenham chorea and chorea due to infarcts of the caudate nucleus often lessen over time without treatment.
Chorea due to hyperthyroidism or another metabolic cause (eg, hyperglycemia) usually lessens over time when thyroid function or blood glucose returns to normal. If chorea does not subside after several weeks of metabolic control,#160;clinicians should check for another cause such as stroke.
Chorea in patients gt; 60 should not be assumed to be senile chorea but should be thoroughly evaluated to identify the cause (eg, toxic, metabolic, autoimmune, paraneoplastic).
Chorea gravidarum occurs during pregnancy, often in patients who have had rheumatic fever. Chorea usually begins during the 1st trimester and resolves spontaneously at or after delivery. If treatment before delivery is necessary because chorea is severe, barbiturates are indicated because they have fewer fetal risks than other drugs used to manage chorea. Rarely, a similar disorder occurs in women taking oral contraceptives.
Hemiballismus is caused by a lesion, usually an infarct, in or around the contralateral subthalamic nucleus. Although disabling, hemiballismus is usually self-limited, lasting 6 to 8 weeks. If severe, it can be treated with an antipsychotic for 1 to 2 months or, if antipsychotics are ineffective, with deep brain stimulation.